 Dr. Jonathan McDowell is an astronomer and astrophysicist at the Center for Astrophysics at Harvard and the Smithsonian. There are several thousand satellites that are still orbiting the Earth that are dead. When a satellite dies, it doesn't just fall out of the sky. It's still got orbital velocity, just like the moon. It doesn't need an engine to stay up, right? And so there's plenty of dead satellites up there.