Due to atmospheric resistance, a satellite orbiting around the earth loses kinetic energy. Therefore in a particular orbit, the gravitational attraction on the satellite becomes greater than the centripetal force required to keep the satellite in that orbit. As a result, the satellite moves down to the earth into a lower orbit. In the lower orbit, the gravitational potential energy decreases. So, K.E. correspondingly increases. That is why, the satellite describes a smaller orbit with increased speed. In fact, due to atmospheric friction, the satellite spirals down towards the earth with increasing speed and ultimately burns out in the lower dense atmosphere.
Home Gravitation Reasonings If an earth satellite moves to a lower orbit there is some dissipation of energy, and yet its speed increases. Explain.