Life Support and
Survival Systems for Astronauts
support and survival systems are essential to space
exploration. The human body absolutely cannot live more
than a few minutes unprotected in space. Once a body is
exposed to an empty vacuum and decompresses, several
phenomenon occur. First, the water in the exposed
subject begins to boil and vaporize. This causes many
problems. The vaporization of water occurs because
liquid boils at lower temperatures at lower pressures
and at higher temperatures at higher temperatures. An
explanation for the drop in pressure is Boyle's gas law
– volume and pressure are inversely proportional. When
an astronaut's suit or vessel hull is punctured, gas
flows outward to equalize with limitless space. Pressure
drops to absolute zero if the hole is not closed off
very quickly. As water in the body continues to vaporize
it expands very quickly. This causes the body to enlarge
and bloat. Yet, the body does not explode as film makers
and science fiction writers would like to you to
believe. This rapid expansion of gas causes several
unfortunate events. The increase in arterial pressure
stops the flow of oxygenated blood to the brain
effectively causing unconsciousness in under half a
minute. Rapid water and gas expansion in the lungs can
cause instant bursting. In the off chance you are ever
sucked out into space – do not try to hold your breath.
This could prevent your lungs from exploding instantly.
The lack of pressure causes liquids to boil off into
vapor. Survivors of decompression report feeling the
moisture on their tongue and lining of the mouth
boiling. The lack of external and internal pressure
causes involuntary urination, vomit, and defecation.
Fortunately, victims of rapid decompression can recover
fully if they are pressurized within a matter of
minutes. Rapid decompression is very similar to drowning
in that the time needed for rescue and the main dangers
consisting of a lack of oxygen to the brain and stress
to heart are very similar. If a victim can be
re-pressurized quickly, they will most likely be able to
recover in a few days.
Besides the threat of rapid decompression, the human in
space must also face ultraviolet radiation, varying
frequencies of radiation, microwaves, and extreme cold.
Space on average is approximately -455 degrees
Fahrenheit. However, if a human is exposed to space,
rapid decompression will kill them before the cold will.
Even if the human body is pressurized and protected from
these elements, it will not live long without the basic
necessities of food, water, shelter, and warmth. Because
of these unique and challenging conditions, engineers
and scientists around the world have developed life
support and survival systems essential to preserving
life in space. Over the years they have continued to
became smaller, more efficient, and more dependable.
Space exploration is relatively young and has come a
long way in forty years. It will continue to advance
with proper support, research, and funding. Living and
surviving in space will become less and less of a
challenge with innovative technology.
Copyright Devonshire Schools Space Project 2009