The short answer is the astronauts and cosmonauts (that means a Russian astronaut) bring oxygen from Earth, and they make oxygen by running electricity through water. This is called electrolysis.
The air and water on the Space Station all originally came from Earth. Astronauts and cosmonauts transport these vital supplies to the Space Station when they travel there on Soyuz capsules (a type of spacecraft). Astronauts and cosmonauts also receive supplies from uncrewed spaceships, such as the Russian Progress and American Dragon. Uncrewed means with no people on board.
Water is also used onboard the ISS to produce oxygen. ‘We electrolyse water to split it open to hydrogen and oxygen,’ says Laura. ‘The oxygen goes into the atmosphere for the crew to breathe.’ The hydrogen is then combined with another waste product – carbon dioxide breathed out by the crew – to make methane and water. This is known as the Sabatier reaction. ‘The water gets reused and the methane is currently vented overboard,’ says Laura.
The NASA team is also developing a way to crack open the methane to produce more hydrogen. ‘If we had more hydrogen we could be more efficient on that Sabatier process and produce more water, which we can then turn into more oxygen. So we’d have to resupply less water for that process,’ she explains.
Credit : RSC Education
Picture Credit : Google
