INTRODUCTION

All satellite are held in balance between the inertia due to their motion and the centripetal force of the gravity. This is called orbital satellites.

There are several different types of satellite orbits for space systems in orbit around the Earth. The types vary in altitude, real or apparent path with respect to the earth, and duration of each orbit. Altitude further divides into the lowest perigee and highest apogee in the orbit.

A low perigee is valuable for missions in which sensors need to be close to the earth, or where low-power communications are being sent to the satellite. Satellites rotate around the Earth in an elliptical pattern or circular pattern. In circular pattern, apogee equal to perigee or rotation is constant. But in the elliptical pattern, apogee not equal to perigee and the speed depends on the height of the satellite to Earth. When it close to Earth, the speed is greater than it is farther away.