How much work is done on a satelite in circular orbit about earth?

In a circular orbit, a satellite is in free fall and moves with a constant speed, which means that the gravitational force acting on it provides the necessary centripetal force for its circular motion. Since the gravitational force is always perpendicular to the satellite's displacement, the work done on the satellite by gravity is zero. Therefore, no net work is done on a satellite in a stable circular orbit around the Earth.