Computers monitor these changes to ensure they are done accurately. Much of the equipment on a space vehicle is turned off or tied down during launch. Once in space, the astronauts must set up and turn on the equipment. At the end of the mission, they must secure it for landing. Conducting scientific observations and research.
Astronauts use special instruments to observe the earth, the stars, and the sun.
They also experiment with the effects of microgravity on various materials, plants, animals, and themselves. As a spacecraft approaches a target, such as a space station or an artificial satellite, radar helps the crew members control the craft's course and speed. Such a meeting in space is called a rendezvous . A space shuttle can also use its robot arm to make contact with targets. Maintaining and repairing equipment.