They need air and an atmospheric pressurized environment.
They have to check up that the instruments are all in working order.
Project Gemini and Project Apollo had astronauts practice piloting and working in space.
space station
A space station
Astronauts were able to conduct experiments when working in the space station. One of the space stations that was launched was the Skylab in 1973.
effects and accommodations
i hate your mom
Having neutral buoyancy underwater simulates the weightlessness the astronauts will experience in space.
If the space station is pressurized, I don't think astronauts need to where space suits.
Ensure all systems are working correctly.
NASSS
Astronauts use instruments that are designed to travel in space and withstand extreme temperatures. Some of these kinds of instruments include a pistol grip tool, a robot crane, safety tethers, and a trace gas analyzer.