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Molniya (satellite)
Encyclopedia
Military
A military is an organization authorized by its greater society to use lethal force, usually including use of weapons, in defending its country by combating actual or perceived threats. The military may have additional functions of use to its greater society, such as advancing a political agenda e.g...
communications satellite
Communications satellite
A communications satellite is an artificial satellite stationed in space for the purpose of telecommunications...
system used by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
. The satellites were placed into highly eccentric
Orbital eccentricity
The orbital eccentricity of an astronomical body is the amount by which its orbit deviates from a perfect circle, where 0 is perfectly circular, and 1.0 is a parabola, and no longer a closed orbit...
elliptical orbits known as Molniya orbit
Molniya orbit
Molniya orbit is a type of highly elliptical orbit with an inclination of 63.4 degrees, an argument of perigee of -90 degree and an orbital period of one half of a sidereal day...
s, characterised by an inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
of +63.4 degree
Degree (angle)
A degree , usually denoted by ° , is a measurement of plane angle, representing 1⁄360 of a full rotation; one degree is equivalent to π/180 radians...
s and a period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of around 12 hours. Such orbits allowed them to remain visible to sites in polar regions for extended periods, unlike satellites in geosynchronous orbit
Geosynchronous orbit
A geosynchronous orbit is an orbit around the Earth with an orbital period that matches the Earth's sidereal rotation period...
s.
The Molniya program was authorized by a government decree in late 1960. After some initial failures in 1964, the first operational satellite, Molniya 1-01, was successfully launched on April 23, 1965.
Since October 1967, Molniya satellites have been used by Russia to broadcast their national Orbita
Orbita
Orbita is a Soviet-Russian system of broadcasting and delivering TV signals via satellites. It is considered to be the first national network of satellite television....
television network
Television network
A television network is a telecommunications network for distribution of television program content, whereby a central operation provides programming to many television stations or pay TV providers. Until the mid-1980s, television programming in most countries of the world was dominated by a small...
.