How do astronauts train in zero gravity?

1, you can do zero-gravity simulation training underwater. It is difficult to get dressed underwater. Of course, you can't breathe underwater. If you breathe, you will die. If water is sucked into the lung cavity, you will suffocate and you can't breathe at all.

2, very dangerous training, the plane flies to a certain height, that is, rises, rises, and suddenly turns off the engine. Due to the gravity of the earth, the plane will fall to the ground. When flying and turning off the engine, the rising power is gone, only the falling gravity, and the feeling of people in the cabin is the so-called "zero gravity". The zero gravity state lasts for a very short time, only a few seconds. In those few seconds, people felt