|Spacecraft: Molniya-1. |
First Soviet communications satellite, using the twelve-hour elliptical orbit known as a 'Molniya orbit'. Such orbits require less rocket power to achieve than a geosynchronous orbit, and are better suited to communications with northern latitudes. Since they move very slowly at apogee, they appear to 'hover' for hours at a time over northern latitudes. The disadvantage is that the sending/receiving dish must track the satellite, whereas for a geosynchronous satellite a fixed dish can be used.
Molniya-1 was developed by Korolev's OKB-1. It was initially an experimental spacecraft to test the utility of such a satellite for command and control of the armed forces. It quickly proved the new technologies of automatic satellite control and 3 axis stabilisation. The Alfa on-board retransmitter operated on the 10 m band in both simplex and duplex modes. Existing tropospheric communication Gorizont ground stations required minimal modification for use with Molniya. Initial flights proved Moscow-Vladivostok strategic communications in 1965 to 1967.
|Spacecraft: Molniya-2. |
It had originally been foreseen that the Molniya-1 was only for use in experiments in long-distance communications. Therefore a decree on 31 October 1961 authorised work on the Molniya-1M production model, providing international communications on the centimetre band. But actually Molniya-1 worked so well that it was taken directly into service, and the -1M was skipped.
Using the common KAUR-2 bus and engineering work done on the -1M, the -2 version was defined. The draft project was completed in 1965 and a decree of 24 October 1968 authorised its development for strategic communications under the code name Kristall. The requirement was for a universal satellite to provide services to many users - the so-called Unified System of Satellite Communications (YeSSS). On 5 April 1972 the YeSSS was defined as the Molniya-2 in elliptical orbit and Raduga (Statsionar) in geosynchronous orbit.
|Spacecraft: Molniya-Yu. |
The Soviet manned lunar programs needed new tracking methods - how to translate doppler and location readings into orbital parameters quickly in order to make manoeuvres in lunar and translunar orbit. To investigate this Ryazanskiy modified a Molniya-1 spacecraft with measuring systems in place of the retransmitter. This Molniya-Yu was used to confirm new methods of orbital measurement.
|Spacecraft: Molniya-1T. |
Modernised Molniya-1 communications satellite with the 'Beta' retransmitter; began flight tests in 1970. The system was operational by 1972. Communications stations for the Rocket Forces, Air Force, and Navy were in place by 1975 (Ruchey Command and Control System). The satellite itself was part of the Korund system, which allowed strategic communications and telephony with military units in Siberia and the Far East. The complete system included 8 spacecraft on orbit, replenished as necessary. The satellite reliability improved over time. The system used Surgut secure radio lines and had a 20 year system life, with 70 launches total. The improved Korund-M system began flight trials in 1983 and was accepted into military service in 1987.
|Spacecraft: Molniya-3. |
Communications satellite. Development of Molniya-2M began in 1972. It was later called Molniya-3. It used the Segment-3 three-channel repeater (cm-band, 4-6 GHZ). Flight trials began in November 1974. The Molniya-3 was used to create the 'Orbita' communications system for northern regions, with groups of four satellites. The land segment used a 12 m diameter parabolic antenna, which was pointed automatically at the satellite using autonomous electromechanical equipment. Later versions were to be part of the YeSSS Unified Satellite Communications System. Trials of this version began in the 1980's, with the system being accepted by the military in 1983-1985.