A Molniya orbit is a type of satellite orbit designed to provide communications and remote sensing coverage over high latitudes. It is a highly elliptical orbit with an inclination of 63.4 degrees, an argument of perigee of 270 degrees, and an orbital period of approximately half a sidereal day. The name comes from the Molniya satellites, a series of Soviet/Russian civilian and military communications satellites which have used this type of orbit since the mid-1960s.
Figure 3: Groundtrack of a Molniya orbit. In the operational part of the orbit (four hours on each side of apogee), the satellite is north of 55.5° N (latitude of, for example, central Scotland, Moscow and southern part of Hudson Bay). A satellite in this orbits spends most of its time over the northern hemisphere and passes quickly over the southern hemisphere.
The Molniya series satellites were military and communications satellites launched by the Soviet Union from 1965 to 2004. These satellites used highly eccentric elliptical orbits known as Molniya orbits, which have a long dwell time over high latitudes. They are suited for communications purposes in polar regions, in the same way that geostationary satellites are used for equatorial regions.
Molniya 1
Groundtrack of Molniya orbit. In the operational part of the orbit (4 hours on each side of apogee), the satellite is north of 55.5° N (latitude of for example central Scotland, Moscow and southern part of Hudson Bay). A satellite in this orbits spends most of its time in the northern hemisphere and passes quickly over the southern hemisphere.
