Molniya (satellite) in the context of "Communications satellites"

This timeline of Russian innovation encompasses key events in the history of technology in Russia.

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The Konstantin E. Tsiolkovsky State Museum of the History of Cosmonautics (Russian: Государственный музей истории космонавтики имени К.Э.Циолковского) is the first museum in the world dedicated to the history of space exploration. It was opened on 3 October 1967 in Kaluga, and is named after Konstantin Tsiolkovsky, a school master and rocket science pioneer who lived most of his life in this city. The driving force behind the creation of the museum was Sergei Korolyov, chief designer of RKK Energiya. The building was designed by Boris Barkhin, Evgeny Kireev, Nataliya Orlova, Valentin Strogy and Kirill Fomin, and the cornerstone was laid by Yuri Gagarin on 13 June 1961. The museum has over 100,000 visitors per year and has 127 employees, of whom 43 are curators.

A highly elliptical orbit (HEO) or highly eccentric orbit is an orbit of one body about another with high eccentricity, usually referring to one around Earth.

Examples of inclined HEO orbits include Molniya orbits, named after the Molniya Soviet communication satellites which used them, and Tundra orbits. Many US satellites also have used these orbits, satellites such as the Trumpet electronics intelligence satellites.

A Molniya orbit (Russian: Молния, IPA: [ˈmolnʲɪjə] , "Lightning") 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. A variation on the Molniya orbit is the so-called Three Apogee (TAP) orbit, whose period is a third of a sidereal day.

The Molniya orbit has a long dwell time over the hemisphere of interest, while moving very quickly over the other. In practice, this places it over either Russia or Canada for the majority of its orbit, providing a high angle of view to communications and monitoring satellites covering these high-latitude areas. Geostationary orbits, which are necessarily inclined over the equator, can only view these regions from a low angle, hampering performance. In practice, a satellite in a Molniya orbit serves the same purpose for high latitudes as a geostationary satellite does for equatorial regions, except that multiple satellites are required for continuous coverage.