Molniya orbit

noun5

1. •
   A highly elliptical orbit with an eccentricity of 0.74, inclination of 63.4 degrees, an argument of perigee of −90 degrees, and an orbital period of half a sidereal day, around the Earth.
2. •
   By analogy, the equivalent orbit for the southern hemisphere, with the argument of perigee changed to +90 degrees.
3. •
   Both the northern and southern hemisphere orbits for the Earth.
4. •
   By analogy, equivalent orbits for other bodies, which provide low apparent motion across the dome of the sky at apoapsis, allowing long duration communications/observation with low tracking rates at polar latitudes.
5. •
   The orbits around Earth and other bodies with these qualities.