What does the term 'perigee' refer to in satellite orbits?

The term 'perigee' refers specifically to the closest point in an elliptical orbit of a satellite around the Earth. This is significant in orbital mechanics because it defines the position where the gravitational pull on the satellite is at its strongest, leading to the highest orbital speed due to the conservation of angular momentum. Understanding perigee is crucial for satellite operators and engineers, as it affects communication, imaging, and other satellite functions.

In contrast, the highest point in an orbit is known as 'apogee,' while the point where a satellite is furthest from Earth also relates to apogee. The entry point into the Earth's atmosphere does not relate to the concept of perigee at all, as that involves different dynamics entirely, such as orbital decay and atmospheric re-entry protocols.