Escape Craft

RocketCat sez

Oh, so you want a freaking lifeboat on your spacecraft, do you? Where did you get that brilliant idea, Einstein, a Star Trek episode?

Use your brain: if the life boat is actually going to preserve your crew's life it'll have to have enough stuff so that it'll actually be a spacecraft. Only with a more limited life support, much lower delta V, drastically less elbow room, and more likely to kill the crew. I'm giving you the benefit of the doubt and assuming you intended the lifeboat to be smaller that the actual ship.

Why would you want to waste valuable payload mass on something so worthless? I guess you've forgotten Every Gram Counts! Galaxy! I'm going to have to staple it to your forehead or something. You'd be much better off taking whatever is threatening the ship and throwing that overboard instead, and making do with the rest of the ship.

And don't even talk to me about escape pods. Might as well hop into a coffin for all the good they'd do. Actually a coffin would be better, at least that will save on funeral expenses.

(h/t to John)

For certain spacecraft emergencies, it is best if the crew and passengers abandon ship in some type of rescue craft.

A "lifeboat" or "life pod" is a long endurance device carrying many castaways that generally is not reentry capable. It is much like a wet-navy lifeboat. It is discussed here.

A "Reentry capsule" or "escape pod" is a short duration devices carrying few or one castaway that allows them to bail out of a spacecraft in orbit around a planet and safely land on the surface. It is much like a parachute on an aircraft. It is discussed here.

Life Boats

To reiterate: "lifeboat" or "life pod" is a long endurance device carrying many castaways that generally is not reentry capable. It is much like a wet-navy lifeboat. The main difference between a liferaft and a lifeboat is that the liferaft does not have a motor.

There are some nifty lifeboat and one man reentry vehicles detailed here.

Christopher Weuve says that a merchant ship's primary piece of damage control equipment is a lifeboat.

If the lifeboat is designed for prolonged use, it would be useful for it to contain equipment to put the people into suspended animation. This will reduce the consumption of air, food, and sanity. The lifeboat Narcissus from the movie Alien had a suspended animation capsule.

However, Jim Cambias raises an important point:

I've never understood the purpose of life pods. Why abandon a spaceship, however shot up or meteor-damaged it may be, just to hang around in a flimsy balloon or cramped pod? You're still on the same course, since no life pod can carry much delta-v, and the life-support problems are considerable. Why not include some kind of pressure balloon to provide temporary airtight containment in a hulled compartment and use the ship's own life-support? That way you get the ship's radiation shielding, power, etc.

If it's a reactor emergency you're worried about, don't eject the crew in pods, EJECT THE REACTOR!

(Actually, I realize perfectly well the purpose of life pods: it lets sf writers tell lifeboat stories in space.)

Jim Cambias

Dark Inferno Lifeboat

There is a good description of lifeboats in the eponomously named novel Lifeboat (AKA Dark Inferno) by James White.

The NTR passenger rocket's habitat module spins on its axis for artificial gravity. Since the rocket's designer failed to consult with Mr. Cambias, in the event of a nuclear engine disaster the crew and passengers escape in lifeboats.

The hatch to each lifeboat are set in the floor of the habitat module. The lifeboats are cylindrical but inflate into spheres once they are clear of the ship. At the top is the pressure hatch. 2.4 meters below the hatch is a plastic bag containing lightweight screens used for dividing the inflated pod. Below that is the service module and food store. While uninflated, the walls are folded with convolutions projecting inward. When inflated each lifeboat is three meters in diameter. The upper half of the sphere is transparent, the lower half is covered in reflective foil as a sun-screen.

The service module contains a two shot pre-measured solid rocket, a radio, one heavy set of sunglasses, and a lifesupport system. The lifesystem contains the breathing mix equipment, thermal control, toilet, and water reclamation.

The first passenger jumps into the pod. They then press backward into the side wall and raise their hands to help the next passenger into the pod. The second passenger does not jump, instead they sit on the edge of the hatch with legs dangling down while gripping the hatch coaming with both hands. The first passenger grabs the second's legs and helps them down. They both press backward and the second passenger helps the third in the same way. Three passengers is what the lifeboat lifesupport system is rated for. Passengers are warned to leave behind anything made of metal or having sharp edges, which could puncture the lifeboat walls.

The lifeboats are ejected radially perpendicular to the habitat module's spin axis, at a velocity of 2.45 m/s (1/4 g). Under normal conditions, each lifeboat's umbilical power line is remotely severed before ejection. In the event of a ship control failure, the umbilicals will not be severed, and will give each lifeboat an off-center tug as they separate. This will cause the lifeboats to slowly tumble. If there is an crewperson available, they can manually sever the umbilicals.

The crew cabins eject as four wedge shaped sections. Since they are closer to the spin axis than the floor of the passenger module, the ship's spin has to be increased so they too will be ejected at 2.45 m/s. The medical officer's cabin has a radio powerful enough to reach all the passenger lifeboats, since the officer will have to offer medical advice.

A radio beacon is left behind to designate the rendezvous point.

If a lifeboat is tumbling, the passengers can arrest the tumble by crawling. Lie flat on the transparent section of the lifeboat skin while holding the moulded finger-grips. Rotate their body until the Sun appears to be coming from the top of your head, passing in front of you, and then moving under your feet. Then start crawling in as straight a line as possible. When you come to the lock section or the services panel, or when you are crawling over plastic, which is not transparent, try to keep your line of movement straight by looking ahead to the next transparent section to see where the Sun is. Gradually the tumble will stop. If the Sun is moving too fast to see, blink as fast as you can to visually slow it down. If there is more than one passenger in the pod, they can help by crawling along the same line, evenly spaced around the interior wall. Or even hold on to each other with feet on the walls and heads near the center, and walk in the proper direction.

The desired attitude of each lifeboat is with zero tumble, and the silver section of the wall aimed at the Sun.

The ship proper, still under thrust, leaves the rendezvous point. Once the ship is safely away (after a few days), each lifeboat burns a pre-measured solid rocket to reverse their vector. The engine is oriented so that the thrust axis is aimed at the rendezvous point. The "A" pre-measured rocket is burned for 4.9 m/s of delta V. This cancels the 2.45 m/s outward vector, and gives a 2.45 m/s inward vector in the direction of the rendezvous point.

If the radio beacon is operational, orienting a lifeboat in the proper direction is easy, using fancy electronics.

If the disaster renders the beacon inoperable, the passengers in the lifeboats have to do orientation the hard way. The navigation officer will calculate the reference stars for each lifeboat. The stars will be in a plane perpendicular to the desired vector. The boat's passengers will have to orient such that the line of demarcation between the transparent and the silvered skin hemispheres touches each of the reference stars. They use the same technique used to arrest lifeboat tumble: by crawling on the skin. The officer will have to teach the passengers enough constellations so they can identify the reference stars. Failure to properly orient the lifeboat will probably doom the occupants.

The navigational officer will give each specific lifeboat a precise count-down to igniting the "A" pre-measured rocket.

When the lifeboats near the rendezvous point, the lifeboat will orient itself so that the thrust axis point away. Then on command from the navigational officer they burn the "B" pre-measured rocket and come to a halt. The rocket gives a delta V of 2.45 m/s, cancelling their vector. In this case the proper orientation of the lifeboat is secondary to igniting the B rocket at precisely the correct time. Improper orientation will merely result in a small amount of lateral drift. Improper timing means the lifeboat could stop way short or way past the rendezvous point, possibly even far outside the rendezvous area.

At the rendezvous point they will meet the rescue ship.

The life support section can supply breathable atmosphere enough for three people for two weeks (42 person-days).

The life support section can handle the body heat of up to three adults. Past that the environment will become hotter. Passengers should avoid exertions and remove some clothing in order to prevent heat build up.

The food supply is low-residue and highly concentrated. This is to avoid straining the toilet. The lack of bulk will mean the passengers will always be hungry even though there is enough nourishment to keep them alive. There is enough food for three persons to last two weeks (also 42 person-days).

Water is reclaimed from the toilet and atmospheric humidity. It is more pure than most tap water, but passengers might detect a psychosomatic stink from it if they dwell too much on its source.

Perry Rhodan Rescue Pod

For you ugly Americans who have not heard of Perry Rhodan, it is a German science fiction series that has been steadily published installments since 1960 (more than 2,850 as of April 2016). Pretty much the most successful science fiction book series ever written.

Rescue Pod of the League of Free Terrans

Type: 12-person Emergency Rescue Pod (ERP), carried by long haul spaceships (Year 1289 NGZ or 4876 A.D.)

An element of ship safety on large space ships are the Rescue Pods. They serve along with dinghies and assorted matter transmitters as additional ways to rapidly abandon the ship in a emergency. Although the ERP are considered antiquated from technical view, they are still very robust and economical. ERP are deployed on space ships in the 500 and 800 meter class, especially for ships operating beyond the main routes with no planets, bases, or outposts in the immediate environ. Crew enter the ERP by an express antigrav elevator monitored by a rescue positronic computer (elevator enters ERP from the bottom at point labeled "Einstieg"). Every crew member has an allocated seat in an ERP in case of emergency.

Note that upper compartment (crew section) can be jettisoned from lower section along plane-of-separation located immediately below spotlights (24).

Technical Data

  • Dimensions: height 8.2 m, maximum diameter 6.0 m
  • Mass: 19.25 metric tons
  • Crew capacity: maximum 18, standard 12
  • Offensive weapons: none
  • Defensive weapons: x2 staggered force fields (High-overload and Paratron)
  • Slower-Than-Light engine: Puls proton beam
  • Faster-Than-Light engine: Lineardrive (range 12,000 light-years)
  • Power plant: NUGAS-fed Schwarzschild-reactors

  1. Crew-compartment landing parachutes (jettison)
  2. Automatic hyperspace emergency transmitter
  3. FTL Lineardrive astrogation sensor
  4. Hyperspace transmitter back-up conventional metal antenna
  5. RCS
  6. Life support system and consumables storage
  7. RCS fuel tanks
  8. Wrap-around sensor array for normal-space sensors
  9. Acceleration couches with integrated inertia dampers
  10. Storage for emergency supplies and equipment
  11. Antigrav shaft exit
  12. Rescue positronic computer
  13. Antigrav generators
  14. Sickbay deck, equipment and spare part storage
  15. FTL Lineardrive
  16. Puls proton beam STL normal-space engine
  17. Power reactor
  18. Batteries
  19. NUGAS ball fuel storage (engine and reactors)
  20. Force field generators
  21. Service and repair robot
  22. Landing gear
  23. Launch rack
  24. Spotlights
  25. Emergency hatch (jettison)
  26. Hyperspace transmitter main malleable-energy antenna (projectors)

Text and artwork by Gregor Paulmann

Translation from German by Michel Van

From Rettungspod der LFT from PR 1876

Reentry Capsule

To reiterate: A "Reentry capsule" or "escape pod" is a short duration devices carrying few or one castaway that allows them to bail out of a spacecraft in orbit around a planet and safely land on the surface. It is much like a parachute on an aircraft. Except when you pull the ripcord on one of these things the fall will be about two orders of magnitude higher.

Note that all of the reentry capsules shown here rely heavily upon aerobraking, they would not work on an airless planet or moon.

Under the heading of "some people have too much free time", there are a few science fiction writers who talk about bored people using reentry capsules as a sport, much like sky-diver do today. Adrenaline junkies will always be with us.

The escape pods were lenticular ceramic heat shields with thermoplastic covers, hardly bigger than Porta Potties. Stored inside each was a parachute and an inflatable raft in an ejection rig and -- the only really specialized gadget -- a hand-aimed, gyro-stabilized, solid-fuel retrorocket. An astronaut who had to leave orbit in a hurry was supposed to climb in, lie back, clutch the retrorocket to his or her chest, adjust position and attitude with its gas jets, then take aim at an easily identifiable star specified by mission control and pull the trigger.

The impulse from the solid-fuel rocket would gradually slow the pod until orbital velocity was lost, whereupon the astronaut threw away the rocket, closed the flimsy hatch with its little bubble window, and tried to relax while falling through the atmosphere, on fire, decelerating at five gees plus. Below about 7,000 meters or so the pod's cover would pop off, spilling the astronaut and deploying the chute.


In seconds he had the nearer pod free of its straps. Lifting the thermoplastic lid, he found all the neat packages of equipment nestled where they should be. He ripped open Velcro fastening of yellow webbing, yanked at cotter pins festooned with red warning strips. One of them activated a SARSAT radar beacon...

...Flipping over to squat on the pod, he shrugged off his life-support backpack and hooked into the pod's portable emergency oxygen supply. He wrestled himself onto his back and tugged the parachute straps across his chest and shoulders, pulling the life raft package up under his rump. The strap edges scrunched thick layers of suit material into an oppressive lump in his crotch. It was exhausting work, and he heated up fast without the coolant flow from this abandoned backpack, but it had to be done right; parachutists had dismembered themselves with loose harnesses.

From Starfire by Paul Preuss (1988)
The Future in Space: Escape Pods

A SF Staple

For me, the introduction to escape pods came via Episode 1 of Star Wars, and the small capsule that R2-D2 and C3PO used to escape from the Tantive IV. Then there were the triangular Sovereign class pods from Star Trek: First Contact, the spherical escape pod from Starship Troopers 3: Marauder, and the flying coffins from Prometheus (yes, I am going to wash my mouth out with soap after mentioning that abomination). Escape pods are an established feature of SF spacecraft, and unlike many other features shown by Hollywood as vital, they appear to be a logical addition to any ship. In a more realistic SF 'Verse, however, it seems unlikely that a deep-space craft will be so equipped, for reasons that will be explored later. The type of spacecraft, its mission, and the 'flavour' of the 'Verse all affect the utility of a escape pod, and while they may make sense in the context of Star Wars, they may not apply to many situations in a hard SF world.

Escape Pod: Definition

Like many kinds of SF tech the escape pod is often confused with other vehicles, and/or misnamed. Quite often there are small spacecraft that serve the same role, such as the Narcissus shuttle from Alien, or the escape craft in which Ripley, Newt, and Hicks escape from the USCSS Nostromo in Alien3 (more soap). These two craft do not qualify as escape pods because they have an extended flight capability, enabling in them to make planetfall from beyond orbit, or reach a inhabited system from deal space. As in the case of the Narcissus a 'lifeboat' the craft such as these may in fact be the auxiliary vessel carried as part of normal operation; this is seen in Star Trek (2009) when the USS Kelvin was evacuated with the shuttles.

An escape pod can only be used to reach the surface of a planet from orbit, and possesses only enough DeltaV to deorbit, often combined with atmospheric braking. If used in deep space the pod would simply float until help arrived, as it could if the planet was unsuitable for landing. This is the type seen often in Star Wars, especially the animated Clone Wars, although those are far more sophisticated than might be the case. Unlike a 'lifeboat' craft escape pods are often seems as disposable, having only enough power to make a safe landing and call for help.

Arguments For & Against

Escaping from a dying spaceship just in time to see it exploded in a nuclear fireball moments before the escape pod begins to tear into the atmosphere of the inhabitable, uncharted planet... This is kind of fiction that inspires the inclusion of escape pods in spacecraft designs. Desirable as it might be, however, it is only a fiction. Space is a relatively benign environment; a crippled spaceship will not sink, be torn apart, or explode as an aircraft, ship, or submarine might. And don't forget, in space none can hear you scream, so you will be waiting a long time for help.

Deep space is a different case to a planetary system or orbit itself, so I'll discuss it separately. The most effective way of analysing an escape pod in deep space is to compare it to the lifeboats on a cruse ship. I know, space isn't an ocean, but in this case it is a helpful analogy. If a cruise ship sinks the lifeboats have on job — keep people alive until help arrives, which, given the number of ships in major shipping lanes, should not be too long. It seems safe to assume that a space liner could use escape pods in the same way, but this fails under several criteria. One, the spaceship cannot sink, so there is no danger to staying aboard a spaceship that has been disabled by a failure or meteor strike. Note that NSWR spacecraft are an exception to this, as they can explode if the tanks fail; but even then it would be better to jettison the tanks themselves. The ship will be compartmentalised, so even severe damage should leave habitable sections. Two; the pods cannot carry sufficient life support, food, or power. One a lifeboat in the pacific there is air, sun for solar power, edible fish, etc. to help you survive. In space, any escape pod or 'lifeboat' needs to carry oxygen, filters to scrub CO2, water recycling, etc. This might be doable for the short term, say a few days to a week, but on a Hohmann transfer that is going to do no more than prolong the agony. And if the ships in the 'Verse are fast enough to rescue the survivors, then escape pods are not needed, they could just stay with the ship and its greater supply of food, power, oxygen, etc. So it can be seen that escape pods are infeasible for deep space; dangers like fissioning fuel can be easily dumped, and the pods are going to have fewer resources.

Near space has the same limitations as deep space, but orbit does allow the use of escape pods. Over a habitable planet all the pods have to do is land, something that can be accomplished with far less weight than survival for a few weeks in deeps space. For this task a escape pod might be a one man device scarcely larger than a phone booth; the drop pods used by the ODST in Halo would be quite similar to what would be needed. Or it could be larger, carrying several people and enough supplies to last them for weeks or months, along with communications equipment. If the planet is hostile — incompatible atmosphere — then there is no point landing, and it is better to stay in orbit where the arguments against escape pods in deep space apply.

It seems that pods are of the most use when in the vicinity of a planet, which means that Star Trek and Star Wars got something right at least. It also makes them unlikely to be found on spacecraft that spend a long time in transit between destinations, due to the weight penalty. The place they are most likely to be found is on a space station. Stations likely carry far more people aboard than can be evacuated by shuttle alone, have less of a weight limit, and are normally close to planets. Which brings up another constraint; the planet must be habitable, or at the very least, non-hostile. And these may be few and far between in the real world.

The above points can be extrapolated to indicate the type of 'Verse in which escape pods are going to be a commonplace, and where they will be used. Space stations over habitable planets will be the main use, followed by ships that have large crew/passenger numbers and which regularly pass habitable planets. Note that within a solar system this is unlikely, so you are looking at starships. Given the difficulty of interstellar flight, and the time spent in deep space away from any planet, means that only FTL starship really befit from escape pods. This is the case in Star Wars, where hyperspace is used to jump from one habitable planet to another. Usually the starships are close enough to a habitable planet that escape pods are a perfect safety measure. FTL comms also make them more practical, as it allows for a much higher probability of rescue, especially if the starship went down outside normal travel routes.

So you end up with a moderately hard 'Verse. One in which the technology and setting are generally crammed with realistic science, but in which there is FTL travel and communication, a unlikely number of human habitable planets, and starship design that goes in for catastrophic failure (or space battles in orbit, although it is unlikely anyone would survive from the loosing ship, no matter what escape methods they had planned).

From The Future in Space: Escape Pods, Part I by William Moran (2015)

Survival Kit

A deluxe reentry capsule will also contain a survival kit. There are two basic types:

Shirt-sleeve environment survival kit: those kits that assist survival on nice planets you can walk around in your shirt-sleeves without dying horribly. Habitable planets, in other words.

Hostile environment survival kit: those kits that assist survival on nasty deadly planets that will kill unprotected humans in a few seconds. Non-habitable planets, in other words.

Shirt-sleeve Environment Survival Kit

A habitable planet survival kit is going to be more or less identical to a conventional survival kit you can purchase right here on Terra.

Emergency rations will be included. If you expect to live off the alien land and eat alien native food ("xenorations"), don't forget to bring your tracetabs.

A first-aid kit and other medical gear which are useable by an untrained person. You can assume a nurse or doctor will have their own full medical kits.


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

Kelly seemed puzzled.

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

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

From Space Angel by John Maddox Roberts (1979)
Survival Kit

A survival kit is a package of basic tools and supplies prepared in advance as an aid to survival in an emergency. Civil and military aircraft, lifeboats, and spacecraft are equipped with survival kits.

Survival kits, in a variety of sizes, contain supplies and tools to provide a survivor with basic shelter against the elements, help him or her to keep warm, meet basic health and first aid needs, provide food and water, signal to rescuers, and assist in finding the way back to help. Supplies in a survival kit normally contain a knife (often a Swiss army knife or a multi-tool), matches, tinder, first aid kit, bandana, fish hooks, sewing kit, and a flashlight.

General contents

The general contents of an emergency survival kit depend on the location. Basic components in a survival kit address the needs of first aid, food, water, shelter, navigation, and signalling.

Shelter and warmth

A variety of materials are recommended for emergency shelters, and vary between geographic regions. Options often included in survival kits may consist of:

Health and first aid

First aid kits will often include a combination of the following:

  • Bandages
    • Sterile combine dressing, and gauze pads
  • Adhesive tape, and gauze tape
    • Disinfectant pads
    • A 30-day supply of personal prescription medication
  • Antibiotic cream
  • Burn cream
  • Aspirin
  • Sunscreen (where appropriate, above 30 SPF)
  • 100% UV protective sunglasses ("UV 400") (protects eyes from harmful UV radiation. Polarized glasses are not necessarily UV protective, but aid with glare only)

Food and water

Most survival kits involve sustenance for short periods of time, to be used and replenished before contents spoil.

  • Water in sealed containers for dry areas, or water purification tablets or household bleach in areas where water is available but may be contaminated. For emergency water purification see: water purification techniques
  • Canteen full of water, and a filter if needed
  • Heavy duty aluminum foil to create a distillation tube to remove salt from salt water during boiling/condensation. Must have another receptacle to collect condensate.
  • Canned food, Meals Ready-to-Eat (MRE), or high-energy foods such as chocolate or emergency food bars.
  • Fishing line and gear (fish hooks, lures, and split shot leads)
  • Snare wire
  • Gillnetting (for emergency fishing)

Some dry fruits, peanuts or roasted grams.

Signaling, navigation and reference

Since the primary goal of a survival kit for lost or injured persons is rescue, this part of the kit may be considered the most essential. Key elements for rescue include:

  • Distress radiobeacon
  • Whistle
  • Signal mirror
  • High power LED light (able to have batteries replaced, and carry an extra battery), white lens, with signaling capabilities. Strobe versions are available for some lights. Use lithium cells only, due to superior shelf life.
  • Flare: three fires in a triangle is the international distress signal
  • Laser pointer with lithium batteries, for superior signaling range. Laser pointers have resulted in at least one rescue: during the night in August 2010 two men and a boy were rescued from marshland after their red laser pen was spotted by rescue teams.
  • Surveyor's tape - orange or chartreuse for marking location for rescuers
  • Pen/pencil and paper for leaving notes to rescuers about direction of travel
  • Compass. Analog watch can also be used to determine orientation when the sun is visible - See direction finding using a watch
  • Trail maps/charts (if location is known in advance)
  • Survival manual for technique reference
  • Glow stick

Multipurpose tools or materials

Survival kit tools emphasize portability and versatility. Tools recommended for many types of survival kit include:

  • Fixed-blade knife, or multitool such as a Swiss Army knife.
  • Can opener such as the P-38 or the P-51
  • Heavy-duty needle and thread for repairing clothing and equipment
  • Red or orange plastic bag(s) or trash bags
  • Sturdy cord or "550" parachute cord for setting up a tarpaulin and snaring small animals
  • Hatchet with sheath for cold conditions, or machete for tropical conditions (shelter and fire)
  • Camp stove or some type of gas burner and fuel such as bottled propane or Liquefied petroleum gas (LPG)
  • Candles for light, signaling, fire-starting
  • Metal billycan or "water bottle" for water storage, boiling, purification, cooking
  • Compact saw such as Japanese style backsaw with coarse teeth (folding models available). Bow saws can quickly cut larger diameter limbs and small to medium thick trees, and Folding saws can be small enough to fit into a kit, but big enough to cut small to medium diameter limbs, and possibly smaller trees.
  • Solar charger
  • Helmet

Lifeboat survival kits

Lifeboat survival kits are stowed in inflatable or rigid lifeboats or life rafts; the contents of these kits are mandated by coast guard or maritime regulations. These kits provide basic survival tools and supplies to enable passengers to survive until they are rescued. In addition to relying on lifeboat survival kits, many mariners will assemble a "ditch bag" or "abandon ship bag" containing additional survival supplies. Lifeboat survival kit items typically include:

Safety equipment
Communications and navigation
  • Compass
  • Distress beacons or (EPIRBs) to alert the Cospas-Sarsat rescue consortium, an international satellite-based search and rescue distress alert agency and identify the registered beacon owner's specific information from their registration file
  • Red flare, rocket parachute flare, and/or smoke signal flare
  • Laser pointer for signaling aircraft (red is color of distress, but green color is higher power and will be seen farther), with lithium cells, in double waterproof plastic pouch (pointers of high power are a theoretical hazard to eyes of low-flying pilots at night)
  • Radar reflector (to help rescuers locate the raft)
  • Lighter
  • Lantern and fuel, the fuel doubles as firestarter
  • Radio transceiver, standard VHF marine when operating near inland shore, 121.5MHz AM VHF guard channel capable aircraft band transceiver to contact rescuers and high overflying commercial and military aircraft visible by contrails, an optional amateur radio if a licensed radio amateur, (see Ham Radio) or an AM/FM/Weather/Shortwave radio receiver to receive precise time for celestial navigation as well as weather information
  • GPS navigation device
Food and water
Other tools and boating items
From the Wikipedia entry for Survival kit
Russian Soyuz survival kit

NAZ-3 survival kit. It was designed in 1968 for the Soviet Soyuz spacecraft, the reliable workhorse of space flight which is still in use today. As outlined on this interesting site about the Russian space program, the kit contained the following from top left to bottom right:

  • Makarov pistol and ammunition
  • wrist compass
  • 18 waterproof matches with striker
  • machete; fishing kit
  • strobe light with spare battery
  • 8 fire starters
  • folding knife
  • antenna
  • 3-pair wool gloves
  • signal mirror
  • NAZ-7M type medical kit
  • penlight
  • R-855-YM or R-855-A1 radio
  • two “Priboy 2S”, ПРИБОЙ-2С radio batteries
  • three wool balaclava hoods.
From Inside the Cosmonaut Survival Kit by Benjamin Breen (2013)

Hostile Environment Survival Kit

Hostile environment survival kits will contain pretty much everything in a shirt-sleeve environment kit, plus extra equipment to cope with such problems as the lack of a breathable atmosphere.

Making a survival kit for a planet with an enviroment lethal to an unprotected human is incredibly difficult. An castaway using a reentry capsule to land on Terra might wind up in unpleasant places such as a jungle, desert, or ocean; but at least they will have access to unlimited amounts of breathable air. Maybe even food and water. A castaway landing on Mars will not be so lucky. Just ask Mark Watney.

Basically the kit will have to include a pup tent sized habitat module with an entire life support system (Poul Anderson called them "sealtents"). Might as well just make the reentry capsule into a freaking spacecraft. It will probably take the form of some type of inflatable habitat module.

Alternatively you'll need compact equipment to re-fill your space suit's oxygen tanks (and make more O2). Meaning your space suit will be your habitat module. I hope the suit has sanitary facilities or it is going to be really nasty as the suit fills up with poop.

In a paper entitled An overnight habitat for expanding lunar surface exploration by Samuel S. Schreiner et al is described a piece of equipment that could be adapated into a hostile enviroment pup-tent. The item was intended only to be an overnight habitat used for eight hours or so, but it is a start.

An overnight habitat for expanding lunar surface exploration

The system is intended to enable two astronauts, exploring with an unpressurized rover, to remove their space suits for an 8-h rest away from the lunar base and then conduct a second day of surface exploration before returning to base. This system is composed of an Environmental Control and Life Support System (ECLSS) on the rover, an inflatable habitat, a solar shield and a solar power array...

...The mass, volume, and power analyses of each subsystem are integrated to generate a total system mass of 124 kg and a volume of 594 L, both of which can be accommodated on the Apollo Lunar Roving Vehicle with minor improvements.

The rover ECLSS connects to the habitat via umbilical cables to maintain the atmosphere in the habitat. A thermal control unit on the rover is connected to the liquid cooling garments worn by the astronauts to provide active thermal control, while a solar shield is used to provide passive thermal control to minimize the load on the thermal control unit. The ECLSS contains a carbon dioxide scrubber, a “slurper” to remove humidity, an oxygen tank for respiration, and a water tank for the sublimator, crew hydration, food preparation, hygiene or medical use. The solar array provides power for the overnight system and recharges the rover batteries for the second day of exploration...

2.1. Inflatable ribbing concept

When the astronauts first enter the inflatable habitat, the airlock volume requires a support structure in order to retain its internal shape while at zero internal pressure. Inflatable ribbing may be chosen for structural support. This ribbing consists of a frame of small-diameter inflatable tubes that, when inflated to high pressure, provide a rigid structure for the habitat. Thus, the astronauts can inflate the ribbing prior to entry without filling the interior of the habitat with O2. Then the astronauts can enter the habitat, close the airlock, and fill the interior of the habitat to the desired pressure. A similar inflatable ribbing concept is used in commercially available inflatable camping tents.

2.2. Flexible membrane airlock design

To reduce the total size of the habitat, a novel flexible membrane was designed such that the same internal volume could function as both an airlock and habitat. As shown in Fig. 3, a thin, flexible, airtight membrane divides the internal habitat volume into an airlock side (left) and a habitat side (right). The membrane material is similar to the habitat outer surface without the micrometeorite protection, resulting in approximately 1/4 the surface density. The membrane is sized such that at any given time the entire volume can be used either as an airlock or as a habitat.

The concept of operations for entering the habitat using the flexible membrane airlock is illustrated in Fig. 3. After the astronauts have entered the habitat and pressurized the airlock, they remove their suits on the airlock side (top row of Fig. 3). Next, the airlock membrane is moved manually by the astronauts to its neutral transition configuration (middle row of Fig. 3). A valve in the membrane is used to regulate air flow from one side of the habitat to the other while the membrane is moved and the flow path is filtered to ensure that lunar dust is not transferred from the airlock side to the habitat side. After moving the membrane to the neutral position (in which it divides the habitat into two equal halves), the astronauts unzip an airtight zipper and proceed to the habitat side through the hole in the airlock membrane. Equipment is passed through in the same way. Next, the airtight zipper is closed and the membrane is manually moved towards the airlock side, maximizing the volume of the habitat side (bottom row in Fig. 3). The astronauts close the valve to the airlock side and then conduct activities within the habitat...

...When considering entry and exit of the habitat, a net could potentially be used to restrain the airlock membrane in its neutral transition position in circumstances where the habitat side is pressurized but the airlock side is not. With a net in place, only partial venting of the volume would be required for entry and exit. The flexible membrane concept makes efficient use of the available space and reduces the total required internal volume of the habitat.

2.3. Inflatable geometry optimization

A preliminary geometric analysis was used to select a cylindrical geometry with hemisphere end caps and a flat floor. The cylinder was designed to accommodate the two astronauts standing vertically to don/doff their suits and the two astronauts sleeping side-by-side. The design was further constrained to a minimum interior volume of 12 m3 as a conservative estimate [9], and was required to have a flat cylinder wall between the end caps that was long enough to accommodate a door 0.75 m wide for entry and egress. The radius of the cylinder, the width of the flat floor, and the length of the cylinder were optimized to ensure that these requirements were met while minimizing the total mass of the inflatable skin and ribbing...

Table 1. Optimal inflatable pill mass and volume
Support ribbing1.100.090.0007
Adjustable airlock4.0410.0160
Packed volume0.2879
Table 2. The optimized geometry of the inflatable cylindrical flat-floor habitat
Cylinder radius1.29 m
Cylinder flat side length0.75 m
Maximum floor width1.80 m
Maximum floor length2.55 m
Maximum height2.21 m
Interior volume12.00 m3
Door height1.84 m

2.5. Inflatable deployment and stowing

...Using the packaged volume of 0.2879 m3 determined in Section 2.3 (packing factor of 2), the folded inflatable can be expected to fit into a rectangular prism of dimensions 1.4 m×0.7 m×0.294 m...

4. Environmental Control and Life Support Systems

To enable an overnight stay on the lunar surface, the system needs to provide a suitable environment and consumables such as water and food. To meet this need, an Environmental Control and Life Support System (ECLSS) was designed to support two astronauts during the overnight stay and to recharge the astronauts׳ Portable Life Support Systems (PLSS) for a second day of exploration. The demands of the first day were not included in the system design because they would be met by the astronauts׳ (PLSS)...

Table 5. Oxygen and water requirements and storage system sizing for the overnight mission
Consumables storageOxygenWater
Quantity required (kg)8.123.9
Tank mass (kg)6.84.0
Tank volume (L)99.923.9

6. Results: system mass and volume estimates

Mass Breakdown
ECLSS28.5 kg
Emergency Power2.0 kg
Emergency Inflatable Seat6.0 kg
Power13.2 kg
Thermal Shield4.6 kg
Inflatable35.0 kg
ECLSS Consumables34.1 kg
Total123.4 kg
ECLSS Consumables Mass Breakdown
H2O - Med, Hygeine, Food Prep7.8 kg
H2O - Crew Hydration7.1 kg
H2O - Rover Sublimator5.9 kg
H2O - Refill Suit Sublimator3.9 kg
Oxygen for Ribs1.5 kg
Oxygen for Habitat + Respiration6.6 kg
Food1.3 kg
Total34.1 kg
Volume Breakdown
Inflatable Habitat
287.9 L
Thermal Shield4.1 L
Power62.6 L
ECLSS186.0 L
Emergency Inflatable Seat
51.2 L
Total34.1 kg
A Fall of Moondust

     It was at least two years since Lawrence had been inside an igloo. There was a time, when he had been a junior engineer out on construction projects, when he had lived in one for weeks on end, and had forgotten what it was like to be surrounded by rigid walls. Since those days, of course, there had been many improvements in design; it was now no particular hardship to live in a home that would fold up into a small trunk.
     This was one of the latest models—a Goodyear Mark XX—and it could sustain six men for an indefinite period, as long as they were supplied with power, water, food, and oxygen. The igloo could provide everything else-even entertainment, for it had a built-in microlibrary of books, music, and video. This was no extravagant luxury, though the auditors queried it with great regularity. In space, boredom could be a killer. It might take longer than, say, a leak in an air line, but it could be just as effective, and was sometimes much messier.
     Lawrence stooped slightly to enter the air lock. In some of the old models, he remembered, you practically had to go down on hands and knees. He waited for the “pressure equalized” signal, then stepped into the hemispherical main chamber.
     It was like being inside a balloon; indeed, that was exactly where he was. He could see only part of the interior, for it had been divided into several compartments by movable screens. (Another modern refinement; in his day, the only privacy was that given by the curtain across the toilet.) Overhead, three meters above the floor, were the lights and the air-conditioning grille, suspended from the ceiling by elastic webbing. Against the curved wall stood collapsible metal racks, only partly erected. From the other side of the nearest screen came the sound of a voice reading from an inventory, while every few seconds another interjected, “Check.”
     Lawrence stepped around the screen and found himself in the dormitory section of the igloo. Like the wall racks, the double bunks had not been fully erected; it was merely necessary to see that all the bits and pieces were in their place, for as soon as the inventory was completed everything would be packed and rushed to the site.
     Lawrence did not interrupt the two storemen as they continued their careful stock-taking. This was one of those unexciting but vital jobs—of which there were so many on the Moon—upon which lives could depend. A mistake here could be a sentence of death for someone, sometime in the future.
     When the checkers had come to the end of a sheet, Lawrence said, “Is this the largest model you have in stock?”
     “The largest that’s serviceable” was the answer. “We have a twelve-man Mark Nineteen, but there’s a slow leak in the outer envelope that has to be fixed.”
     “How long will that take?”
     “Only a few minutes. But then there’s a twelve-hour inflation test before we’re allowed to check it out.
     This was one of those times when the man who made the rules had to break them.
     “We can’t wait to make the full test. Put on a double patch and take a leak reading; if it’s inside the standard tolerance, get the igloo checked out right away. I’ll authorize the clearance.”

From A Fall of Moondust by Arthur C. Clarke (1961)


Castaways will need survival skills or they will be facing a real short life-span. They will get to see how good they are at playing Robinson Crusoe or Swiss Family Robinson. Which could be a real challenge if the planet does not have a human-habitable biome.

As the duration on the planet without rescue drags on, the line between castaway and colonist becomes blurred. A few old-timey science fiction stories postulate a "castaway's code" where people marooned on a habitable planet with no hope of rescue must marry each other and found a colony, by law. Left unstated is why such a bizarre law would have been passed in the first place. Rampant imperialism, I guess.

Sometimes space explorers won't crash but will discover a shipwrecked spacecraft or life boat and will do a search for castaways. That is, of course, if it is a Terran spacecraft. If it is extraterrestrial, more caution is needed. If it from an unknown extraterrestrial species, call out the marines and the first contact specialists. And do keep in mind the movie "Alien."

If explorers discover lots of shipwrecked spacecraft, go to red alert because you have apparently discovered a "Sargasso of Space planet". And if you are not real careful you'll be the next shipwreck. Whatever wrecked all those other spacecraft might still be active.

Old pulp science fiction stories sometimes take the slant that deliberately marooning another human on a wilderness planet for the rest of their life is an unspeakable act, the crime of crimes. It doesn't matter if they are your worst enemy, it just isn't done.

More recent science fiction is a bit more cynical. Vaporizing your enemy with a laser pistol is too merciful, marooning them ensures they suffer your maximum revenge.

Novels and short stories that cover the shipwrecked spaceship and castaway theme include:

Movies that cover the shipwrecked spaceship and castaway theme include:


A castaway is a person who is cast adrift or ashore. While the situation usually happens after a shipwreck, some people voluntarily stay behind on a deserted island, either to evade captors or the world in general. A person may also be left ashore as punishment (marooned).

The provisions and resources available to castaways may allow them to live on the island until other people arrive to take them off the island. However, such rescue missions may never happen if the person is not known to still be alive, if the fact that they are missing is unknown or if the island is not mapped. These scenarios have given rise to the plots of numerous stories in the form of novels and film.

From the Wikipedia entry for CASTAWAY

Marooning is the intentional act of abandoning someone in an uninhabited area, such as a desert island. The word first appears in writing in approximately 1709, and is derived from the term maroon, a word for a fugitive slave, which could be a corruption of Spanish cimarrón, meaning a household animal (or slave) who has run "wild".

The practice was a penalty for crewmen, or for captains at the hands of a crew in cases of mutiny. Generally, a marooned man was set on a deserted island, often no more than a sand bar at low tide. He would be given some food, a container of water, and a loaded pistol so he could commit suicide if he desired. The outcome of marooning was usually fatal, but William Greenaway and some men loyal to him survived being marooned, as did pirate captain Edward England.

The chief practitioners of marooning were 17th and 18th century pirates, to such a degree that they were frequently referred to as "marooners". The pirate articles of captains Bartholomew Roberts and John Phillips specify marooning as a punishment for cheating one's fellow pirates or other offenses. In this context, to be marooned is euphemistically to be "made governor of an island".

From the Wikipedia entry for MAROONING

It is on a world whose name I do not know, on the slopes of a great mountain, that the Javelin came down. She is surrounded by black boulders which are too heavy for a man to move. I have sealed the cracks in her silver skin with mud and clay, but she no longer has a door. Inside, she is not badly damaged — the drive chamber and the tailfins are shattered beyond all hope, but living quarters are still sound. If it were not for the fact that she was built to stand upright, but lies on her side, she would be comfortable. But who can sleep in a vertical bunk?

Some thirty or forty yards from the ship there is a cross planted in the ground. It marks Lapthorn's grave. It is a shallow grave because there is not a great deal of dirt caught in the crack between the faces of implacable rock. The cross is often blown down, as though the wind is able to seek it out and pluck it away. Lapthorn is not welcome here; neither am I. The wind continuously tells me so.

To right and left, as I look down the mountain, the view is excised by more gigantic slopes of languid black rock, but before my resting place is a channel which leads down to the plain away across the ashen desert. Far off, beyond the expended sands, more mountains form a distant wall which shines all colours from red to violet as the sun walks the grey sky from dawn till dusk. Brown clouds move sullenly across the sulky face of the sky, washing the black mountain faces with hazy tears. The sparse bushes, the shifting sand, the grey ridges are obscured by a constant floating dust which likewise changes colour with the advancing hours of every day.

I wear a long beard. My hair is never cut save for the tufts which threaten to invade my eyes and rob me of sight. I take no pride in cleanliness. I live in misery and regret, and make no effort to assert my humanity. I am an invader, a beast. There is no need to remind myself that I belong elsewhere. I am not wanted here.

Another day is draining away, and the desert is cold tedious blue-turning-grey. I was not always so despairing. I used to go down every evening to the plain to bring water from the small pools which are constantly maintained by the rain which flows from the slopes. I would bring water for washing as well as for drinking. But I found that I could carry water enough for three days if I did not bother to wash, and I grew idle, long ago. I used to occupy my days in mending my ill-used home, in trying to improve the meagre quality of my life here. I mounted expeditions to all points of the compass, and planned the circumnavigation of the world which I had inherited by virtue of being stranded. But what I found on the peak, in the far plain, and on other slopes never repaid the effort I put into reaching them, and mental fatigue soon drowned my adventure with pointlessness.

The sky is as black as the mountains now. The desert plan is invisible. I light the fire. The light hasn't much warmth. Lapthorn would have complained of its dull colour and its foul taste. But it's all I have. The ship retains a reservoir of power, but all of it is directed to one single purpose - maintaining the faint, surely futile, mayday bleep which is my solitary hope of eventual rescue. The bleep has a limited range, and no ship is likely to pass within it, because I am within the fringes of a dark nebula, where no sane captain would bring his ship. But the bleep is my one link with the universe beyond the mountain, and it surely deserves every last vestige of the Javelin's power.

The fire is dying. It's time for sleep. I wish that for once I didn't have to go to bed hungry. But I wish the same things every night. There's not much that's edible growing on the mountain or living down in the desert. The ship's supplies of deep-space gruel ran out some time ago. Somehow, though, I don't starve. I chew leaves and I snare mice, and I contrive to live. But I'm always hungry. Perhaps I ought to be thankful that I haven't poisoned myself. But the world sustains my kind of life. I'm not wanted, but I'm tolerated, because I'm not too much of a nuisance.

I sleep in the control room, because my bunk is wrong way up, and the control room is the only space big enough for the wall to make an adequate floor and vice versa.

From THE HALCYON DRIFT by Brian Stableford (1972)

Civilian Survival

Sometimes in an emergency situation, the crew will have to deal with people who cannot wear a space suit. This includes people who are too wounded, too unconscious, too untrained, or too stupid to use a suit (or even put one on). It will be useful to have some kind of basic no-frills life support equipment that you can shove the people into and trust it to keep them alive without your attention.

Life Support Balls

Personal Rescue Enclosures
Crew Size1
Oxygen Supply1 hour
Habitable Volume0.33 m3
Height0.86 m
Span0.86 m

It will also be useful to supplement one's supply of space suits with Personal Rescue Enclosures aka 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.

The ball had three layers: urethane inner enclosure, Kevlar middle layer, and a white outer thermal protective cover. The user enters the ball, puts on the oxygen mask, cradled in their arms a carbon dioxide scrubber/oxygen supply box, and a crewperson outside zips it up. The ball would be connected by an umbilical to the shuttle to supply air until the airlock depressurized. Then the oxygen box gives the user one hour of breathable air, while a crewperson tows the ball to safety.

Mercifully the ball included a tiny Lexan window to prevent total sensory deprivation.

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. 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.

For passengers, 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.


     Arvid was out of his seat and trying to reach God knows what, and Wes was checking his seat belt, when the whole station rang and shuddered. Wes yelled and clapped hands over his ears. The others were floating out of their seats — freefall? He swept an arm out to push Giselle back into her seat, and she clutched the arms. He couldn’t reach anyone else.
     Freefall? How could that be? The connecting tunnel must have come apart! Nikolai was screaming into a microphone. He stopped suddenly. He turned and looked around, stunned, ashen.
     Behind Wes the wall smashed inward, then outward. The buckle on Wes’s seat harness popped open. Wes grabbed instinctively, a death grip on the arm of his chair, even before the shock wave reached him. The Nigerian snatched at Wes’s belt and clung tight. He was screaming. Good! So was Wes. Hold your breath and you’d rupture your lungs.
     For the stars were glaring in at them through the ripped metal, and the air was roaring away, carrying anything loose...
     ...Vacuum! Dawson’s eyes and ears felt ready to pop. Giorge’s grip was growing feeble, but so was the wind; the air was almost gone. So. What have I got, a minute before the blood boils out through my lungs? I’ll never reach my million-dollar pressure suit, so where are the beach balls? I located them first thing, every compartment, the emergency pressure balloons, where the hell were they? If Americans had built this place they’d be popping out of the walls...
     ...Nothing was popping out of the walls. Dawson’s intestinal tract was spewing air at both ends. His eyes sought … Rogachev, there, clawing at a wall. Dawson patted the shoulder at his waist and kicked himself toward Rogachev. Giorge hung on, in good sense or simple panic.
     His throat tried to cough but it couldn’t get a grip.
     Wes bounced against a wall, couldn’t find a handhold, bounced away. Losing control. Dying? The black man caught something. but kept one arm around Wes’s waist. Rogachev looked like a puffer-fish. He was fighting to tear open a plastic wall panel. It jerked open and he bounced away.
     Bulky disks, four feet across, turned out to be flattened plastic bags. Wes skimmed one at Rogachev. He pulled another open, crawled inside and pulled the black man in too. Zipper? He zipped them inside. Tight fit. Some kind of lock at the end of the zipper. With his chin on the black man’s shoulder Wes reached around the man’s neck and flipped the lock shut, he hoped.
     Air jetted immediately.
     Reverse pressure in his ears. He pulled in air, in, in, no need to exhale at all. They were going to live. They were floating loose, and nothing to be done about it, because the pressure packages were nothing but balloons with an air supply attached. Rogachev’s too was bouncing about like a toy, but at least he’d gotten inside.
     Wes’s passenger was beginning to struggle. It was uncomfortable. Wes wanted to say something comforting, or just tell him not to rip the g****m beach ball! But now his throat had air to cough with, and he couldn’t stop coughing. He sounded like he was dying. So did Giorge.

From FOOTFALL by Larry Niven and Jerry Pournelle (1985)

     I noted with approval that Carlos' mouth was wide open, like mine, to clear his lungs so that they wouldn't burst when the air was gone.
     Daggers in my ears and sinuses, pressure in my gut...
     ...The air was deadly thin but not gone. My lungs thought they were gasping vacuum. But my blood was not boiling. I'd have known it.
     So I gasped, and kept gasping. It was all I had attention for. Black spots flickered before my eyes, but I was still gasping and alive when Ausfaller reached us carrying a clear plastic package and an enormous handgun.
     He came in fast, on a rocket backpack. Even as he decelerated he was looking around for something to shoot. He returned in a loop of fire. He studied us through his faceplate, possibly wondering if we were dead.
     He flipped the plastic package open. It was a thin sack with a zipper and a small tank attached. He had to dig for a torch to cut our bonds. He freed Carlos first, helped him into the sack. Carlos bled from the nose and ears. He was barely mobile. So was I, but Ausfaller got me into the sack with Carlos and zipped it up. Air hissed in around us.
     I wondered what came next. As an inflated sphere the rescue bag was too big for the tunnels. Ausfaller had thought of that. He fired at the dome, blasted a gaping hole in it, and flew us out on the rocket backpack.
     Hobo Kelly was grounded nearby. I saw that the rescue bag wouldn't fit the airlock either... and Ausfaller confirmed my worst fear. He signaled us by opening his mouth wide. Then he zipped open the rescue bag and half-carried us into the airlock while the air was still roaring out of our lungs.
     When there was air again Carlos whispered, "Please don't do that any more."

From THE BORDERLAND OF SOL by Larry Niven (1975)

Personnel Module


     “All right, dearie. Ready to get on in?” the tech asked, her voice far gentler than Sianna had expected.
     “Ah, um, almost,” Sianna said. “Just—just a second.” Sianna looked down at the personnel module, a box for transporting a person to space at absolutely minimum cost in the smallest space possible. The permod was lightweight, and could be loaded and boosted in any number of launch systems. This one was to be stacked in with a hold full of cargo modules and boosted direct to NaPurHab (space colony).
     The personnel module was completely self-contained, and could keep a human being alive for perhaps weeks at a time in a pinch—if the human didn’t mind losing all semblance of dignity, and, perhaps, any shred of sanity. The permod treated a human being like a slab of meat that had to be kept at a certain temperature, in a certain atmosphere, with nutrient going in one end and waste products coming out the other. It was, in effect, a storage locker designed to hold a person.
     Sianna did not like it, to put it mildly. The fact that the permod was almost precisely the size and shape of a coffin did not do much to make her feel better.

     The suit tech stepped down on a treadle switch set into one corner of the module, and the safety catches released with a disconcertingly loud clunk. The tech pulled open a small access panel and yanked on the lever inside it. The top of the module swung open in exactly the manner of a coffin. Whoever had designed this thing had not given much thought to the psychology of the occupant.
     Sianna stepped forward and peered inside. She had gotten a quick training session the day before, but reality was rarely in conformity with training or expectations. The interior was an off-white rubber sort of material, all smooth, rounded contours. The outlines of a human body were molded into the bottom to create a form-fitting shape that was dished-out a bit wider than it ought to be at the base of the torso. Naturally. There was the issue of sanitation, after all.
     “All right, time for the plumbing,” the tech said. “Off with the robe now.”

     The robe dropped to the floor, and Sianna stared straight ahead at the tiled wall, determined that the suit tech be utterly invisible. A hand Sianna was determined not to see presented her with the waste control unit, an ungainly white object shaped roughly like an oversized, rigidized diaper that opened up with a hinge between the legs. Tube couplings whose purposes she did not wish to consider came out of it here and there.
     Sianna took the thing in her two hands with as much enthusiasm as she would have felt in accepting a dead rat. She opened the clamshell hinge and looked inside. The interior was coated with a clear lubricant gel intended to keep the parts of it that touched her skin from chafing. The parts of the interior that wouldn’t touch her were all odd-shaped recesses and discreet bits of valving and tubing.

     All right, then, she would be a mannequin. It wouldn’t be her she was putting it on, but an inanimate object. Spread the legs. Swing the unit around and hold it between the legs. Use her right hand to push the rear half up against the buttocks—good, clinical, impersonal word, buttocks —stoop down just a bit to open up her—no, the —legs, reach down with the left hand and pull the front half up and closed. Snap the six latches shut, and the mannequin had the unit on.
     It hung loosely on Sianna’s body. She switched on the inflator, and felt the unit snug up to her body in a most disturbing way. It felt cold, and stiff, and sterile. The lubricant was unpleasantly cool and slick again her skin.
     All right, she had it on. The suit tech could now be allowed to exist, at least somewhat. The tech nodded her approval. “Good. Fine. Nice fit. But wait until we get you launched and you’re in zero gee before you try the thing out. The suction system will pull off the waste products while you’re in zero gee, but you’ll get one hell of a mess if you try using it on the ground. Okay?”

     “Good. All right.” The tech stepped around in front of her and started to point out the controls. Sianna forced herself to look down. “Suction is that green switch on the left front. Post-use sanitizer is the red switch on the right front. And make sure the suction system is on and running before you try anything unless you want big problems. But once it’s powered up, you can urinate and defecate normally.”
     Normally? How the hell was she supposed to do anything normally when she was wearing a fiberglass diaper and stuffed into a coffin?
     Coffin. Damnation. She had been trying to avoid thinking about that part of it. Coffins. Death. Sealed in. Closed spaces. Tiny space, no space, lost in deep space, out of control sealed in a black death box blasted into the sky—
     No. Stop. Calm. Calm.
     But there was no calm. There was only raging fear and the pounding of her heart, and the thought of the fast-coming moment when the tech would close the lid on her and—

     “That’s it,” the suit tech said, completely oblivious to Sianna’s rising sense of panic—or perhaps determinedly ignoring it. “All set.” The tech seemed to have a limitless supply of meaningless little phrases of encouragement. “We need to spray you down next.”
     Sianna nodded, not quite willing to speak. The spray was a combination of a skin moisturizer, to combat chafing, and an antiseptic-antifungal agent, to keep her from molding over in the confines of the module as she became increasingly ripe over the next few days.

     “All set now, dearie. Now let’s get the shirt and leggings on and we’ll be all squared away.”
     Sianna did as she was told. She stood on one leg, then the other, as the tech slipped the leggings on and did up the fabric-clasps that held them on. The shirt went on in something more like the normal manner, buttoning up the front. Both leggings and shirt were made of a very warm, soft, absorbent flannel cotton—the one concession to comfort in the whole operation. They felt good next to her skin.

     “Two hours until boost, and it’s going to be just about a three-day ride. Long time to be in a box, but you won’t be anywhere near the record. And you should be asleep most of that time, anyway.”
     “Suppose I, ah, can’t sleep?”
     “Then you take a pill, and sleep until it wears off and then take another pill. Keeping you zonked out saves on life support—and boredom. All right then, let’s get you in there.” And, maybe, if we keep you asleep enough of the time, you won’t go insane quite so fast. Even if the tech didn’t say the words, Sianna knew they were there. Thrown off balance by the bulk of the waste control unit, Sianna tottered most unwillingly toward the module.
     After all the briefing and preparation, getting in seemed almost too simple. Sianna simply sat down on the edge of the module, and then put first one leg and then the other over the edge, bracing herself with a hand on either side of the box as she eased herself down into the module, as if she were getting into a bathtub full of slightly over-hot water. Except getting into a tub didn’t put her on the ragged edge of terror. She sat up in the module, and found that her waste control unit wasn’t quite fitting into the recess intended for it. She wiggled herself down a bit, and it dropped into place rather neatly and a bit abruptly, like one of those puzzle games where you roll a ball into a hole.
     “Lie down, dear,” the tech said. Sianna did as she was told. She found herself lying very still, staring at the ceiling. The tech leaned over her for a minute, checking this and that, attaching hoses to the waste control unit and to the interior of the module.
     “All set there. Now, I want you to try the sanitation system. Red switch on the left first, then the green on the right.”
     What point in color-coding the switches if she has to lie on her back and can’t see them? But Sianna reached down and found them after some fumbling. She flipped the left switch. There was a sudden, high whirring noise, and the feel of cold air blowing past her skin. She threw the right switch, and jumped a bit as warm water jetted through the unit. She shut down the water jet and let the suction system run a bit longer to help dry her off. She shut off the left switch and listened as the purifier kicked in, reclaiming the water for its next use in cleaning—or as drinking water. Even the lunatic optimist who had run yesterday’s training session and had told her how great the system was allowed as how the water wasn’t likely to taste real good after the fourth or fifth time.

     “Okay, now,” the tech said. “I’m going to close up now, and this hatch isn’t going to open until you’re safe at NaPurHab. You’ll have the use of your arms and hands for an hour or so, but once you get loaded into the launcher, the restraint system is going to come on. The airbags will inflate and hold you in place. You have got to get your arms down into the recesses molded into the padding before that happens.
     “You’re going to be boosted at about ten gees. More if they change the flight plan. If your arm is lying against your stomach or something when the restraints inflate, it will be pinned in place. If that happens, you’ll be lucky to get away with a broken arm and crushed ribs. Internal injuries and bleeding, more likely.” The tech pointed to a small panel light that read “prepare for restraint” set into the inner lid of the module. “When that light goes off, arms and legs in the restraint recesses, and no excuses. You ought to have three minutes warning, but people who count on ‘ought’ get dead. If your nose itches after that light goes on, don’t scratch. Do you understand?”

     There was, quite sensibly, no way to open a personnel module from the inside. The danger of a panicky transportee popping the thing open at the wrong time was far greater than the danger of a transportee not being able to get out someplace it was safe.

     Wait a second. There was an external view control, right? She could look out. Yes. That would help a lot. She stared intently at the control panel directly over her face. Which one was it? She stabbed a nervous finger at one button, then another. There. That turned the monitor on, anyway. The flat screen came to life, about thirty centimeters in front of her face. Good. Nothing on it but a status display. Air good, temp good, clock showing the time. But what about the external view? External. There! An old-fashioned selector knob. She twisted it hard to the right

     The permod was all toughened padding inside, the comm and display and dispenser controls carefully recessed so you couldn’t switch them on by accident. Damn thing was a miniaturized spacegoing padded cell.

     She wanted to turn her head away, but the restraint pads had inflated around her head as well, holding it quite gently but quite firmly in place. You could snap your neck by having your head turn when a high-gee boost kicked in, and the permod designers had taken no chances.

(ed note: and of course when the permod reaches its destination, the poor cargo master who has to open it is assaulted with a stench that has to be experienced to be believed. And they are occasionally assaulted by the permod inhabitant, who have gone insane with claustrophobia.)

From The Shattered Sphere by Roger MacBride Allen (1994)

Space Burial

This section has been moved here

Damage Control

Damage control facilities are generally only found on military vessels. One room will be Damage Control Central (DCC), often near or in the engineering section. This is where the Damage Control Officer coordinates the damage control parties. Generally you want the DCC to be in the section of the ship that is hardest to damage (actually, the second hardest spot to damage. The hardest spot should be occupied by the bridge/CIC).

There may be small damage control lockers sited at strategic locations throughout the ship. Locker contents may include hull patches, emergency power cables (i.e., glorified extension cords), short range radios, testing and sensing instruments, portable emergency power generators, fuses, fire extinguishers and tools. They may also have first-aid kits.

Lockers near the reactor or drive will also include geiger counters or other radiation detection and monitoring gear. The detectors will be mounted on long telescoping rods, so one can poke the detector around a corner or near a suspicious breach without exposing oneself.

On wet-navy ships there is a special damage-control deck, which is the lowest deck with longitudinal breaks in the watertight bulkheads. This allows quick access to all parts of the ship. However, since our ships are tail-landers instead of belly-landers, in place of a damage-control deck might be one or more special ladderways running along the core of the spacecraft.

The cables, pipes, and duct work will either be exposed along the corridors, behind removable panels to protect them from clumsy crew, or accessable via manholes.

If the ship's power grid goes dead, the emergency lighting will go on. This will be red to preserve the night vision of the damage control parties. This means the cables and pipes will be labeled in black text since red lighting makes color coding ambiguous.

Christopher Weuve says that a merchant ship's primary piece of damage control equipment is a lifeboat.

A well-trained damage control crew can limit the collateral damage and allow a ship to limp home rather than die a lonely death in the vacuum. Each damage control team is assigned a certain area of the vessel. They learn its various pathways and systems by heart, and can move quickly even through darkness and variable gravity conditions. Though they carry most of their equipment with them, the rest is stored in Damage Control Lockers (DCLs), small rooms that serve as home base for the various teams.

A standard DCL is little more than a roomy closet. Each contains a full set of tools, power cutters and fire fighting equipment, plus a complete database of that particular area of the ship. A dedicated expert system is on hand to monitor the team's progress and inform them of the nature of the problem (if known) or the characteristics and schematics of the problem area.

(ed note: The Jovian Confederation ship books have spacecraft designs that are remarkably scientifically accurate and will repay careful study. The accuracy is due to precise oversight by Marc Vezina.)


Then, before Benno could check his own side of the console to verify whether things were indeed alright, his internal debate was blown away by the unforgiving, indiscriminate lance of an offensive x-ray laser.

The single beam struck the Puller a glancing blow, centered on a space just beneath the outer hull and aimed outboard. Armor plate, radiation shielding, piping, wireways, conduit, decking, internal honeycombed structure, atmosphere, and people all ionized and ablated into a dense, mixed plasma. This plasma exploded outward, crushing the spaces surrounding the hit and dealing further physical and thermal damage. Combat Systems Maintenance Central, or CSMC, lay deep within the Puller’s battle hull—three spaces inward from where the x-ray laser struck—but that meant little next to the awesome destructive power of a Dauphine capital-class xaser warhead.

Benno cut the channel before Johnson could respond and switched his suit radio to the Combat Systems Maintenance Net. “All stations, this is CSMC, we’ve taken a slice through our hull, and all our point-defense is offline. Assuming no mounts were hit, it means the beam cut the control runs, and we need to string emergency data lines and power. Mounts should switch to local control. Unless you’re a mount captain or a gunner/loader, I need you to unstrap and meet me outside CSMC, now. This is an all hands effort!”

Every mount and several auxiliary control stations had internal communication and data techs to handle problems locally as they arose. Anything they couldn’t immediately fix in situ, they would shut down and rely on backups, or they would send out maintenance drones to repair remotely.

Benno glared at him. “This situation is salvageable, but with so few, we have to work smart, and we have to work fast.” Benno called up the ship’s schematic on his suit’s forearm info panel and was pleased to note Damage Control had just updated it. An angry, red scar sliced through an edge of the Puller’s long, hexagonal, forward battle hull, just in front of the amidships’ radiator banks. He flipped through a number of overlays, disregarding the layers for piping, structure, ventilation, and power, and finally stopped at the Combat Systems data network overlay. He made it live and pushed it to the others. ("live" means the notations he makes on his copy will be repeated on everybody's copy)

Benno marked vital nodes and stretched out lines to note where they would string emergency fiber runs. Where the damage was too significant, they would have to work backward to a clear node and set up wireless re-transmitters to cover the gaps. Fiber would be more secure in a battle environment with electromagnetic pulses, nukes, and the electronically noisy snap of lasers going off all around them, but speed mattered more than fidelity. He hoped to be done at the same time or before the electricians finished rigging casualty power.

Benno de-aired the corridor and passed back through the door into what remained of CSMC. Picking up a repair pack, he approached the melted, sparking scar sliced through the side of the compartment. A stationary, quiescent star field yawned wide over the top of the cut. Across the chasm, the other side of the gash was not a clean cutaway like one would find in a virtual tour. It was melted and torn, broken and jumbled, but Benno could just make out the arrangement of decks and compartments.

He gingerly climbed down into the hellscape. His suit insulated him from the still-hot edges, but he had to be careful. The metal pieces would cool rapidly, conduction bleeding their heat into the structure of the Puller, but anything that had broken free of its mount, anything non-metallic or well-insulated, might remain white-hot for some time. Radiation into the vacuum of space was a slow method of heat transfer.

Benno reached his first objective, an operational network multiplexer hub. The fiber data trunk it fed into had been vaporized, but the yellow and red LEDs on the hub blinked merrily away, waiting for the opportunity to send their data from radars and lidars to combat direction computers, and from direction systems to illuminators and weapons mounts. The network was designed to be fault and battle damage tolerant, to automatically re-route from damaged or missing components to backup data lines and remain working. Slice out half the battle hull, however, and you would overtax even a robust system’s tolerances. The copper backup trunk running through the centerline of the Puller only had enough bandwidth to maintain essential ship systems—nothing approaching the volume of data it took to accurately aim and direct fire across hundreds and thousands of kilometers of empty space.

He worked quickly, opening the hub and replacing the existing trunk interface with a new network interface card. He clipped in an armored fiber cable, anchored it down, and began unspooling it from the reel he had brought. Stepping gingerly, he crossed the hull gash to the other side and another working hub. These components had never been directly connected before, but Benno couldn’t care less about the system’s original design. If they could jury-rig enough connections, the system would re-route itself. Satisfied, he went on to the next task on the list.

Benno passed other techs, repair drones, and damage control teams, laboring as expeditiously as he was, making temporary repairs to primary power, cooling lines, and air supplies. He could also see a couple of his techs, stringing their own data cables or replacing components battered beyond repair.

In the middle of the gash, en route to his next task, thrust gravity cut out. Before his gorge had a chance to rise at the sudden freefall, the accelerometers in his suit detected the shift and switched on magnets in his boots, knees, elbows, and palms. Benno reached out and grabbed hold of the nearest exposed structural girder, anchoring himself with the magnets.

Usually, the massive dark matter conversion engines astern turned the long bulk of the Puller into a tower, improbably balanced upon spindles of fire, thrusting upward at a continuous Earth-normal gravity of acceleration (Puller is a tail-sitter, like all real spacecraft). Cutting out meant changing vectors. Changing vectors in battle indicated violent maneuvers. Benno gripped and prayed.

An abrupt scream sounded in his helmet. In the corner of his tortured vision, a figure flashed by, drifting free from one side of the cut and zooming out into empty space as the maneuvers continued. The scream was on Benno’s working channel. That meant it was one of his techs.

Just as abruptly, the scream cut off—far sooner than it should have from the ship merely leaving the tech behind. They might well have heard the unfortunate tech for hours until the Puller thrust beyond his suit’s radio range. But now there was only silence, broken by the continuing snaps of radio noise. Benno supposed the ship had carried on past the technician—exposing him to the hot particle thrust of the main engines.

Regardless, the work had to be done, or they’d all be dead soon. Benno checked the active system diagram on his forearm. They had closed several critical loops and signals were starting to flow again in the combat direction network, but latency and bandwidth were still pitiful. The gunners did not need to shoot at where the incoming warheads had been, they needed to shoot where they were at that moment, or—better yet—extrapolate with sufficient fidelity where they would be.

Benno re-assigned a number of Webb and Ortiz’s tasks to Goldman, Salazar, and Aquino, but he took the lion’s share for himself. These kids had him beat in speed, but his experience had been twice all of theirs combined before he had left the technical enlisted side and earned his warrant. He knew tricks for accomplishing temporary battle repairs they had never even imagined.

The labors became a blur. Find a working node, strip the damage, wire in a replacement module, connector, or transceiver, and string fiber to the next station. And all the while, the Puller jinked and juked, piled on acceleration, went back into freefall, and backed at flank thrust, dodging the relatively tiny warheads and their invisible lances of ship-killing energy. The hull shuddered and vibrated with defensive fire hard enough to shake apart their repairs, but they and the damage control teams gained ground nonetheless. The work was quick and dirty, but as they toiled, the running diagnostic diagram on his forearm grew greener and greener.

Finally, the voice of the TAO cut in over every circuit, “All mounts, we show the combat direction network back online. Take your mounts out of local and shift to coordinated remote fire from CIC.”

From THE MUTINEER'S DAUGHTER by Chris Kennedy and Thomas A. Mays (2018)

In principle Defiant was a better ship than she'd been when she left New Chicago. The engineers had automated all routine spacekeeping tasks, and no United Republic spacer needed to do a job that a robot could perform. Like all of New Chicago's ships, and like few of the Imperial Navy's, Defiant was as automated as a merchantman.

Colvin wondered. Merchantmen do not fight battles. A merchant captain need not worry about random holes punched through his hull. He can ignore the risk that any given piece of equipment will be smashed at any instant. He will never have only minutes to keep his ship fighting or see her destroyed in an instant of blinding heat.

No robot could cope with the complexity of decisions damage control could generate, and if there were such a robot it might easily be the first item destroyed in battle. Colvin had been a merchant captain and had seen no reason to object to the Republic's naval policies, but now that he had experience in warship command, he understood why the Imperials automated as little as possible and kept the crew in working routine tasks: washing down corridors and changing air filters, scrubbing pots and inspecting the hull. Imperial crews might grumble about the work, but they were never idle. After six months, Defiant was a better ship, but...

From REFLEX by Larry Niven and Jerry Pournelle
(the deleted first chapter of The Mote in God's Eye)

      For three days Rod worked on MacArthur. Leaking tankage, burned-out components, all had to be replaced. There were few spares, and MacArthur's crew spent hours in space cannibalizing the Union war fleet hulks in orbit around New Chicago.
     Slowly MacArthur was put back into battle worthy condition. Blaine worked with Jack Cargill, First Lieutenant and now Exec, and Commander Jock Sinclair, the Chief Engineer. Like many engineering officers, Sinclair was from New Scotland. His heavy accent was common among Scots throughout space. Somehow they had preserved it as a badge of pride during the Secession Wars, even on planets where Gaelic was a forgotten language. Rod privately suspected that the Scots studied their speech off duty so they’d be unintelligible to the rest of humanity.
     Hull plates were welded on, enormous patches of armor stripped from Union warships and sweated into place. Sinclair worked wonders adapting New Chicago equipment for use in MacArthur, until he had built a patchwork of components and spares that hardly matched the ship’s original blueprints. The bridge officers worked through the nights trying to explain and describe the changes to the ship’s master computer.

     Cargill and Sinclair nearly came to blows over some of the adaptations, Sinclair maintaining that the important thing was to have the ship ready for space, while the First Lieutenant insisted that he’d never be able to direct combat repairs because God Himself didn’t know what had been done to the ship.
     “I dinna care to hear such blasphemy,” Sinclair was saying as Rod came into range. “And is it nae enough that I ken wha’ we hae done to her?”
     “Not unless you want to be cook too, you maniac tinkerer! This morning the wardroom cook couldn’t operate the coffeepot! One of your artificers took the microwave heater. Now by God you’ll bring that back…
     “Aye, we’ll strip it oot o’ number-three tank, just as soon as you find me parts for the pump it replaces. Can you no be happy, man? The ship can fight again. Or is coffee more important?”

     Cargill took a deep breath, then started over. “The ship can fight,” he said in what amounted to baby talk, “until somebody makes a hole in her. Then she has to be fixed. Now suppose I had to repair this,” he said, laying a hand on something Rod was almost sure was an air absorber converter. “The damned thing looks half-melted now. How would I know what was damaged? Or if it were damaged at all? Suppose…”

     “Man, you wouldna’ hae troubles if you did nae fash yoursel’ wi…”
     “Will you stop that? You talk like everybody else when you get excited!”
     “That’s a damn lie!”

     But at that point Rod thought it better to step into view. He sent the Chief Engineer to his end of the ship and Cargill forward. There would be no settling their dispute until MacArthur could be thoroughly refitted in New Scotland’s Yards.

     “Yes.” Rod stood and offered Sally his arm, and the others scrambled to their feet. She was quiet again as he escorted her through the corridor to her cabin, and only polite as they parted. Rod went back to the bridge. More repairs had to be recorded into the ship’s brain.

     New crew and old hands swarmed around the ship, yanking out damaged equipment and hurriedly thrusting in spares from Brigit’s supply depot, running checkout procedures and rushing to the next job. Other replacement parts were stored as they arrived. Later they could be used to replace Sinclair’s melted-looking jury rigs … if anyone could figure out how. It was difficult enough telling what was inside one of those standardized black boxes. Rod spotted a microwave heater and routed it to the wardroom; Cargill would like that.

From THE MOTE IN GOD'S EYE by Larry Niven and Jerry Pournelle (1974)

Damage Control Gallery

SCRAM the Reactor

Primitive spacecraft (like we make today) tend to use lightweight power supplies. Since the one-lung propulsion systems cannot cope with anything massive, not without savagely cutting into the payload mass. But once the state of the art advances, ships become electricity hogs. Especially if they are warships.

While plentiful power is always welcome, it does come at a cost. Besides the fact that they are aglow with lethal radiation, such plants can occasionally become — how can we put it — unstable. Which is real exciting if the plant is using fission, fusion, or antimatter reactions.

Alternatively, a ship could be inexorably heading for a crash landing and you'd just as soon not share the crash site with a reactor going all China Syndrome on you. Or with magnetic cannisters of antimatter fuel, which are much more touchy than nitroglycerin bottles and contain orders of magnitude more bang.

Remember, Jim Cambias said If it's a reactor emergency you're worried about, don't eject the crew in pods, EJECT THE REACTOR!

The point is there has to be some mechanism to quickly quench the power reaction (whatever it is), and render both the reactor and the fuel inert and safe. Or a mechanism to eject the blasted thing and get it as far away as possible.

There will be a SCRAM button to shut down the power plant and a JETTISON button to eject the power plant. Paranoid designers will also have computerized monitoring systems to watch the power plant and automatically push the appropriate button in a fraction of a second.

The term "Scram" means "the sudden shutting down of a nuclear reactor usually by rapid insertion of control rods." Urban myth alleges it came from "Safety Control Rod Axe Man" but this is incorrect.


(ed note:an "excursion" is when the nuclear chain reaction oscillates enough to generate a short pulse-width surge of neutron flux above the maximum flux limits of the control system. It is sort of like when an automobile start backfiring, except with atomic energy instead of petrol. It means the reactor is starting to get out of control and you'd better do something quick before the engine does its impression of Chernobyl.

Flood poisioning is analogous to flooding the firebox of a steam engine with cold water to extinguish all the burning coal.)

5-12 Emergency Flood Poisoning

Multiple excursions do not necessarily mean widespread physical destruction of the reactor core. Ordinarily, emergency safety systems would become activated upon sensing the first excursion pulse. The most effective excursion-abort safety system is based on “flood poisoning,” In emergency situations, great quantities of neutron absorber materials are dumped into the reactor. This poison flooding promptly chokes down the fission process…and keeps it down. Subsequent excursions cannot occur.

The design concept is to store the flood poison materials outside of the core. These poisons may be powder, pellet, or gaseous in form. They may be one or a combination of the strongest absorber materials previously listed. These poisons would not be functionally related to, nor would they be integral with, the regular control system. They are strictly for emergency use only.

The poisons are stored under high pressure with suitable piping from storage to a manifold around the reactor pressure vessel head. From this manifold, there would be connections to each of the verniering plenums in the control drums around the core. During normal pneumatic verniering, the regulating pressures would be lower than the storage pressure of the flood poisons. Upon release signal, the pneumatic controllant would be overcome by the high pressure of the flood poison. The result: all control drum plenums would be “flooded” with strong neutron absorbers. The quantity of flood poison to override all of the control drums, regardless of their ΔC positions, can be computed. This is simply a matter of comparing macroscopic absorption cross sections such that

Σp » Σd + Σe

Here, the subscripts are p for flood poison, d for control drums, and c for core.

(ed note: the symbol » means "much greater than")

One arrangement of how the flood poisoning scheme might be adapted to rocket reactors is shown in Figure 5-13. Note particularly the excursion sensors. They are threaded into the pressure vessel wall where they are exposed simultaneously to propellant cooling and fission heating. Upon a fission excursion, one or more of the sensors actuates a pneumatic valve which releases the flood poison into the control drum plenums.

When released, the flood poisons would absorb many more neutrons than the normal controllant materials. Since these poisons are predominantly capture-gamma emitters, they would ernit gamma rays in profusion. There would be localized regions of very high gamma heating. As a consequence, special after-cooling of the flood poisoned control drums is required.

After the excursion neutron flux is choked clown, the flood poisons could be removed. This could be done via a vacuum pump and suitable piping (indicated in Figure 5-13). The removed poisons could either be reclaimed and restored under pressure, or they could be dumped overboard. By removing the poisons, the propulsion reactor could be operated normally again.

From NUCLEAR SPACE PROPULSION by Holmes F. Crouch (1965)

      Kzanol swung his chair around so he could see the star map on the rear wall. The sapphire pin seemed to twinkle and gleam across the length of the cabin. For a moment he basked in its radiance, the radiance of unlimited wealth. Then he jumped up and began typing on the brain board.
     Sure there was reason to be impatient! Even now somebody with a map just like his, and a pin where Kzanol had inserted his sapphire marker, might be racing to put in a claim. The control of an entire slave world, for all of Kzanol’s lifetime, was his rightful property; but only if he reached Thrintun first.
     He typed: “How long to recharge the battery?”
     The brain board thudded almost at once. But Kzanol was never to know the answer.

     Suddenly a blinding light shone through the back window. Kzanol’s chair flattened into a couch, a loud musical note rang, and there was pressure. Terrible pressure. The ship wasn’t ever supposed to use that high an acceleration. It lasted for about five seconds. Then —
     There was a sound like two lead doors being slapped together, with the ship between them.
     The pressure eased. Kzanol got to his feet and peered out the rear window at the incandescent cloud that had been his fusor. A machine has no mind to read; you never know when it’s going to betray you —

     The brain board thudded.
     He read, “Time to recharge battery:” followed by the spiral hieroglyph, the sign of infinity.
     With his face pressed against the molded diamond pane, Kzanol watched the burning power plant fade among the stars. The brain must have dropped it the moment it became dangerous. That was why it had been trailed half a mile behind the ship: because fusors sometimes exploded. Just before he lost sight of it altogether, the light flared again into something brighter than a sun.
     Thud, said the brain. Kzanol read, “Reestimate of trip time to Thrintun:” followed by a spiral.
     The shock wave from the far explosion reached the ship. It sounded like a distant door slamming.

     There was no hurry now. For a long time Kzanol stood before his wall map, gazing at the sapphire pin.

From WORLD OF PTAVVS by Larry Niven (1965)

Engine Destruct

In many cases powerful rocket engines incorporate dangerous power technologies integral to their design. Just like dangerous power generators, you will need the ability to SCRAM or eject them in emergencies. A good example is solid-core nuclear thermal rockets, which are literally nuclear reactors with the hot working fluid piped to an exhaust nozzle instead of a generator turbine.

NASA had even more worries during the NERVA project. Instead of just worrying about the crew, they also has to worry about the unfortunate inhabitants on Planet Terra who lived near the (radioactive) engine crash site.

I found two interesting reports: Nuclear Rocket Destruct System Requirements by W. H. Esselman of Westinghouse Electric Corporation (Astronuclear Laboratory) and A Destruct System For the NERVA Engine by K. N. Kreyenhagen, W. H. Thiel, and S. K. Yoder of Aerojet-General Corporation. You can find them in this report along with more scary reading. I'll try to give you an executive summary.

For NASA's purposes, there are actually two separate types of engine jettison: pre-operational ("anti-criticality") and post-operational ("disposal"). Or "before you power-up the reactor" and "after you power-up the reactor". Pre-op happens when the chemical booster lofting the nuclear spacecraft into orbit fails mid-flight. Post-op happens when the nuclear spacecraft has been delivered into orbit, is flying around under nuclear power, and suddenly starts to crash on Terra.

You see, a brand-new nuclear reactor that has never been powered-up is actually not very radioactive. After you power-up the little monster it creates all sorts of hideously radioactive radioisotopes in the fuel rods, and neutron-activates nearby structural members exposed to the neutron flux.

What's the difference? Well, for pre-op jettison you eject the engine and use explosive shaped charges to coarsely chop it into sub-critical bits. Bits that will not undergo nuclear fission even if they land in the ocean (water is a great nuclear moderator). A relatively chunky 0.205 grams of U235 per square centimeter (750 grams within a 27 inch diameter circle). The idea is that uranium is relatively harmless, you just want to prevent the blasted stuff from gathering in a critical mass and undergoing nuclear fission. Even if the fuel elements dissolve into goo and start flowing around.

Post-op is different. Now the engine is full of dangerous radioisotopes. To have less than quote "acceptable" unquote levels of contamination, you have to use explosives to finely pulverize the reactor into itty-bitty fragments that will ablate down to less than 25 microns (9.84×10-4 inches) in size by the time they fall down to the 30 kilometer altitude level. The report figures the bits will have to start out at 1 mm in diameter to ablade enough. The report helpfully defines "acceptable" as "no excessive radioactivity returns to a populated area."

They did lots of math that you can read all about in the report to analyse various reactor fragment sizes, see what size it will ablade down to, and calculate the radiation dose it emits. They assumed the nuclear engine operated for 30 minutes at 1120 megawatts. The results are in the table below. The important parts are the last two columns. They figured a dose rate of 0.018 Rads per hour (1.8×10-4 Grays per hour) was acceptable. This translates to an initial fragment size of 1/32 inch (0.79 mm or "about 1 mm").

Now, since the post-op minimum fragment size is smaller than the pre-op fragment size, one would assume that you could use the same post-op explosives system for either type of engine destruct. But you'd be wrong. You see, pre-op the nuclear engine is perched on top of the chemical booster, a gigantic thin-walled tank jam-packed with chemical fuel. NASA safety experts concluded that you want to use the smallest explosive system possible because detonating the chemical booster will make everything worse. And the post-op explosives system is much larger that the pre-op, it will detonate the chemical booster for certain. Bottom line is you'll need two separate explosive systems, one for pre-op and one for post-op.

Shaped charged explosive systems were selected for the design because they had the lowest mass of all the reactor disassembly systems. (It might be worth while to review the difference between a shaped charge and a self-forging projectile, they are similar enough to be confused together, but are quite different in end result. The report tends to use the two terms interchangeably.)


Concept 1 consists of a girdling array of linear shaped charges. When detonated, they cut through the crunchy outside reactor casing and neutron reflector layers, to get at the chewy core in the center. The shock pulverizes the core, and the sliced and diced reactor casing allows the core to disperse. Simple and reliable.

However, the girdle cannot withstand the radiation or the intense heat of normal engine operation. Before you fire up the reactor you have to somehow dismount or discard the girdle, or it will unexpectedly blow up the engine.

Concept 2. My apologies, the image is almost worthless. I think the original was in color. It is supposed to show a conical shaped charge inside the nozzle. Upon detonation it sends a self-forging hypervelocity jet of metal upward through the throat of the nozzle, scoring a direct hit on the bottom of the reactor core. This shatters the core, and hopefully also ruptures the reactor casing so the fuel rods can escape. While this concept is lighter than Concept 1, it is unclear if the shock will be enough to rupture the casing.

Obviously the pilot had better eject the conical shaped charge before firing up the engine or they will get a very rude surprise. The pilot will find the hot exhaust ignites the shaped charge and shoots them in the a... destroys the engine.

Concept 3 is merging Concept 1 and Concept 2. You reduce the power (and mass) of C1's girdle so it is just strong enough to rupture the casing. C2's up-the-nozzle shot only has to take care of the core. The researchers actually tested this using a steel rocket casing, magnesium bars to simulate reflector segments, and a Titan nozzle. It flew into pieces like a champ. They used 57 kilograms of C-4 plastic explosive for the girdling charge with a cross-sectional area of 29 square centimeters. This actually proved to be over-kill, they wanted to try even smaller charges.


This is a challenge. You have to take a 1,360 kilogram core of fuel-enriched graphite and pulverize it into 1 mm particles.

Since the core is surrounded by pyrolitic graphite tiles, support tiles, a lateral support system, graphite reflector barrel, steel barrel, shim rods, coolant channels, tie bolts, beryllium reflectors, control rods, and the aluminum pressure hull, designers have focused on somehow introducing an explosive charge into the core and detonating it in the center. Otherwise the explosive force has to waste energy cutting through all the crap surrouding the core. This is known as the "central burster" concept.

Obviously the explosive charge cannot be resident inside the core during normal operation, for the same reason you do not store crates of dynamite inside a furnace. You have to somehow quickly get the explosive charge into the core and trigger it.

Concept 4 has the explosive charges inside a series of long projectiles. This are stored in launcher tubes above the engine, behind the radiation shadow shield. The latter is because radiation is bad for the explosives. Upon command, the projectiles are launched, penetrate the shield, enter the core, then blow up. They require an impact velocity of 300 meters per second.

The guns or launchers have to be lightweight, reliable, capable of delivering the projectiles simultaneously and capable of detonating the projectiles simultaneously. This is going to cost you lots of mass, "lightweight" is a relative term. If the explosive charges are 14 kg apiece and there are four projectiles, the total mass will be a whopping 680 kg, not counting the control and power source circuitry.

Concept 5 has a series of shaped charges with self-forging warheads that are attached to vertical bars. These are stored above the radiation shadow shield. Upon command, the bars are slowely lowered so they surround the core. Sort of a three dimensional circular firing squad. When detonated they fire hypervelocity jets of molten metal through the stuff surrouding the core and shred the core.

The advantage over Concept 4 is much lower system mass, it is trival to deliver them simultaneously and it is relatively easy to trigger the charges to go off simultaneously. For the same 680 kg system mass, Concept 5 can utilize a hundred or more shaped charges.

Concept 6 uses slabs of plastic explosive instead of racks of shaped charges. The idea is for the explosion to implode the core, crushing it.


Nothing really enjoys radiation, and explosives are touchier than most. You do not want the radiation from the engine degrading the explosive's punch nor do you want them to detonate prematurely. A NERVA engine typically produces a dose rate of 105 rad/sec at the side and 103 to 104 rad/sec in the shadow of the radiation shield. So over an operating time of 1,200 seconds the total dose will be from 106 to 108 rads.

Premature detonation happens when the radiation flux heats the explosive by gamma absorption and inelastic scattering. Typically explosives blow up when they reach a temperature of 150 to 200°C. They may not actually explode, but it is almost as bad if the stuff undergoes decompostion or deflagrates. They will not be able to perform their duty. Some coolant may be required.

Explosive degradation happens as radiation breaks chemical bonds in the explosive's molecules. This gradually turns the plastic explosive into just plain plastic. This seems to happen at about 107 to 108 rad which means the radiation shadow shield might provide enough protection. There is some suggestive evidence that cooling helps slow degradation, which is a good thing. Coolant weighs less than radiation shielding.

Self-Destruct Mechanism

Self-destruct is a mechanism (protocol or device) that can cause an object to destroy itself on command. The object can be totally blown into smithereens or merely render the object useless if captured by the enemy (the latter is called scuttling). It is rather common in media science fiction since it is so dramatic. That agonizing count-down really ratchets up the tension.

Reasons for including such a device on a spacecraft, space station, or planetary base include:

Range Safety
     If a spacecraft or missile is on a collision course with something valuable or full of innocent bystanders, the range safety officer will trigger the self destruct to prevent a crash. If the destructive energy is from the engine (e.g., antimatter) the destruct charge will just have to neutralize the engine. But if the destructive energy is the ship acting like an impromptu kinetic energy weapon, the closer the charge can come to vaporizing the entire ship the better.
     Most real-world boosters and spacecraft include self destructs to prevent lawsuits and massive negative publicity if the rocket goes off course. Manned rockets generally have some sort of launch escape system to propel the habitat module clear of the blast radius (with the notable exception of the Space Shuttle).
     The range safety officer with their finger on the big red button are usually located at some distance from the object they are blowing up. So they will have some objectivity (i.e., not hesitate because they are scared of committing suicide).
     If civilian owned spacecraft have propulsion systems frightful enough to be weapons of mass destruction then by law all such ships will be equipped with destruct devices controlled by the Launch Guard. Just in case a tramp freighter with an antimatter engine has a drunk pilot and starts heading towards a major metropolitan area.
     Military ships do not have self-destructs for range safety reasons, but they might have them for scuttling purposes. Or because the civilian goverment does not trust the space navy.
     In times of warfare, a warship becoming disabled allows it to be captured by the enemy. There are two items the enemy desires: the intelligence in the warship's data banks and the warship itself.
     The data banks are a treasure trove of valuable information: space navy secret code books, battle plans, task force compositions, etc. If the enemy gets their hands on any of that, the results could be more damaging than losing a battle. All data stores will need some kind of explosive charge or whatever to render the data unreadable. With the charges capable of being detonated on remote command from the CIC or manually by the crew stationed nearby. In the old wet navy the code books had covers made out of lead, to help speed them to Davy Jone's Locker when the captain throws them overboard. That won't work in space.
     Building space warships takes such an inconveniently long time. If the enemy captures one of your warships intact they will gleefully replace the crew, hastily paint on their national insignia, and thus instantly have a new (slightly used) unit in their space navy. To prevent that you want to scuttle your ship. You don't have to atomize it, just damage it enough so that its major contribution to the enemy's war effort is as a load of scrap metal.
Keeping Homeworld a Secret
     If a deep space exploration ship makes first contact with a new alien race, it is imperative that the aliens do not learn the loacation of any of your colonized planets, or your homeworld. Otherwise they can make your species extinct while you flail about trying to locate any of their planets.
     This is a specialized form of scuttling a captured warship's data banks, where the emphasis is on destroying any star charts you have on board.
     If you are super paranoid you might have to destroy the entire ship with crew. It is surprising how much aliens can learn about your home planet by examining seemingly innocent details of the ship. For instance, they can learn clues to your homeworld star's spectral class by analyzing the frequencies emitted by the ship's lamps and track lighting. And the crew can be tortured for information, especially the astrogators (to get them to cough up your homeworld's coordinates) .
Government Does Not Trust Space Navy

(ed note: General Nakamura of the U.N. Forces is staging a military coup of the Asterome space habitat. Commander Mason shuts him down, hard.)

     "In a few moments," the general (Nakamura) said, "my warship will fire a missile at your sun mirror, perhaps at one of your fusion plants. Where will your Asterome be without them?"
     Sam noticed the sweat stains on the general's back and under his armpits. Alard did not answer...
     ..."Ship approaching fast," one of the communications officers said.
     An insert appeared in the lower-right-hand corner of the screen, showing a telescopic view of a military vessel identical to the one in the left-hand insert...
     ..."No answer from the ship," the com officer said.
     Nakamura shifted and held the gun near Sam's face. "It's another one of ours," he said calmly...
     ..."General—voice link," the communications officer said.
     Sam looked at the insert; the incoming ship was larger now. A third insert appeared in the top left corner, a woman's face, middle-aged, with handsomely groomed short gray hair.
     "This is Commander Alberta Mason, U.N. Forces. General Nakamura, you are relieved of command. Place yourself in immediate custody under military or civilian personnel at Ganymede City."
     Nakamura surveyed the room. No one moved. Sam expected that at any moment the general would point the gun at Richard or Margot. It's what I would do. The thought surprised Sam.
     "Surrender," Mason said. "The coup is over. It's been over for a while."
     Nakamura grew rigid. He lowered the gun, but kept it pointed in Sam's direction. Slowly the general reached up with his left hand, took off his military cap and threw it to the floor. "So much for U.N. rank." He ran his fingers across his wet forehead and back through his hair.
     "Surrender," Mason said, "or I will open fire on your ship. Do you hear me also, Captain Scorto?"
     "I hear you."
     "Land your ship and prepare to be boarded," Nakamura replied, "or I will kill these hostages before your eyes."
     Sam was grateful that Janet was not in immediate reach.
     "Scorto—open fire on Asterome and the Mars vessel when I give the command."
     Sam felt the gun press against his temple. The floor seemed to shift slightly as he tried to keep his eyes on the screen.
     "Mason, you can't fight a triple threat!"
     "I will not bargain with you, General."
     The gun pushed Sam's head sideways. With one eye he peered at the lower-left insert, where Nakamura's ship was suddenly coming apart, its center glowing cherry red, turning white until the hull was lost in a bright flash. The concussion shook the floor. Sam faced the screen as Nakamura moved the gun away. Gas and debris filled the insert, clearing slowly to show a crater where the ship had stood.
     "I regret the loss of misguided lives," Mason said. "They and the ship might have served us better."
     "How?" Nakamura asked as he stepped back from Sam. "You're too far away."
     "A simple destruct sequence code. The civilian governments that gathered the taxes to build these old ships kept that much insurance against them. Of course, such a safeguard is only effective when not too many people know about it."
     Sam looked at Nakamura, aware that the general would take the explanation as an insult, since it implied that he was not important enough to have known.

From Macrolife by George Zebrowski (1979)
Keeping Homeworld A Secret

(ed note: human ("monster") ship has surprised the alien Ryall planet and Ryall ship the Space Swimmer)

     “I have a message for you from Ossfil of Space Swimmer.”
     “Proceed with the message.”
     “‘The monsters have me surrounded and I am unable to reach the gateway. I am taking evasive action, but will not be able to escape. Request instructions. Ossfil, commanding Space Swimmer.’“
     Varlan muttered a few deep imprecations to the evil star before replying. “Transmit the following: ‘From Varlan of the Scented Waters to Ossfil of Space Swimmer. As a minimum, you will destroy your astrogation computer and trigger the amnesia of your astrogator. After that is done, you may act on your own initiative.’“

(ed note: the humans have captured the alien ship Space Swimmer, and are puzzling over the alien's strange behavior)

     “Naw. Shot him with a dart. He’ll be all right, ‘cept that he’s crazy as a high plateau jumper.”
     “How so?”
     “I found him amidships in one of the equipment rooms. He had this big bar he’d ripped out of some machinery and was using it to beat holy hell out of some access panel. Looked to me like he wanted to get through it and into the machinery beyond...
     ...“What did you say just now, Corporal?” he asked.
     “I said this damned crazy centaur attacked me, sir...”
     “No, about his trying to smash a machine. What machine?”
     “‘Fraid I don’t recognize this alien machinery too good, sir.”
     “Take me to it.”
     Sayers led the way, followed by Philip Walkirk and Sergeant Barthol. They moved through gloomy corridors until they reached a small compartment almost at the very center of the spherical ship.
     “Yonder machine over there, sir!” Sayer said, playing the beam from his hand lamp over a dented access panel.
     Philip gazed at the panel, blinked, and then emitted a low whistle.
     “This thing important, sir?” Barthol asked.
     “You might say that,” Philip replied. “What Corporal Sayers refers to as ‘yonder machine’ is their astrogation computer. The fact that he was trying to beat it to death may mean that their normal destruct mechanism failed to operate properly.
     “That good, sir?”
     Philip Walkirk’s sudden laughter startled the two noncoms. “That box, Sergeant, may well contain information vital to the conduct of the war.
     “What information, sir?”
     “If we’ve been very, very lucky, we may just dredge up a foldspace topology chart for the whole damned Ryall hegemony!”

Scuttling Battleship Donnager

     "Roger, Lieutenant," Holden gasped out. "Why board you?"
     "The command information center," Alex said. "It's the holy grail. Codes, deployments, computer cores, the works. Takin' a flagship's CIC is a strategist's wet dream."
     ..."That means they'll blow the core rather than let that happen, right?"
     "Yep," Alex replied. "Standard ops for boarders. Marines hold the bridge, CIC, and engineering. If any of the three is breached, the other two flip the switch. The ship turns into a star for a few seconds."

(ed note: They escape in the small ship. The Donnager self destructs behind them.)

     "The Donnie went up behind us, Cap. Guess the marines didn't hold. She's gone," Alex said in a subdued voice.
     "The six attacking ships?"
     "I haven't seen any sign of them since the explosion. I'd guess they're toast."
     Holden nodded to himself. Summary roadside justice, indeed. Boarding a ship was one of the riskiest maneuvers in naval combat. It was basically a race between the boarders rushing to the engine room and the collective will of those who had their fingers on the self-destruct button. After even one look at Captain Yao, Holden could have told them who'd lose that race.
     Still. Someone had thought it was worth the risk.

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

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