In Star Trek, the loss of life-support for any time—minutes or seconds—seems like an extremely time-critical problem where people must be immediately transported out or every system is shut down save for it to hide/save power. While there is no doubt that life support is a necessity, it seems like the immediate limiting issues would be atmosphere and temperature.

The volume of the rooms in fictional ships is a sight larger than some real ones (Apollo), so I'd figure our heroes could last at least several hours before poisoning themselves with their breath.

Given enough time, a ship in deep space would freeze its occupants to death, but the ship would have to radiate ample amounts of heat to cool its significant mass. On some Star Trek ships, I think I recall the temperature issue being the other way around; where the warp core or other reactors would bake the crew to death, though other episodes had passengers freezing after a while (Odo and Weyoun, I think).

Can anyone point out what happens (if inconsistent) in the Trek-verse when life-support fails?

  • This doesn't relate to any particular sci-fi work. I vote to close. Perhaps there's a way to edit this so it's more on-topic? Jul 8, 2011 at 3:39
  • I also vote to close as this is more of a science fact question. Jul 8, 2011 at 18:59
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    @neil I edited it a bit and turned around what I was asking
    – Nick T
    Jul 8, 2011 at 21:03
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    Much better. I wish I can undo my close vote now Jul 8, 2011 at 22:32
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    @OghmaOsiris - Close votes will expire soon. Jul 9, 2011 at 17:58

7 Answers 7


Note that within Star Trek, life support includes artificial gravity, inertial dampers, as well as HVAC. The Star Trek The Next Generation Technical Manual says (section 12.1) that

Other emergency provisions include distributed reserve life support systems, emergency support shelter areas, and contingency support modules intended to provide shipwide breathable atmosphere for up to thirty minutes in a major systemwide failure.

30 minutes is a very short period of time, although this is the ultimate reserve, which (in theory) you'd never need because all the other reserves would have sufficed.

The reserve atmospheric processors (which remove CO2 and replenish O2) were designed to provide up to 50% performance for up to 24 hours (depending on load). 24 hours, while longer than 30 minutes, still isn't a huge amount of time when you consider the distance from outposts an exploration vessel typically travelled. If using this system was necessary, then it would be important to act as efficiently as possible, to maximise the available time.

The Technical Manual has a lot of detail about how redundant and safe the life support systems are (all of sections 12.1 and 12.2 can be read using Amazon's "Look Inside" feature). Given that life support systems are this redundant, that means that if they are failing and the ultimate reserves are being used, then the situation is always very bad - so many problems must have already occurred, that the likelihood of critical failure is very high.

There's also an out-of-universe note about how this appeared to differ from reality:

Believability (not to mention crew safety) demands that the Enterprise environmental support systems be extremely reliable with many redundant backups. The problem from a television standpoint is this makes it a little tough to create story situations in which our crew can be threatened by life support failure. In one episode, "Brothers", writer-producer Rick Burman needed all bridge atmospheric support systems to fail. He rationalized it by having Geordi express amazement that seven independent safety interlocks had been bypassed, thereby acknowledging that the ship is indeed designed to make such failures extremely improbable.

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    If you can't manage to keep up life support, you certainly have no means to warp to any place that can stabilize the ship, leaving options like crash landing onto planets, or evacuating to later die on life boats (since your in a situation where apparently no one can bother to warp to your location to help?!?) Feb 17, 2012 at 14:45
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    And an artificial gravity failure would blow the budget for the TV program... Nov 15, 2014 at 10:51
  • Rick Burman? Is it really misspelt like this in an official source?
    – chirlu
    Apr 9, 2017 at 14:21

This question is highly dependent on the size of the vehicle, the number of crew, and what equipment is still operational.

You are right that one of the biggest problems with a space craft is temperature, but what you are missing is that space is a vacuum. Heat exchange primarily occurs by atoms interacting and exchanging energy. The vacuum of space means that atoms occur vary rarely, so the vehicle would have no way to vent the heat. The crew would bake.

The other issue of course is oxygen and carbon dioxide. A person needs about 550 liters of oxygen per day (citation: Discovery health site), so the amount of oxygen is dependent on the atmosphere composition of the ship (Earth's atmosphere is ~80% nitrogen, ~20% oxygen, and small fractions of many other gases. After about 8% atmosphere carbon dioxide a person starts to lose consciousness. At that point the crew would be disabled and death would be inevitable barring outside assistance.

  • A wise answer. So the trick to applying it to a particular sci-fi work would be to estimate the breathable volume on the ship, and the number of people producing CO2.
    – Saiboogu
    Jul 8, 2011 at 6:05
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    Heat exchange also can occur by radiation. The ship would radiate (mostly in the infrared spectrum) at its surface. Jul 8, 2011 at 22:44
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    Whether a ship would bake or freeze would depend on how close it is to a star, or anything else at a different temperature from the cosmic background. In deep space, it would certainly freeze as radiational cooling would eventually bring it to equilibrium with the 2.7K background. Closer than one AU to a star like the sun, and baking could be the result. Obviously anything in between the extremes could also be found, even including the possibility of being 'just right'.
    – JustJeff
    Jul 10, 2011 at 3:38
  • There is always a loss of heat on the outside of the ship, being near absolute zero. There would have to be some hefty insulation going on on the outside, and so logically the danger lies in too much heat, not too little.
    – Neil
    Jul 11, 2011 at 12:47
  • the cited source has a serious issue: it failed to accout for the fact that humans use less than half the O2 in the mix... well less. 50mL/kg/min peak for the average football player at full tilt. Resting rates down to 3.0mL/kg/min can be obtained. That's resting 4.32L per kilogram of bodymass per day - for an average person mentally active, figure 10L per kg per day. nismat.org/physcor/max_o2.html wiki.answers.com/Q/…
    – aramis
    Jul 12, 2011 at 21:39

It's time-critical because it makes for more dramatic plots -- "We're all going to die in five minutes unless we can restore life support" makes for a lot more tension than "We're all going to die in a day or two unless we can restore life support", and fits better into a 42 minute TV show.

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    It's the same reason that "the radiation" will kill everybody in thirty seconds, but up until that time will have no ill effects at all. Jul 14, 2011 at 21:21
  • @DJClayworth "The radiation" will be within acceptable levels until thirty seconds, at which point there would be sufficient levels to alter the body to die within a month. Either way it's critical failure, just a matter of time. Feb 17, 2012 at 14:48
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    I actually think there is a lot more dramatic potential in "We're all going to die in a day or two unless we can restore life support". Look what happened in Firefly, for example. Aug 2, 2016 at 17:14

I would like to add a few additional points to the previous answers:

  • Humans are not the only members of the crew. For all we know a Horta crewmember consumes oxygen - or some other gas - in ridiculous quantities when compared to a human. Alien crew members might also be far more sensitive to atmospheric variations than humans. Not to mention that the non-human crew members might also release gases more dangerous than carbon dioxide in the atmosphere. We've never seen (I think?) any discussions of the lets-space-that-pink-alien-to-survive variety, but that's hardly a surprise, considering how important being politically correct seems to be for the Federation.

  • It seems to me that, at least post-TNG, the Starfleet vessels rely a lot on active technologies, rather than passive material structures - probably due to the strength requirements. While there is often talk of sealing damaged parts of a ship, I do not really remember a lot of cases where actual physical seals were used. Structural Integrity Fields for the hull, force fields for the bay doors, force fields for the containment of various dangerous substances, active radiation shielding and so on. For all we know, the seals for the various hatches and windows are also in the form of force fields (rubber seals? How... primitive...). Wouldn't those be considered part of the life support system ?

  • The ships in the Star Trek universe are not single-use ships like our current spacecraft. Due to this, they appear to carry a lot of supplies, some of which may be extremely perishable or even dangerous when released. While we would expect the existence of a separate emergency power supply for these storage modules, that power supply may impose a relatively low time limit when out of power. You wouldn't want that deadly Andorian flu nano-virus strain released once the emergency power fails would you?

  • Due to the various redudancies, the reason that the life support systems fail in the first place is usually something like battle damage or a very severe accident. In that case I don't think that you can make any assumptions, such as that the time-to-live is something as simple as dividing the volume of the ship with the oxygen requirement of the crew. Such damage usually has far more side-effects than just knocking out life support: fires, hull breaches, toxic gases from damaged systems and so on.

Therefore, I believe that severe damage to the life support systems would have several additional implications. I have not read any of the Star Trek manuals, so forgive me if I am wrong, but I would at least consider things like the fire suppression systems and the emergency seal force fields to be part of the life support systems. If these fail due to the aforementioned damage, you could easily have a ship that's leaking atmosphere like a sieve, with various toxins and uncontrollable fires on board and - for the really unlucky ones - with no gravity at all.

That sounds like a real emergency to me...

  • I think the first reason here is very strong, not all species are alike They are however pretty damn alike since it is never a concern, some species have a better time than others. Battle damage is extremely common, and you would plan for it. It's just not very believable that everything would fail without main power. On the other hand brigs were definitely dependant on force fields....
    – Lodewijk
    Mar 24, 2014 at 15:59

I think that they made it a big deal because they knew that if life support failed, they would all inevitably die, despite the fact that they could survive for a few hours. If they were stranded in space and life support would fail, they almost surely wouldn't last long enough for a rescue crew to save them.

  • Here's where I have a problem. Apparently they can communicate, and warp to a safe place, but no one can warp to them. If you can't warp somewhere, how can you communicate to there. Feb 17, 2012 at 14:50
  • Subspace is different from distorting the space-time continuum.
    – Lodewijk
    Mar 24, 2014 at 16:00

Because it's the final stage of urgency/ indication of serverity of the situation. Movies involving potential nuclear war have defcon levels, star trek has system failures. Sheilds off-line, teleporters, weapon systems, warp-core, structural integrety fields, life support. It's usually the last to go so if it's down, everything else is likely gone as well. The only thing still running is the ship's computer, and that's just to tell everyone that the ship is crumbling and every thing is off line.


Various answers already mention the threat of asphyxiation and of too much/too little heat. There is another danger: pollutants. There are lots of substances which are not very healthy if inhaled after they escape and/or burn, for example plasma coolant. Federation technology uses lots of other exotic materials, and it's not far-fetched to assume that they are poisonous as well.

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