Can you survive in space without a spacesuit?

[E. Q. Taft]

In the new sci-fi film Sunshine, an astronaut named Mace must leave his spacecraft without a protective suit. He makes it through his exposure with only a case of frostbite. Could you really survive outer space without a suit?

http://www.slate.com/id/2171522/nav/ais/

[hambubba]

Did you watch 2001: A Space Odyssey?

I haven't timed the sequence, but it's about right according to the article.

[diddy]

Originally Posted by E. Q. Taft

Could you really survive outer space without a suit?

Not really. The temperatures and vacuum of space would kill you fairly quickly, but the movies make it look really bad. We have spacesuits to protect the body from the harsh environment of outer space though. According to Wiki:

The environment of space is highly dangerous without appropriate protection. The greatest threat is from the lack of pressure in the vacuum environment, while temperature and radiation effects also have an influence.

Contrary to imagery in the public media (as in such films as Outland, Total Recall, and Sunshine), a short term exposure to vacuum of up to 30 seconds is unlikely to cause permanent physical damage. Thanks to the containing tension of the skin, the body will not explode, though swelling may occur. Due to the lack of a medium to allow conduction or convection, loss of heat is by radiation only, which would take place in a very slow process. Therefore, there is no danger of immediately freezing.
Some physical damage may result if the victim attempted to hold his/her breath on introduction to the low pressure environment. In that case, a ruptured lung may result from the imbalance in pressure. Damage may also be done to ear drums, and the gastric system. Without the protection of the atmosphere, solar radiation, particularly ultraviolet rays may cause severe sunburn in a few seconds. After 10 seconds, decompression sickness (the bends) may also result.

However, the primary threat is of asphyxiation. In the low pressure environment, normal gas exchange would instead cause the rapid deoxygenation of the bloodstream. After up to 15 seconds, the deoxygenated blood would reach the brain, and loss of consciousness would result. Death would gradually follow after two minutes of exposure - though the limits are uncertain. If actions are taken quickly, and normal pressure restored within around 90 seconds, the victim may well make a full recovery.

Explosive decompression will not occur though. Wiki:
research and high-altitude causes swelling,

Misunderstandings of the meaning of the words are quite likely to be a fuelling factor for a persistent myth that humans would explode if exposed to the non-pressure of space. Accidents in space explorationaviation have shown that while vacuum exposurehuman skin is tough enough to handle a drop of one atm. A sudden drop of eight atm in the Byford Dolphin accident had intensely fatal results.

So it looks like unless your really quick, the biggest risk is death by asphyxiation, radiation, temperatures. So while it is possible to survive in space without a suit, you won't last too long without one anyway.

In the Byford Dolphin incident, the pressure dropped from 8atm (117.6 psi) to 1 atm (14.7 psi) in a fraction of a second. The "intensely fatal" results on one of divers was due to his body being forced through a 24" opening, in addition to the expansion of the gases in his body. The other divers did not explode. The autopsy findings on the other three did yield some suprising findings about lipid solubility, etc, though.

[Chloe]

Awww. I thought this was going to be a quiz.

1. How important is oxygen to your body?

a) Very
b) Somewhat
c) Meh. Could live without it

2. How do you feel about the cold?
a) Love it!
b) It's ok.
c) Brrrrrr!

Congratulations! You have a 20% chance of surviving in space without a spacesuit!

Etc.

[Troberg]

2. How do you feel about the cold?

The cold is not a big problem on the time scale we are talking about here. Sure' it's very cold, but it's also an almost perfect vacuum, so there will be very few very cold atoms to cool you. In fact, sufficient cooling is a big problem for satellites, as vacuum tends to be a splendid isolator.

[1958Fury]

I think the question should have been "How long can you survive in space without a space suit?"

Just "Can you survive..." makes me think of people setting up a tent on the moon, building a campfire and living off the land. Like in some future TV series spinoff, "Survivor: Moon".

I think Hitchhiker's Guide to the Galaxy said you could survive 30 seconds, and it was obviously a very well-researched series of books.

[diddy]

Originally Posted by 1958Fury

I think the question should have been "How long can you survive in space without a space suit?"

Just "Can you survive..." makes me think of people setting up a tent on the moon, building a campfire and living off the land. Like in some future TV series spinoff, "Survivor: Moon".

I think Hitchhiker's Guide to the Galaxy said you could survive 30 seconds, and it was obviously a very well-researched series of books.

Thirty seconds is a pretty good choice in my book, anything over that is really stretching. For the record I interpreted the OP in the way you propose.

[ganzfeld]

About the cold and heat: It's true that your body wouldn't lose its heat immediately and therefore wouldn't necessarily get frostbite (or burns) but if you had to touch objects that were on a lunar surface or the door handle of a spaceship or somthing you could defintely get burned or frostbitten.

[Silas Sparkhammer]

Didn't they do "destructive testing" on chimpanzees in the pre-Mercury era? To some of us, that pathway to research is uncomfortably reminiscent of Josef Mengele, determining how long people could live in ice-water, but, whether obtained morally or not, don't the data exist?

Silas

[ganzfeld]

Originally Posted by Silas Sparkhammer

Didn't they do "destructive testing" on chimpanzees in the pre-Mercury era?

Yes, there have been animal tests on this. (I don't know if any were done on chimps. A chimp is a valuable animal.) But three cosmonauts also tragically became test subjects for this experiment when their capsule depressurized on descent. They died but their bodies survived and can probably provide some of the data on this kind of incident.
http://www.damninteresting.com/?p=741

[ganzfeld]

This page decribes a couple of other incidents in which the people survived short-term or partial exposure:
http://en.allexperts.com/q/Popular-S...Space-suit.htm

[Recklessmess]

Originally Posted by 1958Fury

I think the question should have been "How long can you survive in space without a space suit?"

Just "Can you survive..." makes me think of people setting up a tent on the moon, building a campfire and living off the land. Like in some future TV series spinoff, "Survivor: Moon".

I think Hitchhiker's Guide to the Galaxy said you could survive 30 seconds, and it was obviously a very well-researched series of books.

Arthur C. Clarke hits upon this in 2001, A Space Odyssey, I think if I remember saying that a normal person would last about 15 seconds before blacking out, but a prepared astronaut (or person trained to deal with such effects) could last about 2 minutes. Then again, he wrote about this back in the 60s, but his stuff is widely acclaimed for its accuracy.

[1958Fury]

Originally Posted by Recklessmess

Arthur C. Clarke hits upon this in 2001, A Space Odyssey, I think if I remember saying that a normal person would last about 15 seconds before blacking out, but a prepared astronaut (or person trained to deal with such effects) could last about 2 minutes. Then again, he wrote about this back in the 60s, but his stuff is widely acclaimed for its accuracy.

I haven't read the book, but I always wondered how accurate that scene was in the movie. All I can say is, I'm not going to try it.

[E. Q. Taft]

Well, it wouldn't be pleasant even if you could survive....

I'll have to try to look up an essay Clarke wrote about the time 2001 came out, defending that scene (it's somewhat different in the book than the film). He noted that tests were done on both dogs and chimpanzees; however, all the chimpanzees recovered, so, as Clarke said, were clearly taken nowhere near their limits.

I think, however, that Clarke may have been somewhat wrong. He did say that an unprepared man probably wouldn't be able to stay conscious more than ten or fifteen seconds -- but he thought that one who had a chance to prepare might be able to stay conscious for as much as a minute. From the data above, it appears this is not correct; there's no preparation you can do that would give you more than a few extra seconds, if that, before the deoxygenated blood gets to the brain. You can't hold your breath without suffering a fatal air embolism.

Still, I always thought the "exploding heads" bit from Outland was laughably absurd -- for one thing, if you were going to explode, it would presumably be your chest. But you wouldn't. (But then, it was hardly the only silly part of that movie...)

[1958Fury]

I'm trying to think of other movies that have scenes like that, but I'm drawing a near-blank. I keep thinking of the end of Total Recall, where they almost die until the air comes back, and some of their body parts are swelling, eyes bulging, etc. At the end of the novelization of Alien, it says the alien explodes after it is blown out into space, but in the movie it just sails away. Though it's body is constructed so differently from a human, that's not a good example.

[Eddylizard]

Originally Posted by E. Q. Taft

Well, it wouldn't be pleasantI think, however, that Clarke may have been somewhat wrong. He did say that an unprepared man probably wouldn't be able to stay conscious more than ten or fifteen seconds -- but he thought that one who had a chance to prepare might be able to stay conscious for as much as a minute. From the data above, it appears this is not correct; there's no preparation you can do that would give you more than a few extra seconds, if that, before the deoxygenated blood gets to the brain.

Assuming we are talking about a planned suitless EVA as opposed to a sudden unexpected loss of cabin or suit atmosphere, wouldn't a few moments of hyperventilating (though not to the point of feeling the ill effects of hyperventilation) before starting increase the amount of oxygen stored in the blood cells?

If you had quite some time to prepare, could you not also use blood doping?

[Mycroft]

Athrhur C Clarke covers the situation more fully in Earthlight, scenario is that crew have to abandon damaged shaceship and do it successfully. as terms of human endurance the brain takes several minutes before damage when there is no oxygen supply at all during a heart attack. When ascending rapidly in an emergency, submariners are trained to continualy exhale (slightly different situation to divers as the submarine would only be put under high pressure just before escape). In space this would probably be more severe as the pressure drop would be more immediate. In practice I believe NASA carry rescue balls, essentially large balloons which can hold non-suited personel in an evacuation situation in orbit (they are of course presurized).

[Troodon]

Originally Posted by Eddylizard

Assuming we are talking about a planned suitless EVA as opposed to a sudden unexpected loss of cabin or suit atmosphere, wouldn't a few moments of hyperventilating (though not to the point of feeling the ill effects of hyperventilation) before starting increase the amount of oxygen stored in the blood cells?

If you had quite some time to prepare, could you not also use blood doping?

That wouldn't work well because the blood would still go to your lungs, where it would be exposed to vacuum. The lugs are designed to equilibrate the gasses in the blood with the environment, so whatever oxygen was being carried would escape through the lungs.

[ganzfeld]

Originally Posted by Troodon

That wouldn't work well because the blood would still go to your lungs, where it would be exposed to vacuum. The lugs are designed to equilibrate the gasses in the blood with the environment, so whatever oxygen was being carried would escape through the lungs.

That seems to suggest that some specially designed scuba gear could allow you to last a long time. (The question says "without a space suit". I don't think most people would call a simple oxygen mask a space suit.)