4 ms·
IIRC they continued to use 100% oxygen in space. O2 N2 mix on the ground at above sea-level pressure, replaced with 100% at low pressure in space (5PSI). Thereb
by 0_____0 5y ago
IIRC they continued to use 100% oxygen in space. O2 N2 mix on the ground at above sea-level pressure, replaced with 100% at low pressure in space (5PSI). Thereby mitigating the need for N2 tanks and associated equipment, and also mitigating the fire risk on the ground when above ambient pressures were required in the spacecraft.
After Apollo they moved away from 100% O2, I think the ISS has a similar composition and pressure to terrestrial atmosphere.
- kirrent 5y agoThe EVA suits continue to operate on only oxygen though, which makes sense given that internal suit pressure is a major challenge for manoeuvrability as was famously demonstrated by Alexei Leonov during the first spacewalk. This does mean that astronauts spacewalking from the ISS need to prebreath pure O2 to purge nitrogen for preventing the bends, a detail that was captured in the Netflix SciFi film Stowaway.
- Raidion 5y agoCan you elaborate on why the internal pressure is an issue? Is the resisting force something like trying to flex a balloon animal x 1000?
- grogenaut 5y agohttps://www.youtube.com/watch?v=0FKxM-zNZBk https://www.youtube.com/watch?v=0FKxM-zNZBk adam savage talks a lot about it during this video, but yes, bending a baloon is a good example. A better one might be a fully inflated inner tube or filled camelback.