Is it possible to Decompress to 0bar (Space, Vacuum)

[Duke Dive Medicine]

I'm not doubt you, but I find it odd that they would design for that much pressure. 21% is as safe as air on earth in regards to a fire and human survival. But they could have saved a lot and get the same results by running a lower pressure. .8 or .9 ATA. But that gets into spacecraft design. I don't have the meeting notes on why 1 ATA was chosen.

I did see the James Webb telescope a few months before it was shipped off and flung into space. But that one isn't trying to keep anyone alive.

I will defer to the engineers on that one. I only know this because Duke helped develop the O2 pre-breathe protocol.

Best regards,
DDM

 

[inquis]

ISS is pressurized to 1 ATA and runs 21% O2.

Thanks for the correction on the ISS, a poor example on my part. Looking further, the various space shuttles were similarly configured (1 atm/21%). The shuttle EVA suits, on the other hand, used 100% O2 at about 0.3 atm (perhaps most applicable to the OP's question).

 

[Mobulai]

I'm not doubt you, but I find it odd that they would design for that much pressure. 21% is as safe as air on earth in regards to a fire and human survival. But they could have saved a lot and get the same results by running a lower pressure. .8 or .9 ATA. But that gets into spacecraft design. I don't have the meeting notes on why 1 ATA was chosen.

I did see the James Webb telescope a few months before it was shipped off and flung into space. But that one isn't trying to keep anyone alive.

I have. as tiny guess as for why -- but not an engineering oriented one (not affiliated with Space kinda tech); they run a lot of bio experiments up there on the effects of near-weightlessness on plants and animals (humans); and probably you'd wanna control the other variables

Another guess is; if you run at lower pressure you'd need higher O2% to match the ppo2; riskier for fire (think Cristolube), need better maintnance for air pathways, maybe alos long term exposure has CNS impact? (I didn't think this one through so I could be completely off with my logic)

I hope someone out there can clarify (I also wanna know)

 

[evandroairton]

Some interesting finds on the space deco protocol would be find if you search for the apollo-soyuz 1975 mission, and the intermediate deco Chamber between Soyuz (1 ATA air) and Apollo (0.3 ATA O2)