The force of gravity does work on a satelite when it is in?

The force of gravity does work on a satellite when it is in a non-circular orbit, such as an elliptical orbit. In this case, as the satellite moves closer to the Earth, gravity does positive work, increasing its speed, and as it moves farther away, gravity does negative work, decreasing its speed. However, in a perfectly circular orbit, the gravitational force acts perpendicular to the satellite's motion, resulting in no net work being done, and the satellite maintains a constant speed.