What would happen to your unprotected body in outer space?

So, wouldn't being suddenly transported into space be very similar to getting the bends (bends being from rising from the ocean's depths too fast when scuba diving)?

General Tsao

That would happen. But so would a bunch of other stuff, and who knows what would happen first?

All I know is it sounds like something really disgusting would happen, and you wouldn't last long. Perfect for this idiot I have in mind.

It might make for a stupendous fart.

But no one would hear it.

Don't overload James Bond with too many facts, now. Cabin pressure in commercial airliners is always maintained below 10,000' sea level, but not a heck of a lot below. Spaceships, such as they are, are at an even lower pressure, so the instant, blood boiling explosion isn't that likely. Of course, Kicky's specifing instantaneous transport outside.

At 10000', the pressure is still about 530 mmHg...

The question implies an instant pressure change. At some pounds stray dogs that have not been adopted are killed by sudden pressure change. The room is pressurized to 2 or 3 atmospheres, and dumped abruptly back to one atmosphere.
A one atmosphere change might not always be fatal, but severe swelling and some bleeding would be all but certain.
If the pressure drops slowly the human body can adjust to some extent, but it would not be possible to inhale as the pressure approached zero. The person might survive if repressurized before death from lack of oxygen. Exposed surfaces would suffer frost bite in a few minutes in the shade, but the core body would take perhaps an hour to freeze as heat by convection and conduction does not occur in vacuum. Radiation only. Neil

Found this answer at http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/970603.html

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.



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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.



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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 a High-Energy Astronomer Team

The answer Brandon posted is the same one I've heard before, so I think it's correct.

I would also add that from my flight training experience, I've heard from pilots who have experienced explosive depressurization at high altitudes, and they say the experience is very painful. You do not necessarily lose consciousness immediately, but you may wish you did. Depending on the altitude, pilots who run into an explosive depressurization event usually have about 15 seconds to find an alternate oxygen source, or they lose consciousness and pass out (resulting in a crash). This is apparently what happened to golfer Payne Stewart a couple of years ago ( http://sportsillustrated.cnn.com/golf/pga/news/1999/10/25/stewart_plane_ap/ )

This is incorrect.
Heat transfer by conduction does indeed occur.
It is only convection that is prevented because there is no gravity gradient..
Radiative heat transfer continues normally.

If you were to go into space unprotected, your head would become mishaped, like Rocky Dennis from the movie "Mask." It's a fact.

How does the body lose heat by conduction if there is nothing for it to conduct to? Not refuting, just curious.

Huh.

If you are floating in space, there is no chance for conduction, because there is nothing to conduct the heat to. There might be a little convection if water boils off of your body, or you lose other fluids. Clearly, though, the primary form of heat gain/loss would be by electromagnetic radiation.

OK.
Lets' take a trip into space.
You hold one end of this steel bar and I'll heat the other with a space worthy blowtorch.

How's the hand ?

Duh !

No one is saying that conduction, as a phenomenon, doesn't work in space.

If the body is merely floating free in space, as the first post stated, it will not lose heat to conduction, because it is not on contact with anything. If, contrary to the statement of the problem, the body is touching something, and that object is at also a lower temperature than the body, the body may lose some heat to it by conduction, but that object will only delay the inevitable by one step and lose its own heat by radiation.

Next !

As you, yourself, pointed out, conduction, as a phenomenon, works in space if there is something like your hypothetical steel bar to conduct to. The only point I have been making is that the setup of the problem specifies that there is nothing to conduct the body's heat to. For that reason, as I said some posts back, the body will lose most of its heat by radiation.

Sorry, not sure how the absence of a gravity gradient would prevent convection. Sounds incorrect.

True.