At what point can an astronaut take off their helmet and why do they need to wear one for take off? (Asked by an actual 5 year old)
In: Physics
The suits worn for launch are called “flight suits” and are distinct from the suits used for spacewalks *(which are almost closer to suit-shaped vehicles)*.
The flight suits ~~are not sealed/have no life-support systems~~ are sealed/probably have limited life-support systems and can be though of as something like what a test pilot or race car driver wears specifically to minimize/prevent injury during a crash or otherwise violent incident and those helmets are pretty much exclusively to protect their heads/faces from *impact* trauma… *edit:* AND I don’t know if the limited life-support is tied into the vessel or entirely self contained or how long it can function but the “flight suits” of previous programs have traditionally been thought of as “get me down” suits for whatever that tells us about…
[This is the new “spacewalk-suit”.](https://www.wired.com/story/no-more-spacewalk-snafus-nasas-new-space-suit-fits-everyone/) *(note all the hardpoints/metal swively-bits/the fact you basically open the back and “climb in”…)*
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On Earth a human can wear a simple helmet/facemask to overcome an environment with no breathable air but in outer space we need to re-create that protective layer of atmospheric over the *ENTIRE BODY*.
It’s not just that there’s no air in space… When people talk about the *VACUUM* of space that basically means that not only is there no air up there but space is *actively* trying to remove air from anything that has it…
If you’ve ever sucked the air out of a bottle/glass and felt it stick to your lips or mouth you then imagine a force hundreds of times stronger acting *everywhere all at once* and you get an idea of how much more dangerous outer space is for human.
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…and this one just ate at my little noodle for years and I wished someone had explained better when I was little but when people talk about a vacuum or low-pressure environment causing your blood or spit to “boil” it makes a more sense if you think of how the entire atmosphere is a fluid that goes from a very sparse/loose level of compression near the edge of space to a very high level of compression deep below the surface.
We live near sea level at a medium level of atmospheric compression and to transport us to the edge of space is to transport a fleshy pressure vessel to a low-pressure environment.
Boiling is a physical process of releasing pressure from a fluid and we know it takes heat energy to do it down here at sea level and then we know it takes a little less heat energy to boil water at a higher altitude *(food packaging will direct you to boil for longer at a higher elevation because it simply can’t get as hot so it takes longer to achieve the same cooking results)*.
I finally just imagined taking that pot of water all the way up to the edge of space and how without applying any energy at all it would start to froth and “boil” away to vapor as it simply became easier for the fluid to naturally flow from an area of high pressure to an area of low pressure as the area of low pressure became *everywhere*.
“Boiling blood” just sounded like science I couldn’t understand rather than common sense until I imagined that soaring pot of water…
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