How Long Could You Survive in Space?

04 May

A recent New Scientist article discussed this issue. It reminded me of a question I received from a writer and included in my book Forensic & Fiction: Clever, Intriguing, and Downright Odd Questions From Crime Writers. Here is the question:

Q:    What sort of damage does the human body suffer in the vacuum of space? How long can one survive and what will happen to the person who does survive? (My scenario involves an astronaut whose faceplate blows out, but not before he depressurizes his suit sufficiently to prevent immediate death — if that’s even a threat.)

A;    First of all the victim would not explode as in the movie 2010. But some really bad things do happen internally and they happen very quickly. Whether he depressurizes somewhat beforehand or not, his survival would likely be measured in seconds.

Space decompression is similar to that of a scuba diver that rises too rapidly after a prolonged exposure to the pressures of the deep. In this case he is going from excess pressure to normal pressure. In space the victim goes from normal pressure to zero pressure. Same thing physiologically.



In 1965 at NASA’s Manned Spacecraft Center near Houston, TX, a trainee suffered a sudden leak in his spacesuit while in a vacuum chamber. He lost consciousness in 14 seconds, but revived after a few seconds as the chamber was immediately re-pressurized. He suffered no ill effects—due to his very brief exposure—but stated that he could feel water boiling on his tongue. I should point out that in chemical and physical terms boiling simply means the changing of a liquid to a gas. This can be accomplished by adding heat or by lowering the ambient pressure. So in this case it wasn’t that his tongue became hot or anything like that but rather that the pressure was so low the water in his mouth changed to its gaseous phase.



Water in his blood stream would immediately begin to “boil.” That is, it would turn to its gaseous state. This is similar to popping the top on a soft drink. With the release of the pressure the carbon dioxide dissolved in the drink immediately begins to turn to its gas form. Same thing happens in the blood at zero pressure. This causes pressure to build in the blood system and the heart stops. Bubbles may appear in the blood stream and these can cause damage to the body’s organs, particularly the brain. As a result, the brain and nerves cease to function. This increased pressure also causes the tissues of the body to swell but they will not explode.


But what if the exposure is brief and the person is rescued? Treatment would be to immediately return him to a pressurized environment and give him 100% oxygen. He may survive unharmed or may have brain and nerve damage which could be permanent.

For your scenario, the victim’s faceplate would rupture and he would begin to exhale air. He would lose consciousness in 10 to 20 seconds and would then die in short order. If he were quickly rescued, he would be returned to the spacecraft, which would be pressurized, and he would be given 100% oxygen via a face mask. He could survive intact or with brain damage. It’s your call. Either way works.



3 responses to “How Long Could You Survive in Space?

  1. Gayle Carline

    May 4, 2010 at 10:04 am

    So… that scene in Total Recall, where Arnold has been spit out on the planet’s surface and his face starts shrinking and his eyes are bugging out… is that why they call it science FICTION?


  2. Norm

    May 4, 2010 at 10:19 am

    Ick. Way too cool, Doug. Thanks.


  3. Digital Dame

    May 4, 2010 at 12:34 pm

    Another example of what doesn’t happen was in that insipid “Mission to Mars” movie, where Tim Robbins’ character removes his helmet as they float above the planet. According to Phil Plait’s Bad Astronomy page, he wouldn’t be instantly freeze-dried, and have his face be all cracked and gross. 😉



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