Question

A satellite does not need any fuel to orbit the earth why?

Answer 1

Once the satellite has acquired orbital velocity and is firmly in orbit around the Earth it does not require any energy of its own to move. This is because its being constantly acted upon by the gravitational force of the Earth which tries to pull it downwards but due to Earth's curvature it does not fall. So, in effect, its the Earth that's making it move in a circular orbit.