Atomic Rockets

Introduction

RocketCat sez

Listen up, space cadets! Here's the deal:

Spaceship and spacestation cabins have air at full pressure. If you use air at low pressure the blasted atmo is pure oxy, which is like swimming in a pool of gasoline while idly flicking your Zippo.

Soft space suits are only terribly encumbering, like wearing three snow suits at once. This is their advantage. Disadvantages include the fact they can be punctured by a pair of kindergarten safety scissors, causing certain death. Oh, and they can only use low pressure because high pressure will make the suit spread-eagle you like a Saint Andrew's Cross. Low pressure means you have to do a few hours of pre-breathing or the suit will kill you with The Bends. Which is a problem if an emergency strikes and you don't have a few hours.

Hard shell space suits advantages are: they can use high pressure atmo so you can't get the bends, you don't need to pre-breathe, and you'd need a freaking handgun to puncture it. Disadvantage is they are monumentally overwhelmingly hideously encumbering like wearing a suit of medieval plate armor made out of solid lead. Soft space suits are only terribly encumbering.

Semi-rigid space suits are a cross between soft and hard shell suits. Like all attempts to have it both ways, it means they have the draw-backs of both and the advantages of neither.

Skintight suits have the advantage of being about as encumbering as a wearing leotards, they are quick to put on, and puncturing them just gives you a space-hickey instead of certain death. Disadvantage is they have to use low pressure so The Bends once again raises its ugly head. Also people have a problem getting anybody to take it seriously ("Aw, c'mon, gimmie a break! Who the heck is your suit designer, Earle K. Bergey? Where's the brass brassière?)

A space suit is a protective garment that prevents an astronaut from dying horribly when they step into airless space. SF author Ken MacLeod said that the specification of a human being is "a space suit for a fish."

Current NASA suits look like baggy inflated coveralls with a large back pack and a spherical fishbowl over the head. Often in old illustrations there are accordion bellows at the joints. The accuracy of space suits in science fiction was very much hit or miss.

NASA astronaut always put on a transdermal dimenhydrinate anti-nausea patch when suiting up in a space suit, in case of drop sickness. The chances of that are slight, but suffocating inside a helmet full of vomit is a nasty way to die.


Most space suits are Full Pressure suits: they offer full pressure protection of the body in space for extended periods. Partial Pressure suits only pressurize certain parts of the body for a limited time. They are only used as a precaution, worn inside the habitat module during times when there is danger of it springing a leak (such as during lift-off).

Full Pressure suits can be either Low Pressure (pure oxygen at 32.4 kPa) or High Pressure (breathing mix at 101.3 kPa, normal Terran atmospheric pressure).

All NASA spacecraft and space station habitat modules are High Pressure. At least the ones designed after the Apollo 1 tragedy claimed the lives of three astronauts. Ever since NASA has avoided using pure oxygen atmosphere wherever possible, which means using high pressure.

The problem is if you go from a high-pressure environment (like a habitat module) into a low-pressure environment (like a low-pressure space suit) you run the risk of the bends. To avoid this the astronaut must do pre-breathing for a couple of hours. If you go from a high pressure habitat module into a high-pressure space suit the bends does not happen. This is why high pressure spacesuits are called "zero-prebreathe" suits.

I suppose some space-faring nation could use low pressure pure oxygen habitat modules to avoid pre-breathing with low pressure suits, but that would be insanely dangerous. It would be the outer-space equivalent of those stubborn elderly hospital patients who insist on smoking cigarettes while wearing oxygen tanks.

NASA tolerates low pressure pure oxygen pressurization in their soft space suits because they have no choice. There is not a lot of research, but NASA seems to think that if an astronaut in such a suit got punctured by a micro-meteor and it caught fire, the main hazard is a fire enlarging the diameter of the breach, not an astronaut-shaped ball of flame.


Suits can be Soft, Hard-shell, Semi-Rigid/Hybrid or Skintight.

Soft suits have flexible exteriors. This means they cannot be pressurized to the same level as the inside of the habitat module or the space suited person will be forced into a posture like a star-fish and be unable to bend any joints. Lower pressure means the suit uses pure oxygen unlike the habitat module. And pure oxygen means the astronaut has to do hours pre-breathing before wearing the suit or they will be stricken by The Bends.

Soft suits also take forever to put on, they fight your every movement (making EVA work very fatiguing), and if you tear the suit skin you will die horribly in about 90 seconds. When I say "fight your every movement" I mean "raise the energy expenditure to do a task by about 400%".

Currently most of NASA's space suits are soft suits.

Hard-shell suits have rigid exteriors. The advantage is they can be fully pressurized so no pre-breathing is required. They are also much more tear and puncture resistant than soft suits.

The drawback of hard-shell suits is that they make the "forever to put on" and "fight your every movement" problems much worse.

As far as I know there are no hard-shell suits in active use, they are all experimental.

Semi-rigid or Hybrid suits are a cross between soft and hard-shell. For instance, NASA's EMU has a hard-shell upper torso and soft fabric limbs. Current NASA semi-rigid suits are low pressure, but they are working on a high-pressure model.

Skintight suits are a radical concept that is so crazy it just might work. They make the astronaut's skin into the spacesuit, using high-tech spandex to supply pressure instead of using atmosphere. They can be quickly put on, fight your every movement only to the point of a +20% increase in energy, and if the suit is torn the astronaut only gets a bruise instead of certain death. The suits are also much inexpensive than a soft or hard-shell suit. The major draw-back is they require low pressure breathing mix (or the wearer cannot exhale), so astronauts have to pre-breath or face the Bends.

"Planetary suits" are used when there is an atmosphere, but it isn't breathable. They have a slightly different design from space suits.

Partial-Pressure Suits

To recap: Partial Pressure suits only pressurize certain parts of the body for a limited time. They are only used as a precaution, worn inside the habitat module during times when there is danger of it springing a leak, such as during lift-off or if an enemy spacecraft is shooting at you. Partial pressure suits are a trade-off: they only protect you for a short time but in exchange they do not encumber you anywhere near as much as a full pressure suit.

The NASA version is the Launch Entry Suit aka "pumpkin suit." It has ten minutes worth of life support internal to the suit, and can be hooked up to the vehicles life support system for longer duration.

The image above from First Men to the Moon is a partial pressure suit based on an old school Air Force high-altitude suit. If the pressure drops, the pressure regulating tubes along the suit's seams inflate to put the suit under tension. The wearer will then put on the oxygen mask attached to the small tank strapped to their leg.

The crew of a combat spacecraft in battle probably will not wear a soft, hard-shell, or semi-rigid suit during battle. This is for the same reasons that the crew of a military submarine do not wear SCUBA gear in battle even though they too are in a craft surrounded by countless miles of unbreathable stuff while being shot at. It gets in the way.

But they might wear a partial-pressure suit or a skintight suit.

Or a skintight partial-pressure hybrid suit. This might be so unencumbered that it could be used as everday wear. Then if the habitat module loses pressure all you'd need is an oxygen mask and earplugs to survive for a few hours. Wear it with overalls because such a suit will make you almost as naked as wearing nothing but body paint.

Soft Suits

To recap, Soft Suits:

  • Must have lower pressure than the habitat module or the wearer turns into a starfish and cannot bend their limbs. This means the wearer needs an hour of pre-breathing or they will suffer the Bends.
  • In case of emergency, when there is no time for pre-breathing, NASA helpfully directs the astronauts to gulp aspirin, so they can work in spite of the agonizing pain
  • The breathing mix will be close to pure oxygen, with a higher fire risk.
  • Suit encumbrance increases the energy cost to do various tasks by +400%, with a corresponding increase in wearer fatigue.
  • If the soft skin of the suit is torn or punctured, the wearer will die in about 90 seconds.
  • They take forever to put on

For a list of the parameters for a NASA spec space suit, go here.

The only thing that allows an astronaut to bend their limbs at all is the magic of constant volume joints. These are why most pictures of space suits look like the Michelin Man (i.e., like a stack of donuts).

Dan chuckled, then sobered. "Like that, eh? Okay, you won't get any favors. But you'll still stay here today. Look, Jim, when I first came up, there was a guy named Joe with me. The first day he spotted some cargo drifting off and leaped for it. Put out a hand to grab it—and, naturally, when his arm moved one way his body moved the other. His suit hit a sharp edge of metal. A man dies fast out here when the air runs out of his suit, and it's not a pretty thing to see. You stay inside."

Jim practiced dutifully, gaining some proficiency as he did. He had to learn by experience that the twitch of a foot at the wrong moment could throw him off balance.

From Step to the Stars by Lester Del Rey (1954)

Helmet

In The Millennial Project Savage suggests that the helmet will have an outer layer of five millimeters of high density lead crystal. Inside will be two layers of dense borosilicate glass sandwiched between two layers of Lexan. The middle layer of Lexan will add strength and prevent shattering, the inner will act as a reserve helmet. The outer surface will be gold anodized to block glare, ultraviolet, and infra-red. There may be a nested set of telescoping curved armor plates that can be deployed for further protection.

NASA helmets are not quite so grandiose.

NASA helmets are spherical domes, which hits the sweet spot between low mass, pressure compensation, and field of view. All current NASA suits have the astronaut's head is held facing forwards, you have to turn your entire body in order to look sideways. Astronauts call this "alligator head".

The helmet has to be comfortable to wear, and help in controlling the humidity inside the helmet (so it doesn't fog up). Another important part is the radio communication unit, since the lack of air in space prevents the sound of your voice from reaching anybody. The old tagline to the first ALIEN movie was "In Space No One Can Hear You Scream". Well, no one can hear Floyd asking somebody to pass him a socket wrench either. NASA suits use "Snoopy caps" to hold the communciation earphones and microphones (in NASA-speak this is called the Communications Carrier Assembly (CCA)).

Other items might include windshield wipers (inside for condensation, outside for dust), a build-in set of binoculars, headlights for shadowed areas, a mirrored sun-visor to prevent sunlight from burning out your retinas, a water drink dispenser, and maybe a gadget that can supply various medications (pain relievers, anti-nausea, stimulants).

Some SF novels have a space helmets equipped with a tiny airlock near the mouth, called a "chow-lock." It is used to allow the astronaut to eat and drink without venting the helmet's air to the vacuum of space. I am uncertain how practical this concept is, or how idiot proof it can be made. It would be a bad thing if trying to get a bite of a candy bar accidentally killed you.

As previously mentioned, NASA astronaut always put on a transdermal dimenhydrinate anti-nausea patch when suiting up in a space suit, in case of drop sickness. The chances of that are slight, but suffocating inside a helmet full of vomit is a nasty way to die.

Backpack

In NASA-speak, the backpack is called the Personal (or Primary or Portable) Life Support System (PLSS). At a minimum, it provides breathing mix, removes carbon dioxide, and regulates the suit's pressure.

Additionally it may remove humidity, odors, and contaminants from the breathing mix; cools the astronaut's body with oxygen or a liquid cooling garment; provides radio communication; displays and/or does telemetry of suit parameters; displays and/or does telementry of astronaut's health; and/or provides propulsion for EVA.

NASA's current design for PLSS is not foolproof, as astronaut Luca Parmitano discovered on July 16, 2013 when he almost died as his helmet filled up with water. The drum holes in the PLSS water separator got clogged, and the PLSS designers had a mistaken understanding of how water acts in microgravity (the designers thought it was impossible for the water to back up into the helmet).

As is usually the case, the reason astronaut Parmitano is alive today is because he did not panic. He had to move to the airlock and re-enter from memory, since he could not see with 1.5 liters of water covering his eyes.

Gloves

The gloves are especially a problem. Back in the 1950's it was unclear if space suit gloves were even possible. You need to make the various protective layers thin enough to be able to fit between adjacent fingers. And with miniature constant volume cuffs at each finger joint. Some suit designers took a tip from deep sea diving suits and postulated mechanical pincers instead of gloves.

But as we know NASA did manage to design actual space suit gloves. However, they do not work very well. Almost every single NASA astronaut who has performed EVA has complaints about the difficulty of doing any fine work while wearing those gloves.

If you're headed for space, you might rethink that manicure: Astronauts with wider hands are more likely to have their fingernails fall off after working or training in space suit gloves, according to a new study.

In fact, fingernail trauma and other hand injuries—no matter your hand size—are collectively the number one nuisance for spacewalkers, said study co-author Dava Newman, a professor of aeronautics and astronautics at the Massachusetts Institute of Technology.

"The glove in general is just absolutely one of the main engineering challenges," Newman said. "After all, you have almost as many degrees of freedom in your hand as in the rest of your whole body."

The trouble is that the gloves, like the entire space suit, need to simulate the pressure of Earth's atmosphere in the chilly, airless environment of space. The rigid, balloonlike nature of gas-pressurized gloves makes fine motor control a challenge during extravehicular activities (EVAs), aka spacewalks.

A previous study of astronaut injuries sustained during spacewalks had found that about 47 percent of 352 reported symptoms between 2002 and 2004 were hand related. More than half of these hand injuries were due to fingertips and nails making contact with the hard "thimbles" inside the glove fingertips.

In several cases, sustained pressure on the fingertips during EVAs caused intense pain and led to the astronauts' nails detaching from their nailbeds, a condition called fingernail delamination.

While this condition doesn't prevent astronauts from getting their work done, it can become a nuisance if the loose nails gets snagged inside the glove. Also, moisture inside the glove can lead to secondary bacterial or yeast infections in the exposed nailbeds, the study authors say.

If the nail falls off completely, it will eventually grow back, although it might be deformed.

For now, the only solutions are to apply protective dressings, keep nails trimmed short—or do some extreme preventative maintenance.

"I have heard of a couple people who've removed their fingernails in advance of an EVA," Newman said.

From Astronauts' Fingernails Falling Off Due to Glove Design by National Geographic News (2010).

Sticky Boots

Many SF novels have magnetized space boots to allow the rocketeers to adhere to the hull, but magnets do not work very well on hulls composed of titanium, aluminum, or magnesium. If one does have a ferromagnetic hull, it might be best to have magnets just in the boot toes but not the heels, to facilitate walking. These might be used inside the spacecraft's lifesystem, if you think those velcro footies used by the stewardess in 2001 A Space Odyssey are just too unmanly for words.

Hard-Shell Suits

To recap, Hard-Shell Suits:

  • Can have the same pressure as the habitat module without the wearer turning into a starfish. The Bends are avoided.
  • The breathing mix will be the same or very close to that of the habitat module. No additional fire risk.
  • Suit encumbrance increases the energy cost to do various tasks by many times that of a soft suit, with a incredible increase in wearer fatigue.
  • The hard shell of the suit is very puncture resistant.
  • They take longer to put on than a soft suit.

Hard-shell suits try to fix the tearing problem at the expense of making the first two problems much worse. True, hard suits do solve the depressurization problem, but at such a cost.

The AX-5 hard suit was developed by Hubert Vykukal at NASA Ames Research center in the 1960's. It was based on deep sea diving suit technology created by Phil Nuytten of Nuytco Research. The rotating joints are angled with respect to a limb, with two halves each comprising a thick wedge section and a thin section. When a limb is bent, the joint rotate so that the thin sections come together, allowing the suit limb to bend in a correspoinding fashion. For more details, refer to The Rocket Company.

Semi-rigid Suits

Semi-rigid Suits are sort of a cross between soft suits and hard-shell suits, typically with the chest or torso hard and the limbs soft.

The ideal design is to have a hard-shell torso allowing the suit to be high-pressure with zero-prebreathing required, coupled with separately pressurized soft limbs to avoid the encumberance penalty suffered by full hard-shell suits.

Which is why NASA's EMU puzzles me, it is a semi-rigid suit that appears to have the disadvantages of both with the advantages of neither. No doubt there were other considerations that I am unaware of.

The company ILC Dover made the Mark III suit as a technology demonstrator in 1992. It actually was a zero prebreathe suit. One of its main drawbacks was that the suit could not separate at the waist like other NASA suits, you had to enter the suit from the backpack. The Mark III had the shell covering the entire torso, not just the chest like the EMU. NASA decided against further development of the Mark III.

Skintight Suits

An innovative alternative approach is the Mechanical Counter Pressure (MCP) Suit. Instead of trying to hold your body intact with air pressure, it holds it in with spandex. It sounds crazy but it just might be crazy enough to work.

To recap, Skintight Suits:

  • Must have lower pressure than the habitat module or the wearer cannot empty their lungs. This means the wearer needs an hour of pre-breathing or they will suffer the Bends. Higher pressure also increases the risk of catastrophic failure of the helmet, i.e., shooting off like a champagne cork and killing the wearer.
  • In case of emergency, when there is no time for pre-breathing, NASA helpfully directs the astronauts to gulp aspirin, so they can work in spite of the agonizing pain
  • The breathing mix will be close to pure oxygen, with a higher fire risk.
  • Suit encumbrance only increases the energy cost to do various tasks by +20%, compared to the +400% of soft suits and the astronomical increase of hard-shell suits.
  • Suit punctures result in bruises on the wearer's skin, instead of certain death.
  • Skintight suits are the most inexpensive of all the space suits, about $60,000 US in 2005 dollars.
  • It tends to grab male wearers uncomfortably in the crotch.

The original concept was created by Dr. Paul Webb in 1968. It is currently being developed by Dr. Darva Newman at MIT, under the name "Bio-Suit".

A skin-tight suit of high tech cloth exerts pressure over the rocketeer's body to provide pressure. A bubble helmet with oxygen supply allows one to breathe. Open pores in the suit actually allow the body to be cooled by perspiration. Tears will cause bruising to the skin, but are not as lethal as they are on a conventional suit. The suit can be quickly put on. They do not interfere as much with movement (+20% energy expenditure, compared with +400% for a NASA suit). And you can store them by folding them up and putting them inside the bubble helmet. The back pack is still bulky, though.

They do need some care in design, though. Any concave areas on the body that the suit does not hug will bulge out under internal body pressure until it fills the void (i.e., your armpits will become armhills). Putty or fluid filled bladders will be needed to prevent this. Care must be taken around those nether regions, the small of the back, and in certain locations of the female chest. Male wearers will need a rather sophisticated cup to cover the genitals. Even with the cup, the suit will tend to grab male wearers uncomfortably in the crotch.

And upon entering vacuum, one will have an instant attack of dire flatulence. Don't be polite, let it out right away or you may damage your intestines.


There may be a length of tubing added along the seams of the arms, legs, and torso. The suit will be relaxed for easy dressing, then the tubing will be pressurized to put tension on the fabric (This was used in the g-suits worn by early jet pilots). The tubing will automatically pressurize when the helmet is put on and pressured up.

This used to be a standard feature of partial-pressure suits.

A more advanced design uses a strip of "shape metal alloy'. An applied voltage can toggle the metal strip between expanded and contracted.


Unlike other types of space suits, the helmets for skintight suits require something called a "neck dam." This goes around the neck, and tries to keep an air-tight seal. Otherwise the helmet shoots off like a champagne cork and all the air in the helmet will spray out.

I'm sure the neck dam will be the part of the suit that will cause designers the most headaches. I personally would be in favor of straps that go from the neck dam and loop around ones arm around the armpits, but I'm no expert.


In The Millennial Project Savage suggests that light tungsten armor plates be worn over the suit to give some anti-radiation protection (this would only be needed in high radiation areas, like the Van Allen belts).

A minimal version of the skintight suit can be developed for everyday wear inside a spacecraft, i.e., a Partial-pressure Skintight suit. In cases of emergency air pressure loss, all you'd need is an oxygen mask and earplugs to survive for hours (This was used in Jerry Pournelle's "Tinker". The suit was worn like long johns under a coverall. The coverall is due to the fact that the suit is about as modest as wearing a coat of paint.).


Amusingly, the skintight suit made an appearance in a 1995 novel and anime television series called Rocket Girls. Maybe not so surprisingly, Japanese media in general is noted for its high standards of scientific accuracy. In this case the anime series had JAXA (the Japanese Aerospace eXploration Agency) and real-life Japanese astronaut Naoko Yamazaki as technical advisors.

The fictitious Solomon Space Association is developing the low-mass suits since their anemic one-lung LS-5 rocket can barely lift itself off the launch pad, let alone any payload. In a further desperate attempt to save on mass, they are reduce to using 16 year old girls as astronauts (which is a predictable development for a Japanese anime). They only weigh 38 kilograms, instead of the sixty-odd kilograms of the adult male astronauts. They take up less room in the control cabin as well.

There has even been some serious discussion given to suits more like those worn by the girls on the covers of magazines. We cannot really wear nothing but bathing suits in space, even with a bubble on our heads to supply oxygen to our lungs. (Pressure from the oxygen on the inside of the lungs must be balanced by pressure outside to make breathing possible for any length of time.) For a very short period, the bathing-suit affair might be enough — or even a normal suit of clothes, with an oxygen helmet. This type, though, would be used only as an emergency affair, and might prove very painful in even a few minutes, if not fatal.

Still, it appears that a suit could be designed which would not require that most of it be inflated at all.

The development of the simpler spacesuit almost certainly is not something that will be accomplished on the first trips into space. That type of suit might never work, but it is worth thinking about.

Suppose we keep the plastic helmet and air supply. Let the section around the lungs be the usual inflated tube, puffed out just a trifle beyond the skin, so that air pressure surrounds the lungs. We are still dealing with only 3 pounds pressure of oxygen. Now taper the inflated tube down at the shoulders and waist and change to an elastic fabric that will be skintight over legs, arms and hips. This fabric can be woven or formed so that it will have almost exactly 3 pounds pressure against the skin for every square inch. Yet when we move, there is no change of air pressure at the joints, because the fabric fits against our skin snugly.

We can still cover the material with reflective paint and weave tiny heating wires through it to take care of the temperature. We can even make it just a bit porous, so that perspiration can work through and evaporate into space — as it will do at once. Our bodies naturally cool themselves and maintain an even temperature by controlling the amount of perspiration. The same thing might happen while wearing our spacesuit. If the body became too warm, we would perspire more, and so increase the cooling. Or if we grew too cold, the perspiration would lessen, reducing the cooling. By using some kind of porous underclothing, the perspiration from even the sections inside the pressurized and inflated part of the suit might reach the cooling sections. There would be some loss of oxygen this way, but it could be kept to a level that would not matter for short periods of time.

Perhaps even the part of the suit over the lungs could be devised of similar elastic material, so that there would be oxygen only in the helmet. In that case, instead of huge, bulky suits, we might have something that looked like the tights male ballet dancers wear.

From Rockets Through Space by Lester Del Rey (1957)

The pressure suit went on like a diver's wet suit, and looked like one only not so thick. It fit very closely; he had to use talcum power to get into it. Gloves dogged onto the ends of the sleeves, and a seal set firmly around his neck. He slipped into the boots, hung the small equipment bag over his shoulder, and reported back to the technicians.

They pulled and pinched, looking for loose spots. They didn't find any in Kevin's, but the next to come up was the girl he'd seen before, and after a moment they handed her a lump of what looked like clay. "Shove that under your breasts," the technician said. "Yeah, right there. Don't leave any gaps."

"But - " She was obviously embarrassed.

"Lady, you're going into vacuum," the man explained. "Your innards will be pressurized to about seven pounds by the air in your helmet. Outside is nothing. Your skin won't hold that. The suit will, but you've got to be flat against the suit, otherwise you'll swell up to fit any empty spaces. It won't do a lot of good for your figure."

"Oh. Thank you," she said. She turned away and used the clay as she'd been told.

From Exiles To Glory by Jerry Pournelle (1977).

On the big screen forward, two men —clad only in T-shirts and tights —are shown in the cramped air lock, struggling with their bright-colored leotard-like space suits, one red and one yellow.

The material of the suits is lightweight, strong, flexible —but not very elastic. Of necessity, it must be tight fitting; it is a second skin. Two sour-looking crewmen are helping them with the sleeves and leggings.

A fifth man is cramped against one wall, adjusting the helmets. He snaps a camera onto the left side of one —whatever the man is looking at will be relayed back to the bridge.

When the men are at last secure in their suits, their helmets are lowered over their heads. The "valets" complete the connections to the mobility and life-support backpack units and check them out. That done, and the units activated, the men snap their face-plates shut, check the helmet seals for security, and lower the appropriate filters into place. They are now bright-colored golems, each with a great dark eye for a face.

"Radio working?" asks one.

The other touches his device-studded "chastity belt," a plastic frame around his waist and genitals. "Right."

A wall panel flashes red —the other crewmen disappear through a hatch which slides impatiently shut after them. A hiss signals that the air is rapidly being drained from the chamber.

The suits do not puff out; only an occasional bubble of air, trapped under their second skins, reveals that the pressure is quickly decreasing. And then even these too evaporate away. "Bridge, we're ready to go."

From Yesterday's Children by David Gerrolds (1972)

Going Outside

Suiting Up

I had an awful time getting into it - dressing in an upper berth is a cinch by comparison. The photographer said, "Just a minute, kid. I've seen 'em do it at Wright Field. Mind some advice?"

"Uh? No. I mean, yes, tell me."

"You slide in like an Eskimo climbing into a kayak. Then wiggle your right arm in-"

It was fairly easy that way, opening front gaskets wide and sitting down in it, though I almost dislocated a shoulder. There were straps to adjust for size but we didn't bother; he stuffed me into it, zippered the gaskets, helped me to my feet and shut the helmet.

. . .

But I didn't get tired of it; a space suit is a marvelous piece of machinery - a little space station with everything miniaturized. Mine was a chrome-plated helmet and shoulder yoke which merged into a body of silicone, asbestos, and glass-fibre cloth. This hide was stiff except at the joints. They were the same rugged material but were "constant volume" - when you bent a knee a bellows arrangement increased the volume over the knee cap as much as the space back of the knee was squeezed. Without this a man wouldn't be able to move; the pressure inside, which can add up to several tons, would hold him rigid as a statue. These volume compensators were covered with dural armor; even the finger joints had little dural plates over the knuckles.

It had a heavy glass-fibre belt with clips for tools, and there were the straps to adjust for height and weight. There was a back pack, now empty, for air bottles, and zippered pockets inside and out, for batteries and such.

The helmet swung back, taking a bib out of the yoke with it, and the front opened with two gasketed zippers; this left a door you could wiggle into. With helmet clamped and zippers closed it was impossible to open the suit with pressure inside.

Switches were mounted on the shoulder yoke and on the helmet; the helmet was monstrous. It contained a drinking tank, pill dispensers six on each side, a chin plate on the right to switch radio from "receive" to "send," another on the left to increase or decrease flow of air, an automatic polarizer for the face lens, microphone and earphones, space for radio circuits in a bulge back of the head, and an instrument board arched over the head. The instrument dials read backwards because they were reflected in an inside mirror in front of the wearer's forehead at an effective fourteen inches from the eyes.

Above the lens or window there were twin headlights. On top were two antennas, a spike for broadcast and a horn that squirted microwaves like a gun-you aimed it by facing the receiving station. The horn antenna was armored except for its open end.

This sounds as crowded as a lady's purse but everything was beautifully compact; your head didn't touch anything when you looked out the lens. But you could tip your head back and see reflected instruments, or tilt it down and turn it to work chin controls, or simply turn your neck for water nipple or pills. In all remaining space sponge-rubber padding kept you from banging your head no matter what. My suit was like a fine car, its helmet like a Swiss watch. But its air bottles were missing; so was radio gear except for built-in antennas; radar beacon and emergency radar target were gone, pockets inside and out were empty, and there were no tools on the belt. The manual told what it ought to have - it was like a stripped car.

Carry steel bottles on your back; they hold "air" (oxygen and helium) at a hundred and fifty atmospheres, over 2000 pounds per square inch; you draw from them through a reduction valve down to 150 p.s.i. and through still another reduction valve, a "demand" type which keeps pressure in your helmet at three to five pounds per square inch-two pounds of it oxygen. Put a silicone-rubber collar around your neck and put tiny holes in it, so that the pressure in the body of your suit is less, the air movement still faster; then evaporation and cooling will be increased while the effort of bending is decreased. Add exhaust valves, one at each wrist and ankle-these have to pass water as well as gas because you may be ankle deep in sweat.

The bottles are big and clumsy, weighing around sixty pounds apiece, and each holds only about five mass pounds of air even at that enormous pressure; instead of a month's supply you will have only a few hours - my suit was rated at eight hours for the bottles it used to have.

. . .

To make darn sure that you're getting enough (your nose can't tell) you clip a little photoelectric cell to your ear and let it see the color of your blood; the redness of the blood measures the oxygen it carries. Hook this to a galvanometer. If its needle gets into the danger zone, start saying your prayers. (ed. note: in Heinlein's other novels, instead of a galvanometer they use an "anoxia warning light")

. . .

Air sighed softly into the helmet, its flow through the demand valve regulated by the rise and fall of my chest - I could reset it to speed up or slow down by the chin control.

. . .

I didn't bother with a radar target or beacon; the first is childishly simple, the second is fiendishly expensive. But I did want radio for the space-operations band of the spectrum - the antennas suited only those wavelengths.

. . .

The only thing that complicated the rest of the electrical gear was that everything had to be either "fail-safe" or "no-fail"; a man in a space suit can't pull into the next garage if something goes wrong - the stuff has to keep on working or he becomes a vital statistic. That was why the helmet had twin headlights; the second cut in if the first failed - even the peanut lights for the dials over my head were twins. I didn't take short cuts; every duplicate circuit I kept duplicate and tested to make sure that automatic changeover always worked.

Mr. Charton insisted on filling the manual's list on those items a drugstore stocks - maltose and dextrose and amino tablets, vitamins, dexedrine, dramamine, aspirin, antibiotics, antihistamines, codeine, almost any pill a man can take to help him past a hump that might kill him.

. . .

I made it a dress rehearsal - water in the drinking tank, pill dispensers loaded, first-aid kit inside, vacuum-proof duplicate (I hoped it was vacuum-proof) in an outside pocket. All tools on belt, all lanyards tied so that tools wouldn't float away in free fall.

. . .

I ran into a snag. The spare bottles I had filched from those ghouls had screw-thread fittings like mine - but Peewee's bottles had bayonet-and-snap joints. Okay, I guess, for tourists, chaperoned and nursed and who might get panicky while bottles were changed unless it was done fast - but not so good for serious work.

. . .

"Mind your pressure. Kip. You're swelling up too fast." I kicked the chin valve while watching the gauge - and kicking myself for letting a little girl catch me in a greenhorn trick. But she had used a space suit before, while I had merely pretended to.

From Have Space Suit - Will Travel by Robert A. Heinlein, 1958.

(ed note: this is a bit dated since it was writtenin 1939, but still surprisingly good)

"This is a standard service type, general issue, Mark IV, Modification 2." He grasped the suit by the shoulders and shook it out so that it hung like a suit of long winter underwear with the helmet lolling helplessly between the shoulders of the garment. "It's self-sustaining for eight hours, having an oxygen supply for that period. It also has a nitrogen trim tank and a carbon dioxide water-vapor cartridge filter."

He droned on, repeating practically verbatim the description and instructions given in training regulations. McCoy knew these suits like his tongue knew the roof of his mouth; the knowledge had meant his life on more than one occasion.

"The suit is woven from glass fibre laminated with nonvolatile asbesto-cellutite. The resulting fabric is flexible, very durable; and will turn all rays normal to solar space outside the orbit of Mercury. It is worn over your regular clothing, but notice the wire-braced accordion pleats at the major joints. They are so designed as to keep the internal volume of the suit nearly constant when the arms or legs are bent. Otherwise the gas pressure inside would tend to keep the suit blown up in an erect position and movement while wearing the suit would be very fatiguing.

"The helmet is moulded from a transparent silicone, leaded and polarized against too great ray penetration. It may be equipped with external visors of any needed type. Orders are to wear not less than a number-two amber on this body. In addition, a lead plate covers the cranium and extends on down the back of the suit, completely covering the spinal column.

"The suit is equipped with two-way telephony. If your radio quits, as these have a habit of doing, you can talk by putting your helmets in contact. Any questions?"

"How do you eat and drink during the eight hours?"

"You don't stay in 'em any eight hours. You can carry sugar balls in a gadget in the helmet, but you boys will always eat at the base. As for water, there's a nipple in the helmet near your mouth which you can reach by turning your head to the left. It's hooked to a built-in canteen. But don't drink any more water when you're wearing a suit than you have to. These suits ain't got any plumbing."

Suits were passed out to each lad, and McCoy illustrated how to don one. A suit was spread supine on the deck, the front zipper that stretched from neck to crotch was spread wide and one sat down inside this opening, whereupon the lower part was drawn on like long stockings. Then a wiggle into each sleeve and the heavy flexible gauntlets were smoothed and patted into place. Finally an awkward backward stretch of the neck with shoulders hunched enabled the helmet to be placed over the head.

Libby followed the motions of McCoy and stood up in his suit. He examined the zipper which controlled the suit's only opening. It was backed by two soft gaskets which would be pressed together by the zipper and sealed by internal air pressure. Inside the helmet a composition mouthpiece for exhalation led to the filter.

From "Misfit" by Robert Heinlein (1939)

Besides the usual cargo lock we had three Kwikloks. A Kwiklok is an Iron Maiden without spikes; it fits a man in a suit, leaving just a few pints of air to scavenge, and cycles automatically. A big time saver in changing shifts. I passed through the middle-sized one; Tiny, of course, used the big one. Without hesitation the new man pulled himself into the small one.

From Delilah and the Space-Rigger by Robert Heinlein (1949)

Safety Check

On Earth, Andrew Lear's habits would have been no more than a character trait. In a hurry, he might choose mismatched socks. He might put off using the dishwasher for a day or two if he were involved in something interesting. He would prefer a house that looked "lived in." God help the maid who tried to clean up his study. He'd never be able to find anything afterward.

He was a brilliant but one-sided man. Backpacking or skin diving might have changed his habits -- in such pursuits you learn not to forget any least trivial thing -- but they would never have tempted him. An expedition to Mars was something he simply could not turn down. A pity, because neatness is worth your life in space.

You don't leave your fly open in a pressure suit.

A month after the landing, Childrey caught Lear doing just that.

The "fly" on a pressure suit is a soft rubber tube over your male member. It leads to a bladder, and there's a spring clamp on it. You open the clamp to use it. Then you close the clamp and open an outside spigot to evacuate the bladder into vacuum.

Similar designs for women involve a catheter, which is hideously uncomfortable. I presume the designers will keep trying. It seems wrong to bar half the human race from our ultimate destiny.

Lear was addicted to long walks. He was coming back from a walk, and he met Childrey coming out. Childrey noticed that the waste spigot on Lear's suit was open, the spring broken. Lear had been out for hours. If he'd had to go, he might have bled to death through flesh ruptured by vacuum.

From "The Hole Man" by Larry Niven. 1974

The instructor ordered his group to "Suit upl" without preliminary, as it was assumed that they had studied the instruction spool.

The last of the ship's spin had been removed some days before. Matt curled himself into a ball, floating free, and spread open the front of his suit. It was an unhandy process; he found shortly that he was trying to get both legs down one leg of the suit. He backed out and tried again. This time the big fishbowl flopped forward into the opening.

Most of the section were already in their suits. The instructor swam over to Matt and looked at him sharply. "You've passed your free-fall basic?"

"Yes," Matt answered miserably.

"It's hard to believe. You handle yourself like a turtle on its back. Here." The instructor helped Matt to tuck in, much as if he were dressing a baby in a snow suit. Matt blushed.

The instructor ran through the check-off list -- tank pressure, suit pressure, rocket fuel charge, suit oxygen, blood oxygen (measured by a photoelectric gadget clipped to the earlobe) and finally each suit's walky-talky unit. Then he herded them into the airlock.

From SPACE CADET by Robert Heinlein (1948)

First Jamieson, then Wheeler, chanted the alphabetic mnemonic - "A is for air-lines, B is for batteries, C is for couplings, D is for D.F. loop ..." which sounds so childish the first time one hears it, but which so quickly becomes part of the routine of lunar life - and is something nobody ever jokes about.

From EARTHLIGHT by Arthur C. Clarke. 1955.

And in Clarke's "The Haunted Spacesuit" aka "Who's There?" they chant "FORB" for Fuel, Oxygen, Radio, Batteries.

[Steve and Nadia] donned the heavily-insulated, heated suits, and Stevens snapped into their sockets the locking plugs of the drag line.

"Hear me?" he asked. "Sound-disks all x?"

"All x."

"On the radio-all x?"

"All x."

"I tested your tanks and heaters-they're all x. But you'll have to test..."

"I know the ritual by heart, Steve. It's been in every show in the country for the last year, but I didn't know you had to go through it every time you went out-of-doors! Valves, number one all x, two all x, three all x..."

"Quit it!" he snapped. "You aren't testing those valves! That check-up is no joke, guy. These suits are complicated affairs, and some parts are apt to get out of order. You see, a thing to give you fresh air at normal pressure and to keep you warm in absolute space can't be either simple or foolproof. They've worked on them for years, but they're pretty crude yet. They're tricky, and if one goes sour on you out in space it's just too bad-you're lucky to get back alive. A lot of men are out there somewhere yet because of sloppy check-ups."

" 'Scuse it, please-I'll be good," and the careful checking and testing of every vital part of the space-suits went on.

From SPACEHOUNDS OF IPC by E.E. "Doc" Smith, 1931.

First things first, and the first thing you need in space is a space suit. Apart from its necessity for working on space projects (building space stations, etc.) it is absolutely vital for examining the outside of your ship in case of damage from meteorites, etc. It may even be necessary to abandon ship, in extreme cases, and in this event your very existence depends upon its efficiency. You see me here in a self-contained, total-vacuum, mark-seven suit. Below you will find listed some of its most important features:

  1. Radio mast of ultra short-wave radio.
  2. Compressed air cylinder of closed-circuit air supply.
  3. Jet on universal mounting and chemical-fuel container.
  4. All joints reinforced. A punctured space suit means death!
  5. Reinforced plastic boots with electro-magnetic soles.
  6. Large universal-vision, anti-cosmic "Plastilight" helmet.
  7. Scaling ring to visor, metal with rubber "hose" lining, inflated from air supply.
  8. Miniature tele-view tray (referred to as the "T" tray).
  9. Control stick to jet (3). Twist grip rotates jet for manœuvring in space.
  10. Hydro-ammonal container and feed line to flame gun.
From Ron Turner's Space Ace pop up book (1953).

In spite of the fail-safe design of the P-suits— so loss of pressure in one part of the suit won't result in a total loss of suit pressure—we lost a rigger yesterday for a stupid reason.

Riggers working in P-suits are required to use the Buddy System—checking each other's gear before cycling to vacuum. But this crew was in a hurry to get on the job. So the buddy didn't check both of the helmet pressurizing lines where the fittings go into the helmet. From what Pratt determined by studying the P-suit later, neither line was inserted in the fitting past the detent. I've got to admit, it's difficult to tell when you've twisted the fitting past the detent, especially if you're already wearing P-suit gloves.

Out in vacuum, the guy snagged one of the lines and pulled it out of the helmet fitting. The check valve closed when the line left the fitting, just as it's supposed to do. But when he heard the line come out of the fitting, he turned, caught the other line on the same beam element, and pulled the second line far enough out of the fitting so it blew most of his back-pack oxygen supply out into space . . . and at the same time failed to come out of the fitting far enough to activate the check valve. He lost helmet pressure in a few seconds. By the time his buddy got to him, he died from what Fred termed "traumatic abaryia," or rapid and terminal loss of pressurization.


Another case was perhaps worse from our point of view because, although the man was alive when we got him, he was too far gone to save. Writers often talk about the "primordial cold of outer space." But we lost this man to hyperpyrexia—overheating.

P-suit backpacks are designed to get rid of the metabolic heat generated by the individual, plus the environmental heat load from outside. There's a limit to the backpack's capability. Everybody's trained to recognize the symptoms of potential overload—a rise in P-suit temperature, hyperventilation, headache, et cetera. When it starts to happen, you slow down, rest, relax— or you're dead very quickly. This poor guy never had a chance, and it was a genuine industrial accident thai finished him.

While a photovoltaic power module's brought up from LEO Base, where it's assembled, it converts sunlight to electricity, which is used to power the electric thrusters which propel it to GEO Base. The structure isn't metal; it's a carbon-reinforced composite plastic.

The riggers had docked the new module to the main array, and Lucky's crew moved in to make the electrical switchover. Supposedly, it's impossible to create an electric arc in a vacuum, but GEO Base is surrounded by a halo of escaped life-support-system gases, outgas-sing products from materials, and other things that make the vacuum less than perfect. This is a construction site, and I've never seen a clean construction site anywhere.

During one of the switchover sequences, part of an insulator failed and an arc jumped across the rest of the insulator to the structure. It vaporized the carbon-composite plastic, which in turn vapor-deposited on everything within fifty feet, including the P-suit of the man who was nearby. It blackened his P-suit within a fraction of a second. He was in full sunlight at the time. Within ten seconds his suit and backpack were too hot for the backpack system to handle. He practically fried in less than thirty seconds.


"Med Unit, Central!" the intercom rasped. "Accident in vacuum! Reported P-suit fire! Location Array Subassembly Module One Zero Seven. Repeat: One Zero Seven!"


One of the P-suited individuals was obviously unconscious. Tom surmised this from the limp, rag-doll posture and random small movements of the limbs of the P-suit. He looked at the faceplate and discovered that the inside surface was covered with a brownish-black deposit, The injured man was no longer being supported by his own backpack. It had been disconnected, and he had been buddy-coupled to another individual's pack.

"What happened?" Tom asked.

"Fire in the backpack," somebody announced on the radio.

"Jed hollered that's what happened before he choked," another voice cut in. "Pete got him hooked up buddy-style (cross-connect) in about twenty seconds."


It didn't take more than thirty seconds to repressurize the Pumpkin (ambulance). Then Tom opened the faceplate of the injured man's P-suit helmet. The man had had a beard that had been singed off. There were first- and second-degree burns on his face. The most severe burns were in the vicinity of the oxygen inlet couplings from the backpack to the helmet. Tom had no way of knowing the nature or extent of possible burns in the lungs or airways.


It didn't take long to determine the source of the fire. Each backpack contains two high-pressure-oxygen storage bottles. A pressure switch valves a full bottle into the system when it senses the on-line bottle's pressure has dropped below a preset limit. The high-pressure oxygen then flows through a regulator that drops the pressure to about five psi absolute. The plastic O-ring that seals the upstream side of the regulator may have had a trace of contamination on it; the culprit seems to be aluminum shaved off the fitting when a maintenance tech over-tightened it. When the pressure sensor switched tanks, a shock wave of high-pressure oxygen hit the upstream side of the regulator fitting and was heated by shock compression. This action ignited whatever was on the O-ring. The aluminum of the regulator body then began to burn in the hot, oxygen-rich atmosphere, and, in turn, sent an oxygen-rich flame right down the breathing pressure lines to the interior of Hobart's helmet.

A fifty-cent O-ring and an uncalibrated torque wrench killed a man. It could also call a halt to a multibillion-dollar project.

Pratt says it's a simple fix. He's got his maintenance techs replacing O-rings and installing a diffuser upstream of the regulator as each backpack comes in from vacuum for refurbishment at the end of each shift.

From Space Doctor by Lee Correy (G. Harry Stine) 1981

Buddy System

While wearing a space suit in vacuum, the iron-clad rule is The Buddy System. There are many mishaps that are trivial if you have a companion but fatal if you don't. Imagine that your suit springs a slow leak on your back just where you can't reach it with a repair patch. Oops.

In cases of emergency, two space suited people can "cross-connect" their oxygen supplies. This is generally done when one of them runs out of breathable gas, the other shares their oxygen until they get to shelter.

ed note: Kip (a college student) and Peewee (a little girl) are wearing spacesuits and are engaged in a forced march across the surface of Luna. Unfortunately the spare oxygen bottles the are carrying have connections incompatible with Peewee's suit. Kip uses surgical tape as an adapter to recharge Peewee's bottle. Peewee has tied the spare bottles to Kip's front. Oh, and Kip named his spacesuit "Oscar")

We were about halfway down the outer slope when Peewee slowed and stopped—sank to the ground and sat still.

I hurried to her. “Peewee!”

“Kip,” she said faintly, “could you go get somebody? Please? You know the way now. I’ll wait here. Please, Kip?”

“Peewee!” I said sharply. “Get up! You’ve got to keep moving.”

“I c-c- can’t!” She began to cry. “I’m so thirsty … and my legs—” She passed out.

“Peewee!” I shook her shoulder. “You can’t quit now! Mother Thing! —you tell her!”

Her eyelids fluttered. “Keep telling her, Mother Thing!” I flopped Peewee over and got to work. Hypoxia hits as fast as a jab on the button. I didn’t need to see her blood-color index to know it read DANGER; the gauges on her bottles told me. The oxygen bottles showed empty, the oxy-helium tank was practically so. I closed her exhaust valves, overrode her chin valve with the outside valve and let what was left in the oxy-helium bottle flow into her suit. When it started to swell I cut back the flow and barely cracked one exhaust valve. Not until then did I close stop valves and remove the empty bottle.

I found myself balked by a ridiculous thing.

Peewee had tied me too well; I couldn’t reach the knot! I could feel it with my left hand but couldn’t get my right hand around; the bottle on my front was in the way—and I couldn’t work the knot loose with one hand.

I made myself stop panicking. My knife—of course, my knife! It was an old scout knife with a loop to hang it from a belt, which was where it was. But the map hooks on Oscar’s belt were large for it and I had had to force it on. I twisted it until the loop broke.

Then I couldn’t get the little blade open. Space-suit gauntlets don’t have thumb nails.

I said to myself: Kip, quit running in circles. This is easy. All you have to do is open a knife—and you’ve got to … because Peewee is suffocating. I looked around for a sliver of rock, anything that could pinch-hit for a thumb nail. Then I checked my belt.

The prospector’s hammer did it, the chisel end of the head was sharp enough to open the blade. I cut the clothesline away.

I was still blocked. I wanted very badly to get at a bottle on my back. When I had thrown away that empty and put the last fresh one on my back, I had started feeding from it and saved the almost half-charge in the other one. I meant to save it for a rainy day and split it with Peewee. Now was the time—she was out of air, I was practically so in one bottle but still had that half-charge in the other—plus an eighth of a charge or less in the bottle that contained straight oxygen (the best I could hope for in equalizing pressures), I had planned to surprise her with a one-quarter charge of oxy-helium, which would last longer and give more cooling. A real knight-errant plan, I thought. I didn’t waste two seconds discarding it.

I couldn’t get that bottle off my back!

Maybe if I hadn’t modified the backpack for nonregulation bottles I could have done it. The manual says: “Reach over your shoulder with the opposite arm, close stop valves at bottle and helmet, disconnect the shackle—” My pack didn’t have shackles; I had substituted straps. But I still don’t think you can reach over your shoulder in a pressurized suit and do anything effective. I think that was written by a man at a desk. Maybe he had seen it done under favorable conditions. Maybe he had done it, but was one of those freaks who can dislocate both shoulders. But I’ll bet a full charge of oxygen that the riggers around Space Station Two did it for each other as Peewee and I had, or went inside and deflated.

If I ever get a chance, I’ll change that. Everything you have to do in a space suit should be arranged to do in front — valves, shackles, everything, even if it is to affect something in back. We aren’t like Wormface, with eyes all around and arms that bend in a dozen places; we’re built to work in front of us — that goes triple in a space suit.

You need a chin window to let you see what you’re doing, too! A thing can look fine on paper and be utterly crumby in the field.

From Have Space Suit - Will Travel by Robert Heinlein, 1958

Equipment

Visual Identification

Once people are suited up, it does become hard to tell who is who. In Destination Moon, there were four spacemen, and each had a uniquely colored suit. Kind of like colored tooth-brushes. But this won't work if you have more than a few spacemen, er, spacepeople. The person's name stenciled in large letter across the front and back is a possibility.

In Piers Anthony's The Kirlian Quest, he notes that this problem has occurred before: knights in armor are similarly anonymous. The solution is coat of arms and heraldry. When a proposed heraldic "device" (coat of arms) is submitted to the college of heralds, it is compared with all existing devices. The new device must have at least one major and one minor point of visual difference from those already registered. Otherwise it would be too easy to confuse the two devices in the heat of battle. Mistaking a foe for a friend could be fatal.

In Larry Niven's Protector, the Belters of the asteroid belt spend most of their lives inside their space suit. They have a tendency to paint their suits in extravagant colors. One of the characters had Salvador Dali's Madonna of Port Lligat on the front of their suit. In an interesting psychological quirk, Belters also tend to be nudists when in a pressurized environment.

Most Belters decorated their suits. Why not? The interior of his suit was the only place many a Belter could call home, and the one possession he had to keep in perfect condition. But even in the Belt, Nick Sohl's suit was unique.

On an orange background was the painting of a girl. She was short; her head barely reached Nick's neck ring. Her skin was a softly glowing green. Only her lovely back showed across the front of the suit. Her hair was streaming bonfire flames, flickering orange with touches of yellow and white, darkening into red-black smoke as it swept across the girl's left shoulder. She was nude. Her arms were wrapped around the suit's torso, her hands touching the air pac on its back; her legs embraced the suit's thighs, so that her heels touched the backs of the flexible metal knee joints. It was a very beautiful painting, so beautiful that it almost wasn't vulgar. A pity the suit's sanitary outlet wasn't somewhere else.

From PROTECTOR by Larry Niven. 1973

The tiger stripes on Jim's mask, the war paint on Frank's, and a rainbow motif on Phyllis's made the young people easy to identify. The adults could be told apart only by size, shape, and manner; there were two extras, Doctor MacRae and Father Cleary.


He poked his head inside, seemed about to leave, then came inside. He pointed to their outdoor suits, hanging on hooks by the clothes locker. 'Why haven't you removed those barbaric decorations from your masks?'

The boys looked startled; Howe went on, 'Haven't you looked at the bulletin board this morning?'

NOTICE TO STUDENTS

1. The practice of painting respirator masks with so-called identification patterns will cease. Masks will be plain and each student will letter his name neatly in letters one inch high across the chest and across the shoulders of his outdoors suit.

(ed note: headmaster Howe is a stupid little power-mad bureaucrat who does not understand the realities of life out on the frontier)

From RED PLANET by Robert Heinlein. 1949

Safety Line

For strict safely, static lines or safety lines are mandatory. The spacecraft should have plenty of small steel rings bolted at regular intervals over the hull for spacemen to attach their safety lines to. Without a static line, a spaceman who manages to get both magnetic boots separated from the hull will suddenly find themself on a slow impromptu tour of the solar system. If their widows are real lucky the bodies might actually be recovered for burial.

Another useful item is a "line throwing gun". This allows one to shoot a safety line from one spacecraft to another. The line will have to be made of special materials, since most terrestrial ropes and cables will turn glass-like and shatter in vacuum.

Fred braced himself in the open hatch and fired the line-throwing gun. The foam plastic projectile sailed slowly across the void, trailing the line it pulled from the container on the gun. A P-suited figure reached out and caught the slow-moving plastic blob as it sailed past. Fred snubbed the line on a cleat inside the hatch as the other person whipped it through and around a beam of the array. Torn had his running safety line snapped around the main line as quickly as it was secured at both ends. He pushed off and sailed down the line. Fred was behind him.

From Space Doctor by Lee Correy (G. Harry Stine) 1981

Things get real nasty if the ship is a tumbling pigeon or otherwise rotates to provide artificial gravity. The poor EVA spacemen have to swing from hand-hold to hand-hold like trapezes artists. From their viewpoint, the spacecraft is overhead and below is a long fall to infinity. For details read Heinlein's short story "Ordeal in Space".

Radio

Astronauts also have to watch what they say. There is no air in space, so unless you are touching helmets together, you cannot talk with others without a radio. But while speaking on Terra means your voice becomes fainter with distance, over a radio it will be loud and clear out to the limit of the radio's range. This means cursing under your breath or muttering behind somebody's back will not work. There might be several channels to allow a bit of privacy, or if several conversations are going on at once.

Some SF novels suggest that for privacy, two space suited people might turn off their raidos, and touch helmets. The theory is that the sound of the conversation will be conducted through the contact between helmets. However, others maintain that the area of contact will be so small (since the helmets are basically spherical) that no audible sound will manage to pass. In Poul Anderson's TAU ZERO, he says that instead astronauts will learn how to read lips.

Lindgren and Reymont exchanged a look above his bent back. She shaped unspoken words. Once he had taught her the Rescue Corps trick of lip reading when spacesuit radios were unusable. They had practiced it as something that made them more private and more one.

From TAU ZERO by Poul Anderson (1970)

"Do you think they're listening to us? Suppose someone's got a watch on this frequency—they'll have heard every word we've said. After all, we're in direct line of sight."

"Who's being melodramatic now? No one except the Observatory would be listening on this frequency, and the folks at home can't hear us as there's rather a lot of mountain in the way. Sounds as if you've got a guilty conscience; anyone would think that you'd been using naughty words again."

This was a reference to an unfortunate episode soon after Wheeler's arrival. Since then he had been very conscious of the fact that privacy of speech, which is taken for granted on Earth, not always available to the wearers of spacesuits, whose every whisper can be heard by anyone within radio range.

From EARTHLIGHT by Sir. Arthur C. Clarke (1955)

"Beeper"

They may also need a "beeper". This is a low powered radar used to locate small objects nearby (like that zero-recoil wrench you let go of "just for a minute"). You wave it around until is starts beeping (heard over your suit radio). As you approach the object the beep rate increases.

'I'll borrow a Beeper from Stores,' replied Peter. 'Joe Evans will let me sign for one.'

A Beeper, I should explain, is a tiny radar set, not much bigger than a hand-torch, which is used to locate objects that have drifted away from the Station. It's got a range of a few miles on anything as large as a space-suit, and could pick up a ship a lot farther away. You wave it around in space and when its beam hits anything you hear a series of 'Beeps'. The closer you get to the reflecting object, the faster the beeps come, and with a little practice you can judge distances pretty accurately.

From Islands in the Sky by Arthur C. Clarke, 1952.

Suit into Ship

As one adds more gadgets and attachments to a space suit, it gradually morphs into a tiny spaceship. It starts with spring-loaded broomsticks and picks up speed with the addition of tiny attitude jets and maneuvering rockets. As a parallel development, a rocket engine with a skeletal frame to hold astronauts is the first "space taxi". When a space suit is massive enough that one climbs into it instead of putting it on like clothing, equipped with mechanical arms and waldoes, you suddenly have a space pod. Then if the pod grows to the size of a baby spaceship, but with massive over-sized engines, you finally have a space tug.

Life Support Balls

It will also be useful to supplement one's supply of space suits with emergency life support balls. These are basically bare essential spherical suits with no arms, legs, or heads for use by people who are injured or untrained in suit operations. When a passenger liner has a problem, the crew members will stuff the passengers into these balls, zip them up, and tow them to safety. In this case, one would be wise to use balls that cannot be opened from the inside. Passengers can do remarkably silly things at the worst possible moment. And even a person highly skilled in space suits can be a problem if they are unconscious and suffering from a broken arm. It will be much quicker to slip them into a ball instead of trying to suit them up.

"Broomstick"

A broomstick is a spring loaded gizmo used by astronauts to launch themselves from place to place, and to bring themselves to a stop upon arrival.

... This was where the broomsticks came in.

Commander Doyle had invented them, and the name, of course, came from the old idea that once upon a time witches used to ride on broomsticks. We certainly rode around the station on ours. They consisted of one hollow tube, sliding inside another. The two were connected by a powerful spring, one tube ending in a hook, the other in a wide rubber pad. That was all there was to it. If you wanted to move, you put the pad against the nearest wall and shoved. The recoil launched you into space, and when you arrived at your destination you let the spring absorb your velocity and bring you to rest. Trying to stop yourself with your bare hands was liable to result in sprained wrists.

It wasn't quite as easy as it sounds, though, for if you weren't careful you could bounce right back the way you'd come.

From Islands in the Sky by Arthur C. Clarke, 1952.

There are some professions which have evolved unique and characteristic tools - the longshoreman's hook, the potter's wheel, the bricklayer's trowel, the geologist's hammer. The men who had to spend much of their time on zero-gravity construction projects had developed the broomstick.

It was very simple - a hollow tube just a metre long, with a footpad at one end and a retaining loop at the other. At the touch of a button, it could telescope out to five or six times its normal length, and the internal shock-absorbing system allowed a skilled operator to perform the most amazing manoeuvres. The footpad could also become a claw or hook if necessary; there were many other refinements, but that was the basic design. It looked deceptively easy to use; it wasn't.

. . .

Everything happened in about five seconds. Brailovsky triggered his broomstick, so that it telescoped out to its full length of four metres and made contact with the approaching ship. The broomstick started to collapse, its internal spring absorbing Brailovsky's considerable momentum; but it did not, as Curnow had fully expected, bring him to rest beside the antenna mount. It immediately expanded again, reversing the Russian's velocity so that he was, in effect, reflected away from Discovery just as rapidly as he had approached. He flashed past Curnow, heading out into space again, only a few centimetres away. The startled American just had time to glimpse a large grin before Brailovsky shot past him.

A second later, there was a jerk on the line connecting them, and a quick surge of deceleration as they shared momentum. Their opposing velocities had been neatly cancelled; they were virtually at rest with respect to Discovery. Curnow had merely to reach out to the nearest handhold, and drag them both in.

From 2010: Odyssey Two by Arthur C. Clarke, 1982.

Rocket Pack

While engaging in extra-vehicular activity, our space-suited rocketeers may use a "broomstick", or some kind of small jets (a Manned Maneuvering Unit or MMU). NASA has also developed a nitrogen-gas propelled unit that fits on the backpack, called the Simplified Aid for Extravehicular Activity Rescue (SAFER). The SAFER can help an astronaut return to the shuttle or station in the event that they gets separated from the spacecraft. SAFER has a deltaV capacity of 3 m/s.

"The trick to jetting yourself in space,"—he went on, 'lies in balancing your body on the jet—the thrust has to pass through your center of gravity. If you miss and don't correct it quickly, you start to spin, waste your fuel, and have the devil's own time stopping your spin. "It's no harder than balancing a walking stick on your finger—but the first time you try it, it seems hard.

"Rig out your sight." He touched a stud at his belt; a light metal gadget snapped up in front of his helmet so that a small metal ring was about a yard in front of his face. "Pick out a bright star, or a target of any sort, lined up in the direction you want to go. Then take the ready position— no, no! Not yet—I'll take it."

He squatted down, lifted himself on his hands, and very cautiously broke his boots loose from the side, then steadied himself on a cadet within reach. He turned and stretched out, so that he floated with his back to the ship, arms and legs extended. His rocket jet stuck straight back at the ship from the small of his back; his sight stuck out from his helmet in the opposite direction.

He went on, "Have the firing switch ready in your right hand. Now, have you fellows ever seen a pair of adagio dancers? You know what I mean—a man wears a piece of leopard skin and a girl wearing less than that and they go leaping around the stage, with him catching her?"

Several voices answered yes. Hanako continued, "Then you know what I'm talking about. There's one stunt they always do—the girl jumps and the man pushes her up and balances her overhead on one hand. He has his hand at the small of her back and she lays there, artistic-like. "That's exactly the way you got to ride a jet. The push comes at the small of your back and you balance on it. Only you have to do the balancing—if the push doesn't pass exactly through your center of gravity, you'll start to turn. You can see yourself starting to turn by watching through your sight. "You have to correct it before it gets away from you. You do this by shifting your center of gravity. Drag in the arm or leg on the side toward which you've started to turn. The trick is—"

"Just a second, Sarge," someone cut in, "you said that just backwards. You mean; haul in the arm or leg on the other side, don't you?"

"Who's talking?"

"Lathrop, number six. Sorry."

"I meant what I said, Mr. Lathrop."

"But—"

"Go ahead, do it your way. The rest of the class will do it my way. Let's not waste time. Any questions? Okay, stand clear of my jet."

The half circle backed away until stopped by the anchored static lines. A bright orange flame burst from the sergeant's back and he moved straight out or "up," slowly at first, then with increasing speed. His microphone was open; Matt could hear, by radio only, the muted rush of his jet-and could hear the sergeant counting seconds: "And . . . one! . . . and . . . two! . . . and . . . three!" With the count of ten, the jet and the counting stopped.

Their instructor was fifty feet "above" them and moving away, back toward them. He continued to lecture. "No matter how perfectly you've balanced you'll end up with a small amount of spin. When you want to change direction, double up in a ball—" He did so. "—to spin faster—and snap out of it when you've turned as far as you want." He suddenly flattened out and was facing them. "Cut in your jet and balance on it to straighten out on your new course—before you drift past the direction you want."

He did not cut in his jet, but continued to talk, while moving away from them and slowly turning. "There is always some way to squirm around on your axis of rotation so that you can face the way you need to face for a split second at least. For example, if I wanted to head toward the Station—" Terra Station was almost a right angle away from his course; he went through contortions appropriate to a monkey dying in convulsions and again snapped out in starfish spread, facing the Station—but turning slow cartwheels now, his axis of rotation unchanged.

"But I don't want to go to the Station; I want to come back to the ship." The monkey died again; when the convulsions ceased, the sergeant was facing them. He cut in his jet and again counted ten seconds. He hung in space, motionless with respect to the ship and his class and about a quarter mile away. "I'm coming in on a jet landing, to save time." The jet blasted for twenty seconds and died; he moved toward them rapidly.

When he was still a couple of hundred feet away, he flipped over and blasted away from the ship for ten seconds. The sum of his maneuvers was to leave him fifty feet away and approaching at ten feet per second. He curled up in a ball again and came out of it feet toward the ship.

Five seconds later his boots clicked to steel and he let himself collapse without rebound. "But that is not the way you'll do it," he went on. "My tanks hold more juice than yours do—you've got fifty seconds of power, with each second good for a change of speed on one foot-second—that's for three hundred pounds of mass; some of you skinny guys will go a little faster.

"Here's your flight plan: ten seconds out, counted. Turn as quick as you can and blast fifteen seconds back. That means you'll click on with five foot-seconds. Even your crippled grandmother ought to be able to do that without bouncing off. Lathrop! Unhook—-you're first."

As the cadet came up, Hanako anchored himself to the ship with two short lines and took from his belt a very long line. He snapped one end to a hook in the front of the cadet's belt and the other to his own suit. The student looked at it with distaste. "Is the sky hook necessary?"

Sergeant Hanako stared at him. "Sorry, Commodore—regulations. And shut up. Take the ready position."

Silently the cadet crouched, then he was moving away, a fiery brush growing out of his back. He moved fairly straight at first, then started to turn.

He pulled in a leg—and turned completely over.

"Lathrop—cut off your jet!" snapped Hanako. The flame died out, but the figure in the suit continued to turn and to recede. Hanako paid out his safety line. "Got a big fish here, boys," he said cheerfully. "What do you think he'll weigh?" He tugged on the line, which caused Lathrop to spin the other way, as the line had wound itself around him. When the line was free he hauled the cadet in.

Lathrop clicked on. "You were right, sergeant. I want to try it again—your way."

"Sorry. The book says a hundred per cent reserve fuel for this drill; you'd have to recharge." Hanako hesitated. "Sign up for tomorrow morning—I'll take you as an extra."

"Oh—thanks, Sarge!"

"Don't mention it. Number one!"

From Space Cadet by Robert Heinlein. 1948

Jim's job turned out to be running a small welder that operated on compressed oxygen and acetylene. "Youll be working on some tricky alloys," Bart told him. "Keep the oxygen supply a little under what you need for the best burning. And before you turn it on, get a good grip. It's a small rocket, and don't forget that!"

They filed out. Some of the men seemed to be fully at home already, and simply dived off into space, kicking themselves toward the work. They carried tiny rocket tubes which could be used to kick themselves back in case they misjudged, but it wasn't something Jim cared to try yet. He was glad to see that others pulled themselves along the girders hand over hand.

Everything seemed to be done by hand power. Men were moving out to the piles of material scattered about, sorting them, and attaching cords before pulling them back by hand. There was no weight, but the inertia of the objects sometimes required the power of several men to overcome it. Once in motion, anything tended to keep that motion, and jockeying the parts into place and holding them there was a tricky business.

The welding proceeded well enough, however. Out here without air, the metals could never tarnish. They were given a brightening before being assembled to remove any corrosion from Earth's atmosphere, and then remained bright until they would be welded. Even aluminum and the titanium alloys were manageable.

Bart came over after a few minutes and inspected his work. "Good enough. But don't sit facing the same way so long. That Sun's hotter than you think. Sit too long in one direction and you'll heat one side of your suit near melting, while the other side freezes stiff. How do you feel?"

Jim had almost stopped thinking about that, under the pressure of the work. A boy who'd collapsed on the previous shift had put the welding behind the assembly, and Jim was driving himself to catch up. Bart clapped him on the shoulder and started to move on. Then he swung back.

"Jim, don't ever let me find you with your belt unfastened on the job again!" He snapped the silicone-plastic strap around the girder and to a hook in the suit. "I told you that torch was a small rocket! Let go, and you'll sail out like a bird if you're not strapped down."

"I guess I forgot this time," Jim admitted. "Sorry, Bart!"


The welding went on for several hours, until he finished what was ready. Part of the time, he'd been within reach by radio of one of the young college boys, and had struck up a conversation, forcing himself to stop being a lone wolf. He'd found that there was a sound reason for using the oxyacetylene welder instead of an electric rig. The compressed gases were lighter than batteries, and the station was still underpowered. They'd put up a sun mirror out of sheets of station walls and had used sections of pipe to make a boiler where the heat converged. It was driving a small steam plant and generator, but there were only about ten kilowatts to power the whole station until they could get the main power plant going much later.


The work went on more easily in the following days. New men came up from Earth, and most of them went back. One of them did almost the same thing Jim had done, but turned his rocket tube on while it was still pointing toward his helmet. Nobody got much work done that day, and there was no conversation at dinner.

From Step to the Stars by Lester Del Rey. 1954

Legless

Many early designs of spacesuits for use in free fall were lacking legs. This simplifies the design. This gradually becomes a hard suit which allows an astronaut to work in a pressurized environment and so avoid the bends.

At this point, perhaps I should remind you that the suits we use on the station are completely different from the flexible affairs men wear when they want to walk around on the Moon. Ours are really baby space ships, just big enough to hold one man. They are stubby cylinders, about seven feet long, fitted with low-powered propulsion jets, and have a pair of accordion-like sleeves at the upper end for the operator's arms.

As soon as I'd settled down inside my very exclusive space craft, I switched on power and checked the gauges on the tiny instrument panel. All my needles were well in the safety zone, so I gave Tommy a wink for luck, lowered the transparent hemisphere over my head and sealed myself in. For a short trip like this, I did not bother to check the suit's internal lockers, which were used to carry food and special equipment for extended missions.

As the conveyor belt decanted me into the air lock, I felt like an Indian papoose being carried along on its mother's back. Then the pumps brought the pressure down to zero, the outer door opened, and the last traces of air swept me out into the stars, turning very slowly head over heels.

The station was only a dozen feet away, yet I was now an independent planet—a little world of my own. I was sealed up in a tiny, mobile cylinder, with a superb view of the entire universe, but I had practically no freedom of movement inside the suit. The padded seat and safety belts prevented me from turning around, though I could reach all the controls and lockers with my hands or feet.

In space the great enemy is the Sun, which can blast you to blindness in seconds. Very cautiously, I opened up the dark filters on the "night" side of my suit, and turned my head to look out at the stars. At the same time I switched the helmet's external sunshade to automatic, so that whichever way the suit gyrated my eyes would be shielded.

Presently, I found my target—a bright fleck of silver whose metallic glint distinguished it clearly from the surrounding stars. I stamped on the jet control pedal and felt the mild surge of acceleration as the low-powered rockets set me moving away from the station. After ten seconds of steady thrust, I cut off the drive. It would take me five minutes to coast the rest of the way, and not much longer to return with my salvage.

From The Haunted Space Suit by Arthur C. Clarke. 1958

Space Taxi

A space taxi is a short ranged orbit to orbit vehicle used to carry astronauts and small amounts of cargo. At its simplest, it is a frame that astronauts attach themselves to, with a rocket engine at one end. More complicated taxis have an enclosed hull which may or may not be pressurized. Do keep in mind that the direction of "down" will appear to be in the same direction the rocket exhaust shoots.

Orion Space Taxi
PropulsionChemical
Specific Impulse450 s
Exhaust Velocity4,500 m/s
Wet Mass1,584 kg
Dry Mass759 kg
Mass Ratio2.0
ΔV3,120 m/s
Payload136 kg (2 people)
Length3 m
Diameter1 m wide

In this document about Orion drive spacecraft, they mention a space taxi. It carries two crew members, has a hardware mass of 623 kilograms, and a propellant mass of 825 kilograms. As near as I can measure, it can be approximated as a cylinder with a height of two meters and a radius of 0.5 meters, with a hemisphere of radius 0.5 meters on each end.

This gives it an internal volume of 2 m3. Assuming it has chemical propulsion, the propellant would take up about 0.8 cubic meters, and the two crew would take up 0.14 cubic meters. Carrying two crew, it would have a mass ratio of about 2, and thus a deltaV of about 3,120 m/s.

This is an emergency lunar escape vehicle concept, in case an Apollo Lunar Module crashed upon landing. It was designed to be assembled from various parts canibalized from the wreck. Note that in the two-man version, the pilot gets an acceleration chair, but the poor second astronaut is slung under the chair by straps. You can read more about this here, here, and here (PDF files).

Matt pulled himself along, last in line, and found the scooter loaded. He could not find a place; the passenger racks were filled with space-suited cadets, busy strapping down.

The cadet pilot beckoned to him. Matt picked his way forward and touched helmets. "Mister," said the oldster, "can you read instruments?"

Guessing that he referred only to the simple instrument panel of a scooter, Matt answered, "Yes, sir."

"Then get in the co-pilot's chair. What's your mass?"

"Two eighty-seven, sir," Matt answered, giving the combined mass, in pounds, of himself and his suit with all its equipment. Matt strapped down, then looked around, trying to locate Tex and Oscar. He was feeling very important, even though a scooter requires a co-pilot about as much as a hog needs a spare tail.

The oldster entered Mart's mass on his center-of-gravity and moment-of-inertia chart, stared at it thoughtfully and said to Matt, "Tell Gee-three to swap places with Bee-two."

Matt switched on his walky-talky and gave the order. There was a scramble while a heavy-set youngster changed seats with a smaller cadet. The pilot gave a high sign to the cadet manning the hangar pocket; the scooter and its launching cradle swung out of the pocket, pushed by power-driven lazy tongs.

A scooter is a passenger rocket reduced to its simplest terms and has been described as a hat rack with an outboard motor. It operates only in empty space and does not have to be streamlined.

The rocket motor is unenclosed. Around it is a tier of light metal supports, the passenger rack. There is no "ship" in the sense of a hull, airtight compartments, etc. The passengers just belt themselves to the rack and let the rocket motor scoot them along.

From Space Cadet by Robert Heinlein. 1948

The taxi looked like a huge, short salami, twenty feet long and eight in diameter. There was a small dome for the pilot to see out, and an air lock at the front, while the rear carried a small rocket motor. They went through the lock. Inside were two seats, fuel tanks, and steering assembly, as well as cargo space.

Jerry blasted off, after cranking a hand gyroscope to turn them. It was a weak, cautious blast that used little fuel. "Better to take your time and not waste fuel," he explained. "Once you get moving, there's nothing to stop you."

They drifted toward the rocket, turning over by the use of the gyroscope, and Jerry brought them to a stop with a single quick blast of the rocket tube. It was precise, beautiful work. They coasted a few feet away, while he turned them over again until the nose pointed to the rocket's lock, which was open.

"Slip your helmet back on, Jim," Jerry ordered. "Go out into the lock and catch that rope."

The man in the ship ahead had already thrown the cord. Jim found the end and fastened it to a bite inside the lock. The taxi was pulled up to the main lock, where it fitted snugly against the silicone-rubber gasket to make an airtight seal.


They took the passengers back, and then began making trips to ferry the supplies. These were dumped out of the big rocket by the pilot and his men. Apparently they put on space suits, evacuated the air from the cargo section and lock, and simply pitched the crates and pieces into space. It was Jim's job to go out of the taxi and secure these with cords to a ring on the back of the taxi, leaving enough distance so the rocket blast wouldn't hurt them.

From Step to the Stars by Lester Del Rey (1954)

Captain Stone sighed. "I'm going with you. Will your scooter take three?"

"Sure, sure! It's got Reynolds saddles; set any balance you need."


Hazel allotted one-fourth her fuel as safety margin, allotted the working balance for maximum accelerations, figuring the projected mass-ratios in her head.


Hazel worked the new mass figures over; with Edith, her suit, and the spare bottle subtracted she had spare fuel.

She lined up on City Hall by flywheel and stereo, spun on that axis to get the sun out of her eyes, clutched her gyros, and gave it the gun. The next thing she knew she was tumbling like a liner in free fall. She remembered from long habit to cut the throttle but only after a period of aimless acceleration, for she had been chucked around in her saddle, thrown against her belts, and could not at first find the throttle.


Quickly she checked things over. There was not much that could go wrong with the little craft, it being only a rocket motor, an open rack with saddles and safety harness, and a minimum of instruments and controls. It was the gyros, of course; the motor had been sweet and hot. They were hunting the least bit, she found, that being the only evidence that they had just tumbled violently. Delicately she adjusted them by hand, putting her helmet against the case so that she could hear what she was doing.

Only then did she try to find where they were and where they were going. Let's see—the Sun is over there—and that's Betelgeuse over yonder—so City Hall must be out that way. She ducked her helmet into the hemispherical "eye shade" of the stereo. Yup! there she be!

The Eakers place was the obvious close-by point on which to measure her vector. She looked around for it, was startled to discover how far away it was. They must have coasted quite a distance while she was fiddling with the gyros. She measured the vector in amount and direction, then whistled. There were, she thought, few grocery shops out that way—darn few neighbors of any sort.


But she kept trying to call Mrs. Eakers, or anyone else in range of her suit radio while she again lined up the ship for City, with offset to compensate for the new vector. She was cautious and most alert this time—in consequence she wasted only a few seconds of fuel when the gyros again tumbled.

She unclutched the gyros and put them out of her mind, then took careful measure of the situation. The Eakers dump was now a planetary light in the sky, shrinking almost noticeably, but it was still the proper local reference point. She did not like the vector she got. As always, they seemed to be standing still in the exact center of a starry globe—but her instruments showed them speeding for empty space, headed clear outside the node.


Carefully she lined up the craft by flywheel; carefully she checked it when it tried to swing past. She aimed both to offset the new and disastrous vector and to create a vector for City Hall. She intentionally left the gyros unclutched. Then she restrapped Lowell in his saddle, checked its position. "Hold still," she warned. "Move your little finger and Grandma will scalp you."

Just as carefully she positioned herself, considering lever arms, masses, and angular moments in her head. Without gyros the craft must be balanced just so. "Now," she said to herself, "Hazel, we find out whether you are a pilot—or just a Sunday pilot." She ducked her helmet into the eyeshade, picked a distant blip on which to center her crosshairs, and gunned the craft.

The blip wavered; she tried to rebalance by shifting her body. When the blip suddenly slipped off to one side she cut the throttle quickly. Again she checked her vector. Their situation was somewhat improved. Again she called for help, not stopping to cut the child out of hearing. He said nothing and looked grave.

She went through the same routine, cutting power again when the craft "fell off its tail." She measured the vector, called for help—and did it all again. A dozen times she tried it. On the last try the thrust stopped with the throttle still wide open.

With all fuel gone there was no need to be in a hurry. She measured her vector most carefully on the Eakers' ship, now far away, then checked the results against the City Hall blip, all the while calling for help. She ran through the figures again; in a fashion she had been successful. They were now unquestionably headed for City Hall, could not miss it by more than a few miles at most—almost jumping distance. But, while the vector was correct in direction, it was annoyingly small in quantity—six hundred and fifty miles at about forty miles an hour; they would be closest in about sixteen hours.


Roger Stone explained. The twins looked at each other. "Dad," Castor said painfully, "you mean Hazel took Mother out in our scooter?"

"Certainly." The twins questioned each other wordlessly again. "Why shouldn't she? Speak up."

"Well, you see . . . well, it was like this—"

"Speak up!"

"There was a bearing wobble, or something, in one of the gyros," Pollux admitted miserably. "We were working on it." "You were? In Charlie's place!"

"Well, we went over there to see what he had in the way of spare parts and, well, we got detained, sort of."

Their father looked at them for several seconds with no expression of any sort. He then said in a flat voice, "You left a piece of ship's equipment out of commission. You failed to log it. You failed to report it to the Captain." He paused. "Go to your room."

"But Dad! We want to help!"

"Stay in your room; you are under arrest."


Castor thought about it. "That's bad. That could be really bad." He added suddenly, "But quit jittering, just the same. Start thinking instead. What happened? We've got to reconstruct it."

"'What happened?' Are you kidding? Look, the pesky thing tumbles, then anything can happen. No control."

"Use your head, I said. What would Hazel do in this situation?"

They both kept quiet for some moments, then Pollux said, "Cas, that derned thing always tumbled to the left, didn't it? Always."

"What good does that do us? Left can be any direction."

"No! You asked what Hazel would do. She'd be along her homing line, of course—and Hazel always oriented around her drive line so as to get the Sun on the back of her neck, if possible. Her eyes aren't too good."

Castor screwed up his face, trying to visualize it. "Say Eakers' is off that way and City Hall over here; if the Sun is over on this side, then, when it tumbles, she'd vector off that way." He acted it with his hands.

"Sure, sure! When you put in the right coordinates, that is. But what else would she do? What would you do? You'd vector back—I mean vector home."

"Huh? How could she? With no gyros?"

"Think about it. Would you quit? Hazel is a pilot. She'd ride that thing like a broomstick." He shaped the air with his hands. "So she'd be coming back, or trying to, along here—and everybody will be looking for her 'way over here."

Castor scowled. "Could be."

"It had better be. They'll be looking for her in a cone with its vertex at Eakers'—and they ought to be looking in a cone with its vertex right here, and along one side of it at that."


When Charlie had dug his scooter out of the floating junkyard moored to his home they soon saw why he had refused to lend it. It seemed probable that no one else could possibly pilot it. Not only was it of vintage type, repaired with parts from many other sorts, but also the controls were arranged for a man with four hands. Charlie had been in free fall so long that he used his feet almost as readily for grasping and handling as does an ape; his space suit had had the feet thereof modified so that he could grasp things between the big toe and the second, as with Japanese stockings.


The crate was old but Charlie had exceptionally large tanks on it; it could maintain a thrust for plenty of change-of-motion. Its jet felt as sweet as any. But it had no radar of any sort. "Charlie, how do you tell where you are in this thing?"

"That."

"That" proved to be an antiquated radio compass loop. The twins had never seen one, knew how it worked only by theory. They were radar pilots, not used to conning by the seats of their suits. Seeing their faces Charlie added, "Shucks, if you've got any eye for angle, you don't need fancy gear. Anywhere within twenty miles of the City Hall, I don't even turn on my suit jet—I just jump."

They cruised out the line that the twins had picked. Once in free fall Charlie taught them how to handle the compass loop. "Just plug it into your suit in place of your regular receiver. If you pick up a signal, swing the loop until it's least loud. That's the direction of the signal—an arrow right through the middle of the loop."

"But which way? The loop faces both ways."

"You have to know that. Or guess wrong and go back and try again."


Charlie, anticipating what would be needed, had swung ship as soon as he had quit accelerating. Now he blasted back as much as he had accelerated, bringing them dead in space relative to City Hall and the node. He gave it a gentle extra bump to send them cruising slowly back the way they had come. Pollux listened, slowly swinging his loop. Castor strained his eyes, trying to see something, anything, other than the cold stars.

"Got it again!" Pollux pounded his brother.

Old Charlie killed their relative motion; waited. Pollux cautiously tried for a minimum, then swung the loop, and tried again. He pointed, indicating that it had to be one of two directions, a hundred and eighty degrees apart.

"Which way?" Castor asked Charlie.

"Over that way."

"I can't see anything."

"Me neither. I got a hunch."

Castor did not argue. Either direction was equally likely. Charlie gunned it hard in the direction he had picked, roughly toward Vega. He had hardly cut the gun and let it coast in free fall when Pollux was nodding vigorously. They coasted for some minutes, with Pollux reporting the signal stronger and the minimum sharper . . . but still nothing in sight. Castor longed for radar. By now he could hear crying in his own phones. It could be Buster—it must be Buster.

"There she is!"

It was Charlie's shout. Castor could not see anything, even though old Charlie pointed it out to him. At last he got it—a point of light, buried in stars. Pollux unplugged from the compass when it was clear that what they saw was a mass, not a star, and in the proper direction. Old Charlie handled his craft as casually as a bicycle, bringing them up to it fast and killing his headway so that they were dead with it. He insisted on making the jump himself.

From The Rolling Stones by Robert Heinlein (1952)

(ed note: Cot-Vee = Cargo Orbital Transfer Vehicle {COTV}, Pot-Vee = Personnel Orbital Transfer Vehicle {POTV})

There were few amenities on the Pot-Vee Edison. But since the transition to GEO Base took several hours, the craft did have a bathroom of sorts—nothing more than a simple adaptation of the proven technology of the SkyLab "waste management system," as the old NASA circumlocution labeled it. The Personnel Orbital Transfer Vehicle itself was just a double-decked cylindrical cabin section eighteen feet in diameter and fifty-five feet long with a control compartment, docking air lock, and tunnel forward. On its aft end was the cylindrical hydrogen-oxygen propulsion module, the common orbital propulsion module used for both Pot-Vees and Cot-Vees.


"Easy flight today," Jackson remarked. "Three hours, fourteen minutes dock to dock. Relax and enjoy." (ed note: transit from LEO to GEO)

"Pretty short time for such a high lift, isn't it?" Stan Meredith asked. "Planning on high boost?"

"Naw! This flying sewer pipe is boost-limited to point-one-five gees because of its structure," Jackson explained. "Besides, we don't need the boost that's required for Earth-to-orbit. You'll hardly notice it now—but, man, it'll feel like a rock dropped on you after you've spent six weeks in weightlessness!"

The Ancient Astronaut was right. There were some bangs, clanks, muffled clunks, and gentle jolts as the Edison undocked from LEO Base. And when the thrust of the oxygen-hydrogen rocket engines came on, there was the gentlest of accelerations, accompanied by a slight vibration and a damped shaking.

"Combustion noise being transmitted through the thrust structure, plus a little bit of damped pogo oscillation," Fred Fitzsimmons explained.

"Why didn't they get the pogo out of these ships before they put them into operation?" Dave Cabot asked. "Didn't pogo oscillations give the engineers all sorts of trouble on Saturn and the Space Shuttles?"

Fred smiled. "Welcome to private-enterprise astronautics! There's worse vibrations in an airplane. It costs so much to get all pogo oscillations out of a design under all sorts of load conditions—and these Pot-Vees operate with all kinds of loads—that it's more cost-effective to let them shake . . . within reasonable limits, of course."

"But won't this thing eventually shake apart?" A note of anxiety entered Dave's voice.

"Nope," Fred replied. "Never had a Pot-Vee crumple yet. The engines are de-rated so much that the pogo doesn't affect them, and the engines themselves are modernized versions of very old, well-proven designs that never gave a bit of trouble."

"RL-10s," Stan put in.

There were no cabin windows in the Pot-Vee, so it was a three-hour flight without a view.


Stan and Fred discovered that it took almost nineteen minutes just to get to Charlie Victor, Mod Four Seven. There were a lot of hatches to go through and a lot of modules to traverse. "Fred, if we don't find some faster way to move around this rabbit warren, a lot of people are going to be dead before we reach them," Stan pointed out, finally opening the hatch to Mod Four Seven.

Fred was right behind him through the hatch. "I'll ask Doc to see Pratt about getting us an Eff-Mu."

"What's that?"

"Extra Facility Maneuvering Unit. A scooter to anybody but these acronym-happy engineers."


"You want an Eff-Mu so you can get around GEO Base faster."

"Right. We lost the hyperpyrexia case because we couldn't get there fast enough. It takes forever to go through all the hatches and corridors of GEO Base."

"Stan, I agree on both counts," Tom replied. "You need an Eff-Mu, and all of us need to be able to get around GEO Base faster in emergencies. But do you think a standard two-man Eff-Mu will really do the job?"

"Why not?"

"Why don't Earth-bound paramedics use motorcycles?"

"I see what you mean. We need room for the patient."

"Roger. Eventually maybe not, but right now we've got to provide that, too. Is there any Eff-Mu type that'll handle the two of you plus a patient?"


Pratt called him. "Doc, your special ambulance is coming up in the next Cot-Vee supply ship. Should be docking in six hours at Portlock Foxtrot. We're also putting a docking collar module on the free end of your med module, so don't be disturbed when you hear noises. You'll be able to dock right to your sick bay."

(ed note: one hex module is a hexagonal prism, about 3.7 meters wall to wall (12 feet), 15.2 meters long (50 feet), and has a volume of 241 cubic meters (8,500 cubic feet)

The Pumpkin turned out to be a masterpiece of quick-and-dirty engineering. It was half a hex module outfitted with a StarPacket vernier engine as its main propulsion system and a series of electric thrusters for maneuvering. It had no direct view to the outside universe, only an array of video displays—large windows in space were a constant trouble source because the state of the art couldn't keep them from leaking, and the Pumpkin's life-support consumables were limited to twenty-four man-hours with no recycling. The unit sported a universal docking collar on the end of the hex module opposite the StarPacket vernier engine.

Tom went with Fred and Stan to take delivery of their new gadget and bring it around to the med module dock. Pratt's men had latched the half hex of a docking port and pressure lock to the med module a few hours earlier in an operation that took only twenty minutes. GEO Base had been designed like an Erector set with plug-in modules; there was no time to build pretty or permanent space facilities on this job.


He looked over the panel. "Attitude indicator. Four relative velocity indicators linked to eight search radars and three lidars at will. Beacon transponders. You know, this really isn't that much different from flying airplanes on instruments."

And it wasn't. They returned for their P-suits, loaded another twenty-four man-hours of oxygen aboard, then checked out the Pumpkin—propellant load, battery-charge level, life-support-system consumables level, and the rest of a three-page checklist that someone had managed to put together for the Pumpkin when it was assembled at LEO Base. The controls had been highly simplified and were like those of a helicopter, with two sidearm controllers and two foot pedals to provide control in roll, pitch, yaw, and translation in six degrees of freedom. The StarPacket vernier engine offered enough thrust to get the Pumpkin moving for fast sprints, while the electric thrusters—the same kind used to propel the SPS array modules from LEO Base—permitted the gentlest of velocity changes.


The Pumpkin's saved a couple of people already. Three of us have learned how to operate it: Stan, Fred, and myself. Now I understand why space pilots are people who are instrument-rated airplane pilots and also own their own boats. "Flying" the Pumpkin is like flying an airplane by instruments; you must believe what those gauges are telling you, and you can't pay any attention to the inputs from your vestibular apparatus or from kinesthetic senses. Docking and undocking the Pumpkin is like bringing the S.S. Patrick Miller alongside and gently docking to a pier; the Pumpkin has far less momentum, however, and is probably more like docking a row boat. There isn't anything difficult about it provided you aren't in a hurry.

That's going to be the biggest problem with the Pumpkin. When Fred and Stan are on a call, they're in a hurry. I expect to get reports of hard docks. I hope they don't crumple too much stuff until they learn how to handle the Pumpkin under the stress of an emergency. I'm not too worried about them crumpling the Pumpkin; all the stress is column loading on that hex module, and it'd take a big bump to make the structure fail in that mode.


Together, they went through the power-up checklist. Total time, forty-two seconds. Less than three minutes after the call, Fred retracted the docking latches and backed the Pumpkin away from the med module on thruster power. While Fred was doing that, Tom interfaced the ship's computer with the one in GEO Base via radio link; he called up a three-dimensional display of the current GEO Base configuration and had the computer call out the location of the accident site.

"Computer has fed course parameters to the guidance system," Tom reported. Fred slued the ship and coupled the autopilot.

"Roger! Autopilot locked on. Stand by for thrust."

Tom spoke over the radio. "Traffic, Pumpkin. Emergency. Departing med module under primary thrust for Array Subassembly Module One Zero Seven. Are we clear to boost?"

Fred held his finger over the abort switch in anticipation of a possible Traffic delay. But it didn't come. "Pumpkin, Traffic. Clear to boost."

The boost came with a little fishtailing. "Dammit!" Fred swore. "Doc, this autopilot doesn't warm up fast enough. We'll have to go manual follow-up."

"I'll take it, Fred." Flying the Pumpkin wasn't as hard as flying a light airplane on instruments through an overcast at night. In this case, with the course already plotted by the computer, all Tom had to do was keep the marker bugs centered on the attitude-situation and relative-velocity displays. With the sidearm controller in one hand and the thruster and vernier throttles in the other, Tom didn't let the red Xs of the marker bugs deviate from the center of the display.

They picked up the group of P-suited figures on video long before the computer called for retros. To keep the thruster and vernier discharges away from the P-suited workers, Tom slued the Pumpkin in yaw and applied retro thrust by vector.


The paramedic didn't say anything, but reached over and activated Tom's P-suit backpack. Tom did the same for Fred. Only then did they disconnect from the Pumpkin's life-support system.

"Dump pressure, Fred."

Tom felt his suit pressurise as the atmosphere of the Pumpkin was dumped into space through spill valves that equalized the thrust produced. Normal procedure wouldn't have permitted dumping of pressure, nitrogen being the one gas that had to be brought up from Earth. In addition, the venting created a gas halo around the ship that might have permitted arcing of electrical equipment on the SPS array. But in an emergency where the Pumpkin had to be depressurized rapidly, there was no alternative.

From Space Doctor by Lee Correy (G. Harry Stine) 1981

Space Pod

A space pod is a small pressurized vehicle with one or more waldoes or mechanical arms. They are often used for space construction and maintenance. In the movie 2001 A Space Odyssey, they were referred to as "EVA pods." In Wernher von Braun and Disney's Man In Space series, they were called "bottle suits." They are also known as "closed-cabin cherry picker", "manned autonomous work system", and the ever popular "man-in-a-can." One of their main advantages over a soft space suit is that they solve the depressurization problem.

I'm back to trying to put together some semi-realistic design for near-future space flight. In this case, I'm mainly trying to tackle a couple of problems. The first is the restrictions put on by current EVA technology. There's no such thing as being able to put on your spacesuit, go out the airlock and deal with an emergency these days. A minimum of about 20 hours of slow decompression and prebreathing pure oxygen is required before anyone goes out into space. Thats because the cabin environment of the Space Station, and the Shuttle is oxygen/nitrogen at sea level pressure, while the suits operate with pure oxygen at 5 p.s.i. They do that because, with present, vintage 1980 space suits, the arms and legs become impossible to bend if the pressure is any greater. The other problem is radiation shielding. For long stays outside, or any meaningful work beyond the Earth's ionosphere, the present suits just have inadequate radiation protection.

The potential solution is MAWS. It will have the same internal pressure as the station, or whatever long duration habitat we have in the future, because it doesn't have flexible joints. Instead it uses a couple of miniature versions of the station's robot arm. Its possible to put much better radiation shielding around MAWS, too. Probably the first exploration of asteroids or moons of Mars will be done in something like this design.

So this is the baseline look of the MAWS, as loosely worked out by NASA. Should it have a second set of heavier arms? Where would EVA equipment be attached? In general, what do you think of the idea?

From Manned Autonomous Work System by Tom Peters (2010)

Discovery's extravehicular capsules or "space pods" were spheres about nine feet in diameter, and the operator sat behind a bay window which gave him a splendid view. The main rocket drive produced an acceleration of one-fifth of a gravity—just sufficient to hover on the Moon—while small attitude-control nozzles allowed for steering. From an area immediately beneath the bay window sprouted two sets of articulated metal arms or "waldoes," one for heavy duty, the other for delicate manipulation. There was also an extensible turret carrying a variety of power tools, such as screwdrivers, jack-hammers, saws, and drills. Space pods were not the most elegant means of transport devised by man, but they were absolutely essential for construction and maintenance work in vacuum. They were usually christened with feminine names, perhaps in recognition of the fact that their personalities were sometimes slightly unpredictable. Discovery's trio were Anna, Betty, and Clara.

Once he had put on his personal pressure suit—his last line of defense—and climbed inside the pod, Poole spent ten minutes carefully checking the controls. He burped the steering jets, flexed the waldoes, reconfirmed oxygen, fuel, power reserve.

From 2001 A Space Odyssey by Sir Arthur C. Clarke (1969)

He was nearer to the sun than any man had ever been. His damaged space-pod was lying on no hill, but on the steeply curving surface of a world only two miles in diameter.


Even then, it was still possible for men in the tiny self-propelled space-pods — miniature spaceships, only ten feet long — to work on the night side for an hour or so, as long as they were not overtaken by the advancing line of sunrise.


He was still not quite sure what had happened. He had been replacing a seismograph transmitter at Station 145, unofficially known as Mount Everest because it was a full ninety feet above the surrounding territory. The job had been a perfectly straightforward one, even though he had to do it by remote control through the mechanical arms of his pod. Sherrard was an expert at manipulating these; he could tie knots with his metal fingers almost as quickly as with his flesh-and-bone ones.


He had aimed the pod with its gyros, set the rear jets at Strength Two, and pressed the firing button. There had been a violent explosion somewhere in the vicinity of his feet and he had soared away from Icarus—but not toward the ship. Something was horribly wrong; he was tossed to one side of the vehicle, unable to reach the controls. Only one of the jets was firing, and he was pinwheeling across the sky, spinning faster and faster under the off-balanced drive. He tried to find the cutoff, but the spin had completely disorientated aim. When he was able to locate the controls, his first reaction made matters worse—he pushed the throttle over to full, like a nervous driver stepping on the accelerator instead of the brake. It took only a second to correct the mistake and kill the jet, but by then he was spinning so rapidly that the stars were wheeling round in circles.

Everything had happened so quickly that there was no time for fear, no time even to call the ship and report what was happening. He took his hands away from the controls; to touch them now would only make matters worse. It would take two or three minutes of cautious jockeying to unravel his spin, and from the flickering glimpses of the approaching rocks it was obvious that he did not have as many seconds. Sherrard remembered a piece of advice at the front of the Spaceman’s Manual: "When you don’t know what to do, do nothing." He was still doing it when Icarus fell upon him, and the stars went out.

It had been a miracle that the pod was unbroken, and that he was not breathing space. (Thirty minutes from now he might be glad to do so, when the capsule’s heat insulation began to fail… .) There had been some damage, of course. The rear-view mirrors, just outside the dome of transparent plastic that enclosed his head, were both snapped off, so that he could no longer see what lay behind him without twisting his neck. This was a trivial mishap; far more serious was the fact that his radio antennas had been torn away by the impact. He could not call the ship, and the ship could not call him. All that came over the radio was a faint crackling, probably produced inside the set itself. He was absolutely alone, cut off from the rest of the human race.

It was a desperate situation, but there was one faint ray of hope. He was not, after all, completely helpless. Even if he could not use the pod’s rockets—he guessed that the starboard motor had blown back and ruptured a fuel line; something the designers said was impossible—he was still able to move. He had his arms.


He slipped his fingers into the controls that worked his mechanical limbs. Outside the pod, in the hostile vacuum that surrounded him, his substitute arms came to life. They reached down, thrust against the iron surface of the asteroid, and levered the pod from the ground. Sherrard flexed them, and the capsule jerked forward, like some weird, two-legged insect… first the right arm, then the left, then the right… .

It was less difficult than he had feared, and for the first time he felt his confidence return. Though his mechanical arms had been designed for light precision work, it needed very little pull to set the capsule moving in this weightless environment. The gravity of Icarus was ten thousand times weaker than Earth’s: Sherrard and his space-pod weighed less than an ounce here, and once he had set himself in motion he floated forward with an effortless, dreamlike ease.

Yet that very effortlessness had its dangers. He had traveled several hundred yards, and was rapidly overhauling the sinking star of the Prometheus, when overconfidence betrayed him.

From "Summertime on Icarus" by Sir Arthur C. Clarke (1960)

Space Tug

A space tug is a tiny spacecraft with over-sized engines and some means of grappling another spacecraft. If the tug pushes its cargo,it will have a massive push plate on its bow, with a core of structural members to transmit the thrust of its engines to the push plate. If the tug pulls its cargo, it will have cables and winches on its stern, and the engines will be vectored to fire backwards at an angle so it does not torch the ship it is dragging. The engines will suffer a reduction thrust penality proportional to the cosine of the engine angle.

Note that if nuclear propulsion spacecraft are involved, the tugs and the spacecraft will generally be designed to dock bow to bow. Otherwise you will be exposing the other ship to the radiation from your engine.

According to the Technovelgy site, the term "space tug" was invented in 1942 by Eric Frank Russell in his short story "Describe a Circle"

The Last Great War

(ed note: Nuclear Salt Water powered Frigate New Jersey wants to dock with colony on asteroid 624 Hektor. Nuclear Lightbulb powered Tug Brutus assists. Remember, with nuclear drive rockets using shadow shields the only safe way to dock is nose-to-nose.)

"Conn, tug Brutus requests permission to dock."

"Permission granted. Close the fuel valves."

As New Jersey shut down her main engine, the powder blue UN tug approached on thrusters. Fitzthomas watched on external cameras, never liking it when his ship was in others' hands, but powerless to do anything about it. The traffic rules within 100 k-klicks of Hektor were as plain and draconian as those of LEO: no unauthorized burns, and no open cycle nuclear reactors in operation under any circumstances. And the UN tug drivers were pretty good.


"Conn, Brutus is making her final approach. Docking in one minute."

"XO (executive officer), signal all hands."

"Aye sir." A moment later, Allen's voice came over the shipwide intercom. "All hands, prepare for ship to ship dock." He switched back to his private channel to the captain. "Let's hope whatever blue hat is driving that donkey cart knows how to actually fly a spaceship."

As it turned out, he could. Brutus and New Jersey touched nose to nose at barely a meter per second. Heavy duty docking latches locked the ships together, and Brutus extended a fiber optic probe into a receptacle inside New Jersey's docking ring.

"Conn, we have hard dock with Brutus. They are requesting propulsion access."

Fitzthomas removed a hard blue plastic key from his extensive key ring and inserted it into a blue lock. "Transferring propulsion access on my mark....mark." He turned the key and the clear plastic ring around the lock lit up blue. Brutus's pilot now had control over New Jersey's maneuvering thrusters. For the duration of the ride, Fitzthomas's hand would hover over the key, ready to cut Brutus out of the system, just in case.

Brutus's pilot could now also see what New Jersey's docking radar and aft cameras saw, a necessity since the bulk of the frigate would block the tug's line of sight—visual or otherwise—while they maneuvered. Brutus was little more than a nuclear engine (closed cycle, which meant no reactant could escape with the exhaust, at the cost of about half the ship's specific impulse, which didn't matter for a short range, low speed tugboat) with a sturdy docking ring and a cockpit jammed in between. In some operations, the tug was unmanned and guided by computer or radio control operator until it docked with the target ship, and then the tug would relinquish control of its systems to the target ship's pilot, or a harbor pilot brought on board for the purpose, saving some of the mass of reactor shielding for the cockpit and some of the ulcers for shipmasters, but the UN insisted on doing things the old fashioned way. Fitzthomas had heard of tugs which did the entire trip by remote control or onboard computer, but he'd rot in hell before he let some toe-picker play model airplane with his spaceship, and the United States Space Guard agreed.

New Jersey's thrusters fired, heeling the ship around 180 degrees, so that her bow, with the tug latched on, faced Hektor. Brutus then fired her main engine, continuing the deceleration burn New Jersey had started. Fitzthomas felt himself lift ever so slightly out of his chair. His ship's decks were aligned so "down" when they were under thrust was towards her main engine. With Brutus docked with her nose and her thruster pointing the other way, "down" was now, temporarily, in the direction of the overhead. One more thing for Fitzthomas not to like about the tugboat.

"Approaching Hammarskjöld docks. Ten minutes to docking."

From The Last Great War by Matthew Lineberger (not yet published)

NASA Space Tug concept (1970's)

Tinsley Space Tug concept

Space tug concept by Frank Tinsley. Tug has grapples and grippers on its stern. The four square plates around its waist are ion drive units (The crewman's hatch is unfortunately placed right in the line of fire of one of the ion drives).

The petals near the bow are heat radiators. Sadly the radiators are spaced too closely. In reality one would want two radiators at 180° or at the most four radiators at 90°. The arrangement shown would have the heat from one radiator impinging on its neighbors.

And at the tip of the pointed prow would be the tiny nuclear reactor. It would be nice to include a small shadow shield to protect the crew from nuclear radiation.

Lockheed Space Tug concept (1963)

Details are sparse on this design. Click on blueprints for larger image. Blueprint is written in Italian but it has been translated for the website by Alberto Bursi. The engines are around the waist, on swivels. The designers also appear to have a flippant attitude towards maintaining a sense of up and down. If the pilot turns his head he will see his copilot's feet.

Boeing Intra-Orbit Personnel/Cargo Tug concept (1981)

The diagram is from this PDF file. Annoyingly it included lots of facts and figures about the tug, then said and here is a diagram of a totally unrelated Boeing concept that we will not give you any data for. I do like the slanted windows, allowing the crew to view the docking port.

Assorted

Skeletons and Spacesuits

I noticed a couple of pulp covers with skeletons in spacesuits. So I looked on Google image search. I had no idea it was such a wide-spread meme.

Images