Human astronauts are such a bother when it comes to space exploration. The space environment is pretty much the opposite of the conditions that humans evolved for, to the point where an unprotected human exposed to space will die horribly in about ninety seconds flat. Even given oxygen to breath, the human organism is quite insistent on a whole host of demands: food, water, comfortable temperature, gravity, absence of deadly radiation; the list goes on and on.

This is why NASA is so fond of robot space probes. Not only do robots not have any of those requirements, but there also is no problem with sending the probes on suicide one-way missions. Human astronauts would tend to complain about that.

But given organic non-cyborg astronauts, your spacecraft design is going to need a habitat module for the crew to live in, and all sorts of supplies to keep them alive. Since Every Gram Counts, it will be important to use every trick in the book to try and miminize the mass cost of all this.

A useful accounting device for consumables is the "man-day" or "person-day".

If your ship has 30 person-days of food and oxygen, it can support:

  • 30 persons for 1 day (30 / 30 = 1)

  • 15 persons for 2 days (30 / 15 = 2)

  • 3 persons for 10 days (30 / 3 = 10)

  • one person for 30 days (30 / 1 = 30)

...or any other division of 30.

By the same math, a ship with 30 person-days of supplies facing a 10 day mission could support 3 persons (30 / 10 = 3).

So if the exploration ship Arrow-Back becomes marooned in the trackless wastes of unexplored space and is listed as having 20 person-weeks of life support, it makes it really easy for Mr. Selfish to do the arithmetic and figure that he will survive for twenty weeks instead of one if he murders the other 19 crew members. More democratically, if the rescue ship will arrive in 8 days (1.14 weeks), one can calculate that the supplies will stretch for an extra day with 17 crew members (20 / 1.14 = 17.5, round down to 17). The crew draws straws, and the unlucky two who get the short straws have the opportunity to heroically sacrifice themselves so that the rest of the crew may live.

Naturally the kind way to do the math is when initially planning the mission. Multiply the number of crew members by the duration of the mission in days to get the required number of person-days of consumables (and if you are wise you'll add an additional safety margin). Then you can calculate the mass and volume for each vital life-support consumable.

For instance, a 250 day mission with 5 crew would need 1,250 person-days. If food takes up 2.3 kg and 0.0058 m3 per person-day, you multiply by 1,250 to calculate the spacecraft needs to accommodate 2,875 kg and 7.25 m3 for the food supply.

In NASA-speak:

Environmental Control And Life Support System. The part of your spacecraft or space station that makes a livable environment so the astronauts don't all die horribly in ninety seconds flat.
Controlled (or Closed) Ecological Life Support System. A life support system that recycles air, water, and food indefinitely (given input energy). It can vastly cut down on the payload mass "wasted" on food (given the CELSS penalty mass). Drawback is that it can be tricky to maintain the balance.
Primary (or Portable or Personal) Life Support System. A life support system for a space suit, generally contained in the back-pack.

A useful document with nitty-gritty details about life support Human Integration Design Handbook. This include info on the minimum volume needed for such tasks as exercise and hygiene, range of safe breathing mixes, temperature, humidity, acceleration limits, fire extinguishers, and related matter.


The basic requirements for life support are:

  • Breathing Mix: an atmosphere to breath, or the crew will rapidly suffocate. Oxygen must be added as it is consumed and carbon dioxide removed as it is exhaled. Humidity must be maintained at a confortable level. An alarm should be triggered if dangerous contaminants are detected, or the signature of a fire.
  • Water: for drinking and hygiene, or the crew will die of thirst (though probably not die of filth).
  • Food: for eating, or the last surviving cannibal crew member will starve to death.
  • Waste Disposal: or the crew will perish in a sea of sewage.
  • Temperature Regulation: or the crew will either freeze or roast to death, probably the latter.
  • Radiation Shielding: or deadly radiation will take its toll.
  • Artificial Gravity: Need a replacement for gravity or limited duration tours in microgravity or it is death by Old Astronaut Syndrome.

The first three requirements are called "consumables", since they are gradually used up by the crew. Each of those three can be controlled by either an "open" system or a "closed" system.

Open systems are ones where a supply of the consumable in question is lugged along as cargo, enough to last the for the planned duration of the mission. It is renewed by "resupply", by obtaining new supply from a resupply spacecraft, a base, or an orbital supply depot. Things can get ugly if the mission duration becomes unexpectedly prolonged, for instance by a meteor scragging the spacecraft's engine.

Closed systems are ones where the supply of the consumable in question are renewed by some kind of closed ecological life support system. Generally this takes the form of some sort of plants, who use sunlight to turn astronaut sewage and exhaled carbon dioxide into food plants and oxygen.

Note that requirements for consumables can be drastically reduced if some of the crew is placed into suspended animation.

If you want more data on life support than you know what to do with, try reading this NASA document. Otherwise, read on.

For some great notes on spacecraft life support, read Rick Robinson's Rocketpunk Manifesto essay.

As a very rough rule of thumb: one human will need an amount of mass/volume equal to his berthing space for three months of consumables (water, air, food). This was figured with data from submarines, ISS, and Biosphere II. Of course this can be reduced a bit with hydroponics and a closed ecological system. This also makes an attractive option out of freezing one's passengers in cryogenic suspended animation.

Eric Rozier has an on-line calculator that will assist with calculating consumables.


Many of the settlers of Talentar, who would later become dirt farmers and ecopoetic line techs, were drawn from rural areas of Eliéra, seeing an opportunity to apply their sophisticated knowledge of modern agriculture and silviculture to the problems of making this new world blossom.

It is from these settlers that a local variation in the rights and customs of hospitality has become ubiquitous. Many of the foresters and line techs of the Delzhía Terra region in particular were drawn from the wooded upland valleys of the Vintiver region. An age-old custom there was the “traveler’s bite”; a traveler riding through could stop at any farmstead and rap at the kitchen window, receiving in exchange for a few taltis a fill of working-man’s beer for their mug, a handwheel of cheese, a pocket-loaf, and perhaps some trimmings of the day’s roast.

On Talentar, this evolved into the custom of the “traveler’s charge”. A traveler by foot or rover can stop at any of the small domes or prefabs dotting the dusty plains, signal at the service hatch, and receive a charge for their powercells, a fresh oxygen tank for an expended one, and a packed handmeal of the local produce – an invaluable service for traveling light, or in a pinch.

– “Sophontology of the Talentar Settlers”
Mirial Quendocius

Breathing Mix

According to NASA, each astronaut consumes approximately 0.835 kilograms (0.560 cubic meters) of oxygen per day. They breath out 0.998 kilograms of carbon dioxide per day.

As a point of reference, a SCUBA tank is pressurized to about 250 bar i.e., 250 times atmospheric pressure. At that pressure, one person day of oxygen takes up about 0.00224 cubic meters.

Stored as liquid oxygen, 0.8 kilograms would take up about 0.0007 cubic meters. This requires extra mass for the cryogenic equipment to keep the oxygen liquid, but the volume savings are impressive.

So as far as pure oxygen goes, you take 0.8 kg for one person-day of oxygen, muliply it by the number of crewbeings on the ship, and then muliply it by the number of days in a standard mission (i.e., desired "endurance time" or time between supply stops) to discover the total oxygen mass requirement. Repeat with the volume figure for the total oxygen volume requirement.You'd be wise to add an additional reserve of about 25% to take account of pressurization of the hull, loss due to various mishaps, and general military paranoia.

However, this is just pure oxygen. This is insanely dangerous to use as the ship's atmosphere, the accident that killed the Apollo 1 crew proved that. In practice one uses a "breathing mix" of oxygen and another gas.

The Space Shuttle uses a 79% nitrogen/21% oxygen mix at atmospheric pressure (14.7 psi or 760 mm Hg). The shuttle space suits use 4.3 psi of pure oxygen, which means they have to prebreath pure oxygen while suiting up, or the bends will strike. Setting up the optimal breathable atmosphere is complicated.

Making Oxygen

There are two methods of cracking CO2 into C and O2: low energy and high energy.

Low energy requires prohibitive amounts of biomass in plants. Data from Biosphere II indicate roughly seven tons of plant life per person per day, with a need for roughly 4 days for a complete plant aspiration cycle, so call it 25 to 30 tons of plant per crewman. With an average density of 0.5, each ton of greenhouse takes up about 2 cubic meters (m3).

High energy methods take up much less space, but (as the name implies) requires inconveniently large amounts of energy. It also results in lots of messy by-products and waste heat. Practically, it is easier to flush the CO2 instead of cracking it, and instead bringing along an extra supply of water to crack for oxygen. Water is universally useful with a multitude of handy applications, and takes less energy to crack than CO2.

For future Mars missions, it has been suggested that the life support system should utilize the Sabatier Reaction. This takes in CO2 and hydrogen, and produces water and methane. The water can split by electrolysis into oxygen and hydrogen, with the oxygen used for breathing and the hydrogen used for another batch of CO2. Unfortunately the methane accumulates, and its production eventually uses up all the hydrogen. The reaction does require one atmosphere of pressure, a temperature of about 300°, and a catalyst of nickel or ruthenium on alumina.

For emergency use, it would be wise to pack away a few Oxygen Candles. These are composed of a compound of sodium chlorate and iron. When ignited, they smolder at about 600°C, producing iron oxide (rust), sodium chloride (salt), and approximately 6.5 man-hours of oxygen per kilogram of candle. Molecular Product's Chlorate Candle 33 masses 12.2 kilos, cylindrical can dimensions of 16 cm diameter x 29 height, burns for 50 minutes, and produces 3400 liters of oxygen.

Removing Carbon Dioxide

It is not enough to supply oxygen to breath, you also have to remove the carbon dixoide. Bad things happen if the CO2 levels rise too high. NASA says that each astronaut exhales 0.998 kilograms of carbon dioxide per day.

  • 0.04 percent - Typical level in Terra's atmmosphere
  • At 1 percent - drowsiness
  • At 3 percent - impaired hearing, increased heart rate and blood pressure, stupor
  • At 5 percent - shortness of breath, headache, dizziness, confusion
  • At 8 percent - unconsciousness, muscle tremors, sweating
  • Above 8 percent - death

NASA uses Carbon Dioxide Scrubbers. In the Apollo program spacecraft, NASA used lithium hydroxide based scrubbers, which fill up and have to be replaced. Oxygen tanks have enough to last for the duration of the mission, and is gradually used up. Actually it is converted into carbon dioxide and is absorbed into the scrubbers, where it cannot be used any more.

You may remember all the excitement during the Apollo 13 disaster, when NASA learned the life-threatening dangers of non-standardization. The crew had to use the Command Modules' scrubber cartridges to replace the ones in the Lunar module. Unfortunately, due to lack of standardization, the CM cartridges would not fit into the LM life support system (CM's were square, LM were cylindrical). They had to rig an adaptor out of duct tape and whatever else was on-board.

In the Space Shuttle, NASA moved to a Regenerative carbon dioxide removal system. Metal-oxide scrubbers remove the CO2 as before. But when they get full, instead of being replaced, they can have the CO2 flushed out by running hot air through it for ten hours. Then they can be reused.

In the TransHab design, they use a fancier system to remove carbon dioxide and replace it with oxygen. Actually it recycles the oxygen, plucking it out of the carbon dioxide molecules and returning it to the atmosphere to be breathed once again.

Note that the system does not affect the nitrogen inert gas, so it stays at the proper level.

In the following specifications, the mass (kg), volume (m3), and electrical power requirements (W) is for equipment sized to handle a six person crew.

First the stale air is pumped through a 4-Bed Molecular Sieve (217.7 kg, 0.6 m3, 733.9 W). It initially removes the water from the air (and sends it to be added to the life support water supply), then it removes the carbon dioxide.

The carbon dioxide and some hydrogen (from a source to be explained shortly) are fed into a Sabatier Reactor (26 kg, 0.01 m3, 227.4 W). They react producing methane and water: CO2 + 4 H2 → CH4 + 2 H2O + energy.

The methane is vented into space. The water is fed into an electrolyser to be split into hydrogen and oxygen. Specifically a Solid Polymer Electrolysis (SPE) Oxygen Generation Subsystem (OGS) (501 kg, 2.36 m3, 2004 W).

The hydrogen is sent back to the Sabatier Reactor to take care of the next batch of carbon dioxide. The oxygen is added to the breathing mix and released into the habitat module's atmosphere.

The TransHab starts out with a tank of high pressure oxygen (20.4 kg, 0.78 m3, 6W, 30 MPa) and a tank of high pressure nitrogen (94.4 kg, 3.6 m3, 6W, 30 MPa). The oxygen tank has three days worth of breathing for six crew, enough to give the Sabatier Reactor time to get started. The nitrogen tank has enough to establish the proper ratio for the breathing mix, and some extra to compensate for any atmosphere leaking into space.

..."That puts me in mind of something that happened to me when I was 'farmer' in the old Percival Lowell -- the one before the present one," Yancey went on. "We had touched at Venus South Pole and had managed somehow to get a virus infection, a sort of rust, into the 'farm' -- don't look so superior, Mr. Jensen; someday you'll come a cropper with a planet that is new to you!"

"Me, sir? I wasn't looking superior."

"No? Smiling at the pansies, no doubt?"

"Yes, sir."

"Hmmph! As I was saying, we got this rust infection about ten days out. I didn't have any more farm than an Eskimo. I cleaned the place out, sterilized, and reseeded. Same story. The infection was all through the ship and I couldn't chase it down. We finished that trip on preserved foods and short rations and I wasn't allowed to eat at the table the rest of the trip."


"Yes, Dodson?"

"What did you do about air-conditioning?"

"Well. Mister, what would you have done?"

Matt studied it. "Well, sir, I would have jury-rigged something to take the Cee-Oh-Two out of the air."

"Precisely. I exhausted the air from an empty compartment, suited up, and drilled a couple of holes to the outside. Then I did a piping job to carry foul air out of the dark side of the ship in a fractional still arrangement -- freeze out the water first, then freeze out the carbon dioxide. Pesky thing was always freezing up solid and forcing me to tinker with it. But it worked well enough to get us home."

From SPACE CADET by Robert Heinlein. 1948.

"Check the oxygen supplies first," the voice of Thorndyke, the head engineer, suggested.

Bart and Dan went off to do that, and Jim followed behind them. But from their faces, he could tell that their hopes weren't too high. Obviously, most of the oxygen had been put into the new extension, since there was more room there for the big containers of liquid oxygen. They had been in the shadow, below the main part of the hull, where they could stay liquid; but the heat of the fire had bent and twisted them, and some had even exploded violently.

"Takes three pounds of oxygen a day for a man," Dan said. "You'll find the amount on the outside of the tanks. Gauge will tell you what per cent has been used." He went back into the rear extension, leaving Bart and Jim to count the amount in the original hut. It was a lot less than they would have liked.

"According to those figures, we've got just enough air left for all the men here for about thirty hours! And we don't have chemicals to soak up the carbon dioxide they breathe out for even that long."

"The big problem's in getting rid of the carbon dioxide," Thorndyke said flatly. "If we could handle that, we might just barely survive until the storm had let up enough for another ship to try.

In a vague way, Jim still felt responsible for the trouble. He should have checked on his assistant. He'd been beating his head, trying to remember what he'd learned in high school about the behavior of the gas. His father had always maintained that a man could accomplish almost anything by reducing things down to the basic characteristics, and then finding out what was done in other fields.

"It's a heavy gas," someone said suddenly. "If we all climb up to the top where the lighter oxygen is . . ."

He realized his mistake before the others swung on him. Thorndyke chuckled grimly. "It's the same here as anything else—neither fight nor heavy," he pointed out. "But all the same, you're moving in the right direction. What are the basic characteristics of carbon dioxide?"

The young man who'd studied chemistry piped up again. "It's a heavy gas, composed of one atom of carbon and two of oxygen. Animals breathe it out, and plants breathe it in, releasing the oxygen again. It freezes directly to a solid, without any real liquid state, and is then known as dry ice. It evaporates . . ."

"It freezes at a higher temperature than air!" Jim shouted. "That's how they make dry ice—they lower the temperature enough for carbon dioxide to freeze, but the rest of the atmosphere stays a gas. What about the cold side—does it get cold enough to freeze it out?"

"How cold?" Thorndyke asked. "Never mind." He reached over for a copy of the Handbook of Chemistry and Physics and ran through it. "If we didn't pass it through too fast, our air would probably lose most of the gas from the cold. Dan, any way to get a gastight pan . . ."

"You've got the pipes under the solar mirror trough," Dan pointed out. "They're all coupled up. We could blow it through there slowly enough—trial and error should tell us how slowly."

From STEP TO THE STARS by Lester Del Rey. 1954


In most space program, they use two breathing mixes for the atmosphere inside the habitat modules and space suits. Low Pressure (pure oxygen at 32.4 kiloPascals [kPa]) or High Pressure (breathing mix at 101.3 kPa). High pressure breathing mix is pretty close to ordinary Terran air at sea level.

Breathing Mix
Below Pressure
Above Pressure
32.4 kPa
(4.7 psi)
5.3 kPa
(0.77 psi)
53.3 kPa
(7.73 psi)
32.4 kPa
(4.7 psi)
101.3 kPa
(14.5 psi)
25.2 kPa
(3.7 psi)
254.0 kPa
(36.8 psi)
21.3 kPa
(3.1 psi)
  • Mix: Name of breathing Mix
  • Pressure: Normal atmospheric pressure of breathing mix
  • Oxygen Percent: Percentage of the gas that is oxygen
  • Anoxia Below Pressure: Death by anoxia if atmospheric pressure drop below this
  • Oxygen Toxicity Above Pressure: Death by oxygen toxicity of atmospheric pressure rises above this
  • Oxygen Partial Pressure: Pressure of the oxygen component

The important thing to note is that for a low pressure breathing mix, the crew will die of anoxia if the atmospheric pressure falls below 5.3 kPa and the crew will die of oxygen toxicity if the pressure rises above 53.3 kPa.

For a high pressure breathing mix, anoxia lies below 25.2 kPa and oxygen toxicity is above 254.0 kPa.

How do you calculate safe breathing mixes for yourself?

The basic limit is anoxia ocurrs when the Partial Pressure of oxygen drops below 5.3 kPa and oxygen toxicity ocurrs when the partial pressure of oxygen rises above 53.3 kPa.

How do you calculate the partial pressure of oxygen?

pO2 = pMix * O%

pMix = pO2 / O%


  • pO2 = partial pressure of oxygen (kPa)
  • pMix = pressure of the atmosphere (kPa)
  • O% = percentage of breathing mix that is oxygen (0.0 to 1.0)

High pressure breathing mix is 21% oxygen (0.21). Anoxia will hit the crew when the atmospheric pressure drops to what pressure? (anoxia pO2 = 5.3 kPa)

pMix = pO2 / O%
pMix = 5.3 / 0.21
pMix = 25.2 mPa

Low pressure is attractive; since it uses less mass and the atmosphere will escape more slowly through a meteor hole. Unfortunately the required higher oxygen level make living in such an environment as hazardous as chain-smoking inside a napalm factory. NASA found that out the hard way in the Apollo 1 tragedy. Since then NASA always uses high pressure, they use low pressure in space suits only because they cannot avoid it.

This does raise a new problem. There is a chance that the high-oxygen atmosphere will allow a meteor to ignite a fire inside the suit. There isn't a lot of research on this, but NASA seems to think that the main hazard is a fire enlarging the diameter of the breach, not an astronaut-shaped ball of flame.

The increased fire risk is one reason why NASA isn't fond of low-pressure/high oxygen atmospheres in the spacecraft proper. There are other problems as well, the impossibility of air-cooling electronic components and the risk of long-term health problems being two. Setting up the optimal breathable atmosphere is complicated.

A more annoying than serious problem with low pressure atmospheres is the fact that they preclude hot beverages and soups. It is impossible to heat water to a temperature higher than the local boiling point. And the lower the pressure, the lower the boiling point. You may have seen references to this in the directions on certain packaged foods, the "high altitude" directions. The temperature can be increased if one uses a pressure cooker, but safety inspectors might ask if it is worth having a potentially explosive device onboard a spacecraft just so you can have hot coffee.

The Bends

Decompression sickness (also known as DCS, divers' disease, the bends or caisson disease) is one of the more hideous dangers of living in space.

It occurs when a person has been breathing an atmosphere containing inert gases (generally nitrogen or helium) and they move into an environment with lower pressure. This is commonly when they put on a soft space suit or the room suffers an explosive decompression.

It has all sorts of nasty effects, ranging from joint pain and rashes to paralysis and death. The large joints can suffer deep pain from mild to excruciating. Skin can itch, feel like tiny insects are crawling all over, mottling or marbling, swell, and/or suffer pitting edema. The brain can have sudden mood or behavior changes, confusion, memory loss, hallucinations, seizures, and unconsciousness. The legs can become paralyzed. Headache, fatigue, malaise, loss of balance, vertigo, dizziness, nausea, vomiting, hearing loss, shortness of breath, and urinary or fecal incontinence: the list just goes on and on.

Why does it happen? Well, imagine a can of your favorite carbonated soda beverage. Shake it up, and nothing happens. But when you open it, the soda explodes into foam and sprays everywhere. When you open the container of shaken soda, you lower the pressure on the soda fluid. This allows all the dissolved carbon dioxide in the soda to un-dissolve, creating zillions of carbon dioxide bubbles, forming a foam.

Now imagine that the carbon dioxide is nitrogen, the drink is the poor astronaut's blood in their circulatory system, and the foam is the deadly arterial gas embolisms. That's what causes the bends.

Please note that sometimes the bends can occur if one moves from one habitat to another that has the same pressure, but a different ratio of breathing mix (the technical term is "Isobaric counterdiffusion"). Spacecraft of different nations or models could use different breathing mixes, beware. In fact, rival astromilitaries might deliberately utilize odd-ball breathing mixes, to make life difficult for enemy boarding parties invading their ships.

The bends can be prevented by slow decompression, and by prebreathing. Or by breathing an atmosphere containing no inert gases. Slow decompression works great for deep-sea divers but NASA does not favor it for space flight. An atmosphere with no inert gases (pure oxygen) is an insane fire risk. NASA does not allow a pure oxygen atmosphere in spacecraft and space stations, but will allow it in space suit (in a desperate attempt to lower the suit pressure to the point where the astronaut can move their limbs instead of being trapped into a posture like a star-fish).

So NASA astronauts do a lot of prebreathing. This flushes nitrogen out of the blood stream. NASA uses Terra-normal pressure (14.7 psi) inside the Space Shuttle, but only 0.29 pressure (4.5 psi) with pure oxygen in the space suits. The prebreathing is officially called the In Suit Light Exercise (ISLE) Prebreath Protocol, and unofficially called the "Slow Motion Hokey Pokey".

The astronaut(s) enter the airlock, and the airlock pressure is reduced to 10.2 psi. They breath pure oxygen through masks for 60 minutes (because the air in the airlock contains nitrogen). They then put on their space suits and do an EMU purge (i.e., flush out all the airlock-air that got into the suit while they were putting it on, to get rid of stray nitrogen). The air inside their suits is now also pure oxygen. The airlock pressure is then brought back up to the normal 14.7 psi. They then do 100 minutes of in-suit prebreath. Of those 100 minutes, 50 of them are light-exercise minutes and 50 of them are resting minutes. "Light exercise" is defined as: flex your knees for 4 minutes, rest 1 minute, repeat until 50 minutes has passed. Thus "Slow Motion Hokey Pokey". Now they are ready to open the airlock and step into space.

The innovation was the 50 minutes of exercise. Without it, the entire protocol takes twelve hours instead of one hour and fifty minutes.

If the habitat module's pressure was 12 psi an astronaut could use an 8 psi space suit with no prebreathing required (a pity such suits are currently beyond the state of the art), and for a 4.5 psi suit the prebreathing time would be cut in half.

In case of emergency, when there is no time for prebreathing, NASA helpfully directs the astronauts to gulp aspirin, so they can work in spite of the agonizing pain

Please note that most of the problem is due to the fact that soft space suits have a lower atmospheric pressure than the habitat module. So this can be avoided by using a hard space suit or space pod.


All of the atmospheric controls will be on the life support deck.

On a related note, forced ventilation in the spacecraft's lifesystem is not optional. In free fall, the warm exhaled carbon dioxide will not rise away from your face. It will just collect in a cloud around your head until you pass out or suffocate. In Arthur C. Clarke's ISLANDS IN THE SKY the apprentices play a practical joke on the main character using this fact and a common match. In the image above the blue dome shaped flame is an actual candle burning in free fall. And in Clarke's "Feathered Friend", he talks about the wisdom of using an animal sentinel to monitor atmospheric quality. Specifically by using the tried and true "canary in a coal mine" technique.

And yes, on Skylab, the area around the the air vent got pretty disgusting quite quickly, as all the floating food particles and assorted dirt from the entire space station got sucked in. In some SF novels the slang name for the air vents is "The Lost and Found Department."


They're wind chimes. I know most people like to tie little prayer flags and scarves and stuff to the air-vent to make sure it's working, but back home we use wind chimes. You don't have to be looking at 'em to know they're working.

They're not like the chimes they have back on Earth; these only have one note. Most habs around Saturn do it that way — each compartment has a single note. That way, you can tell location of a faulty blower just by the change in the sound. And let me tell you, they are not optional. If you take a set down for anything other than maintenance on the air-vent in question, you can get arrested.

Of course they're loud! That's how you know they're working. But I know what you mean — when I first moved out to Titan, it took me a good month to get used to 'em. I was up all night most nights hearing chimes all over the hab ringing. It was like this constant drone with a few off notes every now and then to make sure you didn't relax. I complained to anybody who'd listen, which was nobody. All I did was get myself a rep as another dumb groundhog fresh off the boat

The chimes didn't just bother me at night, either. They are everywhere. In public spaces they make quiet conversation just about impossible. And I just about failed my first semester in school from being distracted. I tried to use noise-canceling ear buds during study hall one time and almost got expelled for “negligence and reckless endangerment”. Seriously, if I hadn't still been under Immigrant's Probation, I would have had to do a public service sentence. I thought that was crazy — or some kind of bullsh*t hazing for the Earthworms or something. As it was, I did have to take the Habitat Orientation class again — listening to the damned wind chimes the whole time.

But let me tell you — They were absolutely right to bust me. They confiscated my ear buds when I got caught so I didn't have them during a weekend maintenance cycle on the hab. We were living in a retired Trans-Chronian, the kind they used to have before the River-class came out. The counter-spinning rings were always breaking down or getting fatigued or some damn thing, so we only had gravity maybe five days a week. My little sisters loved it — I'd play catch with them, with the toddler standing in as the ball. Anyway, the apartment had only pair of rooms, and my parents got one and the girls the other. I slept in a bag in the living room and lived out of a foot locker. One night I woke up from a dead sleep with the uncontrollable feeling that something was wrong. I couldn't put my finger out what it was, but the effect was disturbing. I figured that I was just having trouble sleeping from the wind chimes when I realized that was what was wrong — I wasn't hearing the chimes.

A glance up told me that the chimes in the living room were still going, but I really didn't need it. The sound of all the chimes in our apartment had gotten so far under my skin over the weeks we'd been living there that I pretty much figured out immediately which chimes had stopped. You guessed it — the girls' room. By the time I got in there they were both awake and holding hands while spinning like they teach you. My parents were in there a couple seconds after me, but only because they had farther to go.

Anyway, it was nothing much as vent problems go. A stuffed rabbit toy had gotten jammed into the fan — so the girls got grounded and had to do extra chores for a week. They whined about it, and kids do, and then we all went back to bed. It took a me good while to go back to sleep after that. For all I my complaining about those annoying, distracting, aggravating wind chimes, if we didn't have 'em up that night my sisters would have never have woken up. Ever again.

So, you don't mind me hanging these up, do you?

There were also, I'd discovered, some interesting tricks and practical jokes that could be played in space. One of the best involved nothing more complicated than an ordinary match. We were in the classroom one afternoon when Norman suddenly turned to me and said: 'Do you know how to test the air to see if it's breathable?'

'If it wasn't, I suppose you'd soon know,' I replied.

'Not at all — you might be knocked out too quickly to do anything about it. But there's a simple test which has been used on Earth for ages, in mines and caves. You just carry a flame ahead of you, and if it goes out — well, you go out too, as quickly as you can!' He fumbled in his pocket and extracted a box of matches. I was mildly surprised to see something so old-fashioned aboard the Station.

'In here, of course,' Norman continued, 'a flame will burn properly. But if the air were bad it would go out at once.' He absent-mindedly stroked the match on the box and it burst into light. A flame formed around the head — and I leaned forward to look at it closely. It was a very odd flame, not long and pointed but quite spherical. Even as I watched it dwindled and died.

It's funny how the mind works, for up to that moment I'd been breathing perfectly comfortably, yet now I seemed to be suffocating. I looked at Norman, and said nervously: 'Try it again — there must be something wrong with the match.'

Obediently he struck another, which expired as quickly as the first.

'Let's get out of here,' I gasped. 'The air-purifier must have packed up.' Then I saw that the others were grinning at me.

'Don't panic, Roy,' said Tim. 'There's a simple answer.' He grabbed the match-box from Norman. 'The air's perfectly O.K. but if you think about it, you'll see that it's impossible for a flame to burn out here. Since there's no gravity and everything stays put, the smoke doesn't rise and the flame just chokes itself. The only way it will keep burning is if you do this.'

He struck another match, but instead of holding it still, kept it moving slowly through the air. It left a trail of smoke behind it, and kept on burning until only the stump was left.

'It was entering fresh air all the time, so it didn't choke itself with burnt gases. And if you think this is just an amusing trick of no practical importance, you're wrong. It means we've got to keep the air in the Station on the move, otherwise we'd soon go the same way as that flame. Norman, will you switch on the ventilators again, now that you've had your little joke?'

From ISLANDS IN THE SKY by Sir Arthur C. Clarke (1954)

The Avenger had long since disappeared and Tom was left alone in space in the tiny jet boat. To conserve his oxygen supply, the curly-haired cadet had set the controls of his boat on a steady orbit around one of the larger asteroids and lay down quietly on the deck. One of the first lessons he had learned at Space Academy was, during an emergency in space when oxygen was low, to lie down and breath as slowly as possible. And, if possible, to go to sleep. Sleep, under such conditions, served two purposes. While relaxed in sleep, the body used less oxygen and should help fail to arrive, the victim would slip into a suffocating unconsciousness, not knowing if and when death took the place of life.

From ON THE TRAIL OF SPACE PIRATES by Carey Rockwell (1953) a Tom Corbett Space Cadet book


Unpleasant odors in the air is a problem, but there is not much one can do about it. After all, you can't just open up a window to let in some fresh air, not in the vacuum of space. NASA carefully screens all materials, sealants, foods, and everything else to ensure that they do not emit noticeable odor in the pressurized habitat sections of spacecraft and space stations. Such odors can quickly become overpowering in such tight quarters.


     A glossed over aspect of interstellar society is the difficulty of accommodating humans (let alone aliens) comfortably on the same ships. I'll just deal with humans for this post.

     Atmosphere is the first thing passengers will notice aboard a ship. Not being able to breathe trumps decor and cuisine. While passengers will be assured of a breathable mix, humidity, pressure, temperature and such will be for the crew (or captain's) norm and not theirs. This is because having your pilot or engineer become light headed at the wrong time may lead to inevitable and infinite delays in reaching your destination. Note that crew will usually forgo any atmospheric contaminants they grew up with (and acclimated to).

     Passengers could have atmospheres set to their comfort zone in their staterooms. In some extreme cases filter masks or compressors might be worn. Contaminants can still become an issue. Consider most free traders and subsidized merchants travel to a number of worlds. The ship and the crew are exposed to all manner of dusts, pollens and pollutants which they then carry onboard. Decorative foliage is usually not a feature on most ships for this reason. Some pollens will send some offworlders to the hospital. But crew will bring back these various ticking allergens back onboard in their hair and clothes. This dust will accumulate despite air filtration systems if the ship is not scrupulously cleaned and your average crew will already be working two jobs on a tramp freighter. They probably won't get the corners or under the fridge.

     Besides this consider that cargo is liable to bring allergens onboard or cause allergic reactions itself. Add to this gases emitted by plastics in a plethora of manufactured products from a multitude of worlds with different health codes written for variant humans with a variety of tolerances. You start to wonder how humans will survive their first trip without sneezing themselves to death.

     An allergic reaction from a passenger or new recruit is almost inevitable. Hopefuly your steward has done a good job researching the passenger's files, identifying common allergens for their human substype and testing for such contaminants before they ever set foot on deck. And you thought your steward was great because he made awesome grilled cheese sandwiches.

From SPECIAL ACCOMMODATIONS by Rob Garitta (2016)

There's a fortune awaiting the man who invents a really good deodorizer for a spaceship. That's the one thing you can't fail to notice.

Oh, they try, I grant them that. The air goes through precipitators each time it is cycled; it is washed, it is perfumed, a precise fraction of ozone is added, and the new oxygen that is put in after the carbon dioxide is distilled out is as pure as a baby's mind; it has to be, for it is newly released as a by-product of the photosynthesis of living plants. That air is so pure that it really ought to be voted a medal by the Society for the Suppression of Evil Thoughts.

Besides that, a simply amazing amount of the crew's time is put into cleaning, polishing, washing, sterilizing - oh, they try!

But nevertheless, even a new, extra-fare luxury liner like the Tricorn simply reeks of human sweat and ancient sin, with undefinable overtones of organic decay and unfortunate accidents and matters best forgotten. Once I was with Daddy when a Martian tomb was being unsealed - and I found out why xenoarchaeologists always have gas masks handy. But a spaceship smells even worse than that tomb.

It does no good to complain to the purser. He'll listen with professional sympathy and send a crewman around to spray your stateroom with something which (I suspect) merely deadens your nose for a while. But his sympathy is not real, because the poor man simply cannot smell anything wrong himself. He has lived in ships for years; it is literally impossible for him to smell the unmistakable reek of a ship that has been lived in - and, besides, he knows that the air is pure; the ship's instruments show it. None of the professional spacers can smell it.

But the purser and all of them are quite used to having passengers complain about the "unbearable stench" - so they pretend sympathy and go through the motions of correcting the matter.

Not that I complained. I was looking forward to having this ship eating out of my hand, and you don't accomplish that sort of coup by becoming known first thing as a complainer. But other first-timers did, and I certainly understood why - in fact I began to have a glimmer of a doubt about my ambitions to become skipper of an explorer ship.

But - Well, in about two days it seemed to me that they had managed to clean up the ship quite a bit, and shortly thereafter I stopped thinking about it. I began to understand why the ship's crew can't smell the things the passengers complain about. Their nervous systems simply cancel out the old familiar stinks - like a cybernetic skywatch canceling out and ignoring any object whose predicted orbit has previously been programmed into the machine.

But the odor is still there. I suspect that it sinks right into polished metal and can never be removed, short of scrapping the ship and melting it down. Thank goodness the human nervous system is endlessly adaptable.

From PODKAYNE OF MARS by Robert Heinlein

(ed note: US captain John Fitzthomas and Chinese captain June Tran are talking)

     (June Tran said) "Take all the politicians, and draft them into the space navies. Make them spend a year cooped up on a spaceship. Don't let them out. Don't even let them go to astrogation and look through the telescope at the stars. Just them and the metal on all sides of them. Food that tastes like plastic. Air that smells like sweat and farts."
     "I know, I know. I'm sorry. It's just, well, we don't have the last problem anymore."

     "No. I want to see the lake. I have heard all their stories anyway. And you haven't told me the secret of how you keep your spaceship from stinking."
     "Oh, it's not a secret. We have a Gadget. It's standard issue."
     "A Gadget?"
     "Yes. Tell me you've never heard of a Gadget."
     "I'm afraid I have not."
     "It's wonderful. It's a little machine you place right at the out vent of your gas exchanger, right where the oxygenated air gets pumped back into the ventilation system. It has some kind of filter that neutralizes all the smells that usually build up; it learns what your ship smells like so it can clean the air more efficiently. Then it perfumes the outgoing air with whatever you want."
     "You're kidding."
     "I'm not kidding at all. It's a godsend. The guy who invented it was this California nisei named Takumi Maeda. He made a fortune selling them. He has a company now that makes all kinds of stuff."
     "I have never heard of this man or his miraculous invention."
     "You mean to tell me you've never heard of International Gadgets?"
     "We don't see many American products in Oz."
     "Apparently not, because you don't have a Gadget."
     "What does yours smell like?"
     "Cinnamon rolls now. The crew votes every week on a new one so we don't get tired of any one smell. Last week it was baby powder."
     Tran laughed and clapped her hands together. "I shall inform my superiors of this miracle invention. Perhaps an exception to the embargo can be found."
     "Maybe they'd be more willing to listen if you had a demo model."
     "Where would I get one of those?"
     "I have two spares. I could loan you one in the name of international peace and understanding."
     "That would be wonderful, John. Assuming, of course, it actually works as advertised."
     "It will. It comes with adapters for different vents, too, so it should fit yours fine even if you don't use the same size we do."

From THE LAST GREAT WAR by Matthew Lineberger (not yet published)

His hole was on the eighth level, off a residential tunnel a hundred meters wide with fifty meters of carefully cultivated green park running down the center. The main corridor's vaulted ceiling was lit by recessed lights and painted a blue that Havelock assured him matched the Earth's summer sky. Living on the surface of a planet, mass sucking at every bone and muscle, and nothing but gravity to keep your air close, seemed like a fast path to crazy. The blue was nice, though.

Some people followed Captain Shaddid's lead by perfuming their air. Not always with coffee and cinnamon scents, of course. Havelock's hole smelled of baking bread. Others opted for floral scents or semipheromones. Candace, Miller's ex-wife, had preferred something called EarthLily, which had always made him think of the waste recycling levels. These days, he left it at the vaguely astringent smell of the station itself. Recycled air that had passed through a million lungs. Water from the tap so clean it could be used for lab work, but it had been p**s and sh*t and tears and blood and would be again. The circle of life on Ceres was so small you could see the curve. He liked it that way.

From LEVIATHAN WAKES by "James S.A. Corey" (Daniel Abraham and Ty Franck) 2011. First novel of The Expanse

Meteor Punctures

Meteors are probably nothing to worry about. On average a spacecraft will have to wait for a couple of million years to be hit by a meteor larger than a grain of sand. But if you insist, there are a couple of precautions one can take.

Whipple Shield

First one can sheath the ship in a thin shell with a few inches of separation from the hull. This "meteor bumper" (aka "Whipple shield") will vaporize the smaller guys.


For larger ones, use radar. It is surprisingly simple. For complicated reasons that I'm sure you can figure out for yourself, a meteor on a collision course will maintain a constant bearing (it's a geometric matter of similar triangles). So if the radar sees an object whose bearing doesn't change, but whose range is decreasing, it knows that You Have A Problem. (This happens on Earth as well. If you are racing a freight train to cross an intersection, and the image of the front of the train stays on one spot on your windshield, you know that you and the engine will reach the intersection simultaneously. This example was from Heinlein's ROCKET SHIP GALILEO.)

(Ken Burnside used this concept in his starship combat game Attack Vector: Tactical. From the point-of-view of the target, the incoming missile will hit if it stays on one bearing and does not move laterally. So a game aid called a ShellStar is used to detect the presence of lateral motion.)

The solution is simple as well, burn the engine a second or two in any direction (That was from Heinlein's SPACE CADET). One can make an hard-wired link between the radar and the engines, but it might be a good idea to have it sound an alarm first. This will give the crew a second to grab a hand-hold. You did install hand-holds on all the walls, didn't you? And require the crew to strap themselves into their bunks while sleeping.

Having said that, Samuel Birchenough points out that anybody who has played the game Kerbal Space Program know that an object that is not on a fixed bearing can still hit you. If your spacecraft and the other object are in orbit around a planet, the object's bearing will be constantly changing up to the last few kilometers before the collision.

The moon, now visibly larger and almost painfully beautiful, hung in the same position in the sky, such that he had to let his gaze drop as he lay in the chair in order to return its stare. This bothered him for a moment -- how were they ever to reach the moon if the moon did not draw toward the point where they were aiming?

It would not have bothered Morrie, trained as he was in a pilot's knowledge of collision bearings, interception courses, and the like. But, since it appeared to run contrary to common sense, Art worried about it until he managed to visualize the situation somewhat thus: if a car is speeding for a railroad crossing and a train is approaching from the left, so that their combined speeds will bring about a wreck, then the bearing of the locomotive from the automobile will not change, right up to the moment of the collision.

It was a simple matter of similar triangles, easy to see with a diagram but hard to keep straight in the head. The moon was speeding to their meeting place at about 2000 miles an hour, yet she would never change direction; she would simply grow and grow and grow until she filled the whole sky.

From ROCKET SHIP GALILEO by Robert Heinlein. 1947.

To guard against larger stuff Captain Yancey set up a meteor-watch much tighter than is usual in most parts of space. Eight radars scanned all space through a global 360°. The only condition necessary for collision is that the other object hold a steady bearing-no fancy calculation is involved. The only action necessary then to avoid collision is to change your own speed, any direction, any amount. This is perhaps the only case where theory of piloting is simple.

Commander Miller put the cadets and the sublieutenants on a continuous heel-and-toe watch, scanning the meteor-guard 'scopes. Even if the human being failed to note a steady bearing the radars would "see" it, for they were so rigged that, if a "blip" burned in at one spot on the screen, thereby showing a steady bearing, an alarm would sound- and the watch officer would cut in the jet, fast!...

From SPACE CADET by Robert Heinlein. 1948.

Hull Patching

What if the meteor hits the ship and punctures the hull? An instrument called a Manometer will register a sudden loss of pressure and trigger an alarm. Life support will start high-pressure flood of oxygen, and release some bubbles. The bubbles will rush to the breach, pointing them out to the crew. The crew will grab an emergency hull patch (thoughtfully affixed near all external hull walls) and seal the breach. A more advanced alternative to bubbles are "plug-ups" or "tag-alongs". These are plastic bubbles full of helium and liquid sealing plastic. The helium is enough to give them neutral buoyancy, so they have no strong tendency to rise or sink. They fly to the breach, pop, and plug it with quick setting goo. Much to the relief of the crew caught in the same room with the breach when the automatic bulkheads slammed shut.

Now you have some breathing space to break out the arc welder and apply a proper patch.

The emergency hull patches are metal discs. They look like saucepan covers with a rubber flange around the edge. They will handle a breach up to six inches in diameter. Never slap them over the breach, place it on the hull next to the breach and slide it over. Once over the breach, air pressure will hold it in place until you can make more permanent repairs.

Assuming Terra-normal pressure and density inside, and zero pressure outside, the effective speed of the air whistling out the breach works out to a smidgen under 400 m/sec. Veteran rocketeers, vacationing on Terra, tend to have a momentary panic if they feel the wind. Their instincts tell them there is a hull breach.

dm/dt = A * sqrt[ 2 * P0 * rho ]


  • dm/dt = the rate (mass per unit time) at which air leaks into vacuum (in rocket engines they call it mDot or ṁ)
  • A = area of the hole it's leaking through
  • P0 = stagnation pressure in room (far from the hole)
  • rho = air density inside the room far from the hole
  • sqrt[x] = square root of x

If you want to get fancy and take the atmospheric temperature into account, use Fliegner's Formula (equation from quote below):

dm/dt = 0.04042 * ((A * P0) / sqrt[ T0 ])


  • dm/dt = the rate at which air leaks into vacuum (kg/sec)
  • P0 = stagnation pressure in room (far from the hole) (Pascals Pa)
  • A = area of the hole (m2)
  • T0 = stagnation temperature in room (far from the hole) (Kelvin, about 293 K for room temperature 20°C)

However, what we (and the hapless people inside the breached compartment) are more interested in is how long it takes the pressure to drop, i.e., how long the hapless people have to live before dying of suffocation (equation from quote below).

t = 0.086 * (V / A) * ( ln[ P0/Pƒ ] / sqrt[ T ])


  • t = time for the pressure to drop (seconds)
  • V = volume of compartment (m3)
  • A = Area of the hole (m2)
  • P0 = stagnation pressure in room (far from the hole) (Pascals)
  • Pƒ = final pressure in room (Pascals) (cabin = 25.2, spacesuit = 5.3)
  • T0 = Stagnation temperature in room (far from the hole) (Kelvin, about 293 K for room temperature 20°C)
  • sqrt[x] = square root of x
  • ln[x] = natural logarithm of x

Remember if the compartment is using high pressure breathing mix anoxia strikes when Pƒ = 25.2 kPa, and with a low pressure breathing mix at Pƒ = 5.3 kPa.


(ed note: Mr. Latchman is discussing The Expanse Season 1, Episode 4 "CQB". Our Heroes are sitting inside a compartment in the Martian Congressional Republic Navy flagship Donnager. A railgun round shoots through the compartment, puncturing it to vacuum. Unfortunately the round also decapitates poor Shed.)

The Physics Of Decompression And Constricted Airflows

We do not see the room explosively decompress when the railgun projectile shoots through the Donnager's hull and wall. Except for the fact that air is being sucked out into "hard vacuum," everyone manages to stay in their seats. This happens for a few reasons. The first is the hole, or constriction, is too small for all the air in the room to explosively leave the room. The second deals with the fact that air is made of atoms. Air escaping the hole in the hull to the vacuum of space leaves at approximately the speed of sound. As air molecules exit the hole, the remaining molecules have to "catch up." Think what happens in a traffic jam. All cars do not move together. One car slowly inches forward and then everyone follows. This means there is no explosive decompression unless the entire wall is suddenly removed. While the crew has some time to act, that time is very limited.

Scientists and engineers have looked at the physics of constricted airflow for some time with regard to aircraft. It is a very good idea to know what happens to an aircraft if a hole forms while in flight. A. Fliegner was one of the first engineers to look at this problem and was able to work out how much air leaves depending on the pressure inside a cabin and the size of a hole. We know this as Fliegner's Formula:

where dm/dt is the mass flow, A is the area of the hole, P0 is the pressure inside the cabin, and T0 is the room temperature.

As we expect, the air flow depends on the hole's area, cabin pressure and temperature. Of course, Fliegner's Formula is not that accurate. As the leak progresses, the pressure in the cabin drops and this also affects air flow through the hole. Have no fear, we can use the equation and a little physics to figure out the time it takes the pressure to drop to a certain level. We get:

We have some new variables: V is the volume of the room they are in and Pƒ is the final pressure. Now that we have figured out the equation, we can model what happens inside the cabin and how much time the Canterbury crew have to act.

The Human Race Needs To Breathe To Survive

Air is approximately 20% oxygen. If that level falls to approximately 10% or half atmospheric pressure, you will not have enough oxygen to function and become hypoxic. While you would not necessarily die, you can fall unconscious. We assume that the Canterbury crew can not help themselves and will eventually die as the cabin pressure decreases until all the air is sucked out to the vacuum. Basically, everyone dies when the pressure falls to 50%. Maybe Shed is the lucky one here.

(ed note: actually the documentation I've seen suggests that hypoxia will hit when the pressure falls to 24.8%, or 25.2 kPa, corresponding to an oxygen partial pressure of 5.3 kPa. But the mathematics are the important thing.)

Graph shows the time for the cabin pressure to fall until no air is left.

While we do not have the exact dimensions of the room, we can make a few assumptions. Based on the body sizes of the crew, I assume the room is 10 meters by 10 meters by 5 meters or 500 cubic meters in size. The temperature of the room is about 27°C (80°F or 293K). If we plot the graph over time we see that the pressure drops to half its value where everyone has a little over a minute to plug up the holes.

Does "The Expanse" Get It Right?

Assuming that everything happens in real-time, from the moment Sed loses his head to the second the holes are sealed, the crew manages to do seal the holes with some seconds to spare. While the estimated size of the room may be larger than it really is, the point is... They survive! The show definitely gets the science right and the urgency the crew must act to save their lives.


(ed note: Our Heroes are sitting inside a compartment in the Martian Congressional Republic Navy flagship Donnager. A railgun round shoots through the compartment, puncturing it to vacuum. Unfortunately the round also decapitates poor Shed.)

Holden froze, watching the blood pump from Shed's neck, then whip away like smoke into an exhaust fan. The sounds of combat began to fade as the air was sucked out of the room. His ears throbbed and then hurt like someone had put ice picks in them. As he fought with his couch restraints, he glanced over at Alex. The pilot was yelling something, but it didn't carry through the thin air. Naomi and Amos had gotten out of their couches already, kicked off, and were flying across the room to the two holes. Amos had a plastic dinner tray in one hand. Naomi, a white three-ring binder. Holden stared at them for the half second it took to understand what they were doing. The world narrowed, his peripheral vision all stars and darkness.

By the time he'd gotten free, Amos and Naomi had already covered the holes with their makeshift patches. The room was filled with a high-pitched whistle as the air tried to force its way out through the imperfect seals. Holden's sight began to return as the air pressure started to rise. He was panting hard, gasping for breath. Someone slowly turned the room's volume knob back up and Naomi's yells for help became audible.

"Jim, open the emergency locker!" she screamed.

She was pointing at a small red-and-yellow panel on the bulkhead near his crash couch. Years of shipboard training made a path through the anoxia and depressurization. and he yanked the tab on the locker's seal and pulled the door open. Inside were a white first aid kit marked with the ancient red-cross symbol, half a dozen oxygen masks, and a sealed bag of hardened plastic disks attached to a glue gun. The emergency-seal kit. He snatched it.

"Just the gun." Naomi yelled at him. He wasn't sure if her voice sounded distant because of the thin air or because the pressure drop had blown his eardrums.

Holden yanked the gun free from the bag of patches and threw it at her. She ran a bead of instant sealing glue around the edge of her three-ring binder. She tossed the gun to Amos, who caught it with an effortless backhand motion and put a seal around his dinner tray. The whistling stopped, replaced by the hiss of the atmosphere system as it labored to bring the pressure back up to normal. Fifteen seconds.

"Gauss round," Alex said. "Those ships have rail guns."

"Belt ships with rail guns?" Amos said. "Did they get a f*****g navy and no one told me?"

"Jim, the hallway outside and the cabin on the other side are both in vacuum," Naomi said. "The ship's compromised."

Holden started to respond, then caught a good look at the binder Naomi had glued over the breach. The white cover was stamped with black letters that read MCRN EMERGENCY PROCEDURES (Martian Congressional Republic Navy). He had to suppress a laugh that would almost certainly go manic on him.

"Jim," Naomi said, her voice worried.

"I'm okay, Naomi," Holden replied, then took a deep breath. "How long do those patches hold?"

Naomi shrugged with her hands, then started pulling her hair behind her head and tying it up with a red elastic band.

"Longer than the air will last. If everything around us is in vacuum, that means the cabin's running on emergency bottles. No recycling. I don't know how much each room has, but it won't be more than a couple hours."

"Kinda makes you wish we'd worn our f*****g suits, don't it?" Amos asked.

"Wouldn't have mattered," Alex said. "We'd come over here in our enviro suits, they'd just have taken 'em away."

From LEVIATHAN WAKES by "James S.A. Corey" (Daniel Abraham and Ty Franck) 2011. First novel of The Expanse

"Where're the plug-ups?" the Commander demands. "Damn it, where the hell are the plug-ups?"

"Oh." The man doing the relay talking hits a switch. Little gas-filled plastic balls swarm into the compartment. They range from golf-ball to tennis-ball size.

"Enough. Enough," Nicastro growls. "We've got to be able to see."

A new man, I decide. He's heard about the Commander. He's too anxious to look good. He's concentrating too much. Doing his job one part at a time, with such thoroughness that he muffs the whole.

The plug-ups will drift aimlessly throughout the patrol, and will soon fade into the background environment. No one will think about them unless the hull is breached. Then our lives could depend on them. They'll rush to the hole, carried by the escaping atmosphere. If the breach is small, they'll break trying to get through. A quick-setting, oxygen-sensitive goo coats their insides.

The cat scrambles after the nearest ball. He bats it around. It survives his attentions. He pretends a towering indifference. He's a master of that talent of the feline breed, of adopting a regal dignity in the face of failure, just in case somebody is watching.

Breaches too big for the plug-ups probably wouldn't matter. We would be dead before we noticed them.

From PASSAGE AT ARMS by Glen Cook (1985)

(ed note: a reporter is touring some Lunar tunnels being drilled to expand the colony)

     "Yes and no. The airlocks would limit an accident all right, if there was one—which there won't be—this place is safe. Primarily they let us work on a section of the tunnel at no pressure without disturbing the rest of it. But they are more than that; each one is a temporary expansion joint. You can tie a compact structure together and let it ride out a quake, but a thing as long as this tunnel has to give, or it will spring a leak. A flexible seal is hard to accomplish in the Moon."
     "What's wrong with rubber?" I demanded. I was feeling jumpy enough to be argumentative. "I've got a ground-car back home with two hundred thousand miles on it, yet I've never touched the tires since they were sealed up in Detroit."
     Knowles sighed. "I should have brought one of the engineers along, Jack. The volatiles that keep rubbers soft tend to boil away in vacuum and the stuff gets stiff. Same for the flexible plastics. When you expose them to low temperature as well they get brittle as eggshells."

     There were perhaps a dozen bladder-like objects in the tunnel, the size and shape of toy balloons. They seemed to displace exactly their own weight of air; they floated without displaying much tendency to rise or settle. Konski batted one out of his way and answered me before I could ask. "This piece of tunnel was pressurized today," he told me. "These tag-alongs search out stray leaks. They're sticky inside. They get sucked up against a leak, break, and the goo gets sucked in, freezes and seals the leak."
     "Is that a permanent repair?" I wanted to know.
     "Are you kidding? It just shows the follow-up man where to weld."
     "Show him a flexible joint," Knowles directed.
     "Coming up." We paused half-way down the tunnel and Konski pointed to a ring segment that ran completely around the tubular tunnel. "We put in a flex joint every hundred feet. It's glass cloth, gasketed onto the two steel sections it joins. Gives the tunnel a certain amount of springiness."
     "Glass cloth? To make an airtight seal?" I objected.
     "The cloth doesn't seal; it's for strength. You got ten layers of cloth, with a silicone grease spread between the layers. It gradually goes bad, from the outside in, but it'll hold five years or more before you have to put on another coat."

(ed note: then the accident happens)

     "Looks tight, but I hear—Oh, oh! Sister!" His beam was focused on a part of the flexible joint, near the floor.
     The "tag-along" balloons were gathering at this spot. Three were already there; others were drifting in slowly. As we watched, one of them burst and collapsed in a sticky mass that marked the leak.
     The hole sucked up the burst balloon and began to hiss. Another rolled onto the spot, joggled about a bit, then it, too, burst. It took a little longer this time for the leak to absorb and swallow the gummy mass.
     Konski passed me the light. "Keep pumping it, kid." He shrugged his right arm out of the suit and placed his bare hand over the spot where, at that moment, a third bladder burst.
     "How about it, Fats?" Mr. Knowles demanded.
     "Couldn't say. Feels like a hole as big as my thumb. Sucks like the devil."
     "You got the leak checked?"
     "I think so. Go back and check the gage. Jack, give him the light."
     Knowles trotted back to the airlock. Presently he sang out, "Pressure steady!"
     "Can you read the vernier?" Konski called to him.
     "Sure. Steady by the vernier."
     "How much we lose?"
     "Not more than a pound or two. What was the pressure before?"
     "Lost a pound four tenths, then."
     "Not bad. Keep on going, Mr. Knowles. There's a tool kit just beyond the lock in the next section. Bring me back a number three patch, or bigger."
     "Right." We heard the door open and clang shut, and we were again in total darkness. I must have made some sound for Konski told me to keep my chin up.
     Presently we heard the door, and the blessed light shone out again. "Got it?" said Konski.
     "No, Fatso. No..." Knowles' voice was shaking. "There's no air on the other side. The other door wouldn't open."
     "Jammed, maybe?"
     "No, I checked the manometer. There's no pressure in the next section."
     Konski whistled again. "Looks like we'll wait till they come for us. In that case — Keep the light on me, Mr. Knowles. Jack, help me out of this suit."
     "What are you planning to do?"
     "If I can't get a patch, I got to make one, Mr. Knowles. This suit is the only thing around." I started to help him—a clumsy job since he had to keep his hand on the leak.
     "You can stuff my shirt in the hole," Knowles suggested.
     "I'd as soon bail water with a fork. It's got to be the suit; there's nothing else around that will hold the pressure." When he was free of the suit, he had me smooth out a portion of the back, then, as he snatched his hand away, I slapped the suit down over the leak. Konski promptly sat on it. "There," he said happily, "we've got it corked. Nothing to do but wait."
     I started to ask him why he hadn't just sat down on the leak while wearing the suit; then I realized that the seat of the suit was corrugated with insulation—he needed a smooth piece to seal on to the sticky stuff left by the balloons.
     "Let me see your hand," Knowles demanded.
     "It's nothing much." But Knowles examined it anyway. I looked at it and got a little sick. He had a mark like a stigma on the palm, a bloody, oozing wound. Knowles made a compress of his handkerchief and then used mine to tie it in place.

From GENTLEMEN, BE SEATED! by Robert Heinlein (1948)

So if a posh passenger cabin of 20 cubic yards has a one square inch hole blown in the bulkhead by a wayward meteor, the inhabitants have an entire 86 seconds (about a minute and a half) before the atmospheric pressure drops to one-half.

Somebody in a space suit doesn't have that kind of time. The suit has a volume of approximately 0.03 cubic yards. A hole a quarter inch in diameter has a hole area of 0.05 square inches. As long as the suit's air tanks can keep up the loss the pressure won't drop. But once the tanks are empty, the pressure will drop by one-half in a mere 2.4 seconds.

Does this mean that crewpeople in a combat spacecraft will do their fighting in space suits? Probably not, for the same reason that crewpeople in combat submarines do not do their fighting while wearing scuba gear. The gear is bulky, confining, and tiring to wear. They will not wear it even though in both cases the vessel is surrounded by stuff you cannot breath. They may, however, wear partial-pressure suits. Those suits will only protect you for ten minutes or so, but in exchange you won't be hampered like you were wearing three sets of snow-suits simultaneously.

Instead, the ship's pressurized inhabitable section will be divided into individual sections by bulkheads, and the connecting airtight hatches will be shut. The air pressure might be lowered a bit.

Brian Davis

This came up in a different newsgroup, and upon trying to answer it I blew it badly. I’m not sure the original group really cares, but folks here might, and it’s kind of interesting to me, so…

Let’s say you have a person (named, let’s say, “Callie”) standing in the middle of a large airlock (10 [m] long by 3[m] by 3[m]). The bad girl opens the large doors at the end, “blowing the lock” (it starts at 1 [Atm]). What happens to the helpless heroine? I understand decompression, but I’m trying to figure out how fast (if at all) they “exit” the airlock. For a first cut, I assumed the doors instantly crack open 10 [cm] along their entire 3 [m] length, forming a “breach” with an area of 0.3 [m2] through which the air starts rushing at roughly Mach 1 (I know it would be less, but ballpark). Back by Callie, the cross-sectional area is about 9 [m2], so conservation of mass (assuming uniform density) says the airspeed by her is a gusty 11.1 [m/s]… which is pretty much trivial. I assumed she is accelerated “breachward” by the stagnation pressure of this flow against the front of her body (frontal surface area 0.36 [m2, mass of 45 [kg]), but the result is a really trivial acceleration. Running it through Excel (to keep track of the rapid density/pressure drop, which reduces the stagnation pressure all the more), I get her hitting the breach after a little over 8.5 [sec], and the leisurely pace of about 0.67 [m/s] (a slow walk). She really only accelerates for the first couple seconds, after that the lock is at such a low pressure that the remaining “wind” just doesn’t have enough force to do anything.

OK, so what did I screw up? I realize approximating the exit velocity as 333 [m/s] isn’t good, and I’m ignoring the question of adiabatic vs. nonadiabatic effects, etc. I do take into account the increased airspeed as she gets very close to the breach (closer than 2 [m] or so). But anything major? Or does Callie really fully decompress in the airlock, and gently drift out about 10 seconds later? One interesting artifact of my calculation is that Callie takes a sharp jump up in velocity during the brief time she “wedges” in the breach, but I’m not as worried about that because in the real situation, the doors would have been fully opened by then.

PS- I’d love to take the rate of the doors opening (i.e., breach area increasing) into account, but it makes things more difficult, and in particular makes the assumption of sonicly-limited flow questionable (if the “breach” is one entire side of your airlock, I think I have to worry about the force required to accelerate the mass of air in addition to everything else, yes?).

John Park

I haven't verified your numbers, but for a quick sanity check, there's about 100 kg of air in the lock, but only half of that is behind her—her own body weight—and most of that will escape past her. If you really want the damsel to experience dramatic accelerations, I think you should start her closer to the opening, or have the inner door open, or maybe use a longer, thinner lock that she almost blocks with her body.

Tim Little

(Brian Davis: She really only accelerates for the first couple seconds, after that the lock is at such a low pressure that the remaining 'wind' just doesn't have enough force to do anything.)

Yes, that's about right, if the door opens outward and sticks at a 10 cm gap. Though actually I'd be very surprised to see an airlock with a door that opened outward at all.

If it did open outward, and was free to swing open wider, consider that it has 100 kPa pressure acting on the inner surface. It will accelerate open very rapidly indeed — probably on the order of tens of milliseconds.

Though even in that situation, I'd guess Callie would exit the airlock with only on the order of 1-3 m/s velocity, long after the air is gone.

(Brian Davis: Or does Callie really fully decompress in the airlock, and gently drift out about 10 seconds later?)


(Brian Davis: if the breach is one entire side of your airlock, I think I have to worry about the force required to accelerate the mass of air in addition to everything else, yes?)

Sort of. The rarefaction front will propagate inward at the speed of sound, with the air accelerated nearly instantaneously as the front passes. The temperature behind the front will be some fraction of the starting temperature — I'd guess about 4/5 from one thermal degree of freedom out of five being converted to kinetic energy.

The relation for adiabatic expansion then gives a pressure behind the front of about 46% of the initial pressure, and an exit speed of about 250 m/s.

That will exert a lot of force on Callie, but only for about 20-30 ms.

Dr J. R. Stockton

(Brian Davis: Let’s say you have a person (named, let’s say, “Callie”) standing in the middle of a large airlock (10 [m] long by 3[m] by 3[m]). The bad girl opens the large doors at the end, “blowing the lock” (it starts at 1 [Atm]). What happens to the helpless heroine?)

At worst, approximately, and assuming a heroine of only moderate size (i.e., not a plug) : since the molecular speed is about the speed of sound, the energy can only accelerate the gas to about the speed of sound, 330 m/s. The heroine, being around a thousand times more dense than air, will be accelerated to about a thousandth of that, around a foot per second.

A worst case approximation is that a transition between 105 Pa and 0 Pa propagates past her at 330 m/s. So, per square metre, she gets 105 N for a duration of T/330 s, where T is her thickness in metres. Her mean density will be, of course, 1000 in SI units, so per square metre her mass is 1000×T; so her change in speed will be 105 × T/330 / 1000×T, which is about 0.3 m/s.

One cannot recommend, for the usual purposes, a heroine who obstructs a substantial proportion of nine square metres.

Tim Little

(Dr J R Stockton: A worst case approximation is that a transition between 105 Pa and 0 Pa propagates past her at 330 m/s. So, per square metre, she gets 105 N for a duration of T/330 s, where T is her thickness in metres.)

The duration is much longer than that, since she is still in the path of the air escaping from further back in the airlock. Even though the static pressure is at 0 Pa, it still has significant density.

In particular, if c is the usual speed of sound, and v is the speed to which the rarefaction wave accelerates the air, simple conservation of mass puts the density ratio at c/(c+v).

So the air rushing past her from further in the airlock will exert pressure as it escapes past her. So for a long airlock, her velocity would asymptotically approach the free outflow speed.

This is a fairly short airlock, but certainly longer than her average thickness.

John Schilling

(Dr J R Stockton: At worst, approximately, and assuming a heroine of only moderate size (i.e. not a plug) : since the molecular speed is about the speed of sound, the energy can only accelerate the gas to about the speed of sound, 330 m/s. The heroine, being around a thousand times more dense than air, will be accelerated to about a thousandth of that, around a foot per second.

A worst case approximation is that a transition between 105 Pa and 0 Pa propagates past her at 330 m/s. So, per square metre, she gets 105 N for a duration of T/330 s, where T is her thickness in metres. Her mean density will be, of course, 1000 in SI units, so per square metre her mass is 1000×T; so her change in speed will be 105 × T/330 / 1000×T, which is about 0.3 m/s.)

Ah, so if I hang a sheet of tissue paper just inside the airlock of an O'Neill habitat, and open the door, it won't go anywhere, right? Because all it will experience is an infinitesimal moment of acceleration as the transition between atmosphere and vacuum propagates past its negligible thickness?

I'm thinking that's not right. I'm also thinking that a propagating transition between atmosphere and vacuum would represent a violation of the law of conservation of mass.

What actually propagates, is a transition between air at 105 Pa, and air at 5.28×104 Pa moving outwards at 310.42 m/s. And that transonic wind condition, remains even after the transition has passed — for as long as it takes for the transition wave to reach the farthest wall of the chamber behind our heroine, and as long beyond that as it takes for the wind to actually empty the chamber.

If the geometry is cylindrical, I get for a standard heroine in a standard atmosphere, a net velocity of 1.8 m/s per meter length of air-filled volume behind her. That's in the low-velocity limit; as she herself approaches transonic velocity downstream, the force will decrease and her own velocity will asymptotically approach 310.42 m/s.

If the geometry is not cylindrical, it gets rather more complicated of course.

Erik Max Francis

(Brian Davis: OK, so what did I screw up?)

Nothing, I'd say. The ability for explosive decompression to push people around is usually exaggerated. Your results sound qualitatively like I'd expect — it'd budge her a little at first but very rapidly the ambient air pressure would drop to the point that it wouldn't have much of an effect.

Russell Wallace

That's interesting, because it appears to conflict with the usual description of explosive decompression on aircraft: even a fairly small hole in e.g., an airliner at altitude, will cause everything that isn't nailed down — including people who aren't strapped into their seats — to be quickly sucked out the hole. Is that description simply inaccurate, or is there a difference in the cases that I'm missing?

Wayne Throop

It's inaccurate. I seem to recall there was a Mythbusters that concluded "busted".

Tim Little

(Russell Wallace: an airliner at altitude, will cause everything that isn't nailed down — including people who aren't strapped into their seats — to be quickly sucked out the hole. Is that description simply inaccurate, or is there a difference in the cases that I'm missing?)

It is simply inaccurate. Yes, decompression is dangerous, and if a significant hole opens up the winds can be extreme. But they're not caused by the decompression!

It should be noted that an airliner at altitude is usually moving at a significant fraction of the speed of sound through the air. The air doesn't just simply leave as it would in a vacuum, or if it were a zeppelin cabin.

From the point of view of the aircraft, the air outside has kinetic energy greater than any hurricane. If a large hole opens up, part of that can get in.

Erik Max Francis

It depends on how much air is in the vessel, how big the hole is, and how close the victim is to the breach. Sure, there are some cases where the victim will likely be forced out of the breach. But probably not in the case Brian was talking about. Not that really helps her chances, since she's exposed to vacuum with no way to get back in.

Michael Ash

The image of everything that's not nailed down flying out the door may be inaccurate, but the earlier estimate of 0.3m/s would appear to be inaccurate as well. Perhaps the most famous explosive decompression incident is Aloha Airlines 243 which suddenly lost a large section of skin but managed to land safely. One flight attendant was thrown to the floor and another one was thrown out of the plane altogether, never to be seen again. A 737 isn't particularly large but it would require substantially more imparted velocity than that to throw somebody out. A spacecraft pressurized to 1 atmosphere should be a bit worse as well, since the accident in question occurred at 24,000ft where the outside air pressure is still about 0.4 atmospheres.

It should be noted that a small hole doesn't do this, because a small hole doesn't result in explosive decompression in the first place. A small hole will leak, not cause a bang, and there would just be some wind. Thus the fears of instant death due to a gunfight piercing the hull are completely overblown, and I believe this is what Mythbusters investigated. But this is an entirely different scenario from opening a large airlock door or the case of the poor Aloha Airlines flight attendant.

Wayne Throop

Sure, but that's what being exposed to 300+mph winds will get you. Just the decompression, not so much. It's the fact that so much of the hull was peeled away.

The Mythbusters bit (iirc) was concerned with two aspects of a fairly small hole. First, will it suck everything inside towards it, and second, will it rip the hull open and expose the interior to the airstream (that is, will any small break in the skin necessarily spread very far). And they concluded, no and no. Of course, they were talking about a bullethole (again iirc). But I doubt things would be much different for anybody at a reasonable distance from, say, a hatch-sized hole. An upper-half-of-the-hull-peels-away-in-a-section-tens-of-feet-long sized hole is another matter entirely, and I doubt anybody will notice the decompression, given the brisk breeze outside.

Robert Martinu

(Wayne Throop: And they concluded, no and no. Of course, they were talking about a bullethole (again iirc). But I doubt things would be much different for anybody at a reasonable distance from, say, a hatch-sized hole.)

Later the episode they tested what a moderate amount of explosives would do to the pressurized hull. The result was iirc a seat cusion sucked out, but the dummy still in its seat. Again its not the decompression you have to fear.

From Explosive decompression - how fast? thread in 4/26/2008

It was just after reveille, "A" deck time, and I was standing by my bunk, making it up. I had my Scout uniform in my hands and was about to fold it up and put it under my pillow. I still didn't wear it. None of the others had uniforms to wear to Scout meetings so I didn't wear mine. But I still kept it tucked away in my bunk.

Suddenly I heard the goldarnest noise I ever heard in my life. It sounded like a rifle going off right by my ear, it sounded like a steel door being slammed, and it sounded like a giant tearing yards and yards of cloth, all at once.

Then I couldn't hear anything but a ringing in my ears and I was dazed. I shook my head and looked down and I was staring at a raw hole in the ship, almost between my feet and nearly as big as my fist. There was scorched insulation around it and in the middle of the hole I could see blackness—then a star whipped past and I realized that I was staring right out into space.

There was a hissing noise.

I don't remember thinking at all. I just wadded up my uniform, squatted down, and stuffed it in the hole. For a moment it seemed as if the suction would pull it on through the hole, then it jammed and stuck and didn't go any further. But we were still losing air. I think that was the point at which I first realized that we were losing air and that we might be suffocated in vacuum.

There was somebody yelling and screaming behind me that he was killed and alarm bells were going off all over the place. You couldn't hear yourself think. The air-tight door to our bunk room slid across automatically and settled into its gaskets and we were locked in.

That scared me to death.

I know it has to be done. I know that it is better to seal off one compartment and kill the people who are in it than to let a whole ship die—but, you see, I was in that compartment, personally. I guess I'm just not the hero type.

I could feel the pressure sucking away at the plug my uniform made. With one part of my mind I was recalling that it had been advertised as "tropical weave, self ventilating" and wishing that it had been a solid plastic rain coat instead. I was afraid to stuff it in any harder, for fear it would go all the way through and leave us sitting there, chewing vacuum. I would have passed up desserts for the next ten years for just one rubber patch, the size of my hand.

The screaming had stopped; now it started up again. It was Noisy Edwards, beating on the air-tight door and yelling, "Let me out of here! Get me out of here!"

On top of that I could hear Captain Harkness's voice coming through the bull horn. He was saying, "H-twelve! Report! H-twelve! Can you hear me?"

On top of that everybody was talking at once.

I yelled: "Quiet!" at the top of my voice—and for a second or so there was quiet.

Peewee Brunn, one of my Cubs, was standing in front of me, looking big-eyed. "What happened, Billy?" he said.

I said, "Grab me a pillow off one of the bunks. Jump!"

He gulped and did it. I said, "Peel off the cover, quick!"

He did, making quite a mess of it, and handed it to me—but I didn't have a hand free. I said, "Put it down on top of my hands."

It was the ordinary sort of pillow, soft foam rubber. I snatched one hand out and then the other, and then I was kneeling on it and pressing down with the heels of my hands. It dimpled a little in the middle and I was scared we were going to have a blowout right through the pillow. But it held. Noisy was screaming again and Captain Harkness was still asking for somebody, anybody, in compartment H-12 to tell him what was going on. I yelled "Quiet!" again, and added, "Somebody slug Noisy and shut him up."

That was a popular idea. About three of them jumped to it. Noisy got clipped in the side of the neck, then somebody poked him in the pit of his stomach and they swarmed over him. "Now everybody keep quiet," I said, "and keep on keeping quiet. If Noisy lets out a peep, slug him again." I gasped and tried to take a deep breath and said, "H-twelve, reporting!"

The Captain's voice answered, "What is the situation there?"

"There is a hole in the ship, Captain, but we got it corked up."

"How? And how big a hole?"

I told him and that is about all there was to it. They took a while to get to us because—I found this out afterward—they isolated that stretch of corridor first, with the air-tight doors, and that meant they had to get everybody out of the rooms on each side of us and across the passageway. But presently two men in space suits opened the door and chased all the kids out, all but me. Then they came back. One of them was Mr. Ortega. "You can get up now, kid," he said, his voice sounding strange and far away through his helmet. The other man squatted down and took over holding the pillow in place.

Mr. Ortega had a big metal patch under one arm. It had sticky padding on one side. I wanted to stay and watch him put it on but he chased me out and closed the door. The corridor outside was empty but I banged on the air-tight door and they let me through to where the rest were waiting. They wanted to know what was happening but I didn't have any news for them because I had been chased out.

After a while we started feeling light and Captain Harkness announced that spin would be off the ship for a short time. Mr. Ortega and the other man came back and went on up to the control room. Spin was off entirely soon after that and I got very sick. Captain Harkness kept the ship's speaker circuits cut in on his conversations with the men who had gone outside to repair the hole, but I didn't listen. I defy anybody to be interested in anything when he is drop sick.

Then spin came back on and everything was all right and we were allowed to go back into our bunkroom. It looked just the same except that there was a plate welded over the place where the meteorite had come in.

Breakfast was two hours late and we didn't have school that morning.

That was how I happened to go up to Captain's mast for the second time. George was there and Molly and Peggy and Dr. Archibald, the Scoutmaster of our deck, and all the fellows from my bunk room and all the ship's officers. The rest of the ship was cut in by visiplate. I wanted to wear my uniform but it was a mess—torn and covered with sticky stuff. I finally cut off the merit badges and put it in the ship's incinerator.

The First Officer shouted, "Captain's Mast for punishments and rewards!" Everybody sort of straightened up and Captain Harkness walked out and faced us. Dad shoved me forward.

The Captain looked at me. "William Lermer?" he said.

I said, "Yessir."

He said, "I will read from yesterday's log: 'On twenty-one August at oh-seven-oh-four system standard, while cruising in free fall according to plan, the ship was broached by a small meteorite. Safety interlocks worked satisfactorily and the punctured volume, compartment H-twelve, was isolated with no serious drop in pressure elsewhere in the ship.

"'Compartment H-twelve is a bunk room and was occupied at the time of the emergency by twenty passengers. One of the passengers, William J. Lermer, contrived a makeshift patch with materials at hand and succeeded in holding sufficient pressure for breathing until a repair party could take over.

"'His quick thinking and immediate action unquestionably saved the lives of all persons in compartment H-twelve.'"

The Captain looked up from the log and went on, "A certified copy of this entry, along with depositions of witnesses, will be sent to Interplanetary Red Cross with recommendation for appropriate action. Another copy will be furnished you. I have no way to reward you except to say that you have my heart-felt gratitude. I know that I speak not only for the officers but for all the passengers and most especially for the parents of your bunk mates."

He paused and waggled a finger for me to come closer. He went on in a low voice, to me alone, "That really was a slick piece of work. You were on your toes. You have a right to feel proud."

I said I guessed I had been lucky.

He said, "Maybe. But that sort of luck comes to the man who is prepared for it."

He waited a moment, then said, "Lermer, have you ever thought of putting in for space training?"

I said I suppose I had but I hadn't thought about it very seriously. He said, "Well, Lermer, if you ever do decide to, let me know. You can reach me care of the Pilots' Association, Luna City."

From FARMER IN THE SKY by Robert Heinlein. 1950.


NASA assumes that each astronaut consumes per day 0.617 kilograms of dry food and 3.909 kilograms of potable water (some mixed in with the food). Astronauts also use 26 kilograms of water per day for personal hygiene.

NASA also assumes that each astronaut excretes 4.254 kg of water per day due to various metabolic processes. For details see below. Some of this water can be reclaimed.

Ken Burnsides and Eric Henry figured that each person has a reserve of 10 liters of water, and requires somewhere between 0.1 and 0.25 liters of water per day to make up for reclamation losses. (Eric used 0.1, Ken used 0.25 mostly due to having worked in a sewage treatment plant)

In the TransHab design, they use a water management subsystem to recover potable water from waste water.

In the following specifications, the mass (kg), volume (m3), and electrical power requirements (W) is for equipment sized to handle a six person crew.

An aluminum potable water storage tank (145.9 kg, 0.54 m3, 5 W) initially contains a three day supply of water for the six crew members. Waste water is sent through a Vapor Phase Catalytic Ammonia Removal (VPCAR) system (1119 kg, 5.5 m3, 6090.7 W). The VPCAR process is a wastewater treatment technology that combines distillation with high-temperature catalytic oxidation of volatile impurities such as ammonia and organic compounds.

The report mentioned that the VPCAR system was selected over a rival system since it had a lower mass, volume, and turnaround time. The VPCAR's drawback was the larger power requirements.


NASA assumes that each astronaut consumes per day 0.617 kilograms of dry food and 3.909 kilograms of potable water.

The food is to have an energy content of 11.82 MJ per astronaut per day, about 2,800 food calories. More precisely:

FemaleAstronautDailyCalories = 655 + (9.6 × W) + (1.7 × H) - (4.7 × A)

MaleAstronautDailyCalories = 66 + (13.7 × W) + (5 × H) - (6.8 × A)


  • W = weight (kg)
  • H = height (cm)
  • A = age (years)

NASA has a variety of space foods. Preparing food for prolonged space missions is always a challenge.

The always worth reading Future War Stories has a good article on Military Field Rations and Space Food.

For food, Eric and Ken ran numbers from the USS Wyoming.

TL;DR: 1 person-day of food is 2.3 kg and 0.0058 m3, food storage space is about 0.012 m3. Food supply is 29% frozen, 57% dry, 14% fresh. If you are not interested in how these numbers were derived, skip to the next section.

150 man crew, 90 day cruise (13,500 person-days), 31,500 kg of food (9,000 kg frozen, 18,000 kg dry, 4,500 kg fresh). This is about 2.3 kg of food per man per day.

Frozen meat has a density of about 0.35 kg/liter (which Ken determined experimentally with a kilo of frozen meat in a 2 liter pitcher in his sink). Frozen veggies were less (0.4 kg/liter), so split the difference and use 0.375 kg/liter. 9,000 kg takes up 24,000 liters (24 m3).

Fresh foods have a density of roughly 0.25 kg/liter, due to air packed around the food by the packaging. 4,500 kg takes up 18,000 liters (18 m3).

Dry and canned goods range from densities of 0.25 kg/liter for flour and bread and 1.0 kg/liters for canned goods. Split the difference and use 0.5 kg/liter. 18,000 kilos takes up 36,000 liters (36 m3).

Total volume is 78,000 liters, or 78 cubic meters of food (1000 liters = 1 m3). Assume that we're off on our calculations and round up to 80 m3 as a reserve.

Storage, including refrigeration wastage is usually three times the space, but the Navy has a tradition of doing things in amazingly tight quarters. So we will merely double it, for 160 m3 to store our food.

Add about 1000 liters of water (water for 150 crew for 90 days, plus a reserve) which of course masses 1000 kg.

Add about 3,500 liters of compressed air (0.2 liters per person per day for 90 days, plus a reserve for general pressurization and a 20% safety margin) which masses 1050 kg.

Together air and water add about 5 m3.

There are alternate figures on life support in this document. It specifies the daily requirements of consumables per person as: 0.83 kg Oxygen, 0.62 kg freeze dried food (which would increase to 2.48 kg when the water was added), 3.56 kg water for drinking and food preparation, and 26.0 kg water for hygiene, flushing, laundry, dishes, and related matters. Note that the value for hygiene water is somewhat dependent on technology — if you have sonic showers and the like the requirements may be less.

William Seney notes that the NC State document specify oxygen consumption figures differ considerably from Eric and Ken's estimate. If we assume their value should be 48L per HOUR instead of per DAY (1.38 kg / day) it is much closer.

When the body uses glucose the reaction is:

C6H12O6 + 6 O2 => 6 CO2 + 6 H2O

so a slight excess of water is produced. According to the NC State document this works out to about 0.39L per person per day, which may be enough to replace losses.

Eeking Out

For a real Spartan bare-minimum cruise, you can probably use a figure of one m3 per person per day. But this would not be recommended for a cruise of longer than 20 to 30 days. Morale will suffer. And don't even think about feeding your crew food pills.

The bare-minimum of consumables mass looks like 0.98 kg water, 2.3 kg food, and 0.0576 kg air per person per day. About 3.3 kg total, round it up to 4. People actually need 2.72 kg of water, but since food is 75% water, it contains an additional 1.72 kgs.

Our 90 day cruise now has about 165 m3 of bare essentials. Put in niceties like better cooking gear, spare clothing, toilet paper, video games, soda, luxury goods, and you are probably getting close to 240 m3. That will fit in a sphere 8 meters in diameter (about 25 feet).

If the spacecraft has no artificial gravity, you'd better include lots of spices and hot sauce. As the body's internal fluids change their balance, crewmembers will get the equivalent of stuffy noses. This will decrease the sense of taste. Food will taste bland like it does when you have a head cold, and for the same reason.

You'll need more space if you want to include hydroponics for fresh veggies. Roughly 800 liters of hydroponics per person per 'green meal' per week. This also helps CO2 scrubbing and crew morale. About 20 m3 per 25 men, or 120 m3 for our 150 man crew. 3 green meals per week takes about 600 m3.

Eating Utensils

On NASA shuttle and ISS missions, the astronauts have conventional knives, forks, and spoons; a hot/cold water injector, a warming oven, and scissor to cut open plastic seals.

When the water injector is set to "hot water" the temperature is between 68° and 74° C. The injector can be set to dispense water in one-half ounce increments up to 8 ounces.

Dehydrated food containers have a "septum adapter", i.e., a little airlock to insert the water injector nozzle. Otherwise when you removed the water injector the container would become a water weenie and drench you. For beverages you would then insert into the septum adapter a drinking straw. The straw has a built-in clamp to prevent the drink from spraying all over your face when you take the straw out of your mouth. For foods you wait until it rehydrates, then use the scissors to cut the container open. You make an X-shaped cut, creating four large flaps to help keep the food from escaping (a "spoon-bowl" package).

The warming oven is a forced air convection oven with internal hot plate. Its internal temperature is from 71° to 77° C. It can hold up to 14 food containers at a time: rehydratable packages, thermostabilized pouches or beverage packages.

NASA's space shuttle used fuel cells for power, which create plenty of water usable to rehydrate food. The shuttle meals were mostly dehydrated to save on mass.

The International Space Station on the other hand uses solar panel for power, which do not produce water. While there is some water available from recycling there is not enough for rehydrating food (there is barely enough for powdered drinks). Therefore the ISS uses no dehydrated food, instead is uses frozen and thermostabilized food which already has the water in it.

You can thank Napoleon Bonaparte for the invention of thermostabilized food in foil containers.

Back in the 1800's, it was tough to get food to armies on the move (the age-old problem of Logistics). An army would have to split up and spread out in order to ransack all the villages and farms in the area for food. Napoleon almost lost the war and his life at the Battle of Marengo because of this. While his army was split up, Napoleon's small army segment got ambushed by the entire Austrian army. If the other French groups had not returned in time, Napoleon might not have even been mentioned in the history books.

Determined not to get caught like that again, Napoleon offered a reward of 12,000 francs to the inventor who could preserve food for army rations in large quantities. The prize was won by Nicolas Appert, who basically invented thermostabilizing (your grandmother calls it "home canning" using Mason jars). He had stumbled upon Louis Pasteur's pasteurization process 50 years before Pasteur. The press went wild, waxing poetically on how Appert had established the art of fixing the seasons, so seasonal foods could be enjoyed year round. The French army was pleased as well.

Appert used glass bottles to hold the food. A short time later, Peter Durand figured out how to thermostabilize food inside tin-plated cans. A couple of decades later artists figured out how to make their studios portable by storing their oil paints in tin tubes. Decades later NASA stored thermostabilized foods inside tin tubes for the Mercury mission (but later abandoned them because the mass of the tube was more than the mass of the food it held). Currently NASA supplies thermostabilized food inside foil pouches for the astronauts of the International Space Station.

NASA packages food in single-service disposable containers to avoid the ugly payload mass requirements of a dishwasher. Eating utensils and food trays are cleaned at the hygiene station with premoistened towelettes.

The containers are in one of five standardized dimensions so they will fit the holes in the "dinner table" and the slots in the oven. All five sizes have the same width. They often have build-in velcro pads on the bottom.


In the galley the girls set about making dainty sandwiches, but the going was very hard indeed. Margaret was particularly inept. Slices of bread went one way, bits of butter another, ham and sausage in several others. She seized two trays and tried to trap the escaping food between them — but in the attempt she released her hold and floated helplessly into the air.

'Oh, Dot, what'll we do anyway?' she wailed. 'Everything wants to fly all over the place!'

'I don't quite know — I wish we had a bird-cage, so we could reach in and grab anything before it could escape. We'd better tie everything down, I guess, and let everybody come in and cut off a chunk of anything they want. But what I'm wondering about is drinking. I'm simply dying of thirst and I'm afraid to open this bottle.' She had a bottle of ginger ale clutched in her left hand, an opener in her right; one leg was hooked around a vertical rail. 'I'm afraid it'll go into a million drops and Dick says if you breathe them in you're apt to choke to death.'

'Seaton was right — as usual.' Dorothy whirled around. DuQuesne was surveying the room, a glint of amusement in his one sound eye. 'I wouldn't recommend playing with charged drinks while weightless. Just a minute — I'll get the net.'

He got it; and while he was deftly clearing the air of floating items of food he went on. 'Charged stuff could be murderous unless you're wearing a mask. Plain liquids you can drink through a straw after you learn how. Your swallowing has got to be conscious, and all muscular with no gravity. But what I came here for was to tell you I'm ready to put on one G of acceleration so we'll have normal gravity. I'll put it on easy, but watch it'

'What a heavenly relief!' Margaret cried, when everything again stayed put. 'I never thought I'd ever be grateful for just being able to stand still in one place, did you?'

From THE SKYLARK OF SPACE by E. E. "Doc" Smith (1928)

Meanwhile, it was time to eat, though he did not feel particularly hungry. One used little physical energy in space, and it was easy to forget about food. Easy — and dangerous; for when an emergency arose, you might not have the reserves needed to deal with it.

He broke open the first of the meal packets, and inspected it without enthusiasm. The name on the label — SPACETASTIES — was enough to put him off. And he had grave doubts about the promise printed underneath: “Guaranteed crumbless.” It had been said that crumbs were a greater danger to space vehicles than meteorites; they could drift into the most unlikely places, causing short circuits, blocking vital jets, and getting into instruments that were supposed to be hermetically sealed.

Still, the liverwurst went down pleasantly enough; so did the chocolate and the pineapple puree. The plastic coffee bulb was warming on the electric heater when the outside world broke in upon his solitude, as the radio operator on the Commodore’s launch routed a call to him.

From THE WIND FROM THE SUN by Sir Arthur C. Clarke (1964)

The stewards, it appeared, were determined to make him eat for the whole twenty-five hours of the trip, and he was continually fending off unwanted meals. Eating in zero gravity was no real problem, contrary to the dark forebodings of the early astronauts. He sat at an ordinary table, to which the plates were clipped, as aboard ship in a rough sea. All the courses had some element of stickiness, so that they would not take off and go wandering round the cabin. Thus a chop would be glued to the plate by a thick sauce, and a salad kept under control by an adhesive dressing. With a little skill and care there were few items that could not be tackled safely; the only things banned were hot soups and excessively crumbly pastries. Drinks of course, were a different matter; all liquids simply had to be kept in plastic squeeze tubes.

From 2001 A SPACE ODYSSEY by Sir Arthur C. Clarke (1969)

Drinking Utensils

Emergency Rations

The always worth reading Future War Stories has a good article on Military Field Rations and Space Food.

Emergency or Survival food is typically found in emergency re-entry capsules and spacecraft lifeboats (although in reality the latter are a really stupid concept).

They also may or may not be stored in the ship proper to help deal with a temporary interruption of the food supply (such as a catastrophic malfunction in the CELSS). If all the algae got incinerated by a solar proton storm, the crew will need something to eat while a new crop of algae is grown to harvest. You see this in a couple of episodes of Star Trek: Enterprise, where emergency rations are used when the food replicator is non-functional.

Real-world emergency rations typically are nutrient bars containing about 2,400 calories (enough food for an entire day).

Emergency rations are optimized to be portable (low mass + low volume), require no preparation, and stable for prolonged periods (years). Flavor is not a design consideration, the starving will eat anything.

In science fiction, emergency rations on re-entry capsules are to help you survive being marooned on an uninhabited planet long enough to figure out what part of the local flora and fauna are edible. In reality, the chance local flora and fauna even existing are remote, edible or otherwise. Especially if you are limited to our Solar System. The most famous science fiction field ration is the Federation Space Forces Emergency Ration, Extraterrestrial, Type Three (aka 'Extee 3' or 'estefee') from Little Fuzzy by H. Beam Piper.

Military field rations are portable easily prepared food issued to soldiers deployed in the field. In the US Army they are called MREs for Meal Ready to Eat. Around World War I these were called "iron rations".

Field Rations are optimized to be portable (low mass + low volume), easy to prepare, and reasonably tasty. You have to sit down to eat them, though.

The US Army Aviation uses Aircrew Build-to-Order Meal Modules (ABOMM). These are MREs designed so that a pilot can eat them while still piloting an airplane, without the use of utensils, and in a confined space. MREs typically require two hands to eat, while it is not recommended that the pilot take both hands off the control yoke.

First Strike rations are for people on the go. This can range from a First-in scout traveling from their hypothetical starship to explore and evaluate a hypothetical habitable planet to an asteroid miner living for several days in their space suit and subsisting on whatever they can squeeze through their helmet's chow-lock.

First Strike rations are optimized to be portable (very low-low mass + low volume), need little or no preparation and are easy to eat while walking or during an EVA (eaten out of hand without the use of utensils).


"Nobody home, Commander. Somebody cleaned the place out. Fuel stores zilch. Medical supplies, zip. Ten cases of emergency rations. That's it."

The First Watch Officer comes through the Weapons hatch. He has a metal case in his arms, a sheet of paper in one hand. The Commander peers into the case. "Pass them around." He snatches the tattered sheet.

Yanevich hands me a ration packet. I laugh softly.

"Something wrong with it?" the Old Man asks.

"Emergency rations! This's better stuff than we've been eating for three months." I pull the heat tab. A minute later, I peel the foil and — lo! — a steaming meal.

It's no gourmet delight. Something like potato hash including gristly gray chopped meat, a couple of unidentifiable vegetables, and a dessert that might be chocolate cake in disguise. The frosting on the cake has melted into the hash. I polish the tray, belch. "Damn, that was good!"

Yanevich gives each man a meal, then hands me another pack. They come forty-two to a case. He sets the last aside for the Chief. To my questioning frown, he says, "That's for your buddy."

Out of nowhere, out of the secret jungles of metal, comes Fearless Fred (the cat), rubbing my shins and purring. I heat his pack, thieve the cake, place the tray on the deckplates. Fred polishes his tray in less time than I did mine.

From PASSAGE AT ARMS by Glen Cook (1985)

At least I was still alive, I was free of the dead ship in a Life Boat, and I had air to breathe even if it was not the air my lungs craved. It would seem my entrance into the projectile had activated its ancient mechanism.

If we were on course for the nearest planet, how long a voyage did we face? And what kind of a landing might we have to endure? I could breathe, but I would need food and water. There might be supplies — E-rations — on board. But could they still be used after all these years — or could a human body be nourished by them?

With my teeth I twisted free the latch which fastened my left glove, scraped that off, and freed my hand. Then I felt along my harness. These suits were meant to be worn planetside as well as for space repairs; they must have a supply of E-rations. My fingers fumbled over some loops of tools and found a seam-sealed pouch. It took me a few moments to pick that open.

I had not felt hunger before; now it was a pain devouring me. I brought the tube I had found up to eye level. It was more than I could manage to sit up or even raise my head higher, but the familiar markings on the tube were heartening. One moment to insert the end between my teeth, bite through, and then the semiliquid contents flooded my mouth and I swallowed greedily. I was close to the end of that bounty when I felt movement against my bared throat and remembered I was not alone. (the alien catlike creature Eet)

It took a great deal of resolution to pinch tight that tube and hold it to the muzzle of the furred one. Its pointed teeth seized upon the container with the same avidity I must have shown, and I squeezed the tube slowly while it sucked with a vigor I could feel through the touching of its small body to mine.

There were three more tubes in my belt pouch. Each one, I knew, was intended to provide a day's rations, perhaps two if a man were hard pushed. Four days — maybe, we could stretch that to eight.

The semiliquid E-ration contained moisture but not really enough to allay thirst.

My fingers closed about a tube of E-ration and I did not have to fake the avidity with which I gripped its tip between my teeth, bit through the stopper, and spit it out, before sucking the semiliquid contents. No meal of my imagination could have topped the flavor of what now filled my mouth, or the satisfaction afforded me as it flowed in gulps down into me. The mixture was meant to sustain a man under working conditions; and it would renew my strength even more than usual food.

From THE ZERO STONE by Andre Norton (1968)

"One thing," Michelle chimed in, "Kelly, take this," , she tossed him a flat metal box, about five centimeters on a side, with a metal chain. "Wear that around your neck at all times from now on. Those are your tracetabs. They contain all the trace elements your body needs. There are about three thousand tabs in that box (8.2 years). If we go on xeno-rations, you'll need them."

Kelly seemed puzzled.

"There are about a thousand planets," Sims explained, "that supply native food edible by humans. On maybe half a dozen of them, all the trace elements necessary for human survival are present in the food."

"If the soil and atmosphere are comparable to Earth's," Michelle continued, "native flora and fauna may give you all the protein, carbohydrates, and vitamins you need, but trace elements can be hard to come by. You'll die just as dead from lack of magnesium, phosphorous, or any number of other elements as from lack of water. If you get stranded on a xenoworld, that box can be your lifeline. Always keep it filled."

From SPACE ANGEL by John Maddox Roberts (1979)

The next day was the sixth we’d been in the fort. We were low on rations. Down at the roadblock we had nothing to eat but a dried meat that the men called “monkey.” It didn’t taste bad, but it had the peculiar property of expanding when you chewed it, so that after a while it seemed as if you had a mouthful of rubber bands. It was said that Line Marines could march a thousand kilometers if they had coffee, wine, and monkey.

From WEST OF HONOR by Jerry Pournelle (1976)

     Captain Bly watched until the spacelock indicator changed from red to green, then thumbed the takeoff warning. The alarm sounded through the ship like a gargantuan eructation and the crew hurried to buckle in. Bill dropped into a vacant seat and pulled the straps tight just as Captian Bly switched on full power. Gravity sat on their chests with the 11G takeoff. Except for Bill who had a rat sitting on his chest as well as gravity, for it had been hurled from the pipes in the ceiling by the blast. It glared at Bill with gleaming red eyes, its lips pulled back by the drag of takeoff blast to expose its long, yellow incisors. Bill glared back, eyes equally red, his yellow fangs equally exposed. Neither could move and they glared in futile hatred until the engines cut out. Bill grabbed for the rat but it leaped to safety and ran out the door.

     A shrill scream cut through his words, followed by the roar and splat of blaster fire.
     "We're being attacked!" Praktis screeched. "I'm unarmed! Don't fire! I am a doctor, a noncombatant, my rank only an honorable one!"
     Bill, his brain cells still so gummed by sleep and ethyl alcohol, drew his blaster and ran down the dune towards the firing instead of away from it which, normally, he would have done. He picked up speed, could not stop, saw Meta before him, standing and firing, could not turn and ran into her at full gallop.
     They collapsed into an inferno of arms and legs. She recovered first and punched him in the eye with a hard fist.
     "That hurt," he whimpered, holding his hand over it. "I'm going to have a shiner."
     "Move your hand and I'll give you another one to match. Why did you knock me down like that?"
     "What was all the shooting about?"
     "Rats!" She grabbed up her blaster and spun about. "All gone now. Except the ones I blasted into atoms. They were getting at our food. At least we know what lives on this planet. Great big nasty gray rats."
     "No they don't," Praktis said, having recovered from his fit of cowardice and rejoined the party. He kicked a piece of exploded rat with his toe. "Rattus Norvegicus. Mankind's companion to the stars. We must have brought them with us."
     "Sure did," Bill agreed. "They bailed out of the spacer even before you did."
     "Interesting," Praktis mused, rubbing his jaw, nodding, squinting, doing all the things that indicate musing. "With a whole planet to nosh in—I ask you —why do they come creeping back here to eat our food?"
     "They don't like the native chow," Bill suggested.
     "Brilliant but incorrect. It is not that they don't like it—there is none of it. This planet is barren of life as any fool can plainly see."

     Cy did and he snipped off samples as instructed. Meta quickly had enough of this metallurgical horticulture and went back to their camp. And resumed shouting and shooting. The others joined her and the surviving rats fled into the desert. Praktis scowled at the torn open boxes of supplies.
     "You, Third Lieutenant, get to work. I want the food repacked and rat-proofed at once. Issue orders. But not you, Cy. I want your help. Over this way."
     Bill seized up a torn plastic container of compressed nutrient bars. Known jocularly to the troops as Iron Rations. Even the rats hadn't been able to dent them; broken rat teeth were stuck in the wrapper. After boiling for twenty-four hours they could be broken with a hammer. Bill searched for something edible and a little more tender. He found some tubes of emergency space rations labeled Yumee-Gunge. The others were watching him intently so he passed the tubes around and they all squeezed and sucked and made retching noises. The gunge was loathsome but promised to sustain life. Although the quality of life that it sustained was open to question. After this repulsive repast they worked together in harmony since the pitiful pile of supplies was all that stood between them and starvation. Or thirsting to death, which is faster.


Waste Disposal

On the topic of human metabolic waste, NASA assumes:

Waste per astronaut per day
Dry Feces0.032 kg
Fecal Water0.091 kg
Dry Urine0.059 kg
Urine Water1.886 kg
Dry Perspiration0.018 kg
Respiration and
Perspiration Water
2.277 kg

An attempt should be made to reclaim the water. 4.254 kg of water per astronaut per day is too much to just throw away.

Male astronauts will use approximately 28 grams per day of toilet paper, minimum. Female will use 64 grams per day, because unlike their male counterparts, they wipe after urination. There will be about 5.1 grams per day of waste clinging to the toilet paper.

More toilet paper is required than is necessary under one gravity since in microgravity the fecal material has no particular inclination to separate from the body.

Women experience menstruation for 4 to 6 days occurring every 26 to 34 days. The total amount of menses is about 113.4 grams, of which about 28 grams is solids and the rest is water. This is highly variable. Approximately 104 grams of menstrual pads or tampons are consumed each period, again highly variable.

Female crew members on the International Space Station use medication to prevent menstruation for up to six months, but this may not be acceptable for longer missions.


This brings up the question of how to use a space toilet in free fall. The sad fact of the matter is "there ain't no graceful way".

Naoto Kimura mentioned that "Oh-gee Whiz" would be a good brandname for space toilet.

Schweickart: In terms of not in the suit, and in the spacecraft again that's varied. In Apollo, for feces you just stuck a plastic bag on your butt which was 6 inches in diameter' something like that' maybe a little bit less 12 inches or so long and the mouth of it had a flange at the top with an adhesive on it, and you'd peel the coating off the adhesive and literally stick it to your butt. Hopefully centrally located. And if you think you know where your rear end is, you really find out, because you'd paste it on very carefully! So, you stick that to your butt, and then you go ahead and take a c**p. But then the problem comes, because there's no particular reason whatsoever for the feces to separate from your rear end. So as a result the problem is left as an exercise to the student to peel the bag off and make sure everything stays within the bag, and get all wiped off. It's basically a one hour procedure.

Warshall: For each time?

Schweickart: Yeah, from the time you start to peel down to stick the bag on and all that, till the time you have finished cleaning up and have everything wrapped up and stowed and have your clothes back on and everything, it's damn near an hour. And at times it's taken longer. Because when you peel that bag off, you try to take a handful of paper, and you know, lead the way in with that, but by the time you get done, you've got stuff spread all over your backsides, and if you're not careful, your clothes, and everything else.

Warshall: Have you ever had an accident where the stuff got out of the bag?

Schweickart: No, because generally speaking it's fairly sticky so once it's in the bag it doesn't come out, but the problem is making sure it's loose of you when you get the bag off. It just is not a simple procedure, no matter what you do. Well, in any case, that was in Apollo.

In terms of the urine system , that was simple in Apollo. It's just the same as a relief tube in airplanes. It's a tube with a funnel on the end that you urinate into. And, at the other end of the tube is lower pressure than at the business end of it. So there's a differential pressure in the outward direction.

Well, we did exactly the same thing, except you know on the other end of the hose you've got a vacuum instead of a couple of psi down or something. So you just basically urinate into a relief tube. There have been various designs so you can use a roll-on cuff to do it or you can just hang it out there in the air and do it. There are a couple of different variations, but basically you urinated directly overboard through a relief tube. And of course, you didn't lose much cabin air, because while the liquid is in the tube, in the hose, no air is going down. It's differential pressure carrying the liquid. So it's only a matter of designing it for the right flow rate.

Warshall: Do you use any kind of special toilet paper?

Schweickart: No, not that I know of. There may be some flame retardant chemicals put into it just so you don't have any unnecessary flammable materials around, but I'm not sure whether that's the case or not.

Warshall: So it's just like any other toilet paper.

Schweickart: It's basically like any other toilet paper.

Warshall: Is it stuck in the bag and then burned, or . . .?

Schweickart: No, it is in the same bag with the fecal material, and in the early missions that was a plastic bag that you mixed in a disinfectant or actually an anti-gas, oh, what's the word I want, I guess disinfectant would be the best word, which holds down the generation of gas, and you mix that disinfectant liquid all through the fecal material. You mix it in, seal the plastic bag.

Warshall: How do you get it in there?

Schweickart: Well, it's in a small, like a ketchup, a little plastic container like you find ketchup in in restaurants, in a cafeteria or something, it's like that. You tear the slit across the top, being careful not to squeeze it so the stuff comes out, and then you drop that into the fecal container, and then seal the fecal container. Then you squeeze it through the, you know, externally, you know, which forces it out of the container, and then you mix it by massaging the fecal bag. It's really fun when it's still warm.

From "THERE AIN'T NO GRACEFUL WAY" Astronaut RUSSELL SCHWEICKART talking to Peter Warshall, collected in CoEvolution Quarterly Winter 1976-77

The Johnson Space Center "potty cam," as it is more casually known, is an astronaut training aid. It provides a vivid, arresting perspective on something you've had intimate contact with all your life but never really seen. Positioning is critical because the opening to a Space Shuttle toilet is 4 inches across, as opposed to the 18-inch maw we are accustomed to on Earth.

"The camera enables you to see if your butt, your..." Broyan pauses in search of a better word: not more polite, just more precise, "...anus lines up with the center." Without gravity, you can't reliably gauge your position by feel. You are not really sitting on the seat. You are hovering in close proximity. The tendency, says Broyan, is to touch down too far back. Then your angle of approach is off, and you sully the back of the transport tube and plug some of the air holes that encircle the rim. Bad, bad move. Space toilets operate like shop vacs; "contributions," to use Broyan's word, are guided along, or "entrained," by flowing air rather than by water and gravity, two things in short-to-nonexistent supply in an orbiting spacecraft. Plugged air holes can disable the toilet. Additionally, if you gum up the holes, it is then your responsibility to clean them out—a task Broyan understates as "arduous."

Zero-gravity excretion is not entirely a joking matter. The simple act of urination can, without gravity, become a medical emergency requiring catheterization and embarrassing radio consults with flight surgeons. "The urge to go is different in space," says Weinstein. There is no early warning system as there is on Earth. Gravity causes liquid waste to accumulate on the floor of the bladder. As the bladder fills, stretch receptors are stimulated, alerting the bladder's owner to the growing volume and delivering an incrementally more insistent signal to go. In zero gravity, the urine doesn't collect at the bottom of the bladder. Surface tension causes it to adhere to the walls all around the organ. Only when the bladder is almost completely full do the sides begin to stretch and trigger the urge. And by then the bladder may be so full that it's pressing the urethra shut. Weinstein counsels astronauts to schedule regular toilet visits even if they don't feel the urge. "And it's the same with BMs," he adds. "You don't get that same sensation."

(ed note: this is why the Shuttle first aid medical kit included a Foley catheter)

Weinstein says he doubts that many of the astronauts use the potty cam. "I get the sense most of them don't want to see themselves." Weinstein provides an alternate positioning tactic, "the two-joint method." The distance between the anus and the front of the seat should equal the distance between the tip of the middle finger and its big knuckle.

Along the same wall as the Positional Trainer is a fully appointed and functioning Space Shuttle commode. It looks less like a toilet than a high-tech, top-loading washing machine. Though the device itself is a high-fidelity version of the one on board the shuttle, the experience is not. There is gravity down here at Johnson Space Center, and that makes all the difference. Gravity facilitates what is known in aerospace waste collection circles as "separation." In weightlessness, fecal matter never becomes heavy enough to break away and drop down and venture forth on its own. The space toilet's air flow is more than an alternate flushing method. It facilitates the Holy Grail of zero-gravity elimination: good separation. Air drag serves to pull the material away from its source.

A separation strategy courtesy of Weinstein: spread the cheeks. That way, there is less contact between the body and the "bolus" (another in the waste engineer's vast arsenal of euphemisms)—and therefore less surface tension to be broken. The newest seat is designed to function as a "cheek spreader" to facilitate a cleaner break.

A more sensible arrangement might be to adopt the posture favored by much of the rest of the world—and by the human excretory system itself. "The squat tends to spread the cheeks," says Don Rethke, a senior engineer at Hamilton Sundstrand, the contractor on many of the NASA waste collection systems over the years. Rethke suggested to NASA that they add a set of foot restraints higher up, to accommodate those who wish to approximate the squatting posture in zero gravity. No go. When it comes to the astronauts' creature comforts, familiarity wins out over practicality.

In the aftermath of Apollo, where there were fecal bags rather than toilets, bathroom facilities became a charged topic. "When the astronauts came back, they physically and psychologically wanted a sit-down commode," says Rethke.

Understandable. The fecal bag is a clear plastic sack, similar to a vomit bag in its size, holding capacity, and ability to inspire dread and revulsion." A molded adhesive ring at the top of the bag was designed for the average curvature of an astronaut's cheeks. It rarely fit. The adhesive pulled hairs. Worse, without gravity or air flow or anything else to foster separation, the astronaut was obliged to employ his finger. Each bag had a small inset pocket near the top, called a "finger cot".

The fun didn't stop there. Before he could roll up and seal the bag to trap the offending monster, the crew member was further burdened with tearing open a small packet of germicide, squeezing the contents into the bag, and manually kneading the germicide through the feces. Failure to do so would allow fecal bacteria to do their bacterial thing, digesting the waste and expelling the gas that, inside your gut, would become your own gas. Since a sealed plastic fecal bag cannot fart, it could, without the germicide, eventually burst.

Given the complexity of the chore, "escapees," as free-floating fecal material is known in astronautical circles, plagued the crews.

From PACKING FOR MARS by Mary Roach (2010)

Feces and Debris

The objective of the feces and debris collection and transport subsystem is to provide a means for collecting and transporting these wastes to the solid waste management subsystem where treating and processing are performed. Collection and transfer must be accomplished under zero gravity conditions, while the escape of solid waste to the cabin is positively prevented. The principal solid wastes include body wastes, unused food, and food containers.

Feces Collection. There are basically two techniques for collecting feces in a weightless state; namely, manual collection with a glove or bag, and pneumatic collection with the use of forced cabin gas for detachment and transfer. The glove method, as developed for Project Gemini, is a simple, low-weight technique but is psychologically objectionable and does not provide a means for preventing flatus from entering the cabin atmosphere. The technique, however, is desirable for use as an emergency fecal collector or where a pneumatic collector cannot be provided. On missions of durations longer than several days, fecal collection equipment is required to maintain the physiological and psychological well-being of the crew.

Feces can be detached from the anus in a weightless state by gas impingement, and then carried into a collection bag or processing device by the same gas flow (e.g. Des Jardins et al., 1960; Charanian et al., 1965. & Rollo et al., 1967). The gas flow rate required is a function of equipment design; experience has shown that it should be in the range of 2 to 10 cfm. The gas is drawn through the device by a centrifugal blower and passed through a filter with activated carbon before being returned to the cabin. Recent laboratory tests have shown that:

1. Separation of feces from perineal surface was best accomplished by short duration impulse from a 30 to 40 psig air stream aimed at the fecal mass; water or air-water streams are not as effective as air alone.

2. Only small amounts of air are needed to effect separation, e.g. 0.1 to 0.2 std. 3 ft. at 30 to 40 psig, flowing at 6 cfm for 2 seconds.

Many types of fecal collection bags have been devised. None of these bags has all the characteristics desired; namely,

High permeability for gases
Impermeable to liquids
High tear strength
Low weight

The two materials proven to be most successful so far are porous cellulose and a polyethylene; both are fabricated from 10 mil material and treated to prevent passage of liquids with pressure differentials less than 4 inches of water. Recently, these materials have been laminated with cloth to provide the tear strength desired.

Experiments have demonstrated that man can reliably defecate into a 4 inch diameter opening—provided this opening is indexed with respect to the anal perimeter. This is the minimum size recommended for a fecal collection bag or the opening in a fecal storage container.

Pneumatic collection provides for more natural defecation. In addition, it also entrains any flatus excreted. To minimize odors, the fecal collection gas should be passed through a bed of activated charcoal. If a catalytic oxidation unit is used for contamination control, the fecal collection gas should be directed to this unit for removal of any H2, CH4, and H2S. Also pneumatic collection provides a suitable means for collecting vomitus (i.e., "praying at the porcelain altar").

Overboard Dump. Wastes can be disposed of overboard in gaseous or liquid form. Dumping of solids is not permitted to avoid imparting the wastes on the ground and/or the aerospace vehicle. Urine, of course, can be dumped as a liquid directly from a urinal or from a urine-gas separator if it is permissible to contaminate the external environment with microorganisms. Solids, however, should be incinerated or thermally decomposed.

A detailed investigation of waste incineration/decomposition is described in Dodson and Wallman (1964). This study concluded that incineration requires (1) an ignition temperature of 1000°F, (2) an energy input of at least 1 kilowatt-hours per man-day, and (3) an oxygen input of up to 0.2 pounds per man-day. Under these conditions the ash remaining is less than 10 grams per man-day and can be easily blown overboard by venting.

If oxygen is not available for incineration, the wastes can be gasified by thermal decomposition. However, this technique requires approximately 4000 BTU/Ib of wastes at a temperature level of 1200°F. In addition, the overboard vent line must be maintained at this temperature to avoid condensation and plugging.

Incineration and thermal decomposition have not appeared to be practical for aerospace vehicles in the absence of a nuclear heat source (atomic sewage treatment, what a concept!). However, when these heat sources are available, it will most likely be advantageous to recover usable products from wastes.

NASA allocates 26 kilograms of water per astronaut per day for personal hygiene.

Bath and showers are very difficult in free fall. The crew will probably be reduced to sponge-baths or maybe a shower while zipped up in a bag. In Robert Silverberg's 1968 novel World's Fair 1992 he mentions "sonic showers" which use sound waves to remove dirt with no water required. And in Andre Norton's space novels, the bathing room is called the "fresher".

People who have gone camping are familiar with how surprisingly difficult it is to keep clean in the absence of running water. As do city-folk living in houses near a water main break who have to make do without tap water for a few days. You tend to take for granted the luxury of accessing unlimited amounts of water out of the faucet. In the space environment, water is strictly limited, and what water there is performs poorly as a cleansing agent in free fall.

Crew will probably be required to take showers "navy style", since wet navy ships also have limited water (non-salt water at least). You turn on the shower water to get your body wet. You then turn off the water to conserve it while you lather up with soap. Then you turn the water back on to rinse off.

Lack of cleanliness

Water is carefully conserved in space because the crew must carry all of their supplies with them on the long journey to Mars, and space (more precisely, mass) is at a premium on such a mission. This makes keeping clean a challenge. Mars-bound astronauts will have moist towelettes for daily scrubbing, but they’ll only be able to shower infrequently. Experienced astronauts say they create a wider buffer of personal space to keep out of odour range of their crew mates.

From THE RACE TO MARS Discovery Channel

The primary hygiene component of a standard shipboard ‘fresher is a cylindrical translucent compartment, resembling a drug capsule set on its end, with a watertight sealing door. At top and bottom, gratings conceal powerful counter-rotating fan/turbine units.

In dynamic mode, these fan/turbines are engaged to blow (at the nominal “top”) and suck (at the nominal “bottom”) a water/air colloid past and over the bather at configurable velocities ranging from strong breeze to hurricane-strength wind, providing the water with a functional simulation of gravitic flow – a “shower”. To conserve water where necessary, many ‘freshers recirculate filtered water while in operation, requiring fresh water input only for the initial fill and the final rinse cycle.

In static mode, the gratings close and the capsule itself fills entirely with water – a microgravity “bath”.

In the former mode, breathing while bathing is, at best, difficult; in the latter, it is downright impossible. Early-model ‘freshers included a built-in breathing mask connected to ship’s life support to ameliorate this problem; in these days of respiratory hemocules which enable the modal transsoph to hold their breath for over an hour, ‘fresher designers tend to assume that this will not be a problem. Those without such hemocules must, therefore, remember to take a portable breather with them when bathing.

– The Starship Handbook, 155th ed.

For a longer period nothing more notable took place than the incident in which Roger Stone lost his breathing mask while taking a shower and almost drowned (so he claimed) before he could find the water cut-off valve. There are very few tasks easier to do in a gravity field than in free fall, but bathing is one of them.

From THE ROLLING STONES by Robert Heinlein (1952)

(ed note: The time agents are trapped on an alien spacecraft traveling to an unknown location, and they have no idea what anything is or how it works. But one of the techs knows how to work the alien shower)

     “I’d guess we’ll have to try a lot of things before this trip is over—if it ever is. Right now I’d like to try a bath, or at least a wash.” Ross surveyed his own scratched, half-naked, and very dirty body with disfavor.
     “That you can have. Come on.”
     Again Renfry played guide, bringing them to a small cubbyhole beyond the mess cabin. “You stand on that—maybe you can hold yourself in place with those.” He pointed to some rods set in the wall (they are in free fall). “But get your feet down on that round plate and then press the circle in the wall.”
     “Then what happens? You roast or broil?” Travis inquired suspiciously.
     “No—this really works. We tried it on a guinea pig yesterday. Then Harvey Bush used it after he upset a can of oil all over him. It’s rather like a shower.”
     Ross jerked at the ties of his disreputable kilt and kicked off his sandals, his movements sending him skidding from wall to wall. “All right. I’m willing to try.” He got his feet on the plate, holding himself in position by the rods, and then pressed the circle. Mist curled from under the edge of the floor plate, enveloped his legs, rose steadily. Renfry pushed shut the door.
     “Hey!” protested Travis, “he’s being gassed!”
     “It’s okay!” Ross’s disembodied voice came from beyond. “In fact—it’s better than okay!”
     When he came out of the fogged cubby a few minutes later, the grime and much of the stain were gone from his body. Moreover, scratches that had been raw and red were now only faint pinkish lines. Ross was smiling.
     “All the comforts of home. I don’t know what that stuff is, but it peels you right down to your second layer of hide and makes you like it. The first good thing we’ve found in this mousetrap.”
     Travis shucked his kilt a little more slowly. He didn’t relish being shut into that box, but neither did he enjoy the present state of his person. Gingerly he stepped onto the floor disk, got his feet flattened on its surface, and pressed the circle. He held his breath as the gassy substance puffed up to enfold him.
     The stuff was not altogether a gas, he discovered, for it was thicker than any vapor. It was as if he were immersed in a flood of frothy bubbles that rubbed and slicked across his skin with the effect of vigorous toweling. Grinning, he relaxed and, closing his eyes, ducked his head under the surface. He felt the smooth swish across his face, drawing the sting out of scratches and the ache out of his bruises and bumps.

From GALACTIC DERELICT by Andre Norton (1959)

Suspended nude in the air, she reached into her padded wall locker, braced a leg, opened the sliding panel and removed a plastic package from a box secured to an overhead shelf with velcro. She peeled away the wrapper, stuffing the plastic in the ever-ready disposal container, and opened a neatly folded, lightly scented towelette. Slowly and luxuriantly she removed the oily perspiration from her body. She smiled as the scent hovered about her. No Soviet quartermaster had ever issued these to the women cosmonauts who left the Earth behind! What she carried with her among her personal belongings were gifts from Susan Foster...

...Whatever their technical prowess, and Tanya knew it was most formidable, it was in the science of personal touch that the Americans were absolutely incredible. They were light years ahead of anything that emerged from Mother Russia. In the packages Susan gave her, concealed within a box supposedly filled with computer disks, were these sealed towels and their lightly scented fragrance, just enough to detect, and moist enough to clean and freshen her skin. It dried within seconds of its application and then you simply disposed of the towelette. She had hundreds of them. Some of the other women learned of her treasure and Tanya shared with them.

It made life infinitely more bearable after weeks and months in weightless orbit. It rendered personal hygiene a pleasure in a complicated, clanging, ear-stabbing vessel that reeked of oil, plastic, garlic and scallions and all manner of unpleasant body odors that soaked into the very "floors" and "walls" of station cubicles. The Americans, Tanya smiled, demanded their little luxuries wherever they went, and their woman cosmonauts were even more fiercely demanding than their men. Hooray for you, Tanya thought generously of the Americans. Long voyages into space with ships that stank left much to be desired, and if nothing else, the Americans were able to make of space adventure a mission that did not permanently wrinkle the nose...

...Susan slipped a personal package to Tanya...

..."How many are in here?"

"Four hundred."

"Tanya's eyes widened. "Four hundred?"

"We're the miracle workers of folded fragrance."

From EXIT EARTH by Martin Caidin (1987)

Keeping the habitat module clean is also a challenge. Water is limited, water does not clean things very well in free fall, and the limited atmosphere prevents one from using any alternate cleanser that it toxic or has a disagreeable odor.

And as mentioned elsewhere, any free floating garbage tends to accumulate on the air-intake vents. The vents on the Skylab space station quickly became quite disgusting with random bits of rotting food and dust particles.



The crews of any aerospace vehicle will generate particulate matter from their bodies and their clothing. Equipment also releases particulates. In a weightless state this debris will float in the cabin until it is entrained by the ventilation gas or is separated and captured by a surface (such as a crewman's lungs). Of course, the ventilation gas and filters will remove most of the debris; however, some spaces in the cabin will tend to accumulate floating debris due to a lack of sufficient ventilation. Therefore, on long duration missions (of one or more weeks) a vacuum cleaner should be provided to collect this material—which may include viable microorganisms and the media necessary for growth.

If the vehicle is provided with a pneumatic collection system for urine and/or feces, the fan used for this purpose can also be used to draw gas into a small debris collection bag. This bag can be made from the same material as the fecal collection bag. A gas flow rate of 5 ft3/min is adequate for this purpose.

A personal grooming device-vacuum cleaner is provided on a branch of the control air circuit of the waste management unit. This collects hair, nail clippings, shaving clippings, etc. Collection bags are provided to dry and store the wastes.

One of the shipboard roaches woke Lindsay by nibbling his eyelashes. With a start of disgust, Lindsay punched it and it scuttled away.

... He shook another roach out of his red-and-silver jumpsuit, where it feasted on flakes of dead skin.

He got into his clothes and looked about the gym room. Two of the Senators were still asleep, their velcro-soled shoes stuck to the walls, their tattooed bodies curled fetally. A roach was sipping sweat from the female senator's neck.

If it weren't for the roaches, the (spacecraft) Red Consensus would eventually smother in a moldy detritus of cast-off skin and built-up layers of sweated and exhaled effluvia. Lysine, alanine, methionine, carbamino compounds, lactic acid, sex pheromones: a constant stream of organic vapors poured invisibly, day and night, from the human body. Roaches were a vital part of the spacecraft ecosystem, cleaning up crumbs of food, licking up grease.

Roaches had haunted spacecraft almost from the beginning, too tough and adaptable to kill. At least now they were well-trained. They were even housebroken, obedient to the chemical lures and controls of the Second Representative. Lindsay still hated them, though, and couldn't watch their grisly swarming and free-fall leaps and clattering flights without a deep conviction that he ought to be somewhere else. Anywhere else.

(ed note: Alistair Young calls those "cleaning roaches")

From SCHISMATRIX PLUS by Bruce Sterling (1996)

(ed note: The Christmas Bush is a Fractal Robot. Tiny parts can be separated to be small robots "sub-motiles")

Now, let me show you some of its other tricks." He reached into his shirt pocket and pulled out a pressurized ball-point pen. He then unbuttoned his shirt front and used the pen to push out a bit of lint from behind a button-hole. He kicked over to a nearby wall and deliberately made an ink mark on the wall. As he kicked back, he let loose the bit of lint into the air. As he came to a halt back with the group, they watched as two tiny segments of the Christmas Branch detached from one of the arms. The smaller one, a minuscule cluster of cilia not much bigger than the bit of lint, flew rapidly through the air with a humming sound like that of a mosquito, captured the floating ball, and flew out the door to another part of the ship, zig-zagging as it went.

"It's picking up other bits of dust on its way to the dust-bin," explained David. "They're too small for us to see, but its little laser radars picked them up from their backscatter."

The larger sub-motile jumped from the Christmas Branch to the wall, and like a spider, used its fine cilia to cling to the wall and walk over to the ink smudge. The cilia scraped the ink out of the wall pores and formed it into a drying ball. The wall now clean, a sub-section of the spider detached and swam off through the low gravity, while the remainder of the spider jumped back to the Christmas Branch where it resumed its normal place.

"Yet housekeeping is a continual chore, so don't be surprised if you see a mosquito flying through the air or a spider walking across the ceiling. They will just be collecting all the dirt and dust you've made that day."

The Christmas Bush was busy weaving cloth using a bright green artificial thread that it had reconstituted from the lint fibers it had collected over the past years.

From ROCHEWORLD by Robert Forward (1982)

Temperature Regulation

NASA directs that the temperature inside a habitat module should be from 291.5 K to 299.8 K with the nominal temperature 295.2 K. That's 18.4°C ⇒ 22°C ⇒ 26.7°C in metric (and 65°F ⇒ 72°F ⇒ 80°F for those poor benighted folk still using Imperial)

NASA assumes that each astronaut emits 11.82 MJ of heat per day.

This is the job of the Spacecraft Thermal Control Systems.

Temperature inside the habitat module is prevented from getting too cold by hull thermal insulation (to prevent the internal heat from escaping), and by adding heat from sources such as electrical resistance heaters.

Temperature inside the habitat module is prevented from getting too hot by hull thermal insulation (to prevent heat from the sun from entering), and by removing heat using heat radiators. In the TransHab design, it needs approximately 96 kilograms of heat radiators and internal thermal equipment per person.

Radiation Shielding

Radiation shielding has its own separate page.

You want to limit the acute dose of radiation to under 0.1 Grays, and the astronaut career chronic dose to under 4.0 Sieverts.

What this boils down to is supplying the habitat module with a small radiation shielded room called a storm cellar or biowell. It will need radiation shielding to the tune of 500 grams per square centimeter of surface. Since this very expensive in terms of mass, storm cellars will be as small as the designers think they can get away with. With the restriction that all the crew has to physically fit inside, and they might have to shelter there for several days.

If the spacecraft has a fission, fusion, or antimatter power plant or propulsion system, it will require an anti-radiation shadow shield to protect the crew.

If the spacecraft is a combat spacecraft who will have to face radiation from nuclear warheads and particle beam weapons, it is going to require lots of very massy armor.

Artificial Gravity

Supplying artificial gravity has its own separate page.

It is unknown what the minimum amount of artifical gravity is required for health. The only data we have are for 1.0 g on Terra, 437 days in 0.0 g in the ISS, and a few hours at 0.16 g for the Apollo lunar vists. NASA limits astronauts on the International Space Station to 180 day visits.

So, for instance, if the minimum required gravity for health is above 0.4 g, Martian colonists living on the ground will still need regular visits to the centrifuge.

Pretty much all the reports I could find on the subject conclude with something like "I have no idea, more research is needed."

Effects of prolonged microgravity include:

A centrifuge would provide gravity to prevent these dire medical effects, but they are a major pain to attach to a spacecraft.

A possible compromise is the personal centrifuge. This is a centrifuge a few meters long, just big enough for one man to strap in, spin up about 30 RPM, and do some exercises. Yes, this will probably give them severe motion sickness, but it will only be for the duration of the exercise period. This will only help some but not all of the damage done to the body by microgravity.

It is tempting to just forget about spin gravity, and just have everybody float around while the ship is not under thrust. One can be an optimist and assume future medical advances will discovere treatment for all the hideous effects. Marshall Savage suggests electro stimulation therapy of the muscles (Ken Burnside says rocket crewmen will have to wear their "jerk-jammies" when they sleep). One would hope that a medical cure will be found for the nausea induced by free fall, or "drop sickness" (they say that the first six months are the worse).

But the only way to guarantee 100% freedom from all of the nasty medical effects is with full 1 g artificial gravity.

Some of the body’s systems adapt to the environment of space quicker than others. This figure represents how quickly each system adapts to microgravity.

The bottom line is the 1g setpoint, or normal gravity level on Earth for each system. The middle line is called the 0g setpoint, or the level each system obtains once it adapts to microgravity in space. The setpoints for 1g and 0g are different, and so it takes some time to adapt. The top line is called the clinical horizon and it is the point that problems in performance can occur.

As you can see, the neurovestibular system is the first to change. This system is responsible for assessing what direction the body is moving. When this system is not functioning properly, motion sickness can occur. You can see at first, there is a high peak for this system, indicating clinical problems. However, after a few days, this peak disappears, and the system adapts to space travel and has a stable value at the 0g setpoint.

You can see it takes the other systems, such as the muscular system, longer to adapt. On the figure, the muscular system is represented in part by the line labeled “lean body mass”. Lean body mass refers to the mass of the body which is not composed of fat. You can see on the figure that lean body mass eventually reaches a stable value at Og although it does take some time. In addition, the value at Og is less than that at 1g, indicating a loss in lean body mass with space flight.

Some systems, such as bone, don’t adapt to spaceflight. The bone system never reaches a stable value at 0g gravity, but instead continues to climb towards the clinical horizon.

From Marc E. Tischler

Countermeasures thus far have addressed the symptoms in a piecemeal fashion, rather than the underlying cause. For example, high-impact strength training may slow the decline of muscle and bone mass, but it does nothing to mitigate the damage to vision from increased fluid pressure in the eyeballs. Dietary and pharmaceutical countermeasures are fraught with complexity and the risk of unintended side effects — further complicated by the fact that weightlessness itself changes the body’s absorption of and reaction to drugs. Adding calcium to the diet to preserve bone structure is not very effective when the bones are leaching out the calcium they already have due to their lack of mechanical stress. (On Earth, that stress triggers a piezoelectric effect that regulates the growth of bone where it’s needed [Chaffin 1984], [Mohler 1962], [Woodard 1984].) On the contrary, calcium supplements are likely to increase the concentration of calcium in the blood and urinary tract, with a concomitant risk of developing kidney stones.

Artificial gravity via rotation — centrifugation — is the only practical countermeasure that addresses the underlying cause, rather than a subset of symptoms, of the health decline due to gravity deprivation. It’s still not known whether some threshold of gravity less than 1 g would be adequate to stave off the decline. Except for a few hours by a few men on the Lunar surface, there is a dearth of human experience in anything between 0 g and 1 g.

To the extent that a health risk is attributable to gravity deprivation, we don’t need to understand the intricate why’s and how’s to have confidence that restoring gravity will mitigate the risk. Whatever gravity’s effects might be, one can travel from Seattle to Sydney knowing that as long as the gravity in each locale is essentially the same there should be no gravitydeprivation illness or injury.

[Chaffin 1984] Chaffin, Don B.; Andersson, Gunnar B. J. Occupational Biomechanics (p. 25). John Wiley and Sons, Inc.
[Mohler 1962] Mohler, Stanley R. (1962 May). "Aging and Space Travel." In, Aerospace Medicine (vol. 33, p. 594597). Aerospace Medical Association.
[Woodard 1984] Woodard, Daniel; Oberg, Alcestis R. (1984). "The Medical Aspects of a Flight to Mars" (AAS 81239). In P. J. Boston (Ed.), The Case for Mars (AAS Science and Technology Series, vol. 57, p. 173180). American Astronautical Society

Dianne Steiger sucked on her bulb of coffee and considered just how much she hated zero gee. Not for herself, mind. After an adult lifetime spent in spacecraft of one sort or another, a shift from this gravity to that meant little to her. The medical problems caused by zero gee were no great challenge, either, if people paid attention and took care of themselves—and she made quite certain that everybody on a ship of hers took care of themselves. Zero-gee debilitation was to spaceflight as scurvy had been to sea travel five or six hundred years before—completely preventable, and fatal all the same, for anyone fool enough not to take precautions.

It was the headaches that zero gee caused in managing the ship. Terra Nova had been designed for operation either in zero gee or in roll mode, rotating along her long axis to produce artificial gravity via the centrifugal effect. The TN could function either way, but roll mode was preferred for almost everything on board, from drinking coffee to flushing the toilets, from pumping coolant to controlling the ship’s thermal load. There were ways to do everything in no-grav, but most of them were awkward and inconvenient, work-arounds rather than straightforward procedures.

From THE SHATTERED SPHERE by Roger MacBride Allen (1994)

Closed Ecological Systems

Remember the fundamental rule of rocket design: Every Gram Counts.

The spacecraft will have to lug along inconveniently large masses of air, food, and water so that the astronauts can live. And if the ship runs out while in a remote location, the crew will be reduced to a castaways in a lifeboat situation drawing straws to see who dies. With the added constraint that castaways in a lifeboat at least have unlimited access to breathable air. The fact that consumables run out at all will limit the duration of any given mission.

Which explains NASA's burning interest in Closed Ecological Life Support Systems (CELSS). In theory the only input such a system needs is energy, either sunlight or some power source to run grow lights. The advantages are:

  1. The astronauts will have air, food, and water forever (or until the equipment breaks down or the energy input stops)
  2. After a certain mission duration, it will be cheaper (in terms of mass) to use a CELSS instead of transporting consumables. With a primitive CELSS this happens at about 145 days, increasing the efficiency will bring the break-even duration point lower. The mass of the CELSS is constant regardless of mission duration, the mass of consumables goes up with mission duration.

The main functions of a CELSS are:

  1. Turn astronaut's exhaled carbon dioxide into oxygen
  2. Turn astronaut poop and table scraps into food
  3. Turn astronaut pee and washing wastewater into drinkable water

The current lines of research focus on doing this the same way Terra's ecosystem does: by using plants. In order to make the CELSS hyper-efficient they have to use hyper-efficient plants. Which explains the focus on algae.

Currently the state of the art is nowhere near achieving a 100% efficient CELSS. But an efficiency of over 75% or so would be a huge help. Sometimes a sub-100% system is called a Controlled Ecological Life Support Systems

In NASA jargon, a closed environment life support system based on algae is called a "yoghurt box", one based on hydroponic leafy plants is called a "salad machine", and one based on a fish farm is called a "sushi maker".

Problems with creating and maintaining a balanced CELSS include carefully controlling the amount of plants consuming carbon dioxide (so they don't gobble more CO2 than the astronauts can produce, resulting in plant death from asphyxiation), and small-closed-loop-ecology buffering problems. The latter means that the smaller your CELSS system is, the more rapid and violent the results from tiny changes. With a closed-loop ecology the size of Terra, tiny changes can take months to years to show any effects, and those will be mild. With a small spacecraft CELSS, tiny changes can cause immediate and drastic effects.

Since maintaining the balance of a CELSS is so tricky, it will be a major undertaking to keep things stable if the number of crew members changes. If the number goes down (by a group on a landing mission the the Martian surface, or by crew casualties) the amount of plants will have to be cut back. Adding new crew is more of a problem. Leafy plants take time to grow to useful size when increasing square meters of cultivation. Algae is less of a problem since single celled plants multiply at a speed that puts rabbits to shame. It will probably be only a few hours to grow the biomass of algae enough to accommodate the new crew.

Another concern is the shipboard supply of phosphorus and nitrogen, since these are biological bottlenecks.

Growing Plants

Terra's ecosystem fundamentally works by plants feeding animals while the animals feed the plants. Pretty much all spacecraft CELSS system try to utilize plants to feed the astronauts. Replacing plants with something else seems like a silly attempt to re-invent the wheel. Why do all that work when Mother Nature has already done it for you, for free?

The plants ingest water, carbon dioxide, sunlight, and some trace elements. Using Mother Nature's photosynthesis process, the plants output carbohydrates and oxygen. The astronauts consume plant carbohydrates and oxygen. Using human digestion, the human body is nourished, while producing water, carbon dioxide, and some trace elements. If you can balance the system, it will keep spinning as long as there is sunlight available.

Photosynthesis essentially splits water into hydrogen and oxygen, spits out the oxygen, and fuses hydrogen and carbon dioxide to form carbohydrates.

According to Chris Wolfe, NASA's best estimate is that the amount of leafy plants needed to handle one astronaut's carbon dioxide exhalation will produce only half of that astronaut's food. This is a problem. If the CELSS is producing all of the crew's food, it will have twice as many plants as needed, which will rapidly deplete the atmosphere of carbon dioxide, which will suffocate all the plants. It will also overproduce oxygen, but that can be extracted from the air and put into tanks for latter breathing, for rocket oxidizer, or exported and sold.

The solution is to recover the carbon trapped in the non-edible parts of the plants harvested for food.

The easiest way is to burn those parts and feed the generated carbon dioxide to hydroponics. The ash will contain other nutrients. Another solution is to feed the leftovers to a supercritical water oxidation unit and let it generate the carbon dioxide.

For CELSS uses, plants are generally grown by using some species of soil-less cultivation. Using actual soil to grow plants, with all of its active cultures and other messy ingredients, is far to unreliable to use in a life-or-death system.

Plants require light in order to perform photosynthesis, but using direct sunlight is a problem. First off you'll have to filter out ultraviolet and other frequencies harmful to plants. A transparent window allowing direct sunlight to illuminate the plants will also allow deadly solar storm radiation to fry them to a crisp. Granted plants tolerate up to 1 Sievert per year, but lets be reasonable here. There ain't no such thing as transparent radiation shielding (as yet).

In theory a shielded shutter will protect the plants from solar storms, but it is yet another possible point of failure. This is unacceptable if you are relying upon your plants to allow the crew to keep on breathing. If the storm detector fails, if the shutter actuators fail, if the crew forget to close manual shutters, all of these mean death by asphyxiation.

A fiber optic pipe fed with filtered sunlight and containing numerous bends to defeat radiation might work. But then if the spacecraft moves further away from Sol than Terra's orbit, the intensity of sunlight drops off rather alarmingly due to the inverse square law. That moron Freeman Lowell took far too long to figure this out in the movie Silent Running.

When you figure in that plants can only use certain wavelengths of sunlight, you might as well give up and use artificial grow-lights. LEDs are best, due to their relatively low waste heat. Feed the LEDs with electricity from the power generator of your choice.

The wavelengths used by photosynthesis are called photosynthetically-active radiation (PAR). They lie in a band from 400 to 700 nanometers, more or less the visible-light spectrum. Chlorophyll, the most abundant plant pigment, is most efficient in capturing red and blue light. This is why plant leaves appear yellowish-green to our eyesight, the chlorophyll doesn't eat those wavelengths so they spit them out. PAR is usually measured in bizarre units of "µmol photons m−2s−1" because photosynthesis is a quantum mechanical process (i.e., a bizarre process).

According to Chris Wolfe, most plants flourish under 26 mol PAR per square meter per day (26,000,000 µmol PAR/m2/d). Assuming that 12 hours (43,200 seconds) of the day are daylight and 12 hours are nightime, this means the plants are enjoying about 601 µmol PAR per square meter per second (µmol m−2s−1, the negative exponents are a cute way of saying "per" or "divided by").

LEDs can produce about 1.7 µmol PAR per watt-second or 6,120 µmol PAR per watt-hour. Supplying 601 µmol m−2s−1 will require about 354 watts (601/1.7 = 354) per square meter.

In other words, your hydroponics LED lights are going to need about 354 watts of electricity per square meter of hydroponic plants, for 12 hours out of every day. Certain plants require different amounts of mols PAR per square meter, and different numbers of illumated hours per day, but this is a good back-of-the-envelope value. Lettuce and spinach want about 250 µmol m−2s−1 (not 601), while tomatoes and cucumbers can get by on only 100 µmol m−2s−1

If I am reading the reports properly, algaculture requires a wee bit more. Chlorella algae wants 450 µmol PAR/m2, and Spirulina's optimal value is about 120 µmol PAR/m2.

So doing the math, Chlorella's 450 µmol PAR/m2 will need about 265 watts/m2 of LED electricity, while Spirulina needs 71 watts/m2. Since algae is typically cultivated in tubes or tanks, I am unsure how to translate the square meters of illumination into volumes of algae culture. The thickness will not be much, because algae is so good at harvesting photons that is is practically opaque.

In terms of area, I've seen values ranging from 10 to 40 square meters and perhaps 40-160 cubic meters per person. My own spreadsheet based on densely stacked racks comes to 11.5 m² floor space, 22.14 m² growing area and 46.2 m³ volume for one person (2.5 kg per day), but we want to allow for safety and variety. People don't want to eat tomato and potato for three meals a day simply because they are excellent producers. I also want to leave volume for animal production and associated equipment, so let's start with 30 m² floor space and 120 m³ per person. About 75% of that will be lit, or 43.3 m² of grow area. We need half of 354 watts per m² or 7,667 watts per person for lighting. Additional power will be needed for pumps and fans.

The extra area provides reserve supplies of storable food like rice and beans, indulgence crops like coffee (1.62g/day*m²), tea (1.92g/day*m²) or cocoa (0.42g/day*m²) {all require several years to establish}, animal feed, plastic feedstock and extra O2 for export. One cup of coffee requires about 10 grams of grounds; a cup a day would use 6.17m² of floor space.

Life Support

Feeding a person requires about 40m³ of hydroponics volume (including row spacing, aisles, nutrient storage, equipment, seeding areas, etc., etc.). The exact amount varies and can be pushed lower (below 20m³ is my guess) but this is a reasonable number to start with. Plants need light (from LEDs), and hydroponic grow systems need pumps, fans and sensors. This gear collectively eats about 5 kW of electricity per person, nearly all of which ends up as low-grade heat.

That same volume will convert two people's CO2 back into oxygen. This is because most of a plant's dry mass is carbon compounds but only about half of that is food; the rest is waste. That carbon comes from CO2, so crops to feed one person trap a second person's worth of carbon as waste. Fortunately we can simply burn the waste to recover that carbon on demand. This would be done in a pyrolysis unit to form neat little carbon blocks for storage and controlled release; these may even be used as filters before ultimately getting burned to keep the CO2 levels high enough for growth. Since plants and humans have very different 'ideal' atmospheres, CO2 scrubbers (zeolite sorbent beds) will be used to actively move CO2 out of human spaces and into plant spaces.

Nitrogen is a buffer gas; it is inert and allows the oxygen percentage in the atmosphere to be low enough to avoid fires. It's also an important part of amino acids (and thus proteins), and is actively cycled in humans and in plants. Nitrogen gas is very stable, meaning it is hard to convert into active forms like urea or nitrate. Nitrogen fixers like legumes and many bacteria can do the job, plus there are methods of making ammonia and other nitrogen-containing chemicals directly (given enough energy). The active nitrogen compounds in the system are assembled in plants to form proteins, eaten by humans, excreted as waste, separated in a waste processor and converted into hydroponic nutrients to be fed to the plants. Some of it is bound up in plant wastes and is either recovered from there or burned back to nitrogen gas depending on how fancy the recovery system is. Quantities of nitrogen are stored in liquid form to replenish atmosphere (everything leaks). That handles the nitrogen cycle, but note that some of it is unavoidably lost over time and resupply is eventually necessary even with perfect recycling. The same applies to all other volatiles (liquids and gases).

Argon will probably be used as a buffer gas and ion engine propellant since it is readily available on Mars. It doesn't get used in biological processes but otherwise would be used in place of nitrogen for maintaining atmosphere.

The waste processing systems will recover other important nutrients like phosphorus, potassium, calcium, iron, etc., usually as salts that can be used directly as fertilizer after purification. Inputs are wastes, water and energy. Outputs are these salts, clean water, heat and CO2 (for the most part). Water circulates through most of these systems; it is taken up by plant roots and evaporated from leaves, bound up in sugars, eaten, drank and excreted, condensed on cold surfaces, etc. Power consumption is minimal for the baseline (relying heavily on bioremediation and SCWO) but could be higher for more advanced systems.

Humidity and temperature is maintained by the CO2 system, since the air must be dried before it can be filtered properly. Incoming warm, wet 'used' air is cooled and dried, passed through the filter, then heated and moistened to the desired level. The filter regenerates by pumping warm, very dry and very high CO2 air through to the plant sections. Any excess water is sent to waste processing for filtration. This means that the atmosphere system needs active refrigeration and is the primary load on the craft's radiators; it needs to be able to handle the entire heat load of the habitat since only a small amount is lost through the solid metal connections to the rest of the craft. Power consumption is roughly 1 kW per person.

A better use of plant waste would be to make animal feed with it and raise fish and chickens. Food fish have a short enough lifespan that they can be raised inside the radiation shielding water, though breeding pairs would be kept inside the storm shelter. Chicken eggs greatly expand the kinds of foods you can create and would be a big benefit to morale. This kind of microfarming can be done even for a very small population; certainly a ship carrying more than a hundred people would be able to sustain populations of both.


As previously mentioned, plants will probably be grown by using soil-less methods.

There are lots of different types of soil-less cultivation, all based around using water (Hydroponics). Some are suitable for CELSS.

  • Hydroponics: growing plants without live bacterial-infested soil ("salad machine")
    • Solution Culture: no substrate, just nutrient water
      • Static solution culture: plants in jars of still nutrient water
      • Continuous-flow solution culture: flows of nutrient water passing over plant roots
      • Aeroponics: plant roots are in the air, misted with a fog of nutrient water
      • Algaculture: microalgae cells cultivated in either static or continuous flow solutions cultures ("yoghurt box")
    • Medium Culture: using a sterile solid substrate bathed in nutrient water
    • Aquaponics: solution or medium cultures in association with tanks of fish and other sea food ("sushi maker")

Growing leafy plants for food is not as efficient as growing algae or other single-cell plant. But it is quite a bit easier. The basic idea is to grow food plants not in soil, but instead in nutrient filled water or in an inert material bathed in nutrient filled water.

Medium cultures can use all sorts of substrates: rock wool, baked clay pellets, glass waste growstones, coco peat, parboiled rice husks, Perlite, Vermiculite, pumice, sand, gravel, wood fibre, sheep wool, brick shards, and polystyrene packing peanuts have all been used.

The Executive Officer assigned other tasks not directly concerned with formal training. Matt was appointed the ship’s “farmer.” As the hydroponics tanks supply both fresh air and green vegetables to a ship he was responsible for the ship’s air-conditioning and shared with Lieutenant Brunn the tasks of the ship’s mess.

Theoretically every ration taken aboard a Patrol vessel is pre-cooked and ready for eating as soon as it is taken out of freeze and subjected to the number of seconds, plainly marked on the package, of high-frequency heating required. Actually many Patrol officers fancy themselves chefs. Mr. Brunn was one and his results justified his conceit—the Aes Triplex set a good table.

(ed note: microwave ovens had been invented about one year before Heinlein wrote this novel. That is what "high-frequency heading" is referring to.)

Matt found that Mr. Brunn expected more of the “farm” than that the green plants should scavenge carbon dioxide from the air and replace it with oxygen; the mess officer wanted tiny green scallions, fragrant fresh mint, cherry tomatoes, Brussels sprouts, new potatoes. Matt began to wonder whether it wouldn’t have been simpler to have stayed in Iowa and grown tall corn.

When he started in as air-conditioning officer Matt was not even sure how to take a carbon-dioxide count, but shortly he was testing his growing solutions and adding capsules of salts with the confidence and speed of a veteran, thanks to Brann and to spool #62A8134 from the ship’s files—“Simplified Hydroponics for Spaceships, with Growth Charts and Additives Formulae.” He began to enjoy tending his “farm.”

Until human beings give up the habit of eating, spaceships on long cruises must carry about seven hundred pounds of food per man per year. The green plants grown in a ship’s air-conditioner enable the stores officer to get around this limitation to some extent, as the growing plants will cycle the same raw materials—air, carbon dioxide, and water—over and over again with only the addition of quite small quantities of such salts as potassium nitrate, iron sulphate, and calcium phosphate.

The balanced economy of a spaceship is much like that of a planet; energy is used to make the cycles work but the same raw materials are used over and over again. Since beefsteak and many other foods can’t be grown conveniently aboard ship some foods have to be carried and the ship tends to collect garbage, waste paper, and other trash. Theoretically this could be processed back into the cycles of balanced biological economy, but in practice this is too complicated.

Even though turnip greens and such can be used in the jet, the primary purpose of the “farm” is to take the carbon dioxide out of the air. For this purpose each man in the ship must be balanced by about ten square feet of green plant leaf. Lieutenant Brunn, with his steady demands for variety in fresh foods, usually caused Matt to have too much growing at one time; the air in the ship would get too fresh and the plants would start to fail for lack of carbon dioxide to feed on. Matt had to watch his CO2 count and sometimes build it up by burning waste paper or plant cuttings.

Brunn kept a file of seeds in his room; Matt went there one “day” (ship’s time) to draw out Persian melon seeds and set a crop. Bran told him to help himself. Matt rummaged away, then said, “For the love of Pete! Look at this, Mr. Brunn.”

“Huh?” The officer looked at the package Matt held. The outside was marked, “Seeds, melon, Persian jumbo fancy, stock #12-Q4728-a”; the envelope inside read Seed, pansies, giant variegated.”

Brunn shook his head. “Let that be a lesson, Dodson—never trust a stock clerk—or you’ll wind up half way to Pluto with a gross of brass spittoons when you ordered blank spacecharts.”

“What’ll I substitute? Cantaloupe?”

“Let’s grow some watermelon—the Old Man likes watermelon.”

Matt left with watermelon seeds, but he took along the truant pansy seeds.

Eight weeks later he devised a vase of sorts by covering a bowl from the galley with the same sponge-cellulose sheet which was used to restrain the solutions used in his farming, thereby to keep said solutions from floating around the “farm” compartment during free fall. He filled his vase with water, arranged his latest crop therein, and clipped the whole to the mess table as a centerpiece.

Captain Yancey smiled broadly when he appeared for dinner and saw the gay display of pansies. “Well, gentlemen,” he applauded, “this is most delightful. All the comforts of home!” He looked along the table at Matt. “I suppose we have you to thank for this, Mr. Dodson?”

“Yes, sir.” Matt’s ears turned pink.

“A lovely idea. Gentlemen, I move that we divest Mr. Dodson of the plebeian title of ‘farmer’ and designate him Horticulturalist extraordinary.’ Do I hear a second?” There were nine “ayes” and a loud “no” from Commander Miller. A second ballot, proposed by the Chief Engineer, required the Executive Officer to finish his meal in the galley.

Lieutenant Brunn explained the mishap that resulted in the flower garden. Captain Yancey frowned. “You’ve checked the rest of your supply of seeds, of course, Mr. Brunn?”

“Uh, no, sir.”

“Then do so.” Lieutenant Brunn immediately started to leave the table, “—after dinner,” added the Captain. Brunn resumed his place.

“That puts me in mind of something that happened to me when I was ‘farmer’ in the old Percival Lowell—the one before the present one,” Yancey went on. “We had touched at Venus South Pole and had managed somehow to get a virus infection, a sort of rust, into the ‘farm’—don’t look so superior, Mr. Jensen; someday you'll come a cropper with a planet that is new to you!”

“Me, sir? I wasn’t looking superior.”

“No? Smiling at the pansies, no doubt?”

“Yes, sir.”

“Hmmph! As I was saying, we got this rust infection and about ten days out I didn’t have any more farm than an Eskimo. I cleaned the place out, sterilized, and reseeded. Same story. The infection was all through the ship and I couldn’t chase it down. We finished that trip on preserved foods and short rations and I wasn’t allowed to eat at the table the rest of the trip.”

From SPACE CADET by Robert Heinlein (1948)


Algaculture in a spacecraft CELSS is always in the form of growing microalgae, not gigantic macroalgae aka seaweed. Popular food microalgae types include Chlorella and Spirulina.

Algae is cultivated in photobioreactors. These try to hold the algae cultures in thin layers because the little greenies are so good at absorbing the light that any algae that is too deep will get no light at all. The concentration of algae is typically something like 5×108 algae cells per mililiter of water.

In 1965, the Russian CELSS experiment BIOS-3 determined that 8 m2 of exposed Chlorella could remove carbon dioxide and replace oxygen within the sealed environment for a single human (I am assuming this is in a very shallow tray). The official figure for Chlorella oxygen production is 25 to 400 femtoMol O2/cell/hour. If am I doing the math correctly, at a concentration of 5×108 cells/ml, this translates into about 0.0032 kg of O2 produced per hour per liter, and 0.768 kg of O2 produced per day per liter. Since astronauts require 0.835 kg of O2 per day, this implies they would need 10.9 liters of chlorella culture.


In THE MILLENNIAL PROJECT, Marshall Savage sings the praises of Spirulina algae. However, you'd best take the following with a grain of salt. There is often a long distance between the ideal and the real.

Anyway, Spirulina is apparently almost the perfect food, nutritional wise. A pity it tastes like green slime (though Savage maintains that genetic engineering can change the flavor). Spirulina is highly digestible since it contains no cellulose. It is 65% protein by weight and contains all eight essential amino acids in quantities equivalent to meat and milk. It also has almost all the vitamins, with the glaring exception of vitamin C (I guess rocketmen will become "limeys" again). It is also a little sparse on carbohydrates. Savage calculates that it will be possible to achieve production rates of 100 grams (dry weight) of algae per liter of water per day. It breaks down 6 liters of algae water per person, supplying both food and oxygen, while consuming sunlight (or grow-lights), CO2 and sewage. 6 liters of algae water will produce 600 grams of "food" (540 grams is 2500 calories, an average daily food requirement), 600 liters of oxygen, and consume 720 liters of CO2 and an unspecified amount of nutrient salts extracted from sewage. Since food is generally 75% water, 600 grams of dry food will convert into about 2.4 kg of moist food, which compares favorably with the 2.3 kg on the USS Wyoming.

600 liters of oxygen is about 0.8574 kg of oxygen, which is above the NASA requirement of 0.835 kg of oxygen per astronaut per day.

NASA commissioned a study back in 1988 to determine how difficult it would be to cultivate Spirulina as part of a closed ecological life support system.

Dr. John Schilling mentions a possible pitfall:

[Spirulina is] [h]igh in nucleic acid, which means you can only eat about fifty grams per day or you're at risk of gout. And it's going to be really, really, really embarassing if you have to list "gout" as the cause of failure for a space mission.

Dr. John Schilling

There are other things you have to be mindful of when cultivating Spirulina. From the Swedish Medical Center:

Various forms of blue-green algae can be naturally contaminated with highly toxic substances called microcystins.

Some states, such as Oregon, require producers to strictly limit the concentration of microcystins in blue-green algae products, but the same protections cannot be assumed to have been applied to all products on the market. Furthermore, the maximum safe intake of microcystins is not clear, and it is possible that when blue-green algae is used for a long time, toxic effects might build up...

...Blue-green algae can also contain a different kind of highly toxic substance, called anatoxin (ed note: AKA "Very Fast Death Factor").

In addition, when spirulina is grown with the use of fermented animal waste fertilizers, contamination with dangerous bacteria could occur. There are also concerns that spirulina might concentrate radioactive ions found in its environment. Probably of most concern is spirulina's ability to absorb and concentrate heavy metals such as lead and mercury if they are present in its environment. One study of spirulinas grown in a number of locations found them to contain an unacceptably high content of these toxic metals. However, a second study on this topic claims that the first used an unreliable method of analyzing heavy metal content, and concludes that a person would have to eat more than 77 g daily of the most heavily contaminated spirulina to reach unsafe mercury and lead consumption levels.

These researchers, however, go on to suggest that it is not prudent to eat more than 50 g of spirulina daily. The reason they give is that the plant contains a high concentration of nucleic acids, substances related to DNA. When these are metabolized, they create uric acid, which could cause gout or kidney stones. This is of special concern to those who have already had uric acid stones or attacks of gout.

SF writers with an evil turn of mind will see some interesting plot possibilites in these facts. The ship's food supply could become contaminated by an incompetent repair of the algae system utilizing lead pipes, an algae culture supplier with poor quality control, or deliberate sabotage.

Algae Tankage

The advantage of algae is that it can theoretically form a closed ecological cycle. This means that 6 liters of algae water, one human, some equipment, and sunlight can keep the human supplied with food and oxygen forever. Theoretically, of course. 0.006 m3 per person compared to 90 m3 per person is a strong argument for lots of green slime dinners for enlisted Solar Guard rocketmen. (Astro once said "I've been eating those synthetic concentrates so long my stomach thinks I've been turned into a test tube") Of course the Biosphere II fiasco shows how far we are from actually achieving a closed ecological cycle. Don't forget the 0.25 liters of water per person per day to make up for reclamation losses.

William Seney points out that as a luxury, some of the algae can be diverted to feed fish such as carp, catfish or tilapia for an occasional treat.

And you'd better keep the algae tanks far from the atomic drive. The last thing you want is for the little green darlings to mutate into something you can't eat. Or worse: something that is really inefficient at producing oxygen.

Christopher Huff begs to differ:

Actually, the algae tanks would make pretty good radiation shielding. "Clean" cultures of the original strain of algae would be easy to carry along to replenish the main tanks if an inedible form did take hold...just stick some packets of dry spores in the radiation shelter. As for the last possibility, a strain that was poor at conversion of CO2 would quickly be out-bred by the better strains. With algae constantly being removed for food, it would quickly be eliminated from the system.

Also, in addition to fish, a small colony of shrimp or crabs could be fed off the algae, providing a bit more variety in the food supply. Clams could also have a place, providing a useful sink for calcium, carbon, and oxygen in their shells as well as helping to process water. A combination of fresh and salt water systems might work out best.

Christopher Huff

There were some figures in a report on a cruder life-support set up written in 1953. This used Chlorella algae, which isn't quite as good as Spirulina since it has an indigestible cellulose cell wall. The figures assume a Chlorella culture density of 55 grams per liter of water and a daily yield of 2.5 grams per liter. Savage's 100 grams per liter sounds a little optimistic, and 2.5 sounds a little pessimistic. The truth is probably somewhere in between.

At a yield of 2.5 g/l, to provide one rocketeer with 500 grams of food (instead of Savage's 600 grams) will require 200 liters of algae culture.

Urine is passed through an absorption tube to remove excess salt (which would kill the algae) but retaining urea and other nitrogen compounds the algae needs. Faeces are irradiated with ultraviolet to kill all bacteria and added to the urine. This is fed to the main algae tank along with pressurized carbon dioxide (previously removed from the air with calcium oxide). A pump sends a flow of algae culture to the growth trays under filtered sunlight. The culture then passes through a centrifugal separator on its way back to the main tank. The separator performs two functions: [1] removing excess gas to maintain a pressure equilibrium with the carbon dioxide injection and [2] periodically harvesting algae for food. Harvest will occur once a day, extracting 500 grams of algae from nine liters of culture per person. The pump will be controlled such that the algae on the average will experience two minutes of sunlight then three minutes in the darkness of the main tank before it starts the cycle anew.

A fresh batch of urine and faeces is added immediately after algae harvest, to give the algae twenty four hours to consume it. So by next harvest there is no human excretions contaminating the food (you hope).

Now for the answer you've been waiting for. Dr. Bowman estimates that the equipment will mass approximately 50 kg, plus 200 kg per man for algae culture. Since the equipment is such a small fraction of the total, mass savings depend upon getting the algae yield higher than 2.5 g/l. Such as Savage's 100 g/l Spirulina with 6 kg per man of algae culture.

Dr. Bowman points out that when one compares an algae system with merely stocking crates of food, the break-even point occurs at a mission of 145 days (about five months). Below this time it takes less mass to bring crates of food, as the mission duration rises above 145 days the algae tanks get more and more attractive.

Growing Meat


Other SF novels have suggested vats of yeast or tissue cultures of meat ("carniculture" or in vitro meat) to supplement food supplies. But unless they can re-cycle wastes from the crew, it seems more efficient to just carry more boxed food.

Currently scientist can only grow tissue cultures as a single sheet of cells, making them thicker will require figuring out how to make them grow blood vessels to nourish all the cells ("vascularization"). But some technicians figure that they can grow lots of meat cell sheets, then laminate the sheet layers together to approximate a slab of meat.

There are researchers exploring several different strategies to make full-blown vascularization. But it ain't easy. Strategies include material functionalization, scaffold design, microfabrication, bioreactor development, endothelial cell seeding, modular assembly, and in vivo systems. See link for details.

The joke name for this process is "In Meatro"

If you are trying a closed cycle with tissue cultures, you will have to deal with the problem of the Food Chain. Typically each higher level of the pyramid has one-tenth the biomass of the one below, for reasons you can read about in the link. What this means is that you will have to feed ten meals worth of algae to the meat tissue culture in order to produce one meal worth of meat. Even on Terra, this is the reason why meat is more expensive than vegetables.

Obviously the food chain effect also applies to diverting some of the algae to fatten up some fish as a special meal.

At least the tissue culture helps increase the meat ratio. For instance, an entire cow is about 40% edible meat. The rest is bones, hooves, hide, and other inedible parts. Tissue cultures would theoretically turn that up to 100% edible meat. Granted the inedible parts can be recycled via supercritical Water Oxidation, but the inefficiency of wasting all that algae food energy on growing inedible bones kills this idea dead. Not that it would have been practical to bring a cow along on your spaceship in the first place.

As a side note, the idea of lab grown in vitro meat has caused some controversy among the vegetarian community. Any person who is vegetarian on the basis of avoiding animal cruelty, should have no objection to eating in vitro meat. But some vegetarians still maintain that one should not eat meat because of Reasons.

Of course things can become a real moral quagmire, as Sir Arthur C. Clarke points out in his disturbing short story The Food of the Gods.

(ed note: "Chicken Little" is a chicken breast meat tissue culture.)

Arielle went to bed, too, but first she stopped off at the sick bay to get patches for her cracked fingernails, then at the galley to get a bite to eat. She had a double helping of protocheese with real garlic from Nels's hydroponic gardens, two algae shakes with energy sticks mixed in for crunch, then, still hungry, she finished with a desert consisting of a half-pound of white-meat sticks from "Chicken Little" — her real-meat ration for a week — sliced into thin strips and hot-cooked with James's secret recipe of herbs and spices.

From ROCHEWORLD by Robert L. Forward. (1990)

You know I admire classical artists like Rembrandt and Bonestell, and don’t care for abstractions or chromodynamics. I’m not very musical. I have a barrack-room sense of humor. My politics are conservative. I prefer tournedos to filet mignon but wish the culture tanks could supply us with either more often. I play a wicked game of poker, or would if there were any point in it aboard this ship.

From TAU ZERO by Poul Anderson (1970)

“What’s it going to be tonight?” Grevan asked, reaching up to guide them in to an even landing.

“Albert II in mushroom sauce,” said Klim. She was a tall, slender blond with huge blue eyes and a deceptively wistful expression. As he grounded the cooker, she put a hand on his shoulder and stepped down. “Not a very original menu, I’ll admit! But there’s a nice dessert anyway. How about sampling some local vegetables to go with Albert?”

“Klim thinks Albert is beginning to look puny again,” Cusat announced. “Probably nothing much to it, but how about coming along and helping us diagnose?”

The Group’s three top biologists adjourned to the ship, with Muscles, whose preferred field was almost-pure mathematics, trailing along just for company. They found Albert II quiescent in vitro—as close a thing to a self-restoring six-foot sirloin steak as ever had been developed.

“He’s quit assimilating, and he’s even a shade off-color,” Klim pointed out, a little anxiously.

They debated his requirements at some length. As a menu staple, Albert was hard to beat, but unfortunately he was rather dainty in his demands. Chemical balances, temperatures, radiations, flows of stimulant, and nutritive currents—all had to be just so; and his notions of what was just so were subject to change without notice. If they weren’t catered to regardless, he languished and within the week perversely died. At least, the particular section of him that was here would die. As an institution, of course, he might go on growing and nourishing his Central Government clients immortally.

They reset the currents finally and, at Cusat’s suggestion, trimmed Albert around the edges. Finding himself growing lighter, he suddenly began to absorb nourishment again at a very satisfactory rate.

“That did it, I guess,” Cusat said, pleased. He glanced at the small pile of filets they’d sliced off. “Might as well have a barbecue now.”

“Run along and get it started,” Grevan suggested. “I’ll be with you as soon as I get Albert buttoned up.”

From THE END OF THE LINE by James H. Schmitz (1951)

Several calves were born, and seemed to be doing well; the biochemistry of Tanith and Khepera were safely alike. Trask had hopes for them. Every Viking ship had its own carniculture vats, but men tired of carniculture meat, and fresh meat was always in demand. Some day, he hoped, kregg-beef would be an item of sale to ships putting in on Tanith, and the long-haired hides might even find a market in the Sword-Worlds.

From SPACE VIKING by H. Beam Piper (1962)

Insect Protein

There is an alternative between eating algae and the daunting task of growing vascularized meat tissue cultures, but you ain't gonna like it.

There are quite a few edible insects that will happily eat algae. Since they are live, they make their own vascularization. They are very efficient at converting algae into insect meat. And a much higher percentage of insect body mass is edible meat.

Yes, most people from western cultures find the thought of eating bugs to be incredibly disgusting. However the astronauts are already drinking recycled urine so it just takes some training. Processing will help, a compressed-protein bar composed of finely ground insects will be easier to eat than a plate full of microwaved bugs with too many legs.

In the following table, the "Algae for 1 kg of animal" is how much algae an entire animal will need to eat in order to increase its weight by one kilogram. "Edible meat" is the percentage of the animal's mass that is edible. "Algae for 1 kg of meat" is how much algae the entire animal will need to eat in order to increase its edible meat mass by one kilogram (i.e., reciprocal of edible meat percent times algae for 1 kg of animal).

You can probably use the "Algae for 1 kg of animal" figure as a ballpark figure for a tissue culture.

Algae to Meat Conversion
AnimalAlgae for
1 kg of animal
Edible meatAlgae for
1 kg of meat
Cow10 kg40%25.0 kg
Pig5 kg55%9.1 kg
Chicken2.5 kg55%4.6 kg
Cricket1.7 kg80%2.1 kg

Data from Edible insects: Future prospects for food and feed security.

If you figure a beef tissue culture requires 10 kg of algae for each new kilogram of beef, the freaking live crickets are still more efficient.

At harvest time, insects are killed by freeze-drying, sun-drying or boiling (in space, exposing them to vacuum probably counts as freeze-drying). They can be processed and consumed in three ways: as whole insects; in ground or paste form; and as an extract of protein, fat or chitin for fortifying food and feed products. Insects are also fried live and consumed, but a deep-fat fryer in microgravity is insanely dangerous. Some species need to have their legs and wings removed before eating.

In practice, extracting insect protein is probably not worth the effort. Needs lots of exotic chemicals and equipment, and reduces the percentage of edible mass. It is easier just to grind them into powder or paste and make bug-burgers.

For more details than you really want to know, read the report.

Science fiction authors could use this as an interesting bit of historical detail. Old-timer spacers can tell tales about back in olden days when they had to eat bugs. You young whipper-snapper spacers have it easy nowadays, what with your vascularized filet mignon tissue cultures.


I was reading the article in Atomic Rockets about growing meat in space where you suggested growing insects as an alternate to lab-grown meat cultures. You use crickets as your example insect. As someone who has raised crickets in captivity I can tell you that there is no way you're going to get a cricket farm in a closed system like a spacecraft. Even a well maintained cricket colony smells like a just-opened bag of chicken feces that has been sitting in the sun.

Go down to a pet store and ask to sniff their crickets if you don't believe me. Those things are absolutely pungent.

Also, crickets are annoying to culture because they eat each other if you're not careful and there's a lot of work that goes into making sure that doesn't happen too much. Plus, they're fast and they jump (and fly!) which makes them hard to keep contained even on earth.

Know what insect is slow moving and has a very mild odor? Cockroaches.

It would thrill me to no end to crack open a paperback one of these days to read about astronauts eating processed cockroach bars. I'm a big fan of cockroaches.

I no longer have a colony of roaches but thinking back to the smell of the colony I'm 95% certain that the only odors were that of decaying paper from the egg cartons and toilet paper rolls I raised the creatures in and the smell of any food I gave them. I raised Blaptica dubia roaches, by the way, because of their inability to climb glass and their lack of sexual behavior at normal room temperature. In case my tank ever broke I would be assured that the subsequent roach infestation would last only a single generation. Also, I could easily throttle the rate that they bred by switching on and off the tank's heater. Male B. dubia roaches have wings, however, and while they do not typically fly they will, apparently, flutter if you pick one up and drop it. I'm not sure how that would work in microgravity. Probably better to choose a species that has no wings at all.

I'll need to think about an ideal roach species for breeding in space, but B dubya is at the top of my list so long as the males don't start flying about in microgravity. A couple factors I would consider is whether or not the roach can cling to glass (so you can open their container without having roach stuck to the lid), whether or not they deposit or carry their egg sacks while they gestate, and whether or not they fly or stink.

From Samantha Davis (2015)


A shmoo is a fictional cartoon creature created by Al Capp, they first appeared in his classic comic strip Li'l Abner in 1948. Shmoos were prolific, required no food (only air), are delicious and nutritious, have no bones or other waste, and are eager to be eaten. (Ironically, they are the greatest menance to humanity ever known. Not because they are bad, but because they are good.)

Oddly enough, shmoos share many common traits with one-celled yeast. Yeast even looks a little like a shmoo. When a yeast cell senses the mating pheromone, it initiate polarized growth towards the mating partner, creating the characteristic outline of a shmoo. The process is called "shmooing", which shows that biologists have a sense of humor. As to the matter of the deliciousness of yeast, see the exerpt from Lucky Starr and the Oceans of Venus below.

The science fiction version of a shmoo is a Frumious Bandersnatch, from Larry Niven's "Known Space" series.

In the real world, left-over brewers' yeast is used to create such foods as Marmite and Vegemite. Even in 1902 people realized that it was a criminal waste to just throw away the huge quantities of perfectly edible yeast protein that was a by-product of making beer. Marmite and Vegemite are still being sold today. Actually in Australia, Vegemite is more or less a food staple.

In science fiction, one occasionally encounters the term "dole yeast". In future societies that have some form of social welfare system for unemployed people, the food given is generally a portion of unpalatable raw yeast, since that is usually the cheapest food available. Single-cell protein is very inexpensive, especially if you grow it on minimally processed sewage.


     He glanced at the menu on a waiter’s chest, and recoiled. “Ye gods. The prices!”
     “This is as expensive as it gets. At the other end is dole yeast, which is free—”
     “—and barely worth it. If you’re down and out it’ll keep you fed, and it practically grows itself."

From PROTECTOR by Larry Niven (1973)

Bigman turned his attention reluctantly to his dessert. The waiter had called it "jelly seeds," and at first the little fellow had regarded the dish suspiciously. The jelly seeds were soft orange ovals, which clung together just a bit but came up readily enough in the spoon. For a moment they felt dry and tasteless to the tongue, but then, suddenly, they melted into a thick, syrupy liquid that was sheer delight.

"Space!" said the astonished Bigman. "Have you tried the dessert?"

"What?" asked Lucky absently.

"Taste the dessert, will you? It's like thick pineapple juice, only a million times better.

Lucky smiled and went on, "Venus is a fairly developed planet. I think there are about fifty cities on it and a total population of six million. Your exports are dried seaweed, which I am told is excellent fertilizer, and dehydrated yeast bricks for animal food."

"Still fairly good," said Morriss. "How was your dinner at the Green Room, gentlemen?"

Lucky paused at the sudden change of topic, then said, "Very good. Why do you ask?"

"You'll see in a moment. What did you have?"

Lucky said, "I couldn't say, exactly. It was the house meal. I should guess we had a kind of beef goulash with a rather interesting sauce and a vegetable I didn't recognize. There was a fruit salad, I believe, before that and a spicy variety of tomato soup."

Bigman broke in. "And jelly seeds for dessert."

Morriss laughed hootingly. "You're all wrong, you know," he said. "You had no beef, no fruit, no tomatoes. Not even coffee. You had only one thing to eat. Only one thing. Yeast!"

"What?" shrieked Bigman.

For a moment Lucky was startled also. His eyes narrowed and he said, "Are you serious?"

"Of course. It's the Green Room's specialty. They never speak of it, or Earthmen would refuse to eat it. Later on, though, you would have been questioned thoroughly as to how you liked this dish or that, how you thought it might have been improved, and so on. The Green Room is Venus's most valuable experimental station."

"I am guessing," said Lucky, "that yeast has some connection with the crime wave on Venus."

"Guessing, are you?" said Morriss, dryly. "Then you haven't read our official reports. I'm not surprised. Earth thinks we are exaggerating here. I assure you, however, we are not. And it isn't merely a crime wave. Yeast, Lucky, yeast! That is the nub and core of everything on this planet."

For a moment they sipped in silence; then Morriss said, "Venus, Lucky, is an expensive world to keep up. Our cities must make oxygen out of water, and that takes huge electrolytic stations. Each city requires tremendous power beams to help support the domes against billions of tons of water. The city of Aphrodite uses as much energy in a year as the entire continent of South America, yet it has only a thousandth the population.

"We've got to earn that energy, naturally. We've got to export to Earth in order to obtain power plants, specialized machinery, atomic fuel, and so on. Venus's only product is seaweed, inexhaustible quantities of it. Some we export as fertilizer, but that is scarcely the answer to the problem. Most of our seaweed, however, we use as culture media for yeast, ten thousand and one varieties of yeast."

Morriss looked soberly at the small Martian and said, "If you wish. Bigman is quite correct in his low opinion of yeast in general. Our most important strains are suitable only for animal food. But even so, it's highly useful. Yeast-fed pork is cheaper and better than any other kind. The yeast is high in calories, proteins, minerals, and vitamins.

"We have other strains of higher quality, which are used in cases where food must be stored over long periods and with little available space. On long space journeys, for instance, so-called Y-rations are frequently taken.

"Finally, we have our top-quality strains, extremely expensive and fragile growths that go into the menus of the Green Room and with which we can imitate or improve upon ordinary food. None of these are in quantity production, but they will be someday. I imagine you see the whole point of all this, Lucky."

"I think I do."

"I don't," said Bigman belligerently.

Morriss was quick to explain. "Venus will have a monopoly on these luxury strains. No other world will possess them. Without Venus's experience in zymoculture.

"In what?" asked Bigman.

"In yeast culture. Without Venus's experience in that, no other world could develop such yeasts or maintain them once they did obtain them. So you see that Venus could build a tremendously profitable trade in yeast strains as luxury items with all the galaxy. That would be important not only to Venus, but to Earth as well- to the entire Solar Confederation. We are the most over-populated system in the Galaxy, being the oldest. If we could exchange a pound of yeast for a ton of grain, things would be well for us."

From LUCKY STARR AND THE OCEANS OF VENUS by Paul French (Isaac Asimov)(1954)

This near the center of Ceres' spin, that wasn't from gravity so much as mass in motion. The air smelled beery with old protein yeast and mushrooms. Local food, so whoever had bounced the girl hard enough to break her bed hadn't paid enough for dinner.

He poured a glass of moss whiskey, a native Ceres liquor made from engineered yeast, then took off his shoes and settled onto the foam bed.

An hour later, his blood warm with drink, he heated up a bowl of real rice and fake beans—yeast and fungus could mimic anything if you had enough whiskey first—opened the door of his hole, and ate dinner looking out at the traffic gently curving by.

Miller took another forkful of fungal beans and vat-grown rice and debated whether to accept connection.

Kate Liu returned to the table with a local beer and a glass of whiskey on her tray. Miller was glad for the distraction. The beer was his. Light and rich and just the faintest bit bitter. An ecology based on yeasts and fermentation meant subtle brews.

From LEVIATHAN WAKES by "James S.A. Corey" (Daniel Abraham and Ty Franck) 2011. First novel of The Expanse

Growing Both

"Aquaponics" is a way of raising both plants and meat in one tank. You use an over-sized deep hydroponic tank to grow the plants. Below the plants you raise fish. The fish are fed food pellets. The hydroponic nutrient media is supplemented by the waste the fish excrete. The plants consume the nutrients, purifying the water and keeping the fish healthy ("rhizofiltration"). The system is more stable than a standard hydroponic rig, since the larger tank will buffer and moderate any changes. The larger volume of water also means you can get away with a more dilute solution of nutrients.

Not just standard fish can be cultivated, the system can also be used for shellfish such as lobsters, shrimp, clams and oysters.

In NASA jargon an aquaculture system is called a "sushi maker".

Recycling Wastes

Wastes have to be fed to the algae, or whatever. But it would be nice to turn the astronaut poop into sterile chemicals first instead of infecting the algae tanks with E. coli bacteria. And the problem of reducing to useable form plant stalks, fish bones, chicken feathers, and other tough scraps. Not to mention all the plastic bag bits.

Enter the Supercritical water oxidation (SCWO) unit.

By placing water at temperatures and pressures above the thermodynamic critical point, it turns into a fluid that combines the worst properties of a blast furnance and sulphuric acid. You feed anything into one of these hellfire-in-a-box thingies and nothing is going to come out the other end except water, oxidized chemicals, and mineral ash. This happens at about 374.1°C and 22.12 Mpa.

The only estimates I've managed to find (Parametric Model of a Lunar Base for Mass and Cost Estimates by Peter Eckart) for a SCWO unit are:

  • Mass: 150 kg per person being supported
  • Expendibles required: 10 kg per person per year
  • Volume: 0.5 m3 per person
  • Power required: 0.36 kilowatts per person
  • Heat load: 0.09 thermal kilowatts per person
  • Liquid waste input: 27.18 kg per person per day
  • Solid waste input: 0.15 kg per person per day

Waste products from the astronaut's septic tanks and tablescraps are run through the SCWO. The appropriate output chemicals are fed to the Spirulina, which multiplies in meters of transparent tubes run under filtered sunlight. Filtered because raw sunlight in outer space is quite deadly to algae, and it isn't too healthy for humans either.

Water is pretty near the universal solvent at room temperature. Heat it to quite high temperatures, under fairly high pressure so that it doesn't boil, and it gets, uh, more so. Dissolve a bit of oxygen in it, and you have a fantastically corrosive witches' brew that will vigorously attack almost anything. Throw in just about any organic substance you care to name, and out comes water, CO2, nitrogen, and sterile ash (oxides of metals, mostly). One of the bigger practical problems, in fact, is making the equipment stand up to it. The other major problem is that it's pretty power-intensive, because of the high temperature and high pressure.

It's pretty much the preferred way to recycle organic wastes — kitchen garbage, human wastes, etc. — in designs for advanced closed-cycle life-support systems.

Henry Spencer

There is more information on SWO units here. The first reference describes a facility with a volume of just over 20 cubic metres that can process 7.5L per minute, more than enough for a crew of 300. (30L/person/day - 20 hours a day). Thanks to William Seney for these link.

General Atomics has some developed some SWO units for waste disposal.

Amino Acids


 Plants are not a particularly efficient source of protein. They tend to be better at producing carbohydrates. As a result, vegetarian diets often focus on a few high-nitrogen plants like beans, soy and peanuts.

 I tend to explore food systems that are familiar, but let's take a minimalist approach and see where it leads. Instead of deriving protein from plant sources directly, what if we use microorganisms to produce amino acids in bioreactors using plant starch as input? This is like that sci-fi staple 'vat meat', but with neither texture nor flavor. Still, amino acids can be stored for years (possibly decades) if powdered and sealed.

As with all my posts, this article is based largely on internet research. I am not a process biologist. I've included sources where possible, but these results should be considered preliminary at best.

Short results: vat-grown amino acids can be yours for 4-6m³ per person.
That includes vats, supporting equipment, hydroponic space and waste treatment.
You will still need to provide bulk calories and other nutrients.

 Let's start with demand. The indispensable amino acids  are tryptophan, threonine, isoleucine, leucine, lysine, methionine, phenylalanine, valine and histidine. Required amounts vary; women typically need the least at about 14g, men in the middle with about 18g and children requiring the most at about 22g. Contrast with protein requirements of 110g, 140g and 90g respectively. These figures are from my menu tracker which is based on US dietary recommendations, so do not take this as specific dietary advice.

 Dietary protein serves two purposes: first as a source of food energy and second as a source of amino acids. If we eat only amino acids then the 'missing' food energy needs to be provided by additional carbohydrates and fats. That also means we only need to eat enough amino acids to satisfy the body's need for building material. The science is not settled, so let's assume we need twice the minimum amount or an average of 36 grams per person per day. Some of this will be provided by other food items but let's ignore any other protein sources for now.

 Production is varied as there are several distinct chemical structures involved in the various amino acids. Each type or family requires a specific environment, feedstocks and process. A basic overview is available on Wikipedia, while a deeper look at processes for the aromatic amino acids is available here. This is just an example; the industry has been active for decades and there is a lot of material available on this technology.
 Plant starches can be readily decomposed into glucose using microbes or enzymes. (see for example the process of making sake; rice is decomposed by a fungus to produce sugar-rich material for yeast to ferment into alcohol.) Sweet potato mash with autolyzed yeast and/or spirulina should be a reasonable starting point for producing a viable nutrient solution.
 The chosen microorganism is grown in a starter culture (1-5l) for half a day and then transferred to a large vat (100-500l) for fermentation over an additional one to three days. For industrial and medical purposes the finished broth is lysed by freezing, vibration or centrifugation and then separated by centrifugation. Further purification steps are applied including filtration and fractional crystallization. For nutritional use this high-grade purification may not be necessary. An example might be alanine as a byproduct of valine production; for an industrial process this would be a contaminant but as a food source it's beneficial. In this case a single-step centrifugation/separation can be applied with the result tested for composition and then dried without further processing.

Yields listed below are lab results, specified in units of product per unit of glucose. Nonessential amino acids are in italics. Many of these values leave significant room for improvement.
There is also a note in the book "Corynebacterium glutamicum: Biology and Biotechnology"  (edited by Nami Tatsumi, Masayuki Inui) on page 111 giving a snapshot look at yields of industrial C. Glutamicum fermentation processes. These values are weight percent, given in {} brackets below; as you can see, most products scale up well but a few do not.

Glutamate - {50%}
Glutamine -  {40%}
Proline - 36% g/g
Arginine - 35% g/g

Aromatic amino acids
Phenylalanine - 25% g/g {50%}
Tyrosine - 30% g/g
Tryptophan - 14% mol/mol {22%}

Lysine - 42% mol/mol {50%}
Asparagine - unknown
Methionine - 20% {17%}
Threonine - 60% {45%}
Isoleucine - 22% {25%}

Ribose 5-phosphate
Histidine - 5.5%

Serine - 45% g/g {32%}
Glycine - unknown
Cysteine - unknown

Alanine - 86% g/g {50%}
Valine - 88% mol/mol {35%}
Leucine - 30% mol/mol

A ballpark value for the overall average yield is perhaps 40% by weight, requiring 90 grams of glucose per person per day.

 Final concentrations average around 20g per liter, with some exceptions (histidine in particular is perhaps 5g/l while some others are over 45g/l). That works out to 8g/l/day or 4.5l per person. Let's double that volume again (for redundancy) and call it about ten liters of bioreactor volume per person. Space is required for starter cultures, nutrient processing and storage; let's assume this supporting volume (and wasted space due to packing issues) is twice that of the vats and call it 30 liters of volume per person. At a thousand liters per cubic meter, 1m³ could serve a bit over 30 people.

Let's go over the drawbacks:

 - The bioreactors have to be controlled (pH, temperature, glucose, nitrogen, oxygen, agitation), which requires energy. Information on power requirements are difficult to find, so I can't offer even a bad guess. This also means some smart tech is required for automation.
 - Product yield is less than 1% of the final broth, so assume that the entire volume has to be treated as wastewater. About 5 liters per person per day.
 - As a biological process, cleanliness is essential. Quantities of soap, alcohol or bleach and washwater will be required.
 - Population control is important. Bacteria evolve rapidly and cross-contamination is a possibility. Vats must be monitored for invasive species and unexpected byproducts. Reserve supplies
 - At least nine separate product lines are required. More may be needed to completely replace food protein needs.
 - The nutrient solution has to provide everything needed for the microbes to grow and thrive. This is on par with intensive hydroponics for complexity.
 - Centrifuges are tricky in microgravity. Angular motion needs to be carefully balanced, so vats should always be counter-spun in mass-matched pairs.
 - The system requires carbohydrates as inputs. These in turn require production of enzymes to break the starch into glucose.
 - Amino acid powders are not particularly appetizing.

These are largely the same drawbacks that apply for alcohol production and can easily be integrated into that workflow. Nutrient supply can be integrated with the hydroponics workflow. Wastewater can be handled largely by evaporation or ultrafiltration (though centrifugation should yield concentrated sludge and fairly clean water as separate outputs), with concentrated wastes blasted in the SCWO reactor and recovered by spirulina. Carbohydrate supply can be provided by either sweet potato (24.0g/m²/day) or wheat (18.5g/m³/day), requiring 3.8 to 4.9 m³ per person. These inputs would co-produce edible protein extracts amounting to 8.6g or 16.5g respectively. Not much can be done for the taste other than combining with protein extracts or other food ingredients, unfortunately; perhaps that will change with applied research.

Here are the advantages:

 - No animals.
 - Simple waste streams.
 - Extremely compact.
 - The tools and techniques can be applied to other biosynthesis products such as ethanol and other industrial feedstocks as well as a broad variety of medicinal compounds.
 - The techniques for producing the necessary inputs are largely the same as for intensive hydroponics.
 - A variety of techniques are available for continual improvement, including selective breeding, directed mutation and outright genetic engineering. Microbial gene editing (such as with CRISPR) allows earth-based developments to be applied to in-space organisms by sending only data.
 - The process can be scaled easily for populations from one to a thousand or more.
 - All of the technology can be built, tested and optimized on Earth. A round of low-gravity performance testing and some engineering sweetness to handle periods of microgravity would be a good idea before deployment but not strictly necessary for use on a spinning habitat.

I still believe it would be beneficial to use all plant wastes as feed for insects, fish and possibly chickens. This represents recapture of energy that would otherwise have gone to waste into food products for variety. Even so, a vat process could be paired with suitable hydroponics for complete nutrition with high efficiency. Sweet potato greens are edible, so a menu could be devised that minimizes plant waste. A steady diet of sweet potatoes, salad and amino acid seasoning doesn't sound very appealing to me but it might be among the earliest self-sufficient space food systems.

Human Factors

The space environment is so inconvenient for human beings. There is so much that one has to bring along to keep them alive.

Life Support has to supply each crew member daily with 0.0576 kilograms of air, about 0.98 kilograms of water, and about 2.3 kilograms of (wet) food (less if you are recycling). Some kind of artificial gravity or a medical way to keep the bones and muscles from wasting away. Protection from the deadly radiation from solar storms and the ship's power plant and propulsion system. Protection from the temperature extremes in the space environment. Protection from acceleration. Medical support. And then there are the psychological factors.

Recently John Lumpkin and I were allowed the rare privilege of submitting questions to NASA astronaut Captain Stephen G. Bowen a couple of questions about life in the space environment.

Me: My main interest are those details about living in a space environment that are "surprising", that is, not intuitively obvious to us earth-bound folk.

Captain Bowen: The most surprising thing is how quickly you adapt to being in the microgravity environment. In addition to floating around the rest of the body adapts pretty quickly (after about 4 days all systems are good). The fluid shift resolves and you lose the puffy face in week. The ISS crewmembers say at about the 6 week point it feels normal to live in space (consequently it takes 6 weeks before earth feels normal). Other than that it takes a while to realize that you can't just put things down and instead of looking down for things you lose you have to look all around.

John Lumpkin: I guess I'd be curious about the little things of life in freefall. Stuff he has to get used to in terms of eating, sleeping, changing clothes, moving around, and so on. Is it easy to hit your head on things? To fly into other people? What are some things that work on Earth but don't in freefall ... Particularly things most people might not think of? This sort of thing makes nice color for antigrav-free science fiction stories.

Captain Bowen: One of the interesting things once you do get adjusted in space is how you think you know how to float and translate. On the Shuttle your never very far from anything so you get really good in a couple days. Once you dock to the ISS however, it is huge. You quickly realize that your not that good and it takes a while to get good at translating 40 feet or so without bumping off the walls (experiments, cables etc...) with different body parts (feet, head, back...) Additionally you can actually try and get yourself into a position where you are stationary and can't reach anything -that is an interesting feeling since swimming in air to get someplace is very inefficient. Other interesting things - you can eat your tea with chopsticks, you can sleep in any configuration, and since dust and debris don't fall it all collects on the intakes of the fans (for the most part but it is odd to watch such things just floating about). One night the ISS bell floated down from the ISS to the middeck of the Shuttle (right past me) without anyone noticing till we woke up the next morning.

John Lumpkin: The Russian/Chinese philosophy on spacecraft design is to make the re-entry capsule small, allowing for less of the total launch mass to be devoted to re-entry protection. This frees up mass for use in the non-re-entering work module, allowing greater capability there. The US philosophy, for both Apollo and Orion, is to put the entire crew area within the re-entry capsule. I understand the advantages to the Russian/Chinese approach -- what compelling advantages are there to the US approach?

Captain Bowen: I've not been a part of the design work. My one input was to get rid of windows. Both Apollo and Orion while more spacious are actually not designed for long term living. Apollo had the additional space once the Lunar module was attached and Orion will have a docked module launched separately for transit to the Moon. For shorter missions (such as going to the ISS) you won't need the extra space. Orion is really sized for launch and reentry of 6 suited astronauts with a specific blunt body shape. We also don't have the same size restrictions the others have for astronauts. Everything else is squeezed around the seats, and for the moon the crew size is reduced to provide more room. I really haven't thought about the size relative to Soyuz other than Soyuz is really tight.

John Lumpkin: How hot can you make that coffee in a microgravity environment? How hot is the food? Do you sleep better (microgravity) or worse (noise) in orbit? How much time do you spend on maintenance? How well do international partners get along in space? Do the people in space get along better than the two ground stations (US and Russia)?

Captain Bowen: The pressure on the ISS and Shuttle are 14.7 just like here. Although the Hubble mission will be at 10.2 for its entire mission for EVA reasons. The hot water does get really hot. The convection oven is pretty hot as well. I averaged about an hour more sleep on orbit than on earth. We all get along really well. The ISS crews train for years with their crewmates and we've all worked with them as well. Some of the ESA and JAXA and CSA astronauts are permanently stationed in Houston. The Cosmonauts we see in Russia and occasionally as they pass through Houston. Yes I think we get along better in space - but then again we know each other better than the ground teams do.

Acceleration Protection

The bottom line seems to be the acceleration should be limited to 4g or less if you want the astronauts capable of using their hands on controls, and limit it to 17g while sitting down or 30g while lying flat to prevent serious injury to the astronauts. But only for less than 10 minutes or so, see graph below for details. This is usually not a problem unless you are dealing with a torchship. Conventional spacecraft cannot accelerate at that rate for much longer than 10 minutes before their propellant tanks run dry.

Acceleration Positions
Transverse forces supine+GxLying on your backEye Balls InRecommended high acceleration position
Transverse forces prone-GxLying face downEye Balls OutSecond-best high acceleration position
Positive longitudinal+GzSitting with head above heartEye Balls UpThird-best high acceleration position
Negative longitudinal-GzStanding on your headEye Balls DownReally stupid

The relative position or orientation of the subject is of prime importance in determining tolerable levels of gravitational or acceleration force, or "g force.' As the g force is gradually increased, certain effects are observed.

Figure 5 shows the time-tolerance relationships for positive longitudinal forces and for transverse forces (either prone or supine, prone being the position of lying face down and supine being the position of lying on one's back).

For the transverse position, human subjects in Germany during World War II were subjected to 17 g's for as long as 4 minutes reportedly with no harmful effects and no loss of consciousness. The curves indicated for very long periods of time are extrapolations and are speculative, since no data are available on long-term effects. Col. John Stapp, Air Force Missile Development Center, has investigated extreme g loadings, up to 45 g's, sustained for fractions of a second; These are the kind of accelerations or decelerations that would be experienced in crash landings. For these brief high g loadings, the rate of change of g exceeds 500 g's per second.

As a matter of interest, the beaded line on the figure indicates the approximate accelerations that would be experienced by a man in a vehicle designed to reach escape velocity with three stages of chemical burning, each stage having a similar load-factor-time pattern. This curve enters the critical region for positive g's. Most individuals would probably black out and some would become unconscious. However, for individuals in the transverse position, this acceleration could be tolerated and the individual would not lose consciousness.

Gross effects of
acceleration forces
Earth normal (32.2 feet/second)1
Hands and feet heavy;
walking and climbing difficult
Walking and climbing impossible;
crawling difficult; soft tissues sag
Movement only with great effort;
crawling almost impossible
Only slight movements of arms
and head possible
Longitudinal g's, short duration
(blood forced from head toward feet):
Visual symptoms appear2.5 - 7.0
Blackout3.5 - 8.0
loss of consciousness
4.0 - 8.5
Structural damage,
especially to spine
18 - 23
Transverse g's, short duration
(head and heart at same hydrostatic level):
No visual symptoms or
loss of consciousness
0 - 17
Tolerated28 - 30
Structural damage may occur> 30 - 45

a. Upward Acceleration Effects (+ Gz) (In Seated Posture)

1 Gz
Equivalent to the erect or seated terrestrial posture
2 Gz
Increased weight; increased pressure on buttocks; drooping of face and body tissue
2.5 Gz
Difficult to raise oneself
3 - 4 Gz
Impossible to raise oneself; difficult to raise arms and legs; movement at right angles impossible; progressive dimming of vision after 3-4 seconds; progressive tunneling of vision
4.5 - 6 Gz
Diminution of vision; progressive blackout after about 5 seconds; hearing and then consciousness lost if exposure continued; mild to severe convulsions in about 50% of the subjects during or following unconsciousness, frequently with bizarre dreams; occasionally paresthesias, confused states, and rarely, gustatory sensations; no incontinence; pain not common, but tension and congestion of lower limbs with cramps and tingling; inspiration difficult; loss of orientation of time and space for up to 15 seconds post-acceleration

b. Downward Acceleration Effects (- Gz) (Standing On Head )

-1 Gz
Unpleasant, but tolerable, facial suffusion and congestion
-2 to -3 Gz
Severe facial congestion; throbbing headache; ori-gressive blurring, , or graying, or occasionally reddening of vision after 5 seconds; congestion disappears slowly; may leave petechial hemorrhages, edematous eye-lids
-5 Gz
Five seconds is limit of tolerance rarely reached by most subjects

c. Forward Acceleration Effects (+ Gx) (Lying On Back)

2 - 3 Gx
Increased weight and abdominal pressure; progressive slight difficulty in focusing and slight spatial disorientation, each subsiding with experience; 2 Gx tolerable for at least 24 hours; 4 Gx tolerable up to at least 60 minutes
3 - 6 Gx
Progressive tightness in chest, chest pain; loss of peripheral vision; difficulty in breathing and speaking; blurring of vision, effort required to maintain focus
6 - 9 Gx
Increased chest pain and pressure; breathing difficult, shallow respiration from position of nearly full inspiration; further reduction in peripheral vision, increased blurring, occasional tunneling, great concentration required to maintain focus; occasional lacrimation; body, legs, and arms cannot be lifted at 8 Gx; head cannot be lifted at 9 Gx
9 - 12 Gx
Breathing difficulty severe, increased chest pain, marked fatigue, loss of peripheral vision, diminution of central acuity, lacrimation
15 Gx
Extreme difficulty in breathing and speaking, severe viselike chest pain; loss of tactile sensation, recurrent complete loss of vision

d. Backward Acceleration Effects (- Gx) (Lying Prone)

Similar to those of + Gx acceleration with modifications produced by reversal of the force vector. Chest pressure reversed, hence, breathing is easier; pain and discomfort from outward pressure toward restraint harness manifest at 8-Gx; forward head tilt cerebral hemodynamic effects akin to Gz; feeling of insecurity from pressure against restraint.

Acceleration Couches

Acceleration Tanks

If you have a torchship, and it is going to accelerate at more than one g for longer than a few minutes, the crew is going to need special couches to lie in. Otherwise the g forces will cause severe injury or even kill.

In "Sky Lift" and Double Star, the crew spent the days of high thrust in acceleration couches that were like advanced waterbeds (called "cider presses"). In The Mote in God's Eye by Larry Niven and Jerry Pournelle, the captain's chair had a built-in "relief tube" (i.e., a rudimentary urinal) for use during prolonged periods of multi-g acceleration. There were also a few motorized acceleration couches used by damage control parties who had to move around during high gs. Such mobile couches also appeared in Joe Haldeman's The Forever War.


He called Bury instead.

Bury was in the gee bath: a film of highly elastic mylar over liquid. Only his face and hands showed above the curved surface. His face looked old—it almost showed his true age.

"Yes, of course, I didn't mean personally. I only want access to information on our progress. At my age I dare not move from this rubber bathtub for the duration of our voyage. How long will we be under four gees?"

"One hundred and twenty-five hours. One twenty-four, now."

He called Sally's cabin.

She looked as if she hadn't slept in a week or smiled in years. Blaine said, "Hello, Sally. Sorry you came?"

"I told you I can take anything you can take," Sally said calmly. She gripped the arms of her chair and stood up. She let go and spread her arms to show how capable she was.

"Be careful," Blaine said, trying to keep his voice steady. "No sudden moves. Keep your knees straight. You can break your back just sitting down. Now stay erect, but reach behind you. Get both the chair arms in your hands before you try to bend at the waist—"

She didn't believe it was dangerous, not until she started to sit down. Then the muscles in her arms knotted, panic flared in her eyes, and she sat much too abruptly, as if MacArthur's gravity had sucked her down.

"Are you hurt?"

"No," she said. "Only my pride."

"Then you stay in that chair, damn your eyes! Do you see me standing up? You do not. And you won't!"

"All right." She turned her head from side to side. She was obviously dizzy from the jolt.

From THE MOTE IN GOD'S EYE by Larry Niven and Jerry Pournelle

“How high, sir?”

Berrio hesitated. “Three and one-half gravities.”

Three and a half g’s! That wasn’t a boost — that was a pullout. Joe heard the surgeon protest, “I’m sorry, sir, but three gravities is all I can approve.”

Berrio frowned. “Legally, it’s up to the captain. But three hundred lives depend on it.”

Kleuger said, “Doctor, let’s see that curve.” The surgeon slid a paper across the desk; Kleuger moved it so that Joe could see it. “Here’s the scoop, Appleby—”

A curve started high, dropped very slowly, made a sudden “knee” and dropped rapidly. The surgeon put his finger on the “knee.” “Here,” he said soberly, “is where the donors are suffering from loss of blood as much as the patients. After that it’s hopeless, without a new source of blood.”

“How did you get this curve?” Joe asked.

“It’s the empirical equation of Larkin’s disease applied to two hundred eighty-nine people.”

Appleby noted vertical lines each marked with an acceleration and a time. Far to the right was one marked: “1 g—18 days” That was the standard trip; it would arrive after the epidemic had burned out. Two gravities cut it to twelve days seventeen hours; even so, half the colony would be dead. Three g’s was better but still bad. He could see why the Commodore wanted them to risk three-and-a-half kicks; that line touched the “knee,” at nine days fifteen hours. That way they could save almost everybody, but, oh, brother!

The time advantage dropped off by inverse squares. Eighteen days required one gravity, so nine days took four, while four-and-a-half days required a fantastic sixteen gravities. But someone had drawn a line at “16 g—4.5 days.” “Hey! This plot must be for a robot-torch — that’s the ticket! Is there one available?”

Berrio said gently, “Yes. But what are its chances?”

Joe shut up. Even between the inner planets robots often went astray. In four-billion-odd miles the chance that one could hit close enough to be caught by radio control was slim. “We’ll try,” Berrio promised. “If it succeeds, I’ll call you at once.” He looked at Kleuger. “Captain, time is short. I must have your decision.”

Kleuger turned to the surgeon. “Doctor, why not another half gravity? I recall a report on a chimpanzee who was centrifuged at high g for an amazingly long time.”

“A chimpanzee is not a man.”

Joe blurted out, “How much did this chimp stand, Surgeon?”

“Three and a quarter gravities for twenty-seven days.”

“He did? What shape was he in when the test ended?”

“He wasn’t,” the doctor grunted.

The ship was built for high boost; controls were over the pilots’ tanks, where they could be fingered without lifting a hand. The flight surgeon and an assistant fitted Kleuger into one tank while two medical technicians arranged Joe in his. One of them asked, “Underwear smooth? No wrinkles?”

“I guess.”

“I’ll check.” He did so, then arranged fittings necessary to a man who must remain in one position for days. “The nipple left of your mouth is water; the two on your right are glucose and bouillon.”

“No solids?”

The surgeon turned in the air and answered, “You don’t need any, you won’t want any, and you mustn’t have any. And be careful in swallowing.”

“I’ve boosted before.”

“Sure, sure. But be careful.”

Each tank was like an oversized bathtub filled with a liquid denser than water. The top was covered by a rubbery sheet, gasketed at the edges; during boost each man would float with the sheet conforming to his body. The Salamander being still in free orbit, everything was weightless and the sheet now served to keep the fluid from floating out. The attendants centered Appleby against the sheet and fastened him with sticky tape, then placed his own acceleration collar, tailored to him, behind his head.

The room had no ports and needed none. The area in front of Joe’s face was filled with screens, instruments, radar, and data displays; near his forehead was his eyepiece for the coelostat. A light blinked green as the passenger tube broke its anchors; Kleuger caught Joe’s eye in a mirror mounted opposite them. “Report, Mister.”

“Minus seven’ minutes oh four. Tracking. Torch warm and idle. Green for light-off.”

“Stand by while I check orientation.” Kleuger’s eyes disappeared into his coelostat eyepiece.

When the counter flashed the last thirty seconds he forgot his foregone leave. The lust to travel possessed him. To go, no matter where, anywhere go! He smiled as the torch lit off.

Then weight hit him.

At three and one-half gravities he weighed six hundred and thirty pounds. It felt as if a load of sand had landed on him, squeezing his chest, making him helpless, forcing his head against his collar. He strove to relax, to let the supporting liquid hold him together. It was all right to tighten up for a pullout, but for a long boost one must relax. He breathed shallowly and slowly; the air was pure oxygen, little lung action was needed. But he labored just to breathe. He could feel his heart struggling to pump blood grown heavy through squeezed vessels. This is awful! he admitted. I’m not sure I can take it. He had once had four g for nine minutes but he had forgotten how bad it was.

Joe then found that he had forgotten, while working, his unbearable weight. It felt worse than ever. His neck ached and he suspected that there was a wrinkle under his left calf. He wiggled in the tank to smooth it, but it made it worse.

He tried to rest — as if a man could when buried under sandbags.

His bones ached and the wrinkle became a nagging nuisance. The pain in his neck got worse; apparently he had wrenched it at light-off. He turned his head, but there were just two positions — bad and worse. Closing his eyes, he attempted to sleep. Ten minutes later he was wider awake than ever, his mind on three things, the lump in his neck, the irritation under his leg, and the squeezing weight.

Look, bud, he told himself, this is a long boost. Take it easy, or adrenalin exhaustion will get you. As the book says, “The ideal pilot is relaxed and unworried. Sanguine in temperament, he never borrows trouble.” Why, you chair-warming so-and-so! Were you at three and a half g’s when you wrote that twaddle?

The integrating accelerograph displayed elapsed time, velocity, and distance, in dead-reckoning for empty space. Under these windows were three more which showed the same by the precomputed tape controlling the torch; by comparing, Joe could tell how results matched predictions. The torch had been lit off for less than seven hours, speed was nearly two million miles per hour and they were over six million miles out. A third display corrected these figures for the Sun’s field, but Joe ignored this; near Earth’s orbit the Sun pulls only one two-thousandth of a gravity — a gnat’s whisker, allowed for in precomputation. Joe merely noted that tape and D.R. agreed; he wanted an outside check.

His ribs hurt, each breath carried the stab of pleurisy. His hands and feet felt “pins-and-needles” from scanty circulation. He wiggled them, which produced crawling sensations and wearied him. So he held still and watched the speed soar. It increased seventy-seven miles per hour every second, more than a quarter million miles per hour every hour. For once he envied rocketship pilots; they took forever to get anywhere but they got there in comfort.

Without the torch, men would never have ventured much past Mars. E = Mc2, mass is energy, and a pound of sand equals fifteen billion horsepower-hours. An atomic rocketship uses but a fraction of one percent of that energy, whereas the new torchers used better than eighty percent. The conversion chamber of a torch was a tiny sun; particles expelled from it approached the speed of light.

“Oh, there’s one thing I don’t understand, uh, what I don’t understand is, uh, this: why do I have to go, uh, to the geriatrics clinic at Luna City? That’s for old people, uh? That’s what I’ve always understood — the way I understand it. Sir?”

The surgeon cut in, “I told you, Joe. They have the very best physiotherapy. We got special permission for you.”

Joe looked perplexed. “Is that right, sir? I feel funny, going to an old folks’, uh, hospital?”

“That’s right, son.”

Joe grinned sheepishly. “Okay, sir, uh, if you say so.”

They started to leave. “Doctor — stay a moment. Messenger, help Mr. Appleby.”

“Joe, can you make it?”

“Uh, sure! My legs are lots better — see?” He went out, leaning on the messenger.

Berrio said, “Doctor, tell me straight: will Joe get well?”

“No, sir.”

“Will he get better?’

“Some, perhaps. Lunar gravity makes it easy to get the most out of what a man has left.”

“But will his mind clear up?”

The doctor hesitated. “It’s this way, sir. Heavy acceleration is a speeded-up aging process. Tissues break down, capillaries rupture, the heart does many times its proper work. And there is hypoxia, from failure to deliver enough oxygen to the brain.”

The Commodore struck his desk an angry blow. The surgeon said gently, “Don’t take it so hard, sir.”

“Damn it, man — think of the way he was. Just a kid, all bounce and vinegar — now look at him! He’s an old man — senile.”

“Look at it this way,” urged the surgeon, “you expended one man, but you saved two hundred and seventy.”

From SKY LIFT by Robert Heinlein (1953)

A hand grabbed my arm, towed me along a narrow passage and into a compartment. Against one bulkhead and flat to it were two bunks, or "cider presses," the bathtub-shaped, hydraulic, pressure-distribution tanks used for high acceleration in torchships. I had never seen one before but we had used quite convincing mock-ups in the space opus The Earth Raiders.

There was a stenciled sign on the bulkhead behind the bunks: WARNING!!! Do Not Take More than Three Gravities without a Gee Suit. By Order of— I rotated slowly out of range of vision before I could finish reading it and someone shoved me into one cider press. Dak and the other men were hurriedly strapping me against it when a horn somewhere near by broke into a horrid hooting. It continued for several seconds, then a voice replaced it: "Red warning! Two gravities! Three minutes! Red warning! Two gravities! Three minutes!" Then the hooting started again.

I looked at him and said wonderingly, "How do you manage to stand up?" Part of my mind, the professional part that works independentiy, was noting how he stood and filing it in a new drawer marked: "How a Man Stands under Two Gravities."

He grinned at me. "Nothing to it. I wear arch supports."


"You can stand up, if you want to. Ordinarily we discourage passengers from getting out of the boost tanks when we are torching at anything over one and a half gees — too much chance that some idiot will fall over his own feet and break a leg. But I once saw a really tough weight-lifter type climb out of the press and walk at five gravities — but he was never good for much afterwards. But two gees is okay — about like carrying another man piggyback."

She did not return. Instead the door was opened by a man who appeared to be inhabiting a giant kiddie stroller. "Howdy there, young fellow!" he boomed out. He was sixtyish, a bit too heavy, and bland; I did not have to see his diploma to be aware that his was a "bedside" manner.

"How do you do, sir?"

"Well enough. Better at lower acceleration." He glanced down at the contrivance he was strapped into. "How do you like my corset-on-wheels? Not stylish, perhaps, but it takes some of the strain off my heart.

At turnover we got that one-gravity rest that Dak had promised. We never were in free fall, not for an instant; instead of putting out the torch, which I gather they hate to do while under way, the ship described what Dak called a 180-degree skew turn. It leaves the ship on boost the whole time and is done rather qulckly, but it has an oddly disturbing effect on the sense of balance. The effect has a name something like Coriolanus. Coriolis?

All I know about spaceships is that the ones that operate from the surface of a planet are true rockets but the voyageurs call them "teakettles" because of the steam jet of water or hydrogen they boost with. They aren't considered real atomic-power ships even though the jet is heated by an atomic pile. The long-jump ships such as the Tom Paine, torchships that is, are (so they tell me) the real thing, making use of F equals MC squared, or is it M equals EC squared? You know — the thing Einstein invented.

Our Moon being an airless planet, a torchship can land on it. But the Tom Paine, being a torchship, was really intended to stay in space and be serviced only at space stations in orbit; she had to be landed in a cradle. I wish I had been awake to see it, for they say that catching an egg on a plate is easy by comparison. Dak was one of the half dozen pilots who could do it.

From DOUBLE STAR by Robert Heinlein, 1956

"Alex, how long?" Holden asked for the third time in ten minutes.

"We're over an hour out. Want to go on the juice?" Alex said.

Going on the juice was pilot-speak for a high-g burn that would knock an unmedicated human unconscious. The juice was the cocktail of drugs the pilot's chair would inject into him to keep him conscious, alert, and hopefully stroke-free when his body weighed five hundred kilos. Holden had used the juice on multiple occasions in the navy, and coming down afterward was unpleasant.

"Not unless we have to," he said.

(ed note: if the apparent body weight is 500 kg, I figure the acceleration is on the order of seven gees.)

From LEVIATHAN WAKES from The Expanse by "James S.A. Corey" 2011.

Flush with the bottom deck were two acceleration couches like a pair of waiting sarcophagi, arranged almost as a "V," heads quite close together about half a metre in from the entrance hatchway, feet further apart. There was a strip of the padded deck between the two couches down to mid-thigh level, then they were seperated by an intrusive part of the solid structure that kept the crew module from collapsing at maximum gee. The flight centre was a split space, a tomb for twins, featureless except for the human shaped deep indentation in each couch, and a pair of fiat and silvery screens in the slightly sloped ceiling an arm's reach above. There were no littering control interfaces, no running readouts.

There was a handle under the upper hatch rim. When pulling gee you went in feet first and then pushed yourself legs extended into the waiting couch. In free fall it was easier—you swung in feet first and steered yourself straight down the narrow slot that belonged to you. Sandra went in first, sliding to the right. The lighting came on, triggered by Nightrider.

She dug her heels into the couch recesses before letting go of the handle inside the hatch, then with ankles gripped by the couch, she had enough purchase to slide her hands into the arm troughs and wriggle neatly into place. Getting into the couch was one of the few things that was easier when pulling gee—getting out was easier in tree fall. You fitted perfectly into the couch, flush with the padded floor. Its quilted material completely covered over your arms and legs, lapped round your sides, cupped your head so that you could only hear through the built-in earphones. Nothing pressed against you, it was like floating in a dry fluid, but the couch held you. It was essentially a water bed, an immersion tank. A layer of water a mere centimetre thick circulated around you, kept you hovering sweetly between cool and warm. The water layer could have been a millimetre thick if it wasn't for the risk of localized pinching of the immersion film because of a creased overall or a tensed elbow. Afloat was afloat. And afloat meant immunity to Nightrider's maximum ten gee.

At 10g acceleration the weight of nine additional breast­bones pressed upon your breastbones, an almost unnoticeable load. But ten times your Earth weight—your evolutionary designed weight—crushed your spine and pelvis into whatever you lay on, tugged your cheeks into your ears, clamped your tongue asphyxiatingly against the back of your throat, stressed your ribs almost until they snapped. If you were lightly muscled from your bone strength, and above all cardiac fit, then it probably wouldn't kill you unless sustained for too long, but you would pass out, which would make you useless. But immersed in a bed of incompressible fluid like water, be it only a suspending centimetre layer, the weight on your back was turned into evenly distributed pressure over your whole body. And because the human body, apart from a few air spaces, is essentially a water volume, then despite a weight gradient form breastbone and abdominal muscle to spine, the internal pressure was evenly distributed. The physical distress was largely cancelled out, you functioned the way you should.

Arms enclosed in the couch, Sandra slipped her fingers into the concealed gloves and touched the key pads, one for each hand. Each pad had five keys, you talked into it by pressing with fingers and thumb in varying patterns. All five at once meant "activate" and "space." You could talk with the left hand, with the right hand, or allegedly with both at once, holding two distinct conversations with the computers. She had yet to meet someone who had been proved to be able to do that.

She swung her arms a little out to the side, the only movement accommodated by the couch, and found the joy-stick trigger grip on the left, the attitude ball control on the right. Those were the controls for manual manoeuvring, and they would never be used. Normally you just lay there and told Nightrider what to do. Otherwise you talked instructions into a key pad and then let the computation run the manoeuver...

From NIGHTRIDER by David Mace (1985)

(ed note: this is pretty much handwavium, but interesting idea)

The acceleration shells were something new, installed while we rested and resupplied at Stargate. They enabled us to use the ship at closer to its theoretical efficiency, the tachyon drive boosting it to as much as 25 gravities...

...The medic came by and gave me my shot. I waited until 1950 and hollered to the squad, "Let's go. Strip down and zip up."

The shell is like a flexible spacesuit; at least the fittings on the inside are pretty similar. But instead of a life support package, there's a hose going into the top of the helmet and two coming out of the heels, as well as two relief tubes per suit. They're crammed in shoulder-to-shoulder on light acceleration couches; getting to your shell is like picking your way through a giant plate of olive drab spaghetti.

When the lights in my helmet showed that everybody was suited up, I pushed the button that flooded the room. No way to see, of course, but I could imagine the pale blue solution—ethylene glycol and something else—foaming up around and over us. The suit material, cool and dry, collapsed in to touch my skin at every point. I knew that my internal body pressure was increasing rapidly to match the increasing fluid pressure outside. That's what the shot was for; keep your cells from getting squished between the devil and the deep blue sea. You could still feel it, though. By the time my meter said "2" (external pressure equivalent to a column of water two nautical miles deep), I felt that I was at the same time being crushed and bloated. By 2005 it was at 2.7 and holding steady. When the maneuvers began at 2010, you couldn't feel the difference. I thought I saw the needle fluctuate a tiny bit, though.

The major drawback to the system is that, of course, anybody caught outside of his shell when the Anniversary hit 25 g's would be just so much strawberry jam. So the guiding and the fighting have to be done by the ship's tactical computer—which does most of it anyway, but it's nice to have a human overseer.

Another small problem is that if the ship gets damaged and the pressure drops, you'll explode like a dropped melon. If it's the internal pressure, you get crushed to death in a microsecond.

And it takes ten minutes, more or less, to get depressurized and another two or three to get untangled and dressed. So it's not exactly something you can hop out of and come up fighting.

From THE FOREVER WAR by Joe Haldeman (1975)

Suspended Animation

The ability to put crew members to sleep for months at a time would be an awfully convenient thing to have. Such crew members would use air and food at a much reduced rate and would not be prey to interplanetary cabin fever or space cafard.

Hibernation or "cold-sleep" would mimic what bears and squirrels do in the winter. The crewmember would sleep and breath slowly. Food would be administered by an intravenous pump or the body's internal fat could be used. The crew member still ages, abet at a slighly slower rate.

Suspended animation, cryo-freeze, or cryogenic suspension is more extreme. The crewmember is frozen solid in liquid nitrogen. They do not breath, eat, nor age. Special techniques must be used to prevent the ice in the body's cells from freezing into tiny jagged knives shredding the organs. This is naturally more dangerous than mere hibernation. It is generally used for slower-than-light interstellar exploration, or to put a crewmember with an acute medical condition into stasis if the ship cannot arrive at a hospital for some months.

Hibernation was shown in the movies Alien, Doppelgänger, 2001 A Space Odyssey, and 2010: The Year We Make Contact.

In Doppelgänger the astronauts spent the three week trip plugged into a "Heart Lung Kidney" machine via veins in their wrists. This kept them oxygenated, fed, and sedated into a deep sleep for the entire trip.

In William Tedford's Silent Galaxy, interplanetary fighter pilots would sometimes find themselves out of fuel and on trajectories that would take years to return to a spot where they could be rescued. They would use hibernation to stretch their consumables and to sleep the time away.

Poul Anderson noted that there is probably a limit to how long a human will remain viable in cryogenic suspension (in other words they have a shelf-life). Naturally occuring radioactive atoms in the body will cause damage. In a non-suspended person such damage is repaired, but in a suspended person it just accumulates. He's talking about this damage happening over suspensions lasting several hundred years, during interstellar trips. This may require one to periodically thaw out crew members and keep them awake for long enough to heal the damage before re-freezing them.

Hibernation and suspension is often encountered in SF novels where large numbers of people have to be shipped, e.g., troop carriers, slave ships, and undesirable persons shipped off as involuntary colonists to some miserable planetary colony. Some passenger liners will have accomodations of First-class, Second-class, and Freeze-class (instead of Steerage). There is often a chance of mortality associated with hibernation and suspension. In some of the crasser passenger ships there will sometimes be a betting pool, placing bets on the number of freeze-class passengers who don't make it.


He took out the little syringe, already loaded with the carefully prepared solution. Narcosamine had been discovered during research into animal hibernation: it was not true to say -- as was popularly believed -- that it produced suspended animation. All it caused was a great slowing-down of the vital processes, though metabolism still continued at a reduced level. It was as if one had banked up the fires of life, so that they smoldered underground. But when, after weeks or months, the effect of the drug wore off, they would burst out again and the sleeper would revive. Narcosamine was perfectly safe. Nature had used it for a million years to protect many of her children from the foodless winter.

From CHILDHOODS END by Sir Arthur C. Clarke

Space Torpor

SpaceWorks Engineering is working on a cold-sleep system for a NASA mission to Mars. You can read their report here. This is for a cold-sleep/hibernation system, since we are no where near knowing how to do full suspended animation.

Having the astronauts pass the journey in cold-sleep has many benefits, but the most remarkable one is the huge payload mass savings. In the table below, the habitat module from the NASA Mars Design Reference Architecture (DRA) 5.0 study is compared to the same module using cold-sleep technology. The mass savings is a whopping 52% !

Mass Comparison
Torpor Hab
Environ Control
Life Support
Thermal Management1,210750-38%
Power System6,2403,420-45%
EVA Systems840840-
Mass Growth
Allowance (30%)
Total Transit
Habitat Mass
(Return+Outbound Trip)
Consumables Mass
TOTAL MASS IN LEO41,33019,860-52%

The report lists the following benefits:

  • Reduction in required amount of consumables
  • Reduction in required pressurized living space volume
  • Elimination of many ancillary crew accommodations (galley, kitchen, exercise equipment, entertainment, etc.)
  • Reduction of psychological challenges for crew

And the Hab Module mass savings can be used to increase payload, increase delta V, expand launch windows and mission options, increase radiation shielding, reduce the number of heavy-lift launches, reduce number of on-orbit assembly operations, increase subsystem mass margins (to improve redundancy, reliability, and safety).

The report focuses on Therapeutic Hypothermia (temperature-based hibernation) as the method of choice to induce cold-sleep. Mostly because it has actually been used medically to treat ailments such as cardiac arrest, ischemic stroke, traumatic brain injury, etc. Chemical/Drug-based (hydrogen sulfide or activating adenosine receptors) and Brain Synaptic-based hibernation are much less mature technologies. The report assumes that therapeutic hypothermia can be advanced to the point where the astronaut's metabolism can be reduced from normal to somewhere between moderate and significant reduction (but not to actual total metabolic stoppage), for periods of many months. Black bears and some rodents can do it, so we know it is possible.

Cooling mechanisms:

  • Invasive: cooled intravenous fluids, e.g., CoolGard 3000Rtm with IcyT catheter by ZOLL Medical
  • Non-invasive: evaporative gases in the nasal and oral cavity, e.g., RhinoChill Systemtm
  • Passive: conductive cooling (and rewarming) with gel pads placed on the body, e.g., KOALA Systemtm

All three methods are low mass, low power, and easily automated.

The astronauts will be fed by Total Parenteral Nutrition (TPN), which means fed intravenously. The nutrient fluid is a mixture containing lipids, amino acids, dextrose, electrolytes, vitamins, and trace elements; all the essential nutrients needed for a human body to function.

  • Delivered via a tunneled central venous catheter or a peripherally inserted central catheter (PICC)
  • Administered through pump or gravity IV, usually given at around 50 ml per hour with supplemental maintenance fluids.
  • Bypasses the usual process of eating and digestion; digestive tract is inactive.

There are some medical challenges to solve, such as blood clotting, bleeding, infection, electrolyte imbalances, fatty liver, liver failure, bone demineralization, hypo/hyper glycemia, bile stasis, and others. The chosen method must have little or no long-term effects, no effects on crew functional abilities, and there should be some protocol for an accelerated warming/wakeup in case of emergencies

Old Astronaut Syndrome

There are some maladies that afflict people who spend prolonged periods in microgravity, exposed to space radiation, and exposed to radiation from nuclear propulsion. These could be characteristic signs of space traveling old-timers.

Maladies from Microgravity

The most obvious effect of microgravity is the astronaut's muscles atrophy and the shedding of calcium by their bones (1% to 1.5% per month, like osteoporosis). Being weak with brittle bones isn't lethal but presumably the astronauts at some point want to return home to Terra and still be able to walk. Science fiction literature is full of mandatory exercise to combat this, with "exercise credits" awarded for time spent under acceleration and in centrifuges. NASA astronauts on the International Space Station have to exercise two hours a day for this reason. Some astronauts (or colonists of low gravity planets and moons) might require man-amplifier prosthetics in order to walk under a full Terran gravity.

Naturally such space osteoporosis can lead to kidney stones, the agony of which is the closest a male will ever come to the sensation of giving birth. Space osteoporosis can also be combated by exercise.

Astronaut's eyes are especially vulnerable. Recently NASA made the horrible discovery that exposure to microgravity for six months or longer causes permanent damage to the eyes, similar to idiopathic intercranial hypertension. There is some evidence that this is due to enzyme polymorphisms that increases astronaut vulnerability to bodily fluid shift in free fall.

Astronauts may appear to be older than they actually are, because microgravity accelerates aging.

And a science fictional favorite is the microgravity adapted astronaut who when on Terra has a tendency to let go of glasses of water in mid air, expecting them to float.

Maladies from Radiation

The two main effects of radiation on an astronaut are [1] cancer and [2] death by radiation sickness. You are unlikely to encounter an old astronaut suffering from [2] unless you like to visit graveyards. But the probability is high that most old astronauts will have undergone treatment for cancer at one time or another. Probably several times. NASA tries to avoid this by ensuring that there are no old astronauts. NASA has strict career limits on astronaut radiation exposure.

Secondary effects of radiation are skin ulceration and blindness due to cataracts scarring. High-mass, high-charged (HZE) cosmic rays might accelerate the development of Alzheimer's disease. Radiation also lowers the immune system (chromosomal aberrations in lymphocytes), but it can recover.

Atomic rocketeers on board an atomic rocket will also without fail have a package of potassium iodide tablets on their persons at all times. Why? If the reactor core is breached, the mildly radioactive fuel and the intensely radioactive fission fragments will be released into the atmosphere. While none of the fission fragment elements are particularly healthy, Iodine-131 is particularly nasty. This is because ones thyroid gland does its level best to soak up iodine, radioactive or not. Thyroid cancer or a hoarse voice from thyroid surgery might be common among atomic rocket old-timers. The tablets prevent this by filling up the thyroid first, before the Iodine-131 arrives. The instant the reactor breach alarm sounds, whip out your potassium iodide tablets and swallow one.

Miscellaneous other Maladies

Astronauts who eat more than fifty grams per day of spirulina algae from your closed ecological life support system run the risk of developing gout. That could be Old Poor Astronaut Syndrome.

Old astronauts might have deformed fingernails due to space suit gloves.

Old astronauts might tend to become alarmed when they feel a breeze. To an astronaut, moving air means you have a hull breech.

Old astronauts might be anal-retentive about having every object either in its holder or tied down. In a spacecraft, unexpected acceleration converts any free-floating object into a deadly missile.


     When the first interplanetary war broke out in 2178, we didn't call it what the history books do now. The Interplanetary Civil War (Terran name) and The War of Martian Interdependence (Mars' preference) were latter fictions to gloss over the root of the conflict.
     No, we called that war, The Ogg-Nat War—or Nat-Ogg, depending on your side.

     The first extra-Terran colonists were volunteers. They had to be. The mid-21st Century brought freefall and shallow gravity wells to hundreds, then thousands, of colonists serving double duty as test subjects on the human body's response to low gravity. And natural selection demanded its due.
     Roughly 80% of humans who permanently settled on the Moon or Mars, fell seriously ill within 20 years of arrival. Theoretically, we could've treated many of the ailments, but stem cells and genetic repairs had their limits. Some of the more serious conditions could only be treated on Earth, which could itself prove fatal. The remaining healthy 20% were forced by circumstance to either break backs to support the colony, or let their fellow colonists—colleagues, friends, spouses—die on a strange world.
     If you ever wondered how "malapert" became synonymous with "disaster" or "massacre," look at a map of the Moon's south pole, and look for the tallest peak. There you'll find the site of the first off-world riot—and a memorial to the 117 people who perished, many of whom were already near death. The riot started with a demand for better health care, and ended with the explosive decompression and collapse of two of the base's four domes.

     Which is why, in 2061, the first Low Gravity Genomic Survey was conducted. We discovered which genes improved survival and quality-of-life when you are no longer Earthbound. By 2080, gene therapy before long-term space travel was as routine as immunizations were for international travelers the century previous—if not nearly as frequent.
     The last unmodified resident of the Moon died in 2093. Jessica Dumas, a survivor of the Malapert Base Riot, was a medic by trade, and a mountain climber by passion. Without those skill sets, she probably would have asphyxiated like the other victims of the dome collapses. Instead she saved her skin—mostly. Burn scars and rosacea plagued her, yet she refused treatment. As she often explained, "I want people to see and understand."
     Dumas became a political activist, her energies focused on improving the health of the off-world colonies. She also popularized "Selenian" as a collective noun for Lunar colonists, as pushback against the derogatory use of "Loony" by Terrans. When she died at age 59 from cancer, she was mourned by three worlds.

     In 2137, the last unmodified Martian, 106-year old Jeferson Schefer, died at Arsia Caverns Hospital. Schefer was also the last living participant in the Low Gravity Genomic Survey—and had 86% of the genes identified as useful to survival off Earth.
     It's often rumored, although easily debunked, that Schefer's genome was the basis for all low-g gene therapies. Some opponents of human genetic modification called Schefer, "Adam Sans Eve." In reality he was a botanist remembered on Mars mostly for cultivating Elysium hazel and other Mars-adapted evergreens. On Earth, however, he's sometimes mentioned along with Henrietta Lacks as an example of unethical medical research, despite Schefer's frequent public defense of the Survey.

     Great care was taken to keep ethics above-board. But that didn't stop accusations from The Light, an ostensibly interfaith conservative think tank, that low-gravity gene therapies were "eugenics." Nor did it help that some of the changes, such as increased brain blood flow to combat hypoxia, tended to make for slightly happier and more imaginative humans.
     If you put a Terran, a Martian, and a Selenian in the same room, you wouldn't notice any glaring differences in overall morphology. Martians and Selenians often had slightly larger heads, due to genes that slow the fusion of cranial sutures during development, to help offset fluid shift. They also tended to slighter, more androgynous builds. Nonetheless, their bodies were well within Terran body norms.

     But personality-wise, there tended to be starker differences.
     Martians and Selenians were... weird. They prefered oblique strategies and independent thinking, but also tended to increased intimacy and bonding. On worlds where survival was tenuous and sustainability a dream, people began to drop the dogmas of Earth life that separated Us from Them. Every person counted in the effort to make these new worlds into homes. Bigots weren't welcome anymore.
     Back on Earth, the climate was becoming more perilous, with flood and famine taking its toll. People were clinging to whatever could give them comfort, including the idea that humanity had sinned by modifying the sacred genetic code and leaving the world we were intended to live and die upon, and that was the true cause of their calamities, rather than the abundance of carbon dioxide.
     Before long, to admit that you had spent any time in space, for any reason, was enough to be labeled an augment and be accused of offending the natural order. Even if you could somehow prove that you were a "natural" human genetically. Even if such a concept truly existed.

(ed note: so in the Ogg-Nat War, the Oggs were the Augmented Martians and Selenians, while the Nats were the Natural Terrans)

"What's you doing up here, Lucky? I thought you were on your way down to LEO Base in the Edison with Ross."

"I was, except I didn't think Ross was in fit shape to drive," Lucky explained.

"What's wrong, Ross?"

The astronaut looked pained. "Had a dizzy spell during preboost checkout, and this redheaded broad, who's a big fan of yours, insisted I come and give you some business."

"Are you still dizzy?"

"A li'l bit." Ross' speech was thick and slurred.

"You didn't bust Rule Three, did you?"

"No, Doc—nothin' alcoholic in the last twenty-four hours. Just like the rule says. Why's everybody think I'm drunk or somethin'? Dammit, gettin' so nobody around here trusts me anymore!"

There was no alcohol on Jackson's breath. "What'd you have at your last meal?"

"Nothin'. Not hungry. Hey, can I use your lav? I gotta take a leak bad." He pushed off in the direction Tom pointed to.

Lucky looked at Tom with concern. "Tom, I've never seen Ross this way before. It wasn't just the dizziness. We all get a little disoriented every once in a while. If it had been just that, I would've boosted with him. But not when he's in this condition."

"I agree with you, Lucky." Tom turned to Jackson as the astronaut floated back from the lavatory. "Ross, do you have an alternate to take your flight?"


"Okay, I'm admitting you to sick bay here for a checkup."

"Hell, Doc, I'm all right! Just give me something for this dizziness and for my upset stomach, and I'll be good as new!"

"You're nauseated? Stomach hurts?"

"Yeah. Don't ground me, Doc! I've never failed my physical!"

"I'm not grounding you, Ross. I want to check you to find out if there's anything wrong with you. If there isn't, you'll get a clean bill from me. Okay?"

"Yeah, okay, but I'm getting damned tired of everybody pickin' on me! Jeez, I've got more time in space than any of you! I'm not gonna run off at the ears and do somethin' that'll kill me or anybody else!"

"I know you're not. Dorothy, let's get urine and blood samples from Ross. And give him ten milligrams of prochlorperazine IM to take care of his nausea and stomach cramps."

Tom left Jackson in Dorothy's watchful care and went to the GALEN terminal. He called up Ross Jackson's medical records.

The former NASA shuttle pilot was forty-seven years old. The record showed he had never varied from the medical norm during his entire flying career with the Air Force, NASA, or, now, SpaceLift, Inc. Tom went back through thirty-one years of medical records to Ross' initial FAA Third Class physical exam as a student pilot. There was nothing in the man's background that would lead Tom to suspect anything abnormal.

Was his problem something that resulted from thousands of hours spent in zero-g—the first symptoms of some syndrome that hit old-timers in space, something that would limit mankind's ability to live in space for long periods?

Tom gave that possibility a low priority. He knew many strange maladies affected human beings. He refused to jump to conclusions until Dave Cabot finished the urine and blood analyses and came up with some concrete data on which to base a diagnosis.

Dave was getting good at body-fluid lab work-ups. He was mastering the new tricks he had had to work out for handling liquids in weightlessness, using surface-tension effects and wetting characteristics to their fullest extent to control the liquids. It took him less than an hour to compile the complete data.

And it didn't make sense to Tom.

There was a slight electrolyte imbalance, but nothing beyond what he saw every day in the analysis of his staff's physiology.

The work-up showed a slight hypoglycemia, which might presage the onset of diabetes mellitus but which was not reflected in the urine sample. Tom had thought about this possibility. Ross was of the age when the disease could manifest itself. But the other symptoms weren't present. And the man said he hadn't eaten recently, which could also explain the low glucose level in the urine sample as well as the low blood-sugar level.

Ross couldn't be suffering from anorexia. By reputation the astronaut was something of a trencherman, and he did have difficulty keeping his body mass under control. Ross showed no tendency toward obesity; he just liked to eat well.

Serum calcium level was 12.1 milligrams per hundred milliliters—high, but not beyond what Torn saw occasionally, usually that was because of calcium resorption in the blood resulting from calcium loss in the bones.

Urine PH normal. Everything within normal range except for the usual suppression of steroids and increases in primary hormone levels associated with orbital living.

"Damn!" he swore under his breath.

Tom keyed the terminal and fed in the blood and urine data. He then typed in the observed symptoms and called for a probable diagnosis.

As usual, GALEN was fast. Almost as quickly as he had hit the RUN key, it flashed its answer across the screen:


"Dorothy, warm up the ECG," Tom called.

Ross revived at this and understood what Tom was talking about. "Oh, no, Doc! Not my heart! I haven't got chest pains! I've got gut pains."

"Don't worry, it's not your heart, but I have to check your ECG to confirm a diagnosis," Tom tried to reassure him.

In less than five minutes, Tom had the answer.

"There it is: shortened Q-T interval on the electrocardiogram." He showed the printout to Ross.

"What's that mean, Doc?" The anxiety in the astronaut's voice penetrated the lethargy that the relaxant drug had caused.

"Hypercalcemia. I'd call it the Ancient Astronaut Syndrome. You've been in weightlessness more than anyone else in GEO Base, Ross. All of us are suffering from some decalcification of our bone mass because our skeletons aren't supporting the weight of our bodies. The calcium is resorbed into the cellular fluid and then into the blood serum. You're reacting in a textbook manner to the fact your body's having trouble getting rid of the excess calcium being poured into your system from your bones."

"Will it ground me?" Ross asked

"I won't ground you, Ross, because I can treat this syndrome," Tom told him. "It's no more incapacitating than any endocrine imbalance, and it can be treated and controlled. People are flying airplanes all over the world with hyperthyroidism, hypothyroidism, hyperuricemia, and a whole list of other endocrine and metabolic disorders. Chemotherapy solves their problems and permits them to function normally. I'm going to do the same for you and put you on fifty milligrams of prednisone every day; you'll just have to take a pill every time you have breakfast. You're the first case of hypercalcemia I've seen in space. Frankly, you're going to be a guinea pig for the rest of us. For right now, I want to keep you here under observation for twenty-four hours—just to make sure I'm right. Then I'll clear you to flight status, but only for a single mission to LEO Base and back. You've got to report back here for a quick test every time you hit GEO Base. Understood?"

"Roger your last, Doc! Hey, thanks. I know doctors who'd ground me for less than this." Relief was evident in his voice. "Doc, you can use me as a guinea pig any time you want," Ross said.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

...but had warned him against exposing his skin to the Sun. That way he could get a very serious and uncomfortable burn. According to Mercer, the only space-tanned astronauts were the ones who appeared in TV plays. Real spacemen avoided the Sun, and if one of them got burned, it was a mark of sheer carelessness. A good spaceman learned to control himself as well as his ship, Mercer had said, and keep his mind busy and alert. Space was a very beautiful, but a very lonely and dangerous place, if one did not keep control.

From LIFEBOAT by James White (1972)

The door opened and the man who'd been missing everything came in. He had one leg, the right one; one arm, the left; and one eye, also the left. He looked to be fifty years old, and there were pale patches in the dark tan on his face and the back of his hand. His hair was patchy, steel grey what there was of it. "O'Grady, this is Mister Shipton," Wiley said. "I'm counting on you to see that he doesn't kill himself. He'll have Hoff's quarters."

"Aye aye, Skipper." O'Grady's voice was cheerful. I couldn't help staring at him, and he saw that. He grinned like a thief. "Don't let the horror show throw you, Mister Shipton. I can still get around." He gestured toward the airtight door.

He was right; he had no trouble getting around. He hopped in arcs that didn't take him far off the deck and carried him in long flights down the corridors to land just in front of the airtight doors every fifty meters or so. We went a long way, around turns and down ramps, until I was thoroughly lost. "If this is the Chief of Staff's office and quarters, why is it so far from Commander Wiley's?" I asked.

"Planned that way. We have a blowout, don't want to lose the whole top layer in one whump, do we?"

I got the picture.

Just in case I hadn't, though, O'Grady chattered on. "Lots of ways to do yourself in. Like me. Got my leg caught in an airtight as it was slammin' for a blowout. Got an arm caught in the hammer mill. That one could of happened on Earth, maybe, except it was being off the deck and no way to move that made it happen.

From BIND YOUR SONS TO EXILE by Jerry Pournelle (1976)

Drop Sickness

Space Adaptation Syndrome aka "drop sickness" is a kind of motion sickness caused by weightlessness. Outer space sea-sickness, so to speak. Symptoms include dizziness, fatigue, nausea, vomiting, and an inability to care about anything but your own private world of pain. The joke is drop sickness makes you feel like you are going to die, and you are actually looking forwards to it.

The French term for seasickness is "mal de mer" so in his Venus Equilateral stories George O. Smith thought it would be cute to call spacesickness "mal de void."

About half of new astronauts suffer from drop-sickness when they first travel into space. Of those who suffer, 50% have mild symptoms, 40% have medium, and 10% have severe. The most severe that NASA ever recorded was that of Senator Jake Garn in 1985. They jokingly use the "Garn scale", where 1.0 Garn is the worst.

Drop sickness usually goes away after two to four days exposure to free fall. Occasionally there is a relapse, which can happen at any time. When suffering from drop sickness, be careful not to rapidly turn or shake your head. This will make the fluid in the inner ear slosh and make things much worse.

Novice NASA astronauts do not take motion-sickness medication on their first trip into orbit. It is considered better for them to be miserable for a day or two but actually adapt to become immune. This is also the reason NASA never schedules EVAs for the first two days of a mission.

Having said that, NASA astronaut always put on a transdermal dimenhydrinate anti-nausea patch when suiting up in a space suit, because throwing up inside a suit can be fatal. A little dramamine is much better than suffocating to death in a vomit-filled helmet.

Drop sickness can be avoided if the spacecraft or station has artificial gravity, though that creates more problems.

What is so funny about a man being dropsick? Those dolts with cast-iron stomachs always laugh — I'll bet they would laugh if Grandma broke both legs.

I was spacesick, of course, as soon as the rocket ship quit blasting and went into free fall. I came out of it fairly quickly as my stomach was practically empty — I'd eaten nothing since breakfast — and was simply wanly miserable the remaining eternity of that awful trip. It took us an hour and forty-three minutes to make rendezvous, which is roughly equal to a thousand years in purgatory to a ground hog like myself.

I'll say this for Dak, though: he did not laugh. Dak was a professional and he treated my normal reaction with the impersonal good manners of a infight nurse — not like those flat-headed, loud-voiced jackasses you'll find on the passenger list of a Moon shuttle. If I had my way, those healthy self-panickers would be spaced in mid-orbit and allowed to laugh themselves to death in vacuum.

Despite the turmoil in my mind and the thousand questions I wanted to ask we had almost made rendezvous with a torchship, which was in parking orbit around Earth, before I could stir up interest in anything. I suspect that if one were to inform a victim of spacesickness that he was to be shot at sunrise his own answer would be, "Yes? Would you hand me that sack, please?"

"Dak?" I said as he signed off.

"Later," he answered. "I'm about to match orbits. The contact may be a little rough, as I am not going to waste time worrying about chuck holes. So pipe down and hang on."

And it was rough. By the time we were in the torchship I was glad to be comfortably back in free fall again; surge nausea is even worse than everyday dropsickness.

From DOUBLE STAR by Robert Heinlein, 1956

(ed note: Mercer is the doctor/steward on a passenger NTR spacecraft headed for the Jovian moons)

"The passengers are settled in, sir," said the darkhaired one. "All have been given medication, but you might keep an eye on Mr. Saddler and Mr. Stone, who may be trying to prove something—I think they palmed their capsules."

Mercer nodded without speaking.

"Are you comfortable, Mr. Saddler?" Mercer said pleasantly to the next in line; then he stopped. This was one of the tough guys who had not taken his medication. Mercer stared at the man's face without really seeing it while his mind sought in vain for a pleasant and friendly way of telling him to take his and-nausea pill and not be a fool. By the end of the allotted minute Mercer still did not have the answer, and he saw that the passenger's face was becoming apprehensive and that he was refusing to meet Mercer's eyes. Suddenly he wriggled sideways in his straps so that he could reach his breast pocket.

"I'm sorry," he mumbled, "I nearly forgot to take my pill."

"It can happen," said Mercer pleasantly, "in the excitement."

The next couch was empty, for the very good reason that it was his own. Beyond it was the one belonging to Stone, the other passenger suspected of missing out on his pre-takeoff medication. Mercer tried the blank stare on him that had worked so well with Saddler, hoping that the man's guilty conscience would do the rest, but Stone simply stared back at him. Maybe his conscience was clear. Mercer had to be content with clearing his throat loudly and slipping a plastic bag between the other's chest straps where Stone could reach it quickly.

Mercer spent the time checking that the vacuum cleaner under his couch was handy and worrying about the period of weightless maneuvering, which would begin when they went into Earth orbit. Both the book and his instructor had painted awful pictures of weightless nausea running wild. It could become critical, they had said, a chain reaction, which could spread even to those who had taken medication, and the job of clearing the air was difficult and distasteful. An incident like that was the one thing guaranteed to sour the whole voyage.

Someone grunted and gave an odd-sounding cough. Mercer swung around to see the passenger called Stone rapidly filling his plastic bag. Stone had been a little late in getting the bag to his mouth, and some of the material was drifting above his couch where the next surge of acceleration would send it flying all over the place. With his feet still held by the webbing Mercer unclipped the sucker from the underside of his couch and went after the stuff, pulling it into the small but powerful vacuum cleaner and leaving in its place a fresh smell of pine trees and heather. Then he helped Stone until he was quite finished, sponged his face and produced a water tube and an anti-nausea pill.

"Sorry about that, Mr. Stone," he said drily, "but there are some people who seem to need double the usual medication."

As he swallowed it, Stone had the grace to blush.

From LIFEBOAT by James White (1972)

The ship's loudspeaker blatted out, "All hands! Free flight in ten minutes. Stand by to lose weight." The Master-at-Arms supervised the rigging of grab-lines. All loose gear was made fast, and little cellulose bags were issued to each man. Hardly was this done when Libby felt himself get light on his feet — a sensation exactly like that experienced when an express elevator makes a quick stop on an upward trip, except that the sensation continued and became more intense. At first it was a pleasant novelty, then it rapidly became distressing. The blood pounded in his ears, and his feet were clammy and cold. His saliva secreted at an abnormal rate. He tried to swallow, choked, and coughed. Then his stomach shuddered and contracted with a violent, painful, convulsive reflex and he was suddenly, disastrously nauseated. After the first excruciating spasm, he heard McCoy's voice shouting.

"Hey! Use your sick-kits like I told you. Don't let that stuff get in the blowers." Dimly Libby realized that the admonishment included him. He fumbled for his cellulose bag just as a second temblor shook him, but he managed to fit the bag over his mouth before the eruption occurred. When it subsided, he became aware that he was floating near the overhead and facing the door. The chief Master-at-Arms slithered in the door and spoke to McCoy.

"How are you making out?"

"Well enough. Some of the boys missed their kits."

"Okay. Mop it up. You can use the starboard lock." He swam out.

McCoy touched Libby's arm. "Here, Pinkie, start catching them butterflies." He handed him a handful of cotton waste, then took another handful himself and neatly dabbed up a globule of the slimy filth that floated about the compartment. "Be sure your sick-kit is on tight. When you get sick, just stop and wait until it's over." Libby imitated him as best as he could. In a few minutes the room was free of the worst of the sickening debris. McCoy looked it over, and spoke:

"Now peel off them dirty duds, and change your kits. Three or four of you bring everything along to the starboard lock."

At the starboard spacelock, the kits were put in first, the inner door closed, and the outer opened. When the inner door was opened again the kits were gone — blown out into space by the escaping air. Pinkie addressed McCoy.

"Do we have to throw away our dirty clothes too?"

"Huh uh, we'll just give them a dose of vacuum. Take 'em into the lock and stop 'em to those hooks on the bulkheads. Tie 'em tight." This time the lock was left closed for about five minutes. When the lock was opened the garments were bone dry — all the moisture boiled out by the vacuum of space. All that remained of the unpleasant rejecta was a sterile powdery residue. McCoy viewed them with approval. "They'll do. Take them back to the compartment. Then brush them — hard — in front of the exhaust blowers."

From MISFIT by Robert Heinlein (1939)


Several SF novels point out the dangers inherent in cooping up people in a tin can surrounded by vacuum for months at a time. They will be prey to "space cafard" (i.e., deep space cabin fever, what the French Foreign Legion called "the beetle").

It can be even worse if the tin can is a little too cramped.

The only solutions seem to be [a] put them in the suspended animation freezer, [b] drug them, or [c] keep them busy, busy, busy! (a bi---, er, ah complaining spacer is a happy spacer) The first officer can assign some worthless busy-work, like a once daily nose to stern ship inspection for micro-meteor holes. One might think that the same problem would be faced by the crew on a military submarine, but as it turns out the analogy is inexact. Christopher Weuve says:

A long submarine mission is six months, and keeping people sane is an issue, solved in part through over-work (which I think helps in the short run) and very careful screening.

Christopher Weuve

A more constructive approach (for officers) is a huge stockpile of study-spools and daily home-work in such topics as higher mathematics, astronavigation, and nuclear physics. Plus other non-space related subjects just to keep the mind flexible. There will also be an active schedule of cross-training, e.g., the astrogator learning how to maintain an atomic drive unit. You never know when knowledge of a job outside of your specialty could prove vital in an emergency.

     Once the handful of novels have been read, the drama tapes have been run to death in the display tank, the music tapes have been played to boredom, once the lies have all been told and the card games have faded for lack of a playable deck, Climber people turn to studying their vessels. To what we call cross-rate training, the study of specialties other than their own.

     The days become weeks, and the weeks pile into a month. Thirty-two days in the patrol zone. Thirty-two days without a contact anywhere. There are three squadrons out here now, and the newly commissioned unit is on its way. Another of the old squadrons will be leaving TerVeen soon. It'll be crowded.
     No contact. This promises to become the longest dry spell in recent history.
     The drills never cease. The Old Man always sounds the alarm at an inconvenient time. Then he stands back to watch the ants scurry. That's the only time we see his sickly smile.
     Hell. They're breaks in the boredom.
     This is oppressive. I haven't made a note in two weeks. If it weren't for guilt, I'd forget my project.
     I think this is our forty-third day in the patrol zone. Nobody keeps track anymore. What the hell does it matter? The ship is our whole universe now. It's always day in here and always night outside.
     If I really wanted to know, I could check the quartermaster's notebook. I could even find out what day of the week it is.
     I'm saving that for hard times, for the day when I need a really big adventure to get me going.

From PASSAGE AT ARMS by Glen Cook (1985)

It takes over 12,000 hours, nearly 18 months Earth time, and there's not much to do on the way. (ed note: Terra to Asteroid Belt) I kept telling myself it wasn't so bad. I had it easier than those poor blokes on sailing ships ever did. They had storms and scurvy and they were wet all the time. They had the sea, but I had all the stars in the universe, rivers of stars, stars without number, and no atmosphere to get in their way.

But the old sailors tired of the beauties of the sea, and it wasn't long before I was sick of the stars.

We had other compensations. I had my choice of more than a hundred programmed learning courses I could take. Foreign languages, ancient history, higher math for amusement; I got a master's in engineering for professional work; I studied up on mining and manufacturing in space. It was all there, anything I wanted. Information stored in holographic chips doesn't mass very much, and if there was anything else one of us wanted they'd beam out a program from Earth. They even sent ball games and movies.

There was also the work. Nothing on the ship was automated. Any job that a human could do, we did for ourselves. Of course we could get clever and build automatic systems, and we did, but that took up time. The ships are designed that way. Space Industries doesn't want its people going stir crazy on the way out. They have too much money tied up in us. Coming back they wouldn't care...

Then there was privacy. We didn't have much. Each of us had a compartment about the size of a bunk. The partitions were as thin as they could make them. No soundproofing. If we wanted quiet, we wore earphones. Not earplugs — there were times when we needed to hear what was happening and hear it fast. Otherwise we wouldn't live to enjoy the privacy.

From BIND YOUR SONS TO EXILE by Jerry Pournelle (1976)

And the sergeant in charge of the enlisted men will have to know when to turn a blind eye to the home-made moonshine "still" hidden on Z deck and the floating poker and dice games. Gambling and rocket-juice will combat boredom. As will other forms of recreation.

In the anime Planetes, they recognize the fact that having male and female crew members cooped up in close quarters for weeks at a time can cause certain tensions. When stocking a spacecraft for a mission, one officially required item is a selection of erotic magazines. This allows the crew members to take care of the problem in solitary fashion.

Since we were falling free in a 24-hour circular orbit, with everything weightless and floating, you'd think that shooting craps was impossible. But a radioman named Peters figured a dodge to substitute steel dice and a magnetic field. He also eliminated the element of chance, so we fired him.

From DELILAH AND THE SPACE-RIGGER by Robert Heinlein (1949)

Space Booze

RocketCat sez

I've got news for all you teetotaler out there. Agriculture may have brought the rise of civilization, but archaeologists have found evidence that making beer pre-dated making barley bread by three thousand freaking years! Agriculture was not invented so people could have food, it was so people could have beer.

We've been enjoying booze for twelve-thousand years, we ain't gonna stop any time soon.

Yeah, since then we've invented an alarming number of controlled substances, but as long as they stay controlled they will be hard to come by in rocketpunk outer space. It's gonna be real hard to make a meth lab in a spaceship without anybody noticing. Plus all the added fun if it explodes, emits toxic fumes into the limited atmosphere, or sets the ship on fire.

But as long as you can make crude hooch by simply leaving a bottle of apple juice on the radiator, alcohol will be part of space culture. It is just too easy to make. And any fool can make a moonshine still that uses vacuum instead of heat. Especially since there is an infinite supply of vacuum, right outside the hab module. The interplanetary internet will have lots of easy-to-follow tutorials.

Hopefully any idiots who venture into dangerous areas while plastered will merely cop a Darwin Award for themselves without taking along any innocent bystanders. If they just manage to kill or seriously injure others while remaining unscathed, I'm sure the surviving crew will be willing to give Darwin a hand. The survivors will just tell the first officer that it was a tragic airlock accident.

While most illegal drugs and other controlled substances are rather difficult to manufacture in the space environment, good old alcohol is relatively easy. After all, convicts manage to make Pruno in prison; even with limited access to raw materials, workspace, and privacy from prison guards.

In most cases, the actual production of alcohol from sugar is done by yeast cultures. These cultures are almost impossible for the authorities to keep out of the hands of illegal brewer-masters of contraband alcoholic beverages. In the case of making wine, the yeast can be conveniently found already living on the grape skins.

And if the CELSS is using yeast to make single-cell protein, there is no way to prevent moonshiners from obtaining a supply. In 2015 the Australian government was considering making the national staple food Vegemite a controlled substance (inspiring howls of outrage). Apparently home-brewers in remote areas were purchasing Vegemite in bulk and using it to make moonshine. After all, the main ingredient of Vegemite is leftover brewers' yeast extract (not baker's yeast, brewers' yeast). In Australia there has already been a ban on Vegemite in prisons since the 1990's for the same reason. Controlling it outside of prison is going to be an uphill battle.

Needless to say, becoming drunk in an inherently dangerous environment such as deep space is a quick way to get yourself killed. In the US the legal drunk driving limit is 0.08% Blood Alcohol Content (other nations have different standards). A rule of thumb is that one standardized "drink" = one hour = no exceptions (that is, if you had three drinks, wait three hours before driving). For private airplane pilots, the rule of thumb is Eight Hours Bottle To Throttle.

In the U.S. (wet) Navy, drinking alcohol is not allowed while aboard a ship (since the passage of General Order No. 99 in 1914), and off ship it is forbidden if the person is on duty or under-aged. In the U.K., which has a tradition of a daily rum-ration for sailors, crew is limited to consume no more than 35mg of alcohol per 100ml when they are on safety-critical duty (same as the U.K. drink-drive limit). For U.K. naval crew handling weapons the limit is 9mg per 100ml. The U.K. Armed Forces Act of 2011 prohibited the consumption of more than five units of alcohol 24 hours before duty and no alcohol was to be consumed in the 10 hours before duty.

In Jerry Pournelle's Falkenberg's Legion series of science fiction novels the CoDominium navy and marines have no regulations against drinking alcohol, even on duty. But there are severe penalties for rendering oneself unfit for duty (penalties up to execution by firing squad). When deployed, CoDominium marines were commonly given a daily wine ration of half a liter per person.


A "wine" is an alcoholic beverage produced by yeast converting the sugar in fruit juice into ethanol. At some point the ethanol level rises high enough to kill off the yeast, halting production. This limits the proof of wines, usually 9%–16% alcohol by volume (ABV) or 18—32 proof.

A fortified wine is a wine with the alcohol content increased by adding some distilled spirits (generally brandy, which is distilled wine). If the brandy is added before the wine fermentation is completed the resulting fortified wine will be sweet. This is because the brandy kills off the yeast before all the sugar is consumed. Fortified wines can be up to 20% ABV (40 proof).

Some anthropologists have a theory that wine was discovered by some cave-man who took a drink out of a puddle full of rotting fruit.


A "beer" is an alcoholic beverage produced from grain, usually barley or wheat. First the grain is "malted": germinated in hot water, then dried. The malting process creates enzymes which can convert starch into sugar.

The malt is mixed with hot water to create what brewers call "wort" but we can call "yeast food." This allows the enzymes to convert the starch in the grains (which yeast cannot eat) into sugar (which yeast will merrily convert into alcohol). See "saccharification of starch".

After about two hours the malt enzymes has converted most of the starch into sugar, and the wort is boiled to get rid of some of the water. After the wort is cooled, it is put in a fermenter along with hungry yeast. The yeast put on their bibs, whip out their knives and forks, and start gobbling sugar while excreting ethanol. Beer is generally 2%—12% ABV (4—24 proof).

A "malt liquor" is a beer made by adding sugar, corn, or other adjuncts to the wort in order to increase the alcohol content (above 6% or 12 proof). The extra yeast food means more alcohol.

Note that when traveling, if the bacterial content of the local water is questionable, it is much safer to drink the local beer instead of the water. Use beer to brush your teeth as well. An ancient Egyptian tomb inscription boasted about the dear departed's generosity by saying "I gave bread to the hungry and beer to the thirsty".

Some anthropologists have a theory that early man invented agriculture not to increase the supply of food, but to increase the supply of beer.

Distilled Spirits

Since people have a tendency to be min-maxers, they looked for ways to increase the ethanol levels in their product. The tried and true method is to use a distillery rig, aka a moonshine "still". Such items have to heat up the source alcoholic beverage using fire, but in space the abundantly available vacuum can be used instead.

John Reiher notes that you do NOT want to use a vacuum still on beer or any other mash containing hops. One of the essential hop oils, Myrcene, has a boiling point of 63.9° C, which is under alcohol's 74° C. If you're not careful, you'll end up with very hoppy ethyl alcohol (i.e., incredibly bitter).

The basic idea is to remove water from the booze, thus increasing the relative percentage of alcohol. Conventional stills take advantage of the fact that water and alcohol have different volatility. That is, ethyl alcohol boils at a much lower temperature than water.

You boil the wine or mash at a temperature (78°C) which vaporizes the alcohol but very little of the water. Then you send the alcohol vapor through a condenser to turn it back into liquid. The alcohol drips out of the condenser into a jug. The condenser is that copper spiral tube (the "worm") you see on classic moonshine stills. Copper is used because it absorbs sulfur-based compounds which would otherwise make the product taste like skunk juice.

The products of a still are called distilled beverage, spirit, liquor, or hard liquor. Typical distilled spirits are about 40% ABV (80 proof), extreme stuff is 75% ABV (150 proof), Everclear grain alcohol is about 95% ABV (190 proof) which is close to being rocket fuel.

Whiskey and the like are made with pot stills where there is lots of water in the vapor sent to the condenser. After two distillations whiskey has a 70% ABV. Moonshine is made in moonshine stills, with very little water in the vapor. It has a 95% ABV, almost suitable for use in a Rocketdyne RS-88 rocket engine.

There are many kinds of distilled spirits. A "brandy" is distilled wine. A "whisky" is distilled from grain mash (like beer's barley or wheat) except whisky can also be made from corn or rye. You can think of whisky as distilled beer without being utterly wrong. A "vodka" is generally distilled from fermented potato mash, its main feature is the almost total lack of flavorings.

A more low-tech way to increase the alcohol level is to use freeze-distillation (aka "jacking"), such as in the manufacture of applejack. Alcohol freezes at a lower temperature than water (this is why you can use it as antifreeze). So in the American colonial period, apple juice from the harvest was allowed to ferment into a sort of fruit beer (less than 10% ABV). Then during the winter, the juice was placed outside to freeze, or at least the water would. The frozen lumps of water were removed, thus raising the alcoholic content of the remainder (up to 40% ABV). This method might be popular on newly colonized Terran planets with a low tech base. A drawback to freeze-distillation is that (unlike conventional distillation) the process concentrates dangerous poisons such as methanol and fusel oil.

Back in the 1920's during Prohibition in the US, amateurs made Bathtub gin. This lead to the creation of many gin cocktails, as the speakeasies desperately experimented with sugary flavors to mask the vile taste of the poorly made gin. Everything old is new again. Enlisted spacecraft crew will also be eager to steal fruit juices from the quartermaster to doctor the foul product of their vacuum stills.

Alcohol is absorbed into the blood stream slowly in the stomach, but the rate can be increased if the beverage is carbonated. This is why strong people who are apparently unaffected by a shot of whisky will sometimes start to giggle if they drink bubbly champagne (carbonated wine). Beer is carbonated, but it is so weak it needs all the help it can get. Champagne has more of a kick than non-carbonated wine. And a cocktail that includes some sort of carbonated mixer is most potent of all.

Some old SF novels call space hooch "rocket juice", as a tribute to the torpedo juice from WW2. In Star Trek, Captain Kirk liked his Saurian Brandy, and McCoy was fond of Romulan ale. And of course Scotty is partial to scotch, even mixed with theragen.

Other noteable alcoholic beverages from science fiction include Pan-Galactic Gargle Blaster, Ambrosa, Bloodwine.

It is also possible to have an alcoholic beverage as the focus of a science fiction story. I highly recommend Golubash, or Wine-Blood-War-Elegy by Catherynne M. Valente


(ed note: this is a real news article)

A distillery that sent unmatured malt whisky into space to study the effect of near-zero gravity on flavour has described its findings as "groundbreaking".

Ardbeg Distillery, on Islay, sent a vial to the International Space Station in a cargo spacecraft in October 2011.

Another vial of the same whisky was kept at the distillery for comparison.

The distillery said its space samples were "noticeably different" in terms of aroma and taste.

The company had set up the experiment to investigate how micro-gravity would affect the behaviour of terpenes, the building blocks of flavour for many foods and wines as well as whisky spirits.

It has now identified "major differences" in its analysis of the two sets of samples.

Ardbeg tasting notes from experiment:

Earth sample: "The sample had a woody aroma, reminiscent of an aged Ardbeg style, with hints of cedar, sweet smoke and aged balsamic vinegar, as well as raisins, treacle toffee, vanilla and burnt oranges.

"On the palate, its woody, balsamic flavours shone through, along with a distant fruitiness, some charcoal and antiseptic notes, leading to a long, lingering aftertaste, with flavours of gentle smoke, tar and creamy fudge."

Space sample: "Its intense aroma had hints of antiseptic smoke, rubber and smoked fish, along with a curious, perfumed note, like violet or cassis, and powerful woody tones, leading to a meaty aroma.

"The taste was very focused, with smoked fruits such as prunes, raisins, sugared plums and cherries, earthy peat smoke, peppermint, aniseed, cinnamon and smoked bacon or hickory-smoked ham. The aftertaste is intense and long, with hints of wood, antiseptic lozenges and rubbery smoke."

Ardbeg said the maturation experiment paved the way for "unprecedented flavour profiles".

Dr Bill Lumsden, Ardbeg's director of distilling and whisky creation, said: "The space samples were noticeably different.

"When I nosed and tasted the space samples, it became clear that much more of Ardbeg's smoky, phenolic character shone through - to reveal a different set of smoky flavours which I have not encountered here on earth before."


(ed note: this is a real news article)

Members of Professor Sir Andre Geim's group at the University of Manchester, where graphene was first identified, were investigating the permiability of a closely related material called graphene oxide. This is graphene which has been reacted with a strong oxidising agent, making it more soluble and easier to deal with.

They created membranes made up of small pieces of graphene oxide which pile up like bricks to form an interlocked structure, and then tested how gas-proof they were by using the film as a lid for a container full of various gases.

They found that despite being 500 times thinner than a human hair, it completely stopped Hydrogen, Nitrogen and Argon from escaping, to the limits of their measurements. It even stopped Helium which, being a tiny single atom will escape from party balloons very quickly, and can even diffuse out through a millimetre of glass.

They then tried various liquids, and found similar behaviour for ethanol, hexane, acetone, decane and propanol vapour, but when they tried normal water it behaved as if the membrane wasn't there, escaping at least a hundred thousand times faster than any of the other materials. They think the water is forming a layer one molecule thick between the layers of graphene, blocking the route for everything else, but if it dries out, this gap shrinks and seals up.

To make use of this behaviour they put some vodka in the container, and left it for a few days. Normally ethanol evaporates faster than water so vodka gets weaker over time, but with their membrane, which blocked the ethanol, the vodka got stronger and stronger.

This is extremely interesting behaviour, as seperating water from other solvents is a huge part of many chemical processes. This is normally done by distillation, which takes a large amount of energy, and the process has to be repeated many times. Ethanol cannot be concentrated to more than 96% without involving poisonous solvents to remove the water, so this material has a huge potential.

(ed note: you'll have to think up a slang name for this new form of contraband. "Still-rag", "'Shine-cloth", etc. John Reiher suggests that a person running a graphene still should be called a "wiper")


(ed note: Mr. Reiher had some observation about using graphene cloth to distill alcohol)

One side effect of this tech is booze. Because the graphene filters only let water pass through, a case of cheap 3.2% ABV beer can be "improved" to something nigh undrinkable. Undrinkable because the graphene filtration doesn't "distill" the beer, it concentrates it.

So if you take a highly hopped beer and graphene it, it becomes impossible to drink. Spacer IPA is usually around 32% alcohol and has a IBU of 240. Most folks can't drink that. Most people. There are few brave souls who will try a shot or two.

But there is a fix for that. Synsepalum Dulcificum, AKA, the Miracle Berry. Eating a berry before quaffing some Spacer IPA results in the sweetest brew you ever drank. Some folks get addicted to that.

Jacking, that's what I was thinking of. I had it happen to me once while I was living in Colorado Springs. It got cold enough that it froze the beer we had left out on the back porch nearly solid. I cracked one open and out poured this syrupy liquid. It was nasty. It was also Miller, but that's another issue.

I'd imagine all the wines, spirits, and various grain beverages would find a new life at the hands of a "wiper", AKA, the guy who runs a graphene "still".

From John Reiher in a Google+ thread (2015)

(ed note: "bactry" means "bacteria factory". The bactries of chemical companies refine volatile asteroid-liquor into useful chemicals with bacterial aid.)

To: the Idiot Riggers in Habitation Module 4V and Their Damn-Fool Party Friends
Re: Your Still

Yes, I know about your still. No, I’m not going to shut you down, because if you don’t have the still I know about, you’ll just set up one l don’t know about. Or start sipping the reactor coolant.

But here are a few points you might not think of. The Flight Commander will have plenty more, I’m sure.

First, I have tested your first batch, and it seems at least one of you knows ‘shine from bactry juice, ‘cause there’s not enough methanol in it to blind you. If you’ve any damn sense at all, you’ll bring me a tester from every batch.

Second, I’m not vouching for anything else that might be in there.

Third, anyone who can’t drink rationally and hold it should come by sickbay at 1600 to hear in great and graphic detail just how fun it is to choke to death on your own aspirated free-falling fluids. There will be pictures. And should you end up in my care from anything hooch-related, you’ll get the long version, so save yourself some pain.

Fourth, my surgical oxygen does not exist to help you sober up. Anyone I catch using it for that purpose will wish they were just thrown out the airlock, especially if you find yourself needing anesthesia in the remains of your tour.

Fifth, we don’t stock enough analgesics aboard to go handing then out as hangover cures. If you can’t live with it, stick your head outside and breathe deep.

Sixth, no vomiting inside the airlock. Commander Steamweaver controls the air you breathe. That should be all the incentive you need to not get your crap in her filters.

Seventh, no vomiting outside the airlock, either. I’m running low on death certificates.

Surgeon Lieutenant Oricalcios

From ORBITSHINE by Alistair Young (2014)

Four riggers showed up at the med module. Rather, two riggers towed two others. Even the two who could move didn't look very well. In spite of weightlessness, they managed to stagger.

"Sweetie, we don't feel so damned good," one told Angela as they entered the module. They rebounded from the edge of the hatch as they did so. "Kin ya give us somethin' to make us feel better? Ol' Jim here—and Al, too—passed out on us. And I'm about to pass out, if I don't heave first."

Angela managed to get a plastic bag to the man before he threw up. But the other conscious man beat her to it.

Fred was the second team member on the scene. He didn't pay any attention to the conscious men, but started checking one of the unconscious ones. "Angela, he's comatose—cyanotic or acidotic. I can't tell without a blood check. Same with the other one."

"They've all been drinking," Angela noted.

"You betcha! Hell of a party!" one of the conscious ones muttered thickly.

"Alcohol poisoning?" Angela ventured to guess.

"Nope," Fred put in. "I'll bet they got a load of orbital moonshine, and what we're seeing are the effects of methanol."

"Dr. Noels!" Angela called out, but Tom was already out of his quarters and into the med module, having been attracted by the commotion. "Possible methyl alcohol poisoning!" she told him as he came up to her.

Tom took one look and acted fast. "Get them down. Angela, Fred, start positive-displacement IVs with sodium bicarbonate on the two who've passed out! Dave, shag it out here stat! You, too, Stan!

"I need blood analysis as fast as you can get it," Tom told his med tech. "Blood-alcohol level, along with pH and electrolyte balance. Accuracy second to speed, because if it's methanol we haven't got much time. Angela, Fred, Stan, we treat for methanol poisoning first! If it's something else, it'll be less serious."

They strapped all four into med module treatment units and started the IVs.

"This guy's going fast," Stan remarked. "Acts like traumatic shock, Doc. Hypotension. BP down to seventy over forty!"

"Gastric lavage!" Tom snapped. "Get it started on the others, too. Whatever is in there, pump it out of them!" He turned to his conscious patient. "Any headache? Leg cramps?"

"Uh . . . naw—but my gut hurts somethin' terrible!" And he passed out.

"What were you drinking?" Tom asked the remaining conscious man. "Tell me fast! It could save your life!"

"Aw, we was just havin' a li'l party with some stuff Al made from raisins and breakfast cereals we took from the cafeteria. Pretty good moonshine, too . . ."

"It could be anything," Stan pointed out.

Tom didn't say a word. He was thinking. He ran through the symptoms of the various alcohol poisonings. He knew he was doing the right thing when it came to wood alcohol ingestion: sodium bicarb IV with gastric lavage. He wouldn't know whether or not to try rebalancing electrolytes until he got the blood work-ups from Dave, who had drawn his samples and was working rapidly in the med lab section of the module.

Dizziness. Discoordination. Gastroenteritis. Hypotension. But no cramps. Obviously no convulsions . . . yet. The unconscious ones were in a stupor with falling blood pressure, but the condition didn't add up to methanol poisoning.

Gastric lavage produced a brownish liquid smelling of alcohol.

"See what Dave can do with it," Tom told Angela.

The initial blood report from the comatose man showed pH in the normal range but various departures from normal in electrolytes. There was also evidence of hypoglycemia.

"All four of them can't be diabetic!" Tom muttered to himself as he looked over the scribbled note from Dave. "They'd never have gotten past the medical check at JSP! What the hell is it? I've never seen this before. Angela, have you?"

"No. Botulism, perhaps?"

"Not from a liquid as loaded with ethanol as their drink was," Tom observed. "Well, this is what I've got GALEN for!"

He pushed off to the med module treatment-bay terminal and got on line. He keyed in the symptoms and requested analysis and most probable diagnosis. The computer worked it over on Earth and shot back the sentence that flashed across the display screen: INCOMPLETE SYMPTOMATIC REPORT. CHECK FOR RETINAL INJURY AND REPORT FINDINGS.

Tom's first peek through the ophthalmoscope into the eyes of the man still semiconscious revealed normal eye grounds. He typed into GALEN: NO RETINAL INJURY. EYE GROUNDS NORMAL.


"Isoamyl alcohol. Fusel oil" Tom said, snapping his fingers.

"I know these guys," Fred added. "Hard drinkers. All of them. Probably tried to smuggle hooch up but got caught. And the limited ration that Pratt permits everyone every week wasn't enough for these boozers. So old Al here—he's from Georgia—I'll bet he figured he'd make himself some moonshine instead. Ten to one, they've got a vacuum still rigged somewhere outside a convenient lock."

Oh, don't worry; we saved them. They were full of fusel oil. Why don't you put some bread in the cafeteria so anybody eke who tries this will at least be able to filter it through a loaf of bread first? Bread won't take out all the fusel oil, but it'll probably keep the concentration below the lethal limit."

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

(ed note: the topic is colonists on a Terran like planet being able to grow edible crops or otherwise find food)


"Assuming the alternative biochemistry uses a different set, some of the 'new' ones might be interchangeable with the ones in the earth biochemistry set and those would count as nutrition. "

Not likely. The metabolism of amino acids is pretty dang specific. Breaking peptide bonds is one thing- simple chemistry. Actually utilizing the amino acids requires all sorts of enzymes, which tend to be extremely specific. Transfer RNA aminoacylation alone is probably an insurmountable barrier to building proteins with foreign amino acids.

Maybe deamination to use the nitrogen and carbon skeletons is possible. I'd have to check the books. But I doubt it. The probability of aliens using a foreign aa just similar enough to ours to screw up our aa metabolism is much higher.


Without looking up details, I think what Zachary says is correct to the extent that humans are concerned. That being said, if you had a foreign stock of amino acids (for whatever reason), you could probably get bacteria to use it as a food source eventually, and get some usable product out of it that way.

If history is any indication, booze of some kind will be the first consumable product made from a foreign food source. The nutritional value, of course, depends on if the microbe in question develops proteins to incorporate the new amino acids (no good for you) or it develops proteins to break down the new amino acids into something familiar (good for you).


If history is any indication, booze of some kind will be the first consumable product made from a foreign food source.

Does this blog get great comments, or what?

This seems entirely likely! I have only the vaguest knowledge of booze production, only that it starts with fermentation of sugars into good old ethanol. I have no idea what sugars are, but ethanol is pretty basic stuff.


-Sugars are basically 5 or 6 ethanols linked together by the carbons in a circle (roughly).
-Starches are a whole bunch of sugars linked together in one way.
-Cellulose is a whole bunch of sugars linked together in a different way.

This is why, on Earth, one can change pretty much any plant into some kind of alcohol or another.


I suppose the prospects for Rigellian green fuming brandy all depend on whether the local life builds its equivalent structures out of ethanol or methanol ...

(ed note: "fuming Rigellian wine" is from James Blish's Cities In Flight)


That being said, if you had a foreign stock of amino acids (for whatever reason), you could probably get bacteria to use it as a food source eventually, and get some usable product out of it that way.

Excellent point. If bacteria can figure out how to eat petroleum, random amino acids should be no problem at all. And the nice thing is, just using them as a carbon source is probably a lot easier than actually incorporating them into proteins.

Developing mutant bacteria strains to utilize common organic molecules would probably be the first step in terraforming a world with alien organic life. If you want to push it, we could engineer our own gastrointestinal symbiotes to digest alien molecules, a la termites.

-Sugars are basically 5 or 6 ethanols linked together by the carbons in a circle (roughly).
-Starches are a whole bunch of sugars linked together in one way.
-Cellulose is a whole bunch of sugars linked together in a different way.

This is why, on Earth, one can change pretty much any plant into some kind of alcohol or another.

Accurate, except for the first part. You could synthesize a sugar that way I suppose, but it would be a weird, overgrown sugar with no friends. The connection between simple sugars and ethanol is pyruvate. Pyruvate just so happens to be a breakdown product of many amino acids...all you need is an enterprising settler with a DIY gene tweaking kit, and xenomorphic rotgut, here we come!


The colonists might not be able to eat the food, but at least they could drown their sorrows!

From GARDEN WORLDS, PARK WORLDS comment section (2009)
Jayne: Mmm. They call it Mudder's Milk. All the protein, vitamins and carbs of your grandma's best turkey dinner, plus fifteen percent alcohol.
Wash: It's horrific!
Simon: Worked for the Egyptians.
Jayne: What's that?
Simon: The ancient Egyptians, back on Earth-That-Was. It's not so different from the ancestral form of beer they fed to the slaves who built their pyramids. Liquid bread. Kept them from starving, and knocked them out at night, so they wouldn't be inclined to insurrection.
Kaylee: Wow, Simon. That's so... so historical.
From TV series Firefly episode JAYNESTOWN (2002)

We fired four of them for being drunk on the job; Tiny had to break one stiff's arm before he would stay fired. What worried us was where did they get it? Turned out a ship fitter had rigged a heatless still, using the vacuum around us. He was making vodka from potatoes swiped from the commissary. I hated to let him go, but he was too smart.

From DELILAH AND THE SPACE-RIGGER by Robert Heinlein (1949)

After about a week of one gee, Private Rudkoski (the cook's assistant) had a still, producing some eight liters a day of 95 percent ethyl alcohol. I didn't want to stop him — life was cheerless enough; I didn't mind as long as people showed up for duty sober — but I was damned curious both how he managed to divert the raw materials out of our sealed-tight ecology, and how the people paid for their booze. So I used the chain of command in reverse, asking Alsever to find out. She asked Jarvil, who asked Carreras, who sat down with Orban, the cook. Turned out that Sergeant Orban had set the whole thing up, letting Rudkoski do the dirty work, and was aching to brag about it to a trustworthy person.

If I had ever taken meals with the enlisted men and women, I might have figured out that something odd was going on. But the scheme didn't extend up to officers' country.

Through Rudkoski, Orban had jury rigged a ship-wide economy based on alcohol. It went like this:

Each meal was prepared with one very sugary dessert — jelly, custard or flan — which you were free to eat if you could stand the cloying taste. But if it was still on your tray when you presented it at the recycling window, Rudkoski would give you a ten-cent chit and scrape the sugary stuff into a fermentation vat. He had two twenty-liter vats, one "working" while the other was being filled.

The ten-cent chit was at the bottom of a system that allowed you to buy a half-liter of straight ethyl (with your choice of flavoring) for five dollars. A squad of five people who skipped all of their desserts could buy about a liter a week, enough for a party but not enough to constitute a public health problem.

From THE FOREVER WAR by Joe Haldeman (1975)

(Lysander is the prince of the planet Sparta. Blaine is the governor of the planet Tanith. BuRelock is the Bureau of Relocation, who forcibly transport undesirable people from the over populated Earth to dump them on the various colony planets.)

"We have an excellent liqueur, rum based with flavoring from the Tanith Passion Fruit, but perhaps it's a bit early in the day for something so sweet. Tanith whiskey, perhaps?"

"Thank you." Lysander sipped gingerly at the dark whiskey. "That's quite good."

"Glad you like it. Bit like Scotch only more so. Some find it strong."

"Sparta's whiskey is descended from Irish," Lysander said. "We think it's better than Earth's best. We had a master distiller from Cork!"

"Much the same story here," Blaine said. "Whole family from near Inverary. Can't imagine what they did to annoy BuRelock, but up they came; Tanith's benefit and Earth's loss. One of my predecessors set them up in the distilling business."

From PRINCE OF MERCENARIES by Jerry Pournelle (1989)

He poured a glass of moss whiskey, a native Ceres liquor made from engineered yeast, then took off his shoes and settled onto the foam bed.

An hour later, his blood warm with drink, he heated up a bowl of real rice and fake beans—yeast and fungus could mimic anything if you had enough whiskey first—opened the door of his hole, and ate dinner looking out at the traffic gently curving by.

Kate Liu returned to the table with a local beer and a glass of whiskey on her tray. Miller was glad for the distraction. The beer was his. Light and rich and just the faintest bit bitter. An ecology based on yeasts and fermentation meant subtle brews.

From LEVIATHAN WAKES by "James S.A. Corey" (Daniel Abraham and Ty Franck) 2011. First novel of The Expanse

Ballistic Brewery, ICC to Hanth & Mallon Restaurants (Pádíäz System), ICC, greetings.

Valmiríän Oricalcios,

Thank you for your interest in our selection of fine beers for the discerning spacer palate.

To be sure that we can satisfy your requirements, let me explain to you how the Ballistic Beer process works. The initial stages of brewing are carried out in our own facilities, in your case at Gallítra Station in the Pádíäz-Solar L4 point. We take grain from the skyfarms surrounding our station, malt, kiln, mash, and sparge it. We then copper and boil the resulting wort with the unique combinations of hops, sugars, and herbs that give each of our beers their unique flavor.

When we receive your order, the selected wort is transferred to one of our Puncheon-class fermenter-tankers, along with the appropriate yeast culture, and the Puncheon is dispatched to you. The transfer orbit of the Puncheon is carefully computed to allow for the necessary weeks or months of fermentation and conditioning under thrust gravity, in order to reach you at the moment of peak flavor. Once the beer is finally racked, wood conditioning or other late-stage refinements can be imparted in the Puncheon’s final tank.

When the Puncheon reaches your station, you offload the beer by fluid transfer, either directly into your own cask tanks or for local bottling or kegging (facilities and resale licenses for either of these can be leased from us). The yeast residue remaining in the fermenter can be returned to us with the Puncheon, or retained for local use for a nominal fee. We request that you refuel the Puncheon for its return voyage as part of your payment schedule.

(Note: All of our beers are naturally carbonic. As such, you should be prepared to accept the listed associated CO2 release into your local life-support capacity. We also recommend that they be served only in non-microgravity areas and that drinkers remain in these areas for the stated effervescence interval to prevent discomfort.)

Available for immediate shipment, in the Pádíäz System, are our Callaneth’s Finest, Starlight Irdesh, Miról Lambic, Three-Axis Pale Ale, Red Rocket Red, Singularity Stout, and Oúrghaz’s Heavy, each available in 25-barrel, 50-barrel, 100-barrel, and 300-barrel shipments. We will, of course, be happy to produce any of our other beers for you given sufficient lead time.

I have enclosed for your further information more details of our beers, along with full details of technical requirements and other necessities, and payment information for a variety of order sizes and schedules.

On behalf of all of us here at the Ballistic Brewery, we hope to be able to offer you a drink soon!

Talan Kellis, Brewmaster’s Second,

for and on behalf of

Ballistic Brewery, ICC


When I was a kid, I used to stand out at the edge of Crashlanding Port watching the ships come in. I'd watch the mob of passengers leave the lock and move in a great clump toward customs, and I'd wonder why they seemed to have trouble navigating. A majority of the starborn would always walk in weaving lines, swaying and blinking teary eyes against the sun. I used to think it was because they came from different worlds with different gravities and different atmospheres beneath differently colored suns.

Later I learned different.

There are no windows in a passenger spacecraft. If there were, half the passengers would go insane; it takes an unusual mentality to watch the blind-spot appearance of hyperspace and still keep one's marbles. For passengers there is nothing to watch and nothing to do, and if you don't like reading sixteen hours a day, then you drink. It's best to drink in company. You get less lushed, knowing you have to keep up your side of a conversation. The ship's doc has cured more hangovers than every other operation combined, right down to manicures and haircuts.

From FLATLANDER by Larry Niven (1967)

Psychological Problems

And then there are mental problems. The dread spectre of space madness.

Obviously there are problems with confining too many astronauts in a too-small habitat module for prolonged periods of time with not enough sleep and practically no privacy. Add pressure from ground control to work the astronauts to death coupled with boredom and you have a real recipe for blood floating all over the module. At least in an Arctic research station a researcher close to snapping can step outside for a breath of fresh air. Not so the astronaut

Cosmonaut Valery Ryumin, twice Hero of the Soviet Union, quotes this passage from The Handbook of Hymen by O. Henry in his autobiographical book about the Salyut 6 mission: “If you want to instigate the art of manslaughter just shut two men up in a eighteen by twenty-foot cabin for a month. Human nature won't stand it.”

This was sort of hinted at by the 1999-2000 Russian Sphinx-99 experiment. This enclosed six crewmembers in a simulated space station for six months. About two months into the experiment there was a bloody fist-fight between two of the Russian crewmembers. Shortly thereafter the Canadian female crewmember (Dr. Judith Lapierre) was dragged off camera by the Russian commander and forcibly french-kissed despite her vigorous protests. In two separate incidents.

And then there is the Break-Off effect. This was first reported before the dawn of space travel, by high altitude military airplane pilots. It was a type of psychological dissociative anomaly, a feeling of detachment. Most pilots felt peaceful, a few euphoric, and about a third were panic-stricken.

It was thought this would also happen with astronauts. But in the 1970's when cosmonauts and astronauts actually started flying the problem seemed to disappear.

It wasn't until recently that it became clear the Break-Off effect did not disappear in astronauts. What disappeared was the astronauts reporting it. Astronauts are in constant terror of being grounded, so they developed a "lie to fly" culture. The last thing they are going to do is report to the flight surgeons some scary mental breakdown that will get them grounded faster than a teenage girl staying out five hours past her curfew.

During the Apollo missions, some astronauts reported how the vision of Earth as the big blue marble caused a sudden cognitive shift in awareness. They suddenly saw Earth as a fragile ball of life where national boundaries became unimportant. A writer named Frank White coined the term The Overview Effect, and wrote a popular book on the topic in 1987. You can find some quotes about the effect here.

And there are some psychologists who suspect that the Break-Off Effect and the Overview Effect are one and the same.


Speculation about revolutionary developments is not, however, immediately relevant to a most pressing question about human adaptation to space: How can groups of people live and work together without psychological impairment or the breakdown of social order in the space stations, lunar bases, and Mars expeditions now being planned? Psychological and social problems in space living constitute, as both Soviet and American space veterans attest (Bluth 1981, Carr 1981), major barriers to be overcome in the humanization of space.

Coping with isolation from Earth, family, and friends and with the cramped confines of a space module or station has been enough of a challenge for carefully selected and highly trained spacefarers of the U.S.S.R. and the U.S.A. As those cosmonauts who have been “pushing the endurance envelope” the farthest attest, staying longer and longer in space provokes severe psychological strain (Bluth 1981; Grigoriev, Kozerenko, and Myasnikov 1985; Oberg 1985, p. 21).

Now life in space is becoming even more complicated as “guest cosmonauts” from many nations join Soviet and American crews; as women join men; and as physicians, physicists, engineers, and other specialists routinely work alongside traditional cosmonauts and astronauts of the “right stuff”. How will all these different kinds of people get along in the space stations of the next decade and the lunar bases and martian outposts which are to follow? What measures can be taken which would reduce stress and make it easier for heterogeneous groups of people to work efficiently and safely and to live together amicably for months or even years in these space habitats?

Among social scientists it has been primarily the psychologists (Helmreich 1983), with a few jurists, sociologists, and political scientists joining in, who have tried to address these problems of space living. However, inasmuch as among the diverse lot of people who call themselves anthropologists there are those who are intensely interested in interpersonal relations and small group behavior, it should not be surprising that anthropologists might also be attracted to work in this field. Interestingly, some recent recruits come from maritime anthropology, where they have worked on the dynamics of small-boat fishing crews.

These and other anthropologists interested in space can bring to the field a degree of “hands-on” experience in working with “real” small groups—be they fishing crews, Antarctic scientists, or hunting and gathering bands.

Here I wish to suggest two specific areas in which this cultural perspective of anthropology could be useful: (1) in addressing the problems of cross-cultural relations among heterogeneous space crews and societies and (2) in the application of cultural resources to develop models for space living.

Cultural factors should not, however, be viewed solely in terms of impediments to successful space living, for they may also constitute valuable human resources to be tapped in adapting to space. In addition to seeking to promote cultural harmony among heterogeneous space crews, we might also seek out, from the multitude of cultural traditions among the Earth’s societies, those practices and institutions which could best promote harmonious and productive life in space.

As an example, consider interpersonal problems in a space habitat. J. Henry Glazer, an attorney who has pioneered the study of “astrolaw,” warns against exporting to space communities the adversarial approach to dispute resolution based on “medieval systems of courtroom combat” (Glazer 1985, p. 16). In small space habitats, where people cannot escape from one another but must work out ways of interacting peacefully and productively, adversarial proceedings would irritate an already sensitive social field. And how could the winners and losers of bitter courtroom battles live and work with each other afterwards?

One obvious suggestion is that systems which are designed to detect interpersonal problems early and head them off through mediation should be considered for space living. Glazer, for example, calls for a new kind of legal specialist—not an adversarial advocate, but someone who settles disputes on behalf of the interests of all spacefarers on a mission. He draws his model from the Tabula de Amalfa, the maritime code of the once powerful Mediterranean naval power of Amalfi. Their code provided for a “consul” who sailed aboard each merchant vessel with the power to adjudicate differences between master, crew, and others on board (Glazer 1985, pp. 26–27; Twiss 1876, p. 11). In addition to looking to this and perhaps other maritime analogs, it is tempting to suggest that, with an eye to the more distant future of large space settlements, we also examine major contemporary societies in which harmony and cooperation is stressed. The example of Japan, with its low crime rate and relative paucity of lawyers, comes to mind—although its utility as a model for international efforts may be limited in that Japan is such an ethnically homogeneous society

Bluth, B. J. 1981. Soviet Space Stress. Science 81, vol. 2, no. 7, pp. 30–35.
Carr, Gerald Paul. 1981. Comments from a Skylab Veteran. The Futurist 15:38.
Glazer, J. Henry. 1985. Astrolaw Jurisprudence in Space as a Place: Right Reason for the Right Stuff. Brooklyn J. Int. Law 11 (1): 1–43.
Grigoriev, A. I.; O. P. Kozerenko; and V. I. Myasnikov. 1985. Selected Problems of Psychological Support of Prolonged Space Flights. Preprint of a paper delivered at the Int. Astronaut. Fed. Congress, Stockholm.
Helmreich, Robert L. 1983. Applying Psychology in Outer Space. American Psychologist 38: 445–450.
Oberg, Alcestis R. 1985. Spacefarers of the ’80s and ’90s: The Next Thousand People in Space. New York: Columbia Univ. Press.
Twiss, Travers. 1876. The Black Book of the Admiralty, Vol. 4. London: Her Majesty’s Stationary Office.
From SPACE MIGRATIONS: ANTHROPOLOGY AND THE HUMANIZATION OF SPACE by Ben R. Finney. Collected in Space Resources NASA SP-509 vol 4

     Rioz said, “Haven't you ever been in space, Ted?”
     “You know I have. Why do you ask?”
     “Sure, I know you have, but you still talk like a Grounder. Have you thought of the distances involved? The average asteroid is a hundred twenty million miles from Mars at the closest. That's twice the Venus-Mars hop and you know that hardly any liners do even that in one jump. They usually stop off at Earth or the Moon. After all, how long do you expect anyone to stay in space, man?
     “I don't know. What's your limit?”
     “You know the limit. You don't have to ask me. It's six months. That's handbook data. After six months, if you're still in space, you're psychotherapy meat. Right, Dick?”
     Swenson nodded.
     “And that's just the asteroids,” Rioz went on. “From Mars to Jupiter is three hundred thirty million miles, and to Saturn it's seven hundred million. How can anyone handle that kind of distance? Suppose you hit standard velocity, or, to make it even, say you get up to a good two hundred kilomiles an hour. It would take you—let's see, allowing time for acceleration and deceleration—about six or seven months to get to Jupiter and nearly a year to get to Saturn. Of course, you could hike the speed to a million miles an hour, theoretically, but where would you get the water to do that?”...
     ...Long said, “I'm talking about Saturn, not Vesta.”
     Rioz addressed an unseen audience. ”I tell him seven hundred million miles and he keeps on talking.”
     “All right,” said Long, “suppose you tell me how you know we can only stay in space six months, Mario?
     “It's common knowledge, damn it.”
     “Because it's in the Handbook of Space Flight. It's data compiled by Earth scientists from experience with Earth pilots and spacemen. You're still thinking Grounder style. You won't think the Martian way.
     “A Martian may be a Martian, but he's still a man.”
     “But how can you be so blind? How many times have you fellows been out for over six months without a break?”
     Rioz said, “That's different.”
     “Because you're Martians? Because you're professional Scavengers?”
     “No. Because we're not on a flight. We can put back for Mars any time we want to.”
     “But you don't want to. That's my point. Earthmen have tremendous ships with libraries of films, with a crew of fifteen plus passengers. Still, they can only stay out six months maximum. Martian Scavengers have a two-room ship with only one partner. But we can stick it out more than six months.
     Dora said, “I suppose you want to stay in a ship for a year and go to Saturn.”
     “Why not, Dora?” said Long. ”We can do it. Don't you see we can? Earthmen can't. They've got a real world. They've got open sky and fresh food, all the air and water they want. Getting into a ship is a terrible change for them. More than six months is too much for them for that very reason. Martians are different. We've been living on a ship our entire lives.
     “That's all Mars is—a ship. It's just a big ship forty-five hundred miles across with one tiny room in it occupied by fifty thousand people. It's closed in like a ship. We breathe packaged air and drink packaged water, which we repurify over and over. We eat the same food rations we eat aboard ship. When we get into a ship, it's the same thing we've known all our lives. We can stand it for a lot more than a year if we have to.

From THE MARTIAN WAY by Isaac Asimov (1952)

Discworld Mine Sign

Terry Pratchett's Discworld novels are satirical fantasy for thinking people. While they are comedy, many of the jokes require a bit of scientific knowledge on the part of the reader. Which explains why I find them so entertaining. My personal favorites are The Truth (the invention of the newspaper), Going Postal (post office vs the Victorian internet), and Raising Steam (the invention of the steam locomotive).

Anyway like many fantasy novels the Discworld has a race of dwarfs. They spend most of their time in cramped mines in very close quarters with other dwarfs. Things can get tense.

Much like spacers on a prolonged deep-space mission in a tiny hab module, actually. Or asteroid miners.

As a sort of social network to reduce tensions Discworld dwarves use something called "mine signs", a species of graffiti. I am wondering of the idea can be adapted to a rocketpunk universe. Imagine Banksy using Spacers Runic


     'And talking of shapes, do you know what this means? I spotted it in the mine, and a dwarf called Helmclever scrawled it in some spilt coffee, and you know what? I think he was only half aware that he'd done it.'
     Carrot picked up the notebook and regarded the sketch solemnly for a moment.
     'Mine sign, sir,' he said. 'It means "the Following Dark".'
     'And what does that mean?'
     'Er, that things are pretty bad down there, sir,' said Carrot earnestly. 'Oh dear.' He put the notebook down slowly, as if half afraid that it might explode.
     'Well, there has been a murder, captain,' Vimes pointed out.
     'Yes, Sir. But this might mean something worse, sir. Mine-sign is a very strange phenomenon.'
     'There was a sign like it over the door, only there was just one line and it was horizontal,' Vimes added.
     'Oh, that'd be the Long Dark rune, sir,' said Carrot dismissively. 'It's just the symbol for a mine. Nothing to worry about.'

     'What are these mine signs all about?' he said. 'That Helmclever sort of drew one at me. I saw one on the wall, too. And you drew one.
     "'The Following Dark",' said Carrot. 'Yes. It was scrawled all over the place.'
     'What does it mean?'
     'Dread, sir,' said Carrot earnestly. 'A warning of terrible things to come.'
     'Well, if one of those little sods so much as surfaces with one of those flame weapons in his hand that will be true. But you mean they scrawl it on walls?'
     Carrot nodded. 'You have to understand about a dwarf mine, sir. It's a kind of—'

     —emotional hothouse, was how Vimes understood it, although no dwarf would ever describe it that way. Humans would have gone insane living like that, cramped together, no real privacy, no real silence, seeing the same faces every day for years on end. And since there were a lot of pointy weapons around, it'd only be a matter of time before the ceilings dripped blood.
     Dwarfs didn't go mad. They stayed thoughtful and sombre and keen on their job. But they scrawled mine-sign.
     It was like an unofficial ballot, voting by graffiti, showing your views on what was going on. In the confines of a mine any problem was everyone's problem, stress leapt from dwarf to dwarf like lightning. The signs earthed it. They were an outlet, a release, a way of showing what you felt without challenging anyone (because of all the pointy weapons).
     The Following Dark: We await what follows with dread. Another translation might mean, in effect: Repent, ye sinners!

     'There's the Waiting Dark that's the dark that fills a new hole. The Closing Dark I don't know about that one, but there's an Opening Dark, too. The Breathing Dark, that's rare. The Calling Dark, very dangerous. The Speaking Dark, the Catching Dark. The Secret Dark, I've seen that. They're all fine. But the Following Dark is a very bad sign. I used to hear the older dwarfs talking about that. They said it could make lamps go out, and much worse things. When people start drawing that sign, things have got very bad.'
     'This is all very interesting, but-'
     'Everyone in the mine is as nervous as heck, sir. Stressed like wires. Angua said she could smell it, but so could I, sir. I grew up in a mine. When something is wrong, everyone catches it. On days like that, sir, my father used to stop all mining operations. You get too many accidents. Frankly, sir, the dwarfs are mad with worry. The Following Dark signs are everywhere. It's probably the miners they've hired since they came here. They feel that something is very wrong, but the only thing they can do about it is sign.'

     'Captain, I'm getting a bit lost here,' said Vimes. 'I didn't grow up in a mine. Are these signs drawn because dwarfs think bad things are going to happen and want to ward them off, or think the mine deserves the bad things happening, or because they want the bad things to happen?'
     'Can be all three at once,' said Carrot, wincing. 'It can get really intense when a mine goes bad.'

From THUD! by Terry Pratchett (2005)

Social Media

On a spacecraft it might be considered a bit ghetto-like to spray-paint Dwarf Mine Signs on the corridor walls to blow off emotional steam, even if you are using Spacer's Runic. Especially if this is a military spacecraft.

A more sophisticated method to deal with crew getting cabin fever would be to use a shipboard version of social media (space twitter) sending hashtags as a reflexive meta-commentary ( #THEFOODSTINKS! ). The main thing is that the messages have to be sent anonymously. Just like graffiti.

There was something like that in Sir Arthur C. Clarke's novel The Songs of Distant Earth, called "Shipnet."


(ed note: the vacuum-energy drive STL starship Magellan is making a stop-over at the interstellar colony Thalassa to renew their solid ice debris shield. During the stop-over, some of the crew figure they might as well stay on Thalassa.)

Annoyed at letting his attention stray from the immediate problem, the captain reread the message he now knew by heart:


Sir: A number of us wish to make the following proposal, which we put forward for your most serious consideration. We suggest that our mission be terminated here at Thalassa.

All its objectives will be realized, without the additional risks involved in proceeding to Sagan 2. We fully recognize that this will involve problems with the existing population, but we believe they can be solved with the technology we possess - specifically, the use of tectonic engineering to increase the available land area.

As per Regulations, Section 14, Para 24 (a), we respectfully request that a Ship’s Council be held to discuss this matter as soon as possible.

     ‘So I should hope,’ Captain Bey said impatiently. ‘Have you any idea who could have sent it?’
     ‘None whatsoever. Excluding the three of us, I’m afraid we have 158 suspects.’…
     …‘That doesn’t narrow the field much,’ the Captain said, managing a bleak smile. ‘Have you any theories, Doctor?’
     Indeed I have, Kaldor thought. I lived on Mars for two of its long years; my money would be on the Sabras. But that’s only a hunch, and I may be wrong…
     ‘Not yet, Captain. But I’ll keep my eyes open. If I find anything, I’ll inform you — as far as possible.’
     The two officers understood him perfectly. In his role as counsellor, Moses Kaldor was not even responsible to the captain. He was the nearest thing aboard Magellan to a father confessor.
     ‘I assume, Dr Kaldor, that you’ll certainly let me know — if you uncover information that could endanger this mission.’
     Kaldor hesitated, then nodded briefly. He hoped he would not find himself in the traditional dilemma of the priest who received the confession of a murderer — who was still planning his crime.
     I’m not getting much help, the captain thought sourly. But I have absolute trust in these two men, and need someone to confide in. Even though the final decision must be mine.
     ‘The first question is should I answer this message or ignore it? Either move could be risky. If it’s only a casual suggestion — perhaps from a single individual in a moment of psychological disturbance — I might be unwise to take it too seriously. But if it’s from a determined group, then perhaps a dialogue may help. It could defuse the situation. It could also identify those concerned.’ And what would you do then? the captain asked himself. Clap them in irons?
     ‘I think you should talk to them,’ Kaldor said. ‘Problems seldom go away if they’re ignored.’
     Captain Bey found it distinctly unsettling, having to go about the ship’s business not knowing who — or how many — of his officers or crew were addressing him through the anonymity of SHIPNET. There was no way that these unlogged inputs could be traced — confidentiality was their very purpose, built in as a stabilizing social mechanism by the long-dead geniuses who had designed Magellan. He had tentatively raised the subject of a tracer with his chief communications engineer, but Commander Rocklyn had been so shocked that he had promptly dropped the matter.

     It was a simple question, but it did not have a simple answer: What would happen to discipline aboard Magellan if the very purpose of the ship’s mission was put to the vote?
     Of course, any result would not be binding, and he could override it if necessary. He would have to, if a majority decided to stay (not that for a moment he imagined …) But such an outcome would be psychologically devastating. The crew would be divided into two factions, and that could lead to situations he preferred not to contemplate…
     …And now his unknown petitioners were calling themselves the New Thalassans. Did that mean, Captain Bey wondered, that there were many of them and they were getting organized into a political movement? If so, perhaps the best thing would be to get them out into the open as soon as possible.
     Yes, it was time to call Ship’s Council.

     …‘And who will present the motions? We can’t expect the New Thalassans to come out into the open and plead their case.’
     ‘I wish we could have a straight vote without any arguments and discussions,’ Deputy Captain Malina had lamented.
     Privately, Captain Bey agreed. But this was a democratic society of responsible, highly educated men, and Ship’s Orders recognized that fact. The New Thalassans had asked for a Council to air their views; if he refused, he would be disobeying his own letters of appointment and violating the trust given him on Earth two hundred years ago.

     It had not been easy to arrange the Council. Since everyone, without exception, had to be given a chance of voting, schedules and duty rosters had to be reorganized and sleep periods disrupted. The fact that half the crew was down on Thalassa presented another problem that had never arisen before — that of security. Whatever its outcome might be, it was highly undesirable that the Lassans overhear the debate …
     And so Loren Lorenson was alone, with the door of his Tarna office locked for the first time he could recall, when the Council began. Once again he was wearing full-view goggles; but this time he was not drifting through a submarine forest. He was aboard Magellan, in the familiar assembly room, looking at the faces of colleagues, and whenever he switched his viewpoint, at the screen on which their comments and their verdict would be displayed. At the moment it bore one brief message:

RESOLVED: That the Starship Magellan terminate its mission at Thalassa as all its prime objectives can be achieved here.
     ‘Captain, officers, fellow crewmembers — although this is our first Council, you all know the rules of procedure. If you wish to speak, hold up your hand to be recognized. If you wish to make a written statement, use your keypad; the addresses have been scrambled to ensure anonymity. In either case, please be as brief as possible…
     …For at least a minute, nothing happened. Then letters began to appear on the screen.




     With total secrecy and neutrality, the computer stored and numbered the inputs from the Council members. In two millennia, no one had been able to invent a better way of sampling group opinion and obtaining a consensus. All over the ship — and down on Thalassa — men and women were tapping out messages on the seven buttons of their little one-hand keypads. Perhaps the earliest skill acquired by any child was the ability to touch-type all the necessary combinations without even thinking about them.
     Loren swept his eye across the audience and was amused to note that almost everyone had both hands in full view. He could see nobody with the typical far-off look, indicating that a private message was being transmitted via a concealed keypad. But somehow, a lot of people were talking.

     That would be, let’s see … Of course — Kingsley Rasmussen. Obviously he had no wish to remain incognito. He was expressing a thought that at one time or other had occurred to almost everyone.

From THE SONGS OF DISTANT EARTH by Sir Arthur C. Clarke (1985)

How Space Kills You

A NASA technician said "If you treat vacuum as you would poison gas you won't go far wrong."

How does space kill you? Let me count the ways. Face it, the human body was not designed to properly function in the vacuum of space. At a rough guess a person can survive space exposure as long as they are placed back inside a pressured atmosphere within 90 seconds. After that time, death might be unavoidable. You will only have about ten seconds before you become unconscious. Dr. Geoffrey Landis has an analysis here. There are some more links on the topic of explosive decompression here.

And anybody who's seen 2001 A Space Odyssey knows that a human exposed to vacuum is not going to pop like a balloon.

In order of lethality the effects are:

Formation of gas bubbles in bodily fluids by reduction of environmental pressure aka your blood starts to boil. Your eyes and mouth freeze due to evaporative cooling, tissue dies with loss of oxygen, entire body swells enormously, circulatory failure, muscle failure due to flaccid paralysis, lungs collapse and fill with ice.
The body being deprived of adequate oxygen supply aka there ain't nothing to breath in space. Ataxia, confusion, disorientation, hallucinations, behavioral change, severe headaches, reduced level of consciousness, papilloedema, breathlessness, pallor, tachycardia, pulmonary hypertension, cyanosis, bradycardia, cor pulmonale, low blood pressure, death
A state of reduced carbod dioxide in the blood aka turbocharged hyperventilation. Transient dizziness, visual disturbances, anxiety, pins and needles sensation, muscle cramps and tetany in hands and feet.
Decompression Sickness
Dissolved gases coming out of solution into bubbles inside the body on depressurisation aka turn your blood stream into red foam like a shaken can of soda pop. Symptoms may range from rash to agonizing joint paint to death.
Extreme Temperature Variations
In sunlight at Terra's orbit the body may overheat, in shadow the body can lose heat at a rate of up to 1,000 watts.
Prolonged exposure to ultraviolet, x-rays, and energized protons can cause death by organ failure, short-term exposure may cause cancer.

If you take glass of water, and lower the air pressure, the temperature point at which the water boils is lowered as well. This is why cake mixes have high altitude instructions: the watery part has a lower boiling point/maximum temperature than normal so it takes longer to cook. If you are living in a habitat module with a pure oxygen breathing mix, the pressure will be at about 32.4 kPa (80% normal Terran atmospheric pressure). Here too the cake mixes will take longer to cook since water boils at 70° C, and your tea will always be lukewarm.

What I am leading up to is the Armstrong Limit. You see, if the pressure drops to 6.3 kPa, water will boil at 37° C. Which just happens to be normal human body temperature. The saliva will boil off your tongue, the tears will boil off your eyes. If you become so frightened that you pee in your pants, that will boil as well. The same goes for poop but that's a horrible image I just don't want to think about.

The blood will boil in your veins too, were it not for the fortunate fact that your skin will pressurize your vascular system enough to prevent that unhappy state of affairs. This is why soft suits can get away with not pressurizing your body.

Naturally astronauts will not commonly be constantly exposed to 6.3 kPa. Much more likly they will briefly encounter it as the pressure plummets to zero kPa, as all the breathing mix goes rushing out a deadly tear in their space suit or a major breech in the hull of the habitat module.

But in any event if your saliva starts to boil, be aware that you have only ten seconds to get to safety before you lose consiousness, and 80 additional seconds for your buddies to drag you into somewhere pressurized before you die. Be quick or be dead.

In addition: hands, feet, arms, and legs that are no pressurized will suffer an attack of Kittinger Syndrome. They will swell up to about twice normal size, with accompanying agonizing pain. Bringing back pressure will return them to normal, but if swollen for more than a few minutes there wil be aneurisms and hematomas.

We've had our expected quota of minor industrial accidents. Cuts, bruises, contusions, a few broken bones, some cases of exhaustion because a rigger worked beyond his limits in vacuum and zero-g, a couple of burns, but nothing really serious until we ran into "vac bite."

The safety compartmentalization of the P-suits hasn't always been a safety measure, although it's undoubtedly saved many lives from traumatic abaryia (sudden loss of all pressure in one's space suit). Nobody thought about secondary effects. The cuff latch on a man's glove jailed yesterday, and the glove blew away. "Vac bite"—which is what we're calling it colloquially until I can figure out a suitable Greco-Latin term —is the result of exposure of the extremities to vacuum conditions.

The extremity—hand, foot, arm, etc.—doesn't explode; connective tissue's strong and the human skin's remarkably tough. But the extremity swells up in the Kittinger Syndrome, first experienced by Captain Joseph Kittinger during a stratospheric parachute jump back in 1960. The absence of atmospheric pressure causes vasodilation and edema, which becomes very painful. The swelling also inhibits movement. If the abaryic condition prevails for several minutes, it can cause aneurism and rupture of the capillary walls followed by hematomas. Unless there's a cut or other opening in the skin, there's little chance of blood loss. But if the abaryic condition continues, tissue's destroyed. The course of the affliction begins to parallel that of frostbite, which is the reason it got its vernacular name. It's painful as hell and immobilizes the extremity. Right now, the only way we know to treat it is with cold packs or hypothermic immersion, along with analgesics and mild diuretics. I'm thinking about the possibility of trying a hyperbaric chamber, but we haven't got one here yet. Maybe in a year or so.

No bends yet. Everyone flushes the nitrogen out of his system for thirty minutes by breathing pure Oh-two before cycling into vacuum. But if there were an explosive decompression of any of the living spaces in GEO Base or with my paramedics on an emergency, we'd get bends because we're running an oxynitrogen atmosphere.

From SPACE DOCTOR by Lee Correy (G. Harry Stine) 1981

"You know what the folks back home don't understand, the ones who've never left Earth, is just how dangerous space can be. Aside from incidents like this, just the everyday reality of living your days and nights in a big tin can surrounded by a vacuum."

"I remember my first time on a transport, on the Moon-Mars run. I was just a kid, maybe seventeen. A buddy of mine was messing around, and zipping through the halls, and he hid in one of the airlocks. I don't know, I guess he was gonna try to scare us or something, I don't know... But just as I got close, he must have hit the wrong button because the air doors slammed shut, the space doors opened, and he... just flew out into space."

"And the one thing they never tell you is that you don't die instantly in vacuum. He just hung there against the black like a puppet with his strings all tangled up... or one of those old cartoons where you run off the edge of the cliff and your legs keep going."

"You could see that he was trying to breathe, but there was nothing. The one thing I remember when they pulled in his body... his eyes were frozen."

"A lot of people make jokes about spacing somebody, about shoving somebody out an airlock -- I don't think it's funny. Never will."

From BABYLON 5: "AND NOW FOR A WORD". Dr. Franklin relates a tragic experience.

"Pegasus to Acheron," he replied. "I have three hundred passengers aboard. I cannot hazard my ship if there is danger of an explosion."

"There is no danger, I can guarantee that. We will have at least five minutes' warning, which will give us ample time to get clear of you."

"Very well—I'll get my airlocks ready and my crew standing by to pass you a line."

There was a pause longer than that dictated by the sluggish progress of radio waves. Then Brennan replied: "That's our trouble. We're cut off in the forward section. There are no external locks here, and we have only five suits among a hundred and twenty men."

Halstead whistled and turned to his navigating officer before answering.

"There's nothing we can do for them," he said. "They'll to crack the hull to get out, and that will be the end of everyone exceed the five men in the suits. We can't even lend them our own suits—there'll be no way we can get them aboard without letting down the pressure." He flicked over microphone switch.

"Pegasus to Acheron. How do you suggest we can assist you?" It was eerie to be speaking to a man who was already as good as dead. The traditions of space were as strict as those of the sea. Five men could leave the Acheron alive, but her captain would not be among them.

Halstead did not know that Commodore Brennan had other ideas, and had by no means abandoned hope, desperate though the situation on board the Acheron seemed. His chief medical officer, who had proposed the plan, was already explaining it to the crew.

"This is what we're going to do," said the small, dark man who a few months ago had been one of the best surgeons on Venus. "We can't get at the airlocks, because there's vacuum all round us and we've only got five suits. This ship was built for fighting, not for carrying passengers, and I'm afraid her designers had other matters to think about besides Standard Spaceworthiness Regs. Here we are, and we have to make the best of it.

"We'll be alongside the Pegasus in a couple of hours. Luckily for us, she's got big locks for loading freight and passengers there's room for thirty or forty men to crowd into them, if they squeeze tight—and aren't wearing suits. Yes, I know that sounds bad, but it's not suicide. You're going to breathe space, and get away with it! I won't say it will be enjoyable, but it will be something to brag about for the rest of your lives.

"Now listen carefully. The first thing I've got to prove to you is that you can live for five minutes without breathing—in fact, without wanting to breathe. It's a simple trick: Yogis and magicians have known it for centuries, but there's nothing occult about it and it's based on common-sense physiology. To give you confidence, I want you to make this test."

The M. O. pulled a stop watch out of his pocket, ad continued: "When I say 'Now!' I want you to exhale completely—empty your lungs of every drop of air—and then see how long you can stay before you have to take a breath. Don't strain—just hold out until it becomes uncomfortable, then start breathing again normally. I'll start counting the seconds after fifteen, so you can tell what you managed to do. If anyone can't take the quarter minute, I'll recommend his instant dismissal from the Service."

The ripple of laughter broke the tension, as it had been intended to; then the M. O. held up his hand, and swept it down with a shout of "Now!" There was a great sigh as the entire company emptied its lungs; then utter silence.

When the M. O. started counting at "Fifteen," there were a few gasps from those who had barely been able to make the grade. He went on counting to "Sixty" accompanied by occasional explosive pants as one man after another capitulated. Some were still stubbornly holding out after a full minute, "That's enough," said the little surgeon. "You tough guys can stop showing off, you're spoiling the experiment."

Again there was a murmur of amusement; the men were rapidly regaining their morale. They still did not understand what was happening, but at least some plan was afoot that offered them a hope of rescue.

"Let's see how we managed," said the M. O. "Hands up all those who held out for fifteen to twenty seconds…Now twenty to twenty-five…Now twenty-five to thirty—Jones, you're a damn liar—you folded up at fifteen!—Now thirty to thirty-five… When he had finished the census, it was clear that more than half the company had managed to hold their breath for thirty seconds, and no one had failed to reach fifteen seconds.

"That's about what I expected," said the M. O. "You can regard this as a control experiment, and now we come on to the real thing. I ought to tell you that we're now breathing almost pure oxygen here, at about three hundred millimeters. So although the pressure in the ship is less than half its sea-level value on Earth, your lungs are taking in twice as much oxygen as they would on Earth, and still more than they would on Mars or Venus. If any of you have sneaked off to have a surreptitious smoke in the toilet, you'll already have noticed that the air was rich, as your cigarette will only have lasted a few seconds.

"I'm telling you all this because it will increase your confidence to know what is going on. What you're going to do now is to flush out your lungs and fill your system with oxygen. It's called hyperventilation, which is simply a ten dollar word for deep breathing. When I give the signal, I want you all to breathe as deeply as you can, then exhale completely, and carry on breathing in the same way until I tell you to stop. I'll tell you do it for a minute; some of you may feel a bit dizzy at the end of that time, but it'll pass. Take in all the air you can with every breath; swing your arms to get maximum chest expansion.

"Then, when the minute's up, I'll tell you to exhale, then stop breathing, and I'll begin counting seconds again. I think I can promise you a big surprise. O. K.—here we go!"

For the next minutes, the overcrowded compartments of the Acheron presented a fantastic spectacle. More than a hundred men were flailing their arms and breathing stertorously, as if each was at his last gasp. Some were too closely packed together to breathe as deeply as they would have liked, and all had to anchor themselves somehow so that their exertion would not cause them to drift around the cabins.

"Now!" shouted the M. O. "Stop breathing—blow out all your air—and see how long you can manage before you've got to start again. I'll count the seconds, but this time I won't begin until half a minute has gone."

The result, it was obvious, left everyone flabbergasted. One man failed to make the minute, otherwise almost two minutes elapsed before most of the men felt the need to breathe again. Indeed, to have taken a breath before then would have demanded a deliberate effort. Some men were still perfectly comfortable after three or four minutes; one was holding out at five when the doctor stopped him.

"I think you'll all see what I was trying to prove. When your lungs are flushed out with oxygen, you just don't want to breathe for several minutes, any more than you want to eat again after a heavy meal. It's no strain or hardship; it's not a question of holding your breath. And if your life depended on it, you could do even better than this, I promise you.

"Now we're going to tie up right alongside the Pegasus; it will take less than thirty seconds to get over to her. She'll have her men out in suits to push along any stragglers, and the air lock doors will be slammed shut as soon as you're all inside. Then the lock will be flooded with air and you'll be none the worse except for some bleeding noses."

He hoped that was true. There was only one way to find out. It was a dangerous and unprecedented gamble, but there was no alternative. At least it would give every man a fighting chance for his life.

"Now," he continued, "you're probably wondering about the pressure drop. That's the only uncomfortable part, but you won't be in a vacuum long enough for severe damage. We'll open the hatches in two stages; first we'll drop pressure slowly to a tenth of an atmosphere, then we'll blow out completely in one bang and make a dash for it. Total decompression's painful, but not dangerous. Forget all that nonsense you may have heard about the human body blowing up in a vacuum. We're a lot tougher than that, and the final drop we're going to make from a tenth of an atmosphere to zero is considerably less than men have already stood in lab tests. Hold your mouth wide open and let yourself break wind. You'll feel your skin stinging all over, but you'll probably be too busy to notice that."

The M. O. paused, and surveyed his quiet, intent audience. They were all taking it very well, but that was only to be expected. Every one was a trained man—they were the pick of the planets' engineers and technicians.

"As a matter of fact," the surgeon continued cheerfully, "you'll probably laugh when I tell you the biggest danger of the lot. It's nothing more than sunburn. Out there you'll be in the sun's raw ultra-violet, unshielded by atmosphere. It can give you a nasty blister in thirty seconds, so we'll make the crossing in the shadow of the Pegasus. If you happen to get outside that shadow, just shield your face with your arm. Those of you who've got gloves might as well wear them.

"Well, that's the picture. I'm going to cross with the first team just to show how easy it is. Now I want you to split up into four groups, and I'll drill you each separately."

Side by side, the Pegasus and the Acheron raced toward the distant planet that only one of them would ever reach. The airlocks of the liner were open, gaping wide no more than a few meters from the hull of the crippled battleship. The space between the two vessels was strung with guide ropes, and among them floated the men of the liner's crew, ready to give assistance if any of the escaping men were overcome during the brief but dangerous crossing.

It was lucky for the crew of the Acheron that four pressure bulkheads were still intact. Their ship could still be divided into four separate compartments, so that a quarter of the crew could leave at a time. The airlocks of the Pegasus could not have held everyone at once if a mass escape had been necessary.

Captain Halstead watched from the bridge as the signal given. There was a sudden puff of smoke from the hull of the battleship, then the emergency hatch—certainly never designed for an emergency such as this—blew away into space. A cloud of dust and condensing vapor blasted out, obscuring the view for a second. He knew how the waiting men would feel the escaping air sucking at their bodies, trying to tear them away from their handholds.

When the cloud had dispersed, the first men had already emerged. The leader was wearing a spacesuit, and all the others were strung on the three lines attached to him. Instantly, men from the Pegasus grabbed two of the lines and darted off to their respective airlocks. The men of the Acheron, Halstead was relieved to see, all appeared to be conscious and to be doing everything they could to help.

It seemed ages before the last figure on its drifting line was towed or pushed into an airlock. Then the voice from one of those spacesuited figures out there shouted, "Close Number Three!" Number One followed almost at once; but there was an agonizing delay before the signal for Two came. Halstead could not see what was happening; presumably someone was still outside and holding up the rest. But at last all the locks were closed. There was no time to fill them in the normal way; valves were jerked open by brute force and the chambers filled with air from the ship.

Aboard the Acheron, Commodore Brennan waited with remaining ninety men, in the three Compartments that were unsealed. They had formed their groups and were strung in chains of ten behind their leaders. Everything had been planned and rehearsed; the next few seconds would prove whether or not in vain.

Then the ship's speakers announced, in an almost quietly conversational tone: Pegasus to Acheron. We've got all your men out of the locks. No casualties. A few hemorrhages. Give us five minutes to get ready for the next batch."

They lost one man on the last transfer. He panicked and they had to slam the lock shut without him, rather than risk the lives of all the others. It seemed a pity that they could not all have made it, but for the moment everyone was too thankful to worry about that.

From EARTHLIGHT by Sir Arthur C. Clarke (1955)

McAndrew stood at the outer lock, ready to open it. I pulled the whistle from the lapel of my jacket and blew hard. The varying triple tone sounded through the lock. Penalty for improper use of any Sturm Invocation was severe, whether you used spoken, whistled, or electronic methods. I had never invoked it before, but anyone who goes into space, even if it is just a short trip from Earth to Moon, must receive Sturm vacuum survival programming. One person in a million uses it. I stood in the lock, waiting to see what would happen to me.

The sensation was strange. I still had full command of my movements, but a new set of involuntary activities came into play. Without any conscious decision to do so I found that I was breathing hard, hyper-ventilating in great gulps. My eye-blinking pattern had reversed. Instead of open eyes with rapid blinks to moisten and clean the eyeball, my lids were closed except for brief instants. I saw the lock and the space outside as quick snapshots.

The Sturm Invocation had the same effect an McAndrew, as his own deep programming took over for vacuum exposure. When I nodded, he swung open the outer lock door. The air was gone in a puff of ice vapor. As my eyes flicked open I saw the capsule at the top of the landing tower. To reach it we had to traverse sixty meters of the interstellar vacuum. And we had to carry Sven Wicklund's unconscious body between us.

For some reason I had imagined that the Sturm vacuum programming would make me insensitive to all pain. Quite illogical, since you could permanently damage your body all too easily in that situation. I felt the agony of expansion through my intestines, as the air rushed out of all my body cavities. My mouth was performing an automatic yawning and gasping, emptying the Eustachian tube to protect my ear drums and delicate inner ear. My eyes were closed to protect the eyeballs from freezing, and open just often enough to guide my body movements.

Holding Wicklund between us, McAndrew and I pushed off into the open depths of space. Ten seconds later, we intersected the landing tower about twenty meters up. Sturm couldn't make a human comfortable in space, but he had provided a set of natural movements that corresponded to a zero-gee environment. They were needed. If we missed the tower there was no other landing point within light-years.

The metal of the landing tower was at a temperature several hundred degrees below freezing. Our hands were unprotected, and I could feel the ripping of skin at each contact. That was perhaps the worst pain. The feeling that I was a ball, over-inflated and ready to burst, was not a pain. What was it? That calls for the same sort of skills as describing sight to a blind man. All I can say is that once in a lifetime is more than enough.

Thirty seconds in the vacuum, and we were still fifteen meters from the capsule. I was getting the first feeling of anoxia, the first moment of panic. As we dropped into the capsule and tagged shut the hatch I could feel the black clouds moving around me, dark nebulae that blanked out the bright star field.

The transfer capsule had no real air lock. When I hit the air supply, the whole interior began to fill with warm oxygen. As the concentration grew to a perceptible fraction of an atmosphere, I felt something turn off abruptly within me. My eye blinking went back to the usual pattern, my mouth closed instead of gaping and gasping, and the black patches started to dwindle and fragment.

From "ALL THE COLORS OF THE VACUUM" by Charles Sheffield (1981)

Artist Nathan Hoste is doing a well-researched series called Bodies in Space on all the damage space does to an unprotected human. Warning, images may be considered NSFW.


Arguably the biggest killer in the space environment is Stupidity.

Larry Niven coined the phrase "Think of it as evolution in action".


“What’s retirement?”

In the inchoate years of the space age, the “old age” cause of death was abrogated in favor of more precise terms: “heart failure”, “secondary infection from weakened immune response”, und so weiter.

In subsequent years, a new cause was added: “stupidity”.

Space is hazardous to the point of absurdity. Leaking atmo? Death. Forget your transfer window? Death. Out of EVA fuel? Death. The universe is cold and dispassionate, and with better tools and equipment, the human error of incompetence increasingly–and vastly–was outstripping pure technological failure.

When the report came in of another deceased spacer, the cause of death ended up being “stupidity” more than 3/4 of the time. Did it really matter that he suffocated on his own vomited organs? No. It mattered that, due to stupidity, he ventured outside the shadow shield of his atom-ship. Did it really matter that her flesh slowly charred away, trapped by her own skeleton in restraints of melting steel? No. It mattered that she crammed her ship full of personal effects and didn’t have enough fuel to break atmo.

Death in space environments is final and harsh. And when a corpse can be recovered, exact specificity in cause is wasted inquiry, and never comfort to the bereaved.

From CAUSAM MORTIS by Ian Mallett (2016)

Space will kill you in any number of ways. So, in fact, will most planets that aren’t your homeworld or close copies of it.

Simple risks will kill you, if you don’t keep a weather eye on them. Radiation, vacuum, dioxide, heat. Leaks, breakdowns, inefficiencies. Not paying attention to where your air and water and other things that just magically exist for the taking downside come from, that’ll kill you, too. Carelessness, inattention, expediency, pragmatism, shortcut-taking, an excessively casual approach to maintenance procedures — all things that bring an automatic death sentence at the hands of the uncaring, pedantic universe. Incompetence, determined ignorance, and native stupidity, even more so. And indulging one’s fond delusions about the nature of reality, that’ll kill you fastest of all.

These are the reasons why many sensible people from many sensible civilizations choose not to go there.

The people who scattered habs across the entire system from Oculus to Farside, from Eurymir to Galine, from corona-scraping Salamandrine to lonely Blackwatch, on the other hand, considered these things advantages.

— introduction to Tin Cans and Checklists: The Early Days, by Aithne Silverfall


Stupidity cannot be cured with money, or through education, or by legislation. Stupidity is not a sin, the victim can't help being stupid. But stupidity is the only universal capital crime; the sentence is death, there is no appeal and execution is carried out automatically and without pity.

From TIME ENOUGH FOR LOVE by Robert Heinlein (1973)

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This week's featured addition is High Specific Impulse Gas Core Reactors

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