We know that astronauts and cosmonauts travel to space in spacecraft and require a spacesuit when they venture out of the spacecraft. An astronaut’s spacesuit creates a pressurised, oxygenated atmosphere to help the astronaut breathe. It also protects the astronaut from ultraviolet rays and extreme temperatures in space. But what would happen to an astronaut if she were to be lost in space without a spacesuit?
Time in hand – not much
The astronaut will not die immediately on being exposed in space. She will have close to 15 seconds before she loses consciousness and another two to three minutes before death comes knocking. Before the two minute mark if she is pulled in by someone from the spacecraft, she does have chances of survival but her body would have gone through quite a bit.
The top cause
Not zero pressure – It is assumed that one would explode in space without a spacesuit due to zero pressure. However, this is not true. The skin is gas-tight and is strong enough to withstand any kind of pressure. Not inflation – While the body won’t explode, it can still inflate due to nitrogen bubbles that would have dissolved in the bloodstream near the surface of the skin, and collected itself into little bubbles. These little bubbles will start expanding, puffing up the body, starting at the hands and feet and moving in. This is called ebullism. Ebullism can cause significant tissue damage, but it won’t be the cause of death.
Not the cold – Space is really, really cold. But it will still not lead to hypothermia instantly. This is because, in a vacuum, the only way to lose heat is by radiation or by evaporation of fluid. And the human body loses heat by radiation very slowly as it is a relatively cool object. The body will eventually freeze if it is in space for too long, but there is something else that would lead to death before any of the points mentioned above. That is asphyxiation.
Yes, asphyxiation – There is no air in space, and our blood holds enough oxygen to last about 15 seconds. Post this, the brain shuts down and the astronaut will lose consciousness. If she is not pulled back in within a minute or two, all the other organs in the body will eventually shut down due to the lack of oxygen, leading to death.
Interesting fact:
Holding the breath while being exposed to the vacuum in space will cause the air in the lungs to rupture the lung tissue as it expands into the chest cavity, forcing air bubbles into the bloodstream. This can prove to be fatal even if the astronaut is rescued.
So, it important for an astronaut to not hold her breath is space.
Picture Credit : Google
