Molniya Orbit

Molniya orbit is a highly elliptical orbit named after the Molniya communication satellites used by the Soviet Union and, later, the Russian Federation. This orbit is used to provide communication and remote sensing services to high latitude areas in the northern hemisphere. The Molniya orbit has an inclination of 63.4 degrees, an argument of perigee —the angle between the point on the orbital path where an object crosses the equator and the point of its closest approach to the Earth— of 270 degrees, and an orbital period of approximately half a sidereal day.