Surviving vacuum

[Zixinus]

1. Say you have to jump from airlock to airlock in a dramatic fashion, all in zero gravity. There is no space suit. Luckily, you would be in darkness or in the shade in either case.

So what should you do in this situation? Take air in? Or do the opposite, to prevent lungs decompressing and just hope that you can put enough time together to live without brain damage? What about the anus? Should one fart to prevent pressure buildup within the body? Just how much pressure would the internal insentiences be at?

2. Similar scenario as above, but with one difference: while there is no spacesuit, you have access to a rundimentary workshop that has an oxygen cannister and/or scuba-diving kit. You have a few hours until you need to leave. Not all workshops are the same of course and I am not familiar with enough to give a median, so assume you can find anything that's not magi-tech. You can only find stuff that already exists (ie, no fabs to make you a new spacesuit).

Would someone survive with an oxygen-mask modified for vacuum and earplugs? How long would one survive? What should one do? Aside air, what other precautions should you take for a few-minute or few-second trip that may cost you your life?

3. Say you are in the above and you have to walk on the surface of the moon (dark side) to get from one pressurized station to another.

Is there any particular threat in doing so that is not true for scenario 2?

4. Finally, vacuum life: I understand that for vacuum life to exist, it has to be photosynthetic, as the organism can't gain energy from the surrounding non-existent air. However, they are frequently portrayed that they must have some shade (Liven's description from Ringworld comes to mind). Why? And aside the possibility of such organisms needing light, how much light? Would they resemble certain microbiological life that is passive in light and active in darkness?
Would it depend on the evolutionary history of the species?

[Lord of the Abyss]

So what should you do in this situation? Take air in? Or do the opposite, to prevent lungs decompressing and just hope that you can put enough time together to live without brain damage?

As I recall, you should let the air out; the lungs have little ability to withstand internal pressure.

[FSTargetDrone]

NASA has something that is relevant:

Ask an Astrophysicist

The Question
(Submitted June 03, 1997)

How would the unprotected human body react to the vacuum of outer space? Would it inflate to bursting? or would it not? or would just the interior gases hyperinflate? We are also relating this to short-term exposure only. This question primarily relates to the pressure differential problems. Temperature or radiation considerations would be interesting as well.

The question arose out of a discussion of the movie 2001. When Dave "blew" himself into the airlock from the pod without a helmet, should he have "blown up" or is there "no difference" as shown in the movie correct?

The Answer

From the now extinct page http://medlib/jsc.nasa.gov/intro/vacuum.html:

How long can a human live unprotected in space?

If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.

Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after ten seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes, you're dying. The limits are not really known.

You do not explode and your blood does not boil because of the containing effect of your skin and circulatory system. You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly. Loss of consciousness occurs only after the body has depleted the supply of oxygen in the blood. If your skin is exposed to direct sunlight without any protection from its intense ultraviolet radiation, you can get a very bad sunburn.

At NASA's Manned Spacecraft Center (now renamed Johnson Space Center) we had a test subject accidentally exposed to a near vacuum (less than 1 psi) in an incident involving a leaking space suit in a vacuum chamber back in '65. He remained conscious for about 14 seconds, which is about the time it takes for O2 deprived blood to go from the lungs to the brain. The suit probably did not reach a hard vacuum, and we began repressurizing the chamber within 15 seconds. The subject regained consciousness at around 15,000 feet equivalent altitude. The subject later reported that he could feel and hear the air leaking out, and his last conscious memory was of the water on his tongue beginning to boil.

Aviation Week and Space Technology (02/13/95) printed a letter by Leonard Gordon which reported another vacuum-packed anecdote:

"The experiment of exposing an unpressurized hand to near vacuum for a significant time while the pilot went about his business occurred in real life on Aug. 16, 1960. Joe Kittinger, during his ascent to 102,800 ft (19.5 miles) in an open gondola, lost pressurization of his right hand. He decided to continue the mission, and the hand became painful and useless as you would expect. However, once back to lower altitudes following his record-breaking parachute jump, the hand returned to normal."

References:

Frequently Asked Questions on sci.space.*/sci.astro

The Effect on the Chimpanzee of Rapid Decompression to a Near Vacuum, Alfred G. Koestler ed., NASA CR-329 (Nov 1965).

Experimental Animal Decompression to a Near Vacuum Environment, R.W. Bancroft, J.E. Dunn, eds, Report SAM-TR-65-48 (June 1965), USAF School of Aerospace Medicine, Brooks AFB, Texas.

Survival Under Near-Vacuum Conditions in the article "Barometric Pressure," by C.E. Billings, Chapter 1 of Bioastronautics Data Book, Second edition, NASA SP-3006, edited by James F. Parker Jr. and Vita R. West, 1973.

Personal communication, James Skipper, NASA/JSC Crew Systems Division, December 14, 1994.

Henry Spencer wrote the following for the sci.space FAQ:

How Long Can a Human Live Unprotected in Space?

If you *don't* try to hold your breath, exposure to space for half a minute of so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs, something scuba divers have to watch out for when ascending, and you'll have eardrum trouble if your Eustachian tubes are badly plugged up, but theory predicts -- and animal experiments confirm -- that otherwise, exposure to vacuum causes no immediate injury. You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness.

Various minor problems (sunburn, possibly "the bends", certainly some [mild, reversible, painless] swelling of skin and underlying tissue) start after 10 seconds or so. At some point you lose consciousness from lack of oxygen. Injuries accumulate. After perhaps one or two minutes you're dying. The limits are not really known.

References:

The Effect on the Chimpanzee of Rapid Decompression to a Near Vacuum, Alfred G. Koestler ed., NASA CR-329 (Nov. 1965)

Experimental Animal Decompression to a Near Vacuum Environment, R.W. Bancroft, J.E. Dunn, eds, Report SAM-TR-65-48 (June 1965), USAF School of Aerospace Medicine, Brooks AFB, Texas.

You would probably pass out in around 15 seconds because your lungs are now exchanging oxygen out of the blood. The reason that a human does not burst is that our skin has some strength. For instance compressed oxygen in a steel tank may be at several hundreds times the pressure of the air outside and the strength of the steel keeps the cylinder from breaking. Although our skin is not steel, it still is strong enough to keep our bodies from bursting in space.

Also, the vapor pressure of water at 37 C is 47 mm Hg. As long as you keep your blood-pressure above that (which you will unless you go deep into shock) your blood will not boil. My guess is that the body seems to regulate blood pressure as a gauge, rather than absolute pressure (e.g. your blood vessels don't collapse when you dive 10 feet into a pool).

The saliva on your tongue might boil, however.

For more information and references, see http://www.sff.net/people/geoffrey.landis/vacuum.html

Hope this helps!
The Ask an Astrophysicist Team

[Broomstick]

So what should you do in this situation? Take air in? Or do the opposite, to prevent lungs decompressing and just hope that you can put enough time together to live without brain damage?

Exhale, and jump with your mouth open. You won't be able to keep it inside anyway, and attempting to do so could do Bad Things like blow out your eardrums or cause a pulmoney embolism or something.

You're better off relying on what oxygen is in your blood/brain, which won't immediately seep out, nor will brain damage be immediate. Of course, this severely limits the time you have for this escapade assuming you wish to actually survive.

What about the anus? Should one fart to prevent pressure buildup within the body? Just how much pressure would the internal insentiences be at?

You won't be able to hold the farts in, anyhow. You start "outgassing" at pressures lower than sea level yet higher than vacuum anyhow - just ask any skydivers you know.

Intestinal contents are pressurized to at least 15 lbs/inch2 or 1 kg/cm2 assuming sea level pressure.

2. Similar scenario as above, but with one difference: while there is no spacesuit, you have access to a rundimentary workshop that has an oxygen cannister and/or scuba-diving kit. You have a few hours until you need to leave. Not all workshops are the same of course and I am not familiar with enough to give a median, so assume you can find anything that's not magi-tech. You can only find stuff that already exists (ie, no fabs to make you a new spacesuit).

Would someone survive with an oxygen-mask modified for vacuum and earplugs? How long would one survive? What should one do? Aside air, what other precautions should you take for a few-minute or few-second trip that may cost you your life?

Wouldn't make a damn bit of difference, the pressure differential is too great. You wouldn't be able to inhale, and even if you did, the gas partial pressure in your blood stream is greater than that in your jury-rig POS so it still wouldn't do you a damn bit of good The earplugs probably won't save your eardrums, either.

3. Say you are in the above and you have to walk on the surface of the moon (dark side) to get from one pressurized station to another.

Wear shoes - the ground will either be hot enough to burn or cold enough to cause frostbite. Either way, you don't want to touch it with bare skin.

And those stations better be damn close - you'll have seconds at best to make the crossing.

[FSTargetDrone]

And those stations better be damn close - you'll have seconds at best to make the crossing.

No more than 15 seconds, given the NASA stuff. And around 10 seconds you're starting to feel the symptoms of being in the vacuum.

So 2001 got it mostly right, except for Bowman holding his breath (the jumping sequence starts around 2:25):



Notice the hatch pops off at about 2:28 and the sound of the tube repressurizing starts at 2:41. That's damn close, but it fits.

[CaptainChewbacca]

I believe in 'Event Horizon' Samuel L. Jackson tells some kid locked in a cycling airlock what to do, and its actually the correct course of action. Exhale everything you have and curl your body together for warmth.

[Zixinus]

Wouldn't make a damn bit of difference, the pressure differential is too great. You wouldn't be able to inhale, and even if you did, the gas partial pressure in your blood stream is greater than that in your jury-rig POS so it still wouldn't do you a damn bit of good The earplugs probably won't save your eardrums, either.

So there is no way to prolong being in vacuum without a spacesuit?

[Broomstick]

Correct.

[Serafina]

Wouldn't make a damn bit of difference, the pressure differential is too great. You wouldn't be able to inhale, and even if you did, the gas partial pressure in your blood stream is greater than that in your jury-rig POS so it still wouldn't do you a damn bit of good The earplugs probably won't save your eardrums, either.

So there is no way to prolong being in vacuum without a spacesuit?

Well, you could make it with just a sealed helmet or even a sealed breather (just covering your mouth) for a while.

You will still get problems with sunburns/frostbites, radiation etc., and if your lungs are properly filled they should get into trouble, but i guess a couple of minutes are survivable.

[Shroom Man 777]

Not even a very tight breathing mask hooked to an O2 tank?

[SCRawl]

I believe in 'Event Horizon' Samuel L. Jackson tells some kid locked in a cycling airlock what to do, and its actually the correct course of action. Exhale everything you have and curl your body together for warmth.

You mean Laurence Fishburne, right?

Anyways, yeah, I recall that scene. The guy started bleeding from everywhere from the moment he hit the hard vacuum, which seems to contradict the story in the third post.

[GrandMasterTerwynn]

Wouldn't make a damn bit of difference, the pressure differential is too great. You wouldn't be able to inhale, and even if you did, the gas partial pressure in your blood stream is greater than that in your jury-rig POS so it still wouldn't do you a damn bit of good The earplugs probably won't save your eardrums, either.

So there is no way to prolong being in vacuum without a spacesuit?

You would need at least a pressurized emergency helmet with a good neck seal. Or, perhaps some Sufficiently Advanced Technologytm which super-oxygenates your blood through the miracle of nanotechnology so that you can last thirty or forty seconds before losing consciousness rather than ten. But, given how silly the second option sounds, you ought to stick with the first.

Not even a very tight breathing mask hooked to an O2 tank?

No. That would just result in rupturing your eardrums when the air tries to escape through your Eustachian tubes. A pressurized helmet is really the minimum required equipment here.

[loomer]

You would need at least a pressurized emergency helmet with a good neck seal. Or, perhaps some Sufficiently Advanced Technologytm which super-oxygenates your blood through the miracle of nanotechnology so that you can last thirty or forty seconds before losing consciousness rather than ten. But, given how silly the second option sounds, you ought to stick with the first.

If memory serves, we can do that already - by hyperventilating with a gas mix for a good half hour, if I recall. One of those crazy endurance-depth divers, the ones who go down like two kilometres on a cable, does so. Gives you a few extra seconds per breath by increasing saturation, so if you did so immediately before hand, you might get to twenty.

[dragon]

Hum wonder about the eyeballs as the article didn't really mention them.

[Broomstick]

They might experience surface damage, but they won't blow out of your head, either.

[RedImperator]

There are speculative spacesuit designs where only the helmet is pressurized; the rest is a skintight, permeable suit that provides counterpressure against your body but isn't actually sealed. The advantage of this is the suit is much lighter and more flexible than traditional spacesuits, and cooling is provided by your own sweat. But you need the helmet. There are just too many holes in the human head for an oxygen mask to work.

[Sheridan]

Wouldn't all of the moisture on your eyes sublimate through the difference in pressure? And wouldn't that also cause your vision to go blurry, at best?

There are speculative spacesuit designs where only the helmet is pressurized; the rest is a skintight, permeable suit that provides counterpressure against your body but isn't actually sealed. The advantage of this is the suit is much lighter and more flexible than traditional spacesuits, and cooling is provided by your own sweat. But you need the helmet. There are just too many holes in the human head for an oxygen mask to work.

Yep, and it has the advantage of lowering the surface area of the suit that can be lethally punctured; instead of having to worry about the whole damned thing, you've only got the helmet that will be potentially lethal if it's cracked or punctured. Anywhere else, and you wind up with a nasty bruise and that's about it.

Of course, the suit has all of the modesty of a coat of paint...

I know it's wikipedia, but: http://en.wikipedia.org/wiki/Space_activity_suit


Edit: Need to read quoted posts, not just skim them, dammit!

[Nyrath]

In Jerry Pournelle's "Tinker", he notes the space activity suit (AKA mechanical counterpressure suit) has all the modesty of a coat of paint, so people usually wear overalls. One of the design problems of such a suit is that since the helmet is pressurized, it wants to blow off like the cork from a champagne bottle. Keeping it hermetically sealed to your neck is not trivial.

[Serafina]

In Jerry Pournelle's "Tinker", he notes the space activity suit (AKA mechanical counterpressure suit) has all the modesty of a coat of paint, so people usually wear overalls. One of the design problems of such a suit is that since the helmet is pressurized, it wants to blow off like the cork from a champagne bottle. Keeping it hermetically sealed to your neck is not trivial.

Um...where does it want to go?
There is no buoyance in space after all - so why should it "want to blow off like a cork from a champagne bottle"?

[Sheridan]

In Jerry Pournelle's "Tinker", he notes the space activity suit (AKA mechanical counterpressure suit) has all the modesty of a coat of paint, so people usually wear overalls. One of the design problems of such a suit is that since the helmet is pressurized, it wants to blow off like the cork from a champagne bottle. Keeping it hermetically sealed to your neck is not trivial.

Um...where does it want to go?
There is no buoyance in space after all - so why should it "want to blow off like a cork from a champagne bottle"?

From the pressure that the atmosphere it contains against your body. The pressure differential between the interior of the helmet and the portions not attached to your body is what causes it to go flying if not perfectly sealed.

[Broomstick]

Yep, and it has the advantage of lowering the surface area of the suit that can be lethally punctured; instead of having to worry about the whole damned thing, you've only got the helmet that will be potentially lethal if it's cracked or punctured. Anywhere else, and you wind up with a nasty bruise and that's about it.

Actually, there have been suit punctures with fully pressurized modern spacesuits (which, typically, aren't pressurized to sea level. They just pressurize them enough so that with pure oxygen to breathe you can function normally, about 3-5 lbs/inch2 in English (sorry, I learned physics before metric arrived in the US classrooms). Results of punctures: not much. Typically, such things occur on the hands while manipulating tools during maintenance/construction. Also typically, the astronauts don't seem aware of said punctures until they come in and realize they have a bruise or blood blister on their hand. The pressure differential is sufficient to break small blood vessels in the skin under the right conditions, but it's not catastrophic by any means. The skin tends to get pressed against the puncture which seals it sufficiently, apparently - a milder version of what occurred in Robert Heinlein's story "Gentlemen, Please Be Seated...."

That said, breaking a helmet could certainly kill you. While vacuum is certainly a hazard it's not like in the movies.

[FSTargetDrone]

Where did this sci-fi business about people exploding while exposed to a vacuum come from, anyway?

In nBSG's episode "A Day In The Life," two of the characters are exposed to and survive a vacuum.

Of course, I cannot find video of it. Here is the relevant text from Battlestar Wiki:
Spoiler

Teaser

* Chief Tyrol arrives in a crew head to talk through the work schedules with his deck crew. He tells Seelix to join the Tyrols at airlock 12, an airlock located on the port aft side of Galactica's "alligator head".
* The Tyrols enter the airlock; equipment and pallets are strewn about, and the observation deck has been unused for over a year. A previous Cylon attack had left this airlock unusable, and minor hull breeches here had been temporarily patched and left for a later repair.
* The Tyrols were to fix the gearing systems of the airlock's doors. As Cally tries to get Galen to discuss their marital problems, specifically Galen's desire to handle workloads as usual despite their marriage, a klaxon activates and the inner airlock doors quickly close. Seelix is confused; she didn't initiate the airlock close. She notifies the Chief of a pressure differential in the compartment; a leak has developed.
* Galen Tyrol, despite Cally's surprise, isn't fazed; he knows that the airlock closure is an automatic safety mechanism. He instructs his wife to search for the leak, knowing that the doors will open once the leak is again patched.

Act 1

* The Tyrols' patching of the breach appears to work initially, but when the pressure test is done, the new patches fail. The leak worsens greatly.

Act 2

* Admiral Adama has been alerted about the worsening airlock emergency with the Tyrols in airlock 12 and makes his way there with Colonel Tigh and their Marine escort in tow. He assesses the damage personally and later consults with his command staff in CIC. There is approximately 30 minutes of air in the lock, and the temperature is dropping considerably as frost begins to form inside the airlock.
* Major Adama notes extensive damage in the airlock that has damaged the redundancies that could manually open the door, leaving no way to open it. Tigh suggests blowing the glass in the airlock's observation deck, but Major Adama warns that the reinforced glass is designed to handle a tylium explosion, and that a detonation sufficient to blow the glass would kill the Tyrols as well. Admiral Adama is angered by the lack of options and demands more thought.
* The pilots prep for an extraordinary rescue attempt: to blow the external door, where the Tyrols, exposed to vacuum, will have to leap into Athena's Raptor. Admiral Adama briefs the Tyrols on the plan shortly after the two don emergency breathing gear.
* After retrieving the Tyrols, it will take seven seconds to close the Raptor's external door and another 10 seconds to re-pressurize the rescue vessel.
* Cally is visibly upset after hearing the plan. The Chief asks if a docking collar will be used, to which Adama states in the negative: there is not enough time. The Tyrols try to prep the area so that the evacuation of the airlock will not pummel them or their rescue ship with flying pallets or other equipment.

Act 3

* The Raptor is in position, with Athena as pilot and Apollo and Starbuck inside, ready to catch the two. Apollo warns everyone of shrapnel and other turbulence that will affect the mission.
* Galen Tyrol apologizes to his wife for being selfish in asking her to join him in the repair. The order was his way of wanting to have her companionship. He instructs her to hold tight as they prepare to leave the airlock.
* Admiral Adama orders the door blown. The Tyrols are flung from the airlock and the Raptor manages to fend off debris from the door, catch the entwined Tyrols, then re-pressurize. Apollo notes the Tyrols are in rough shape but alive.

Act 4

* Seelix arrives in sickbay with baby Tyrol in her arms after retrieving him from day care. Galen Tyrol is in a bunk, resting, but exerts himself to stand and hold his son. He tells Seelix that Cally will be fine, although Dr. Cottle notes it will be some time before she is up to full strength. He slowly walks to Cally, who is recuperating inside a hyperbaric chamber to treat the effects of vacuum exposure.
* Cally Tyrol awakens to glimpse at her family. Her eyes show distress from the vacuum and she is too weak to smile, but holds her hand to the interior window. Galen presses his son's hand to the glass; Admiral Adama is nearby and has watched the entire event.

Actually, there have been suit punctures with fully pressurized modern spacesuits (which, typically, aren't pressurized to sea level. They just pressurize them enough so that with pure oxygen to breathe you can function normally, about 3-5 lbs/inch2 in English (sorry, I learned physics before metric arrived in the US classrooms). Results of punctures: not much. Typically, such things occur on the hands while manipulating tools during maintenance/construction. Also typically, the astronauts don't seem aware of said punctures until they come in and realize they have a bruise or blood blister on their hand. The pressure differential is sufficient to break small blood vessels in the skin under the right conditions, but it's not catastrophic by any means. The skin tends to get pressed against the puncture which seals it sufficiently, apparently - a milder version of what occurred in Robert Heinlein's story "Gentlemen, Please Be Seated...."

That said, breaking a helmet could certainly kill you. While vacuum is certainly a hazard it's not like in the movies.

In 2007, during a space walk, one of the astronauts found he had a torn glove:

Spacewalk shortened by astronaut's cut glove
Irene Klotz
HOUSTON
Wed Aug 15, 2007 4:59pm EDT

HOUSTON (Reuters) - A spacewalking astronaut was forced to cut short his work and return to the International Space Station on Wednesday when he found a small hole in his spacesuit glove, NASA said.

Science

Three-time spacewalker Rick Mastracchio was not in any danger but was ordered back to the station's airlock two hours early as a precaution, said mission commentator Kyle Herring. He returned to the station without incident.

"The suit is perfectly fine," Herring said. "There are many layers to the suit as a precaution."

Mastracchio and his partner, Clay Anderson, had completed the major tasks of their spacewalk, which was the third since Endeavour's arrival at the station last Friday. The outing was to prepare the complex for its first new module in six years.

Anderson stayed outside to finish up his work. NASA decided to leave two experiments that the astronauts had planned to retrieve outside the station and reschedule the job.

Mastracchio went back inside at 1:54 p.m. CDT (1854 GMT), after 4 hours and 17 minutes outside. Anderson returned at 3:05 p.m. CDT (1905 GMT), after 5 hours and 20 minutes outside. The spacewalk had been planned for about 6-1/2 hours.

"The gloves were good. I don't know where this hole came from," Mastracchio radioed to Mission Control in Houston.

NASA said the risk is that pressurized air could leak out of the suit, killing the astronaut, although the suits are equipped to maintain pressure for about 30 minutes for holes up to a quarter-inch.

NASA found a damaged glove after a spacewalk in December and implemented safety checks every 30 minutes during future outings to look for damage. The hole in Mastracchio's left glove was found during a routine check.

"It sure got quiet all of a sudden," said Anderson, who had been bantering with his partner for most of the outing.

"Want me to sing?" offered astronaut Tracy Caldwell, who was overseeing the spacewalk from Endeavour's flight deck.

[Uraniun235]

There are speculative spacesuit designs where only the helmet is pressurized; the rest is a skintight, permeable suit that provides counterpressure against your body but isn't actually sealed. The advantage of this is the suit is much lighter and more flexible than traditional spacesuits, and cooling is provided by your own sweat. But you need the helmet. There are just too many holes in the human head for an oxygen mask to work.

Would that sweat-cooling be sufficient in direct sunlight?

[Zixinus]

No. That would just result in rupturing your eardrums when the air tries to escape through your Eustachian tubes.

And what if the ears are sealed? Not just by earplugs, but by some sort of glue/paste (which might be a bitch to get out once you're safe, but that's a small price to pay to losing your eardrums altogether)?

[GrandMasterTerwynn]

No. That would just result in rupturing your eardrums when the air tries to escape through your Eustachian tubes.

And what if the ears are sealed? Not just by earplugs, but by some sort of glue/paste (which might be a bitch to get out once you're safe, but that's a small price to pay to losing your eardrums altogether)?

Then you have the problem of hermetically sealing the mask (which must be pressurized to the minimum 3 to 5 PSI required for breathing pure oxygen.) And, depending on the configuration of the mask, you'd also have air leaking out of the ducts that drain your tears into your nasal cavity. The problems involved in sealing that mask are much greater than the problem of making a good neck seal.