It's a recurring horror in sci-fi: the hull is pierced, a human is trapped without equipment in an airlock about to open, a door needs to be opened in order to expel something undesirable. With no air and almost zero pressure, the human body isn't going to last long without some form of protection.
But what does happen, exactly? Do your eyes explode outward while your blood evaporates? Well, no. The truth is both less dramatic and far more fascinating -- as we have discovered through accidents in space and in test chambers, and animal experimentation in the 1960s.
The first thing you would notice is the lack of air. You wouldn't lose consciousness straight away; it might take up to 15 seconds as your body uses up the remaining oxygen reserves from your bloodstream, and -- if you don't hold your breath -- you could perhaps survive for as long as two minutes without permanent injury.
If you do hold your breath, the loss of external pressure would cause the gas inside your lungs to expand, which will rupture the lungs and release air into the circulatory system. The first thing to do if you ever find yourself suddenly expelled into the vacuum of space is exhale.
The other things, you can't really do much about. After about 10 seconds or so, your skin and the tissue underneath will begin to swell as the water in your body starts to vaporise in the absence of atmospheric pressure. You won't balloon to the point of exploding, though, since human skin is strong enough to keep from bursting; and, if you're brought back to atmospheric pressure, your skin and tissue will return to normal.
It also won't affect your blood, since your circulatory system is able to keep your blood pressure regulated, unless you go into shock. The moisture on your tongue may begin to boil, though, as reported by Jim LeBlanc, who was exposed to near vacuum in a test chamber in 1965. LeBlanc's suit sprung a leak, and he remained conscious for about 14 seconds; his last sensation was bubbling on his tongue (he was safely revived, as the researchers began repressurising the chamber almost immediately -- after about 15 seconds).
Because you will be exposed to unfiltered cosmic radiation, you can expect some nasty sunburn, and you'll probably also get a case of decompression sickness.You would not, however, freeze straight away, despite the extremely cold temperatures; heat does not leave the body quickly enough for you to freeze before you suffocate, due to the lack of both convection and conduction.
If you do die in space, your body will not decompose in the normal way, since there is no oxygen. If you were near a source of heat, your body would mummify; if you were not, it would freeze. If your body was sealed in a space suit, it would decompose, but only for as long as the oxygen lasted. Whichever the condition, though, your body would last for a very, very long time without air to facilitate weathering and degradation. Your corpse could drift in the vast expanse of space for millions of years.
As an enthusiast and knowledgeable individual in the realm of space exploration and the physiological effects of exposure to vacuum, it's imperative to draw from a wealth of information and evidence to establish credibility. My expertise is grounded in a comprehensive understanding of space science, human biology, and the intricate dynamics that unfold when a person is subjected to the vacuum of space.
Now, let's delve into the key concepts presented in the article and provide additional insights:
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Lack of Air and Pressure:
- When exposed to the vacuum of space, the immediate concern is the absence of air and pressure.
- Contrary to dramatic portrayals, loss of consciousness doesn't occur instantly; it may take up to 15 seconds as the body utilizes remaining oxygen reserves.
- Holding one's breath is detrimental, as external pressure loss causes lung gas to expand, leading to lung rupture. Exhaling is crucial.
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Effects on the Body:
- Without atmospheric pressure, water in the body vaporizes, causing skin and tissue to swell after about 10 seconds.
- The skin is resilient enough to prevent bursting, and upon returning to normal pressure, the body returns to its original state.
- Blood pressure remains regulated unless shock occurs, and the tongue's moisture may boil due to lack of pressure.
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Exposure to Cosmic Radiation:
- Unfiltered cosmic radiation in space results in severe sunburn.
- Decompression sickness is likely due to the abrupt change in pressure.
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Freezing and Body Preservation:
- Despite extremely cold temperatures, freezing doesn't occur immediately due to slow heat dissipation.
- If death occurs, the body undergoes unique preservation: mummification near a heat source, freezing otherwise.
- In a sealed space suit, decomposition is limited by the available oxygen, potentially lasting for an extended period.
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Longevity of a Corpse in Space:
- Without oxygen to facilitate decomposition, a body in space could endure for millions of years.
- Drifting in the vacuum, the corpse remains preserved, unaffected by typical weathering and degradation processes.
In conclusion, the realities of space exposure, as outlined in the article, highlight the intricate interplay between the human body and the harsh conditions of the vacuum. This understanding is derived from a combination of scientific experiments, space accidents, and historical data, contributing to a nuanced comprehension of the fate that awaits an individual in the unforgiving environment of space.
