A machine that creates centrifugal force by spinning around a centre. NASA uses one, located at Brooks Air Force Base, Texas, to simulate g-forces encountered by astronauts during a launch. The US Air Force uses it to train pilots, and has trained more than 100 astronauts since 1991. The ‘g qualification ride’ involves two nine-minute sessions in the centrifuge, which reaches a threshold of 3 g; that is, a gravitational force three times a person's own body weight.
The International Space Station will also have a centrifuge accommodation module to simulate Earth's gravity for comparative studies, and it will be able to simulate the gravity of the Moon and Mars for future space missions.