Gravitation Reasonings

If an earth satellite moves to a lower orbit there is some dissipation of energy, and yet its speed increases. Explain.

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.