In space, the human body changes gradually, but hair will still grow normally, so astronauts have to cut their hair regularly. Our astronauts will have to eat ready-to-eat food during their time in space. In terms of bathing, modern spacecraft use moistened sponges for astronauts to clean their bodies instead of spraying water into a faucet. Resting on the space station is generally the same as on the face. With an average of 8 hours of sleep per day, astronauts will have to sleep in sleeping bags to ensure they do not float and collide.