Question

Why satellites, which are revolving around the earth, do not fall into the earth?

Answer 1

The short answer is, to orbit the planet and not come crashing down, a spacecraft has to travel forward (tangential to Earth) fast enough that it compensates for the fall downwards.

Newton used the idea of a cannon to illustrate this. Fired at a slow speed the cannonball quickly fell to Earth. Fired at a faster speed it went further. Each path could be drawn as a curve. Since the Earth is round and curves down, in front of us - there must, he reasoned, be a forward velocity that, when combined with gravity, would produce a curve that matched the curvature of the Earth and would, thus, never fall to the ground.


So, the satellite is falling towards the Earth but just keeps missing the Earth.