Survival in space?

Losing one's mind doesn't require a great deal of time. The David Syndrome and the Stendhal Syndrome are conditions where people are overwhelmed in the presence of great art, architecture, or other highly cultural stimuli. They can lead to panic, disorientation, the urge to destroy the "offending" object, or even temporary madness. I would imagine there would be some people who would become completely overwhelmed staring out into the blackness of space or down on our beautiful blue jewel of a planet.

Typically, air is the primary concern. Space suits are very well insulated, they're highly efficient at retaining body heat. In fact, they're too efficient and require fans and heat exchangers to bleed off excess heat. They also need to reflect sunlight, which can heat up a space suit pretty quickly. Air is also the larger concern because of carbon dioxide. It can't simply be vented into space, it's filtered through canisters to remove it from the atmosphere inside the space suit.

Modern space suits have a 7 hour supply of oxygen and carbon dioxide removal, plus a 30-minute emergency oxygen supply. Batteries last for 27 hours, as long as they are functioning and the suit's layers are intact, temperature will be regulated.

Check this link for more information.

Lack of oxygen is most likely to kill you first. Going mad is unpredictable but rarely instantly fatal.
Heat is contrary to common believe not an important factor in space. You're packed in millions of kilometres of vacuum, the best insulation you can get. It takes a very long time for you to radiate enough heat to get to dangerously low temperatures. If you are however too close to the sun the side of you pointing towards it will get nice and crispy from the unfiltered radiation.

The following is a somewhat related issue. It doesn't hit the nail on the head for what you are asking, but I thought I'd post it anwyay.


Last year a British movie came out in a blink-or-you'll-miss release of barely a few weeks in theatres. It was Sunshine.

http://www.imdb.com/title/tt0448134/

http://en.wikipedia.org/wiki/Sunshine_(2007_film)

It had one very unique and totally nail-biting scene in it where the atronauts were stuck in a space craft that was either about to explode or was about to be set adrift or something like that. (I did not see this film, I only read about it.) So they had to make a very quick decision to somehow escape from that craft and get to a different one. BUT THEY HAD NO SPACE SUITS! So they had to exit the first craft WITH NO SPACE SUITS!

What I read about was the startled buzz from laymen on the internet regarding the no-suit scene. The scientific response on the internet was: thirty seconds, and it's do-able. After that, you're dead. The movie had two "small" errors in it regarding being suitless in space: 1) you won't get frost bite because there's no medium (like air) to carry the heat away from your body, 2) you don't move in slow motion in space like under water. But the rest of it: the radiation exposure and the potential for embolism, was covered well in the movie. The scientists on the internet said the trick is you need to expell as much air as possible from your lungs to stave off embolism. And so they said the real danger would then be that you might pass out from a lack of air before you reached your destination.

Lhun said:

Lack of oxygen is most likely to kill you first. Going mad is unpredictable but rarely instantly fatal.
Heat is contrary to common believe not an important factor in space. You're packed in millions of kilometres of vacuum, the best insulation you can get. It takes a very long time for you to radiate enough heat to get to dangerously low temperatures. If you are however too close to the sun the side of you pointing towards it will get nice and crispy from the unfiltered radiation.

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Yes, heat gain is more of a problem than heat loss. In space, at the distance of Earth to the Sun, and without atmosphere to block it, your biggest problem is keeping cool.

I forgot to add: one more probem that the scientists on the internet said you'd encounter when exposing your skin in space is that you'd get all these millions of little black speckles all over your skin from surface blood vessels bursting. The scientsts said that THIS was far more of a problem to your skin that frost bite would be.

That can be a problem but is not necessarily one. About the whole "explosive decompression" thing you just have to remember that the pressure difference is just one bar. That's like diving ten metres, or rather resurfacing abruptly after diving at 10 metres for a length of time.
Actually though the pressure would be somewhat lower, since spacecraft (as well as ordinary passenger planes) have lower air pressure than athmospheric pressure at nn.
Passing out in 30 seconds is also possible but also not necessarily the upper limit. Hyperventilating will give more oxygen in the blood for example. You will pass out faster than when just holding your breath, but just try emptying your lungs and then holding your breath.

Also, the slow, underwater-like movements aren't an effect of vacuum but a necessity in a frictionless environment. Sudden, abrupt movements might send you spinning in various directions, something you most definitly want to avoid. Astronauts aren't moving slowly as such, they're moving carefully.

Plot Device said:

I forgot to add: one more probem that the scientists on the internet said you'd encounter when exposing your skin in space is that you'd get all these millions of little black speckles all over your skin from surface blood vessels bursting. The scientsts said that THIS was far more of a problem to your skin that frost bite would be.

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I think Heinlein did a story in which this happened. Delilah and the Space Riggers? They had to cross space to another vessel, a trip of only a few seconds, so they survived as has been described here, but they also got the worst sunburn of their lives.

Crossing space suitless whether 30 secs. or not, may also cause petechial hemorrhaging and blindness when the delicate blood vessels in the eyes burst.

As the link above points out, this scenario was covered in the film 2001. I recall at the time, a major discussion over the feasability of the scene. NASA spokesmen were consulted, and agreed that within the confines of the airlock - (In the scene in question DAVE is blasted directly out of the pod and into the open airlock - he bounces around for a moment, then hits the close and presurize button) - He's not exposed to direct radiation/micrometeorites or such. A few seconds, and he's good. Beyond that and he's toast.

At least, that's what I recall from the talk on TV WAAAAAY back in '69. Before the internet!

The Article ReneC Linked said:

You would become unconscious within 15 seconds because there's no oxygen.

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I call bollocks. 15 seconds?

dempsey said:

I call bollocks. 15 seconds?

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I think this is assuming you don't have lungs full of pure oxygen. Since you're sans space suit, normal air wouldn't remain in your lungs or blood because of the extremely low external pressure.

ReneC said:

I think this is assuming you don't have lungs full of pure oxygen. Since you're sans space suit, normal air wouldn't remain in your lungs or blood because of the extremely low external pressure.

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I call bollocks as well on oxygen not remaining in your blood. Unless there's some sort of strange osmosis going on that would suck exclusively oxygen from your bloodstream.

Also, I'm actually thinking someone who would prepare for this, who would close their mouth and hold their nose shut. But if you're caught by surprise, then yeah, I see all the air fleeing your lungs in a great whoosh, collapsing them in on themselves. At which point, even if you make it to somewhere within 15 seconds, you're going to have a hell of a time breathing ever again.

The 15 seconds is because you can't hold your breath in a vacuum. If you hold air in your lungs, they would rupture as the air escapes. You would have to exhale beforehand, and it takes about 15 seconds for the body to use up the oxygen in the bloodstream. After that, it's lights-out.

Even if successful, the astronaut would suffer from decompression sickness (the bends) unless they were breathing pure oxygen for at least 30 minutes beforehand.

ReneC said:

The 15 seconds is because you can't hold your breath in a vacuum. If you hold air in your lungs, they would rupture as the air escapes. You would have to exhale beforehand, and it takes about 15 seconds for the body to use up the oxygen in the bloodstream. After that, it's lights-out.

Even if successful, the astronaut would suffer from decompression sickness (the bends) unless they were breathing pure oxygen for at least 30 minutes beforehand.

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This isn't quite as universal as you seem to think. I used to be on the swim team and I could last without any air in my lungs for significantly longer than fifteen seconds.

When you exhale, it's not as though you're getting rid of all the air in your lungs. There's still air in there.

Unless everything I remember about vacuums and the respiratory system is wrong.

But, in theory, closing your mouth and holding your nose should keep air in lungs. Is there another way for air to escape your lungs that I'm unaware of? Does it leak out through your tear ducts or something? Or is it a matter that the human body simply can't hold the air in, despite all efforts to the contrary, without external mechanical assistance?

Well, I've heard that if you keep your eyes open when you sneeze, you can pop out an eyeball. *L*

As an additional note, sitting right here in my chair, with no preparation whatsoever and having shunned significant exercise for five years, I made it to 23 seconds before my head began to hurt. The trick is to keep swallowing.

I guess the question really is can you hold your breath in space?
If so how long and why?

In response to an earlier link, http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

Well, guess I have to concede a little.

Anyway, I don't write things in space, so this doesn't worry me.

I like this place, for threads like this

No, it isn't conceding, it's learning! I didn't know much about this before DeaconBlu asked, I learned a lot while researching it.