Sign up ×  How do they provide air on the ISS? I know it is
produced by electrolysis but is that all they breathe, hydrogen
and oxygen? The air here on Earth contains other things like
nitrogen. Do the people on the ISS not need nitrogen? Or do they
take what is needed on each launch? If so how much water do they
take and how long does a certain amount of water last when used
for air? Seems like a whole lot of weight. Now they are planning
a yearlong trip. How much water will they have to launch with?
share|cite|improve this question  3 Answers 3  The ISS is using
electrolysis, in the "Elektron" oxygen generator,  to separate
water to hydrogen and oxygen. NASA claims that those devices
don't work well and prefers bottled oxygen delivered from Earth
which the Russians only consider a backup option. Another backup
option are solid fuel oxygen generator canisters "Vika"
producing oxygen from a liter of lithium perchlorate.  The
atmosphere at the ISS has 101,300 Pa, just like on Earth, and
contains all the right