1.Previous
3.Next

that astronauts in orbit are weightless because they have flown high enough to escape the Earth's gravity. In fact, at an altitude of 400 km, equivalent to a typical orbit of the ISS, gravity is still nearly 90% as strong as at the Earth's surface. Weightlessness actually occurs because orbiting objects are in free-fall.

Depth

An approximate value for gravity at a distance from the center of the Earth can be obtained by assuming that the

1.Previous
3.Next