Astronauts need oxygen wherever they are, so the most reliable source of oxygen is bound to come from the space station itself. In the middle school chemistry class, I believe we all remember the teacher's electrolysis experiment, which can decompose liquid water into hydrogen and oxygen through the input of electrical energy.
In the case of complete electrolysis, 1 liter of water can produce about 620 liters of oxygen, and an astronaut's 24-hour oxygen demand is only about 550 liters, that is, only a small amount of water is required by electrolysis, which can support an astronaut's breathing needs for 1 day. Therefore, the problem of the source of oxygen on the space station can be converted into two problems: the source of water and the source of electricity.
Of course they do. They die without oxygen.
There's oxygen. But in weightlessness.
There must be oxygen. How can we live without it?
Spaceships have oxygen reserves. As for spacesuits, there are in-cabin spacesuits and extra-cabin spacesuits. Extra-cabin spacesuits can provide oxygen and maintain pressure, temperature, etc. The clothes in the cabin are not much different from ordinary clothes
The astronauts have oxygen in the cabin. The environment inside is designed to mimic the environment on Earth.
Early spacecraft were even filled with pure oxygen, which cost them their lives. Later, it was changed to a mixture of gas, of course, the oxygen content will be higher than air.
There must be oxygen! How else can astronauts survive?
Yes, I have! Astronauts rely on oxygen generators to supply oxygen inside the capsule