Surviving in Space Without a Spacesuit

Geoffrey writes "The recent movie Sunshine features a scene (echoing the famous scene in 2001: a Space Odyssey) in which two astronauts have to cross from one ship to another without spacesuits. But, can you survive in space without a spacesuit? Morgan Smith, writing in Slate, asks whether this is realistic, and concludes: "Yes, for a very short time.""

Comments

Re:next time

[Marxist Hacker 42]

I haven't RTFA'd yet- but IIRC, the "Asmovian" version of this required that for maximum survival, you had to hyperventalate (to maximize oxygen storage in the bloodstream), empty the lungs, and be in shadow since the sun puts out so much energy that without an atmosphere you risk a pretty bad sunburn.

low-pressure spaceship env.

[fred fleenblat]

The decompression effects may be reduced/delayed if the space station uses a 100% oxygen atmosphere at a low pressure, then the pressure delta between what your body is equalized to and the vacuum is reduced so the trauma is delayed a bit.

The ISS uses normal sea-level pressure, but I believe some of the spacecraft used for the moon shots used the low-pressure environment.

Re:low-pressure spaceship env.

[evanbd]

There's a bigger problem with that though -- if you lower the pressure of the atmosphere, but add more O2 to keep the partial pressure the same, you increase the fire hazard. Inert gases like nitrogen act as a buffer and reduce flammability. Fires in spacecraft are a big deal, which (I believe) is why ISS uses higher pressure.

The major problem with exposure to vacuum isn't the pressure anyway, it's the lack of air. Furthermore, you can't hold your breath, because your lungs aren't strong enough to hold in the air. Without any air in your lungs, you get about 10-15 seconds of consciousness.

Re:low-pressure spaceship env.

[evanbd]

Actually, it's far from that simple. You can also get cases where you get combustion purely by diffusion, but the heat stays, so you have something that is very slowly smoldering... until a draft hits it and it flares up. There is some NASA data suggesting that flammability is a function of gravity, and that it seems to peak somewhere around 1/6G -- about lunar gravity. Things are less flammable either in free fall or Earth gravity. It will be interesting to see what fire precautions NASA ends up taking on the return to the moon flights.

15 seconds?

[vigmeister]

I just expelled all the air out of my lungs as best as I could and it was exactly 24 seconds before it was physically impossible to hold my breath... I felt a weird kind of giddiness -almost a mild 'hit'. Sort of like when you smoke a strong cigar and inhale.

Surely, astronauts ought to have better lung capacity than yours truly?

Cheers!

Re:Imagine drowning if you couldn't hold your brea

[Raul654]

After he came to, they asked the tech what the last thing he remembered was. He told them the last thing he remembered before blacking out was the saliva on his tongue boiling away (due to the extremely low pressure lowering the boiling point of the saliva)

Vacuum Rose and the Vacuum-breather's club

[Anonymous Coward]

The term for the capillary damage is "vacuum rose"

There was a series of novels back in the 90s about near-future cis-lunar space development. The blue-collar types had a 'vacuum-breather's club' for people who had survived just such events where they had to transfer from a damaged module to another without a suit.

A Serious case of YMMV

[wsanders]

A long time ago I took a pressure chamber ride at NASA to 27,000 ft. I lasted about 15 sec until uselessness (the crew master didn't let us go all the way to LOC), and 27,000 is not a particularly extreme altitude. Generally, 50,000 ft is considered the altitude at which the partial pressure of oxygen is no longer adequate to maintain consciousness. You can survive up to about 80,000 if you "pressure breathe", i.e have a rig that forces oxygen into your lungs at a lightly higher pressure than ambient, but not enough to bust your lungs.

And as TFA pointed out you will embolize if you hold your breath above that more or less 80,000 ft altitude.

So if the acronum YMMV ever applies, it's here.

Re:SG-1 had a similar scene

[OriginalArlen]

And let's not forget Event Horizon. (Hey! I wish I could forget EH... my friend had Sam Neill's decapitated bonce, with realistic gory holes where he'd supposedly torn out his own eyes, on her (street-facing) windowsill for months after working on the effects at Cinesite in London (next door to the Private Eye offices, trivia fans!) I believe he was usually used as a stand for sunglasses during the daytime... but I like to think he freaked a few people out after dark :)

Re:Spoilers by design?

[Renaissance 2K]

It's a very odd marketing tactic. They have web banners using the tagline "EVERYONE DIES" on various Internet sites.

But, the bigger question - which applies to all cold-hearted marketing drones - can we trust them?

I saw the movie last Sunday. The tagline and the campaign aren't as cut-and-dry as they appear. The movie, however, is quite unfortunately the victim of a beautiful universe and an intriguing scenario hampered by a drier-than-sandpaper script and a "jump the shark" moment about 2/3 through the movie that will make everyone in the theater shake their heads disapprovingly.

Wow, and TFA is wrong, too !

[Ihlosi]

At most, an astronaut without a suit would last about 15 seconds before losing conciousness from lack of oxygen. (That's how long it would take the body to use up the oxygen left in the blood.)

First piece of BS. No, your body doesn't use up the oxygen left in the blood in 15 seconds. In a vacuum (or, more broadly speaking, in any condition where the partial pressure of oxygen is lower in the lungs than in the blood), the gas exchange in the lungs is reversed - your blood will actually become deoxygenated while passing through your lungs. After 15 seconds, your brain will get hit by a blood supply that is pretty much completely deoxygenated - it's lights out then.

And then the part about air embolism - the pressure difference from going from the inside of a spacecraft (which is most likely pressurized at less than one atmosphere) to a vacuum is much lower than the pressure difference experienced by a scuba diver surfacing from a depth of, say, just 12 meters. "Vacuum" might sound nasty, but it's the pressure difference that is the problem here.

Re:SG-1 had a similar scene

[profplump]

I'm with you on the exploding -- if you're caught in space you want to do everything possible to reduce your internal pressure.

But it's not that cold in space. There's not a lot of ambient heat, but there's not a lot of conduction or convection either -- you only lose heat as fast as you radiate. So on the timescale of "holding your breath" the temperature of space is not a significant factor. Likewise the radiation you'd absorb over 60 seconds is likely not a large factor, unless you're particularly close to the source (I don't recall the episode, so I can't comment on their depiction of distance from the star(s)).

Re:SG-1 had a similar scene

[amccaf1]

So did an episode of Doctor Who. Only in that version, the Doctor is wearing just a spacesuit helmet without the rest of the suit. In addition, he gets stuck and ends up using a the momentum of throwing a cricket ball, bouncing it against an exterior wall of a spaceship and catching it to propel him in the direction he wanted to go. The physics are a little goofy, but it's probably the least goofy thing about that particular episode...

(The wikipedia page even has a screenshot of the dubious exercise.)

Re:Imagine drowning if you couldn't hold your brea

[xenocide2]

Really, I'd say conciousness for 10-15 seconds, and risk of death approaching 100 percent at 2 minutes, based on the link. Remember, the 2-3 minutes guy was examined by autopsy.

Re:So why do astronauts bother with gloves?

[jschrod]

If you would have followed the link that I posted, you would have seen that this is not a text of mine but a citation from a NASA scientist.

As he describes there, one would be unconscious within 10 seconds and would die within two minutes. This is known from experiments and accidents, not from estimations.

But death won't be due to freezing, what the GP asked and why I posted the citation.

Re:2001 Movie.

[jcgam69]

Well when I took scuba they told us to always breath. Holding your breath and rising even a few feet would be enough pressure differential to rupture a lung. How good that data is I don't know and I am not going to find out. If you hold your breath while ascending during a dive you risk an air embolism, not a ruptured lung.

Re:Imagine drowning if you couldn't hold your brea

[dmpyron]

You can get a pulmonary embolism in 5 feet of water if you do it right (wrong?) It actually takes a lot of work to get bent. There are a number of barotrauma disorders. Most of them occur in the first 20 feet of water.

I've been diving for over 20 years and teaching for over 10. One of the things I do for my advanced class on the deep dive is to fill a balloon to about 1/3 capacity at 100 feet and another to 2/3. Neither survives the ascent. The tennis balls crush, the hot and shaken soda doesn't fizz. And interestingly enough, it takes three or four times as long to solve simple puzzles, like opening combination locks.

SR71 crew wore full up "space suits". At 100,000 feet, water at body temperature doesn't really boil, it sublimates, both boiling and freezing at the same time.

Re:SG-1 had a similar scene

[AdamThor]

you only lose heat as fast as you radiate

No, you'd lose heat as any liquid on your skin boiled away, wouldn't you?

Also you'd pick up heat from the sun. You mention radiation, but not how much of it ends up as heat. Doesn't the space station actually require cooling to keep people alive? I don't know what the final balance works out as...

been there

[starshining]

I've done 4 spacewalks and during vacuum chamber training we open our suit purge valve, allowing the pressure in the suit to drop a bit (from nominal 4.3 psi) and I did feel the sensation of the saliva bubbling; it is similar to the sensation of soda pop on your tongue. I haven't seen the movies mentioned (other than 2001), but my guess about vacuum exposure is that you are more likely to be injured by the flying debris (including your own velocity as you impact a wall or whatever) associated with sudden decompression through a hatch than by a very short exposure to 0 psi. During one chamber run, I had a water line poppet valve stick open when I disconnected from the chamber wall. The water stream broke up into droplets that immediately froze, producing an impressive shower of ice particles. Over about 5 to 10 seconds, the icing point traveled up the water stream and formed a clump around the poppet valve, sealing the leak. Oh, by the way, I tried whistling while EVA and even the nominal suit pressure is too low to produce an audible sound.

Exploding from decompression

[rev063]

I think the guy exploded from the inside out from rapid decompression - but I think that could of been a little Hollywoodish. I used to think of the human body exploding due to decompression being pure Hollywood, too, until I read this:

Subsequent investigation by forensic pathologists determined that diver D4, being exposed to the highest pressure gradient, violently exploded due to the rapid and massive expansion of internal gases. All of his thoracic and abdominal organs, and even his thoracic spine were ejected, as were all of his limbs. Simultaneously, his remains were expelled with force through the narrow trunk opening left by the jammed chamber door, less than 60 centimeters (24 inches) in diameter. Fragments of his body were found scattered about the rig. One part was even found lying on the rig's derrick, 10 meters directly above the chambers.

Now, this was a 6atm almost instantaneous decompression. Jumping into space would be at most a 1atm differential, so nothing like this is likely to happen. Gruesomely cool, though.

Re:SG-1 had a similar scene

[rev063]

And if you want some insight into the effects of truly extreme pressure changes on the human body (next to which the vacuum of space is peanuts) I recommend reading about the Byford Dolphin diving bell accident. Not for the squeamish.

Re:Imagine drowning if you couldn't hold your brea

[Magada]

In other words, The Hitchhiker's Guide gets it right again: DON'T PANIC!