A satellite of mass \(m\) moves in an elliptical orbit around a stationary planet. At perigee (closest approach), the satellite is at a distance \(r_P\) from the center of the planet and has speed \(v_P\). At apogee (farthest approach), the satellite is at a distance \(r_A\) from the center of the planet and has speed \(v_A\). Which of the following expressions represents the net work done on the satellite by the gravitational force as it moves from perigee to apogee?