The first post in my series on basic orbital mechanics. This is a topic that anyone involved in the space industry or even a space enthusiast should have some knowledge of. Knowledge of the technical terms will help anyone be more credible in their communication and be able to better understand technical sources.
This picture shows 2 of the 4 basic types of orbits. An orbit is the curved path of a satellite around a celestial object, in this case, a spacecraft around the Earth.
The circular orbit is where the satellite moves in a perfect circle with the body at the center. They do not exist in nature although the orbits of some of the planets in our solar system are close to circular. Geosynchronous and geostationary orbits of satellites are circular. The velocity of a satellite is constant in a circular orbit.
The elliptical orbit is the typical steady orbit that you find in nature and is also the type of orbit many of our artificial satellites are in. The shape of this orbit is an ellipse with the celestial body at one focus. The velocity of a satellite varies in an elliptical orbit in relation to its distance from the main body.