free fall

The state in which a body is falling freely under the influence of gravity, as in freefall parachuting (skydiving). In a vacuum, a freely falling body accelerates at a rate of 9.806 m sec⁻²/32.174 ft sec⁻²; the value varies slightly at different latitudes and altitudes. A body falling through air accelerates until it reaches a maximum speed called the terminal velocity; thereafter, there is no further acceleration.

In orbit, astronauts and spacecraft are still held by gravity and are in fact falling freely toward the Earth. Because of their speed (orbital velocity), the amount they fall towards the Earth just equals the amount the Earth's surface curves away; in effect they remain at the same height, apparently weightless.