Sunday's science question: Can You Survive in Space Without a Spacesuit?

The important question here; What is the probability of being picked up by a passing spacecraft, before succumbing to the vacuum of space?

The article says "At most, an astronaut without a suit would last about 15 seconds before losing conciousness from lack of oxygen." That does not sound right. I can breath out all the air in lungs and hold my breath for longer than that and I am not a trained astronaut in top fitness. How are things different in vacuum?

"Open the pod bay door, HAL"

"I can't do that, Dave, the mission is too important"

Followed by the opening the airlock, blowing the pod door, Bowman is blown into the airlock and closes the door ... Daisy, daisy"

Clarke knew that there was a short, but significant, survival time in a vacuum and it was in another of his books besides 2001.

The real question is how long you can survive a infestation of zombie ninjas without an armoured spacesuit.

The answer, of course, is not long. Thank Tesla for Mayor Goodrich!

natural cynic -

Jerry Pournelle used a similar situation correctly, though I can't remember which novel. Isaac Asimov talked about this in one of his myriad essays as well. Douglas Adams was close, but did make the assumption that rather than losing consciousness, one would be dead within thirty seconds - he did mention freezing rather than exploding. Dr. Who showed someone who died in the vacuum of space with head intact (we're on series two now, just watched that particular episode last night - the one where Satan gets sucked into the black hole). I think the key to it's proper usage as a plot element, is that the writers must actually care about the accuracy of the science behind it. Babylon 5 is another one that does well with the science (now if only the actual writing was better). Indeed, they showed a corpse in vacuum that had an intact head.

I'm not a YEC, but i don't get this:

Wouldn't an age of billions of years cause the earth's magma to run out of radioactive isotopes?

One would think so. (Otherwise, a mechanism to replenish the radioactive isotopes would have to be found.) However, newly-formed rocks continue to contain radioactive isotopes.

"I can breath out all the air in lungs and hold my breath for longer than that and I am not a trained astronaut in top fitness. How are things different in vacuum?"

The main difference is that when you are not in a vacuum you can't breath out all the air in your lungs; there is still a substantial amount there, and the circulating blood will, for a while, draw oxygen from it. In contrast, the moment you hit a vacuum, all the remaining air in the lungs will rush out. Indeed, the lungs would then act as a sink, removing oxygen as the blood travels through them.

And as all scuba divers know, the very worse thing you could do is try to hold your breath.

"Wouldn't an age of billions of years cause the earth's magma to run out of radioactive isotopes?"

You might want to investigate what a radioactive isotope half-life is (try wikipedia). In brief, in one half life 1/2 of the original isotope still remains. After 2 half lives 1/4th remains, after 3, 1/8th etc. Some isotopes have half lives in the hundreds-of-millions to billions of year range, and so a substantial fraction of those isotopes are still around even 4.55 (+/- 0.2) billion years since the initial formation of the earth.

Clarke knew that there was a short, but significant, survival time in a vacuum and it was in another of his books besides 2001.

Earthlight, in which the crew of a disabled ship have to cross to a rescue vessel without suits.

I have to wonder about the whole breath holding, breath expelling thing would work. As humans we can't really pre-expel all the air in our lungs, so can the pressure outside our chest drop so quickly that even active breath expelling won't be quick enough (i.e. could the gas pressure inside our lungs cause serious damage)?

Of course as others have said, temperature change should be the least of your worries. The only way space has a temperature, is via the level og ambient radiation. Remember the Stephan Boltzman law. The astronaut would be losing heat via infrared radiation, but at no different a flux than I am in my living room. The radiation he is recieving is likely to be not very strong, unless he is near a star. Of course hard UV radiation could be a few orders of magnitude greater than on earth, but presumably the exposure is for not that long for it to be an issue.

What is the probability of being picked up by a passing spacecraft, before succumbing to the vacuum of space?

Well, according to HHGTTG, one can last 30 seconds, and the chances are 1 in 2^267709 (which happens to be the telephone number of an Islington flat where Arthur once went to a very good party and met a very nice girl whom he entirely failed to get off with).

Of course, the book might be inaccurate, but at least it's definitively inaccurate.

Bob

Note that one of the people credited on the Slate story is none other than Professor Geoffrey Landis of the NASA John Glenn Research Centre, where he does things like designing solar-powered aircraft for exploring Venus, and in his spare time writes very well-regarded science fiction.

There's an episode of BSG which involves Chief Tyrol and Cally being exposed to vacuum for a short period of time. They survive, but are in a pretty bad way. I can't remember all the details, but IIRC the main danger in the TV show was from the cold.

Another point is diver's sickness: Going from one atmosphere to hard vacuum the way it's depicted in Space Odyssey is equivalent to being yanked up into the air from ten meter underwater.

- JS

Is diver's sickness the same as what is called "the bends"? Wouldn't that incapacitate you quickly?

I don't know the English term. But theoretically it could do Bad Things for you. It's supposedly kind of iffy, though, with irregular effects and a biggish bit of chance involved...

- JS

JS: The bends occur when you dive deep longer than you should and surface quickly. As the external pressure suddenly decreases, Nitrogen (and other gases) form bubbles in your joints and in other organs, painfully. You end up bent over due to the bubbles in the joints.

Well, if we're listing sci-fi that got it right... John Crichton survived a suitless spacewalk in Farscape episode 2.11 (I think - might be 2.12, definitely part of the "Look at The Princess" trilogy). He did end up in pretty bad shape - lung and skin damage, but no frostbite.

The risk of the bends can be reduced by pre-breathing pure oxygen. The idea is to get all of the nitrogen out of your blood in the first place. Spacewalkers today spend time breathing pure oxygen to prepare. (And when in their suits, they are in a mere 5 PSI pure oxygen environment. A normal atmosphere would inflate the suits to the point where they would be immobile.)

There is one documented case of people perishing from "sucking space", but as they were Soviet, I find that very few articles reference their case. They were the crew of Soyuz 11. It wasn't an explosive decompression situation, so they didn't die as quickly as they might have -- flight logs revealed that it took 115 seconds for the cabin atmosphere to vent after a pressure equalization valve (meant to open shortly before landing) opened after undocking from Salyut 1. Telemetry recordings indicate that they probably were at least minimally aware of their fate:

At separation of the orbital module after retrofire, Volkov was emotional - his pulse was 120. Patsayev's was at 92 to 106, and Dobrovolsky at 78-85. The average for cosmonauts at retrofire in earlier flights was 120, with Tereshkova setting the record at 160. A few seconds later, as the crew became aware of the leak, Drobrovlsky's pulse had increased to 114 and Volkov's to 180. 50 seconds after separation, Patsayev's pulse was down to 42, characteristic of someone suffering oxygen starvation. Dobrovolsky's quickly fell as well. At 110 seconds the hearts of all three men had stopped. Death came at 120 seconds after jettison.

Links from Astronautix.com (text above is from the first link):
Soyuz 11 failure investigation
Landing of Soyuz 11 and death of crew.

I have read elsewhere (don't recall where off the top of my head) that autopsies showed significant hemorrhaging as well, but that the lack of oxygen is what really did them in. They definitely did not explode in any way.

I think the idea of people exploding comes from a common misunderstanding of the term "explosive decompression". It just means that the air vents very rapidly, but people hear "explosive" and get an image in their minds of a person blowing up.

It occurs to me that my post above may be slightly misleading. The valve did not open immediately after undocking; it is believed that it opened when the orbital module of the Soyuz spacecraft was jettisoned, perhaps as a result of vibration although nobody really knows. Following this flight, all subsequent Soyuz flights have required the use of partial pressure suits so that the crew could survive this if it happened. (Fortunately, it hasn't happened again.)

IIRC Luke Skywalker did it in one of Timothy Zahn's Thrawn Trilogy Star Wars books -- the term Zahn used was "cold-shirting". I believe he did sustain a bit of damage (not to mention plowing directly into whoever was waiting in the airlock to catch him -- I think it was Mara Jade) but managed to avoid the worst of it by virtue of being a powerful Jedi.

Earthlight, in which the crew of a disabled ship have to cross to a rescue vessel without suits.

If that's the one I'm thinking of, since they were in Earth orbit the longest-lasting effect was a severe sunburn, as there was no atmosphere to provide UV shielding.

Anybody got any thoughts on a related situation in movies like "Aliens", where the protagonist is clinging to some railing while air rushes out the airlock? How fast would the air be rushing out? Would it even be possible to inhale/exhale in such an environment?

ngong -

I seem to recall a essay that discussed this, by Asimov. The problem is, that I had several years of the magazine SciFi & Fantasy and I cannot begin to remember which issue it would have been in. I am also not certain that it was him - it might have been someone else, in which case, I cannot endorse the veracity of the assertion with certainty. Not that Asimov was the only authority or always right, but he was usually right whereas not everyone else who wrote from asserted authority was. It might well have been Larry Niven, in which case, it was probably accurate too.

Anyhow, the basic premise was that the force of losing pressure, straight from earth normal, to the vacuum of space, would be enough to remove one's arms from the body. This was actually my major problem with the last Dr. Who of series two. With the amount of pressure buffeting them, the Dr and Rose, should have been sucked in, no matter how well they had anchored their arms. Of course, this would have been the end of Dr. Who so I am rather glad they didn't.

Well, technically they would've been blown in, not sucked.

But it doesn't matter. Strictly speaking, it wasn't a vacuum situation anyway. Objects uncontaminated with "void stuff" were completely unaffected, so there shouldn't have been any pressure on them at all -- assuming not much atmosphere was contaminated with void stuff. They weren't being sucked into a vacuum, they were being drawn along by the void stuff on them. More like a magnetic attraction than anything else.

Which arguably should've made it much harder for them to avoid their fate than if it had merely been a vacuum situation. After all, it managed to suck in all of the baddies, so why not them? It could only have been a [url=http://www.jabootu.com/glossary.htm]Hero Battle Death Exemption[/url]. ;-) Another thing unexplained is why the baddies getting sucked along were drawn along arcing trajectories which conveniently managed to miss all of the intervening buildings -- rather than simply following a straight line and leaving millions of Cyberman- and Dalek-shaped holes in all of the buildings in London.

Is diver's sickness the same as what is called "the bends"? Wouldn't that incapacitate you quickly?