| Molniya-2 | ||
Molniya-2 was the elliptical orbit component of the Soviet YeSSS communications satellite system. Flight tests began in 1971, and it had a brief operational career in 1974-1977 before being succeeded in the YeSSS network by the Molniya-3. 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 authorized work on the Molniya-1M production model, providing international communications on the centimeter 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 authorized its development for strategic communications under the code name Kristal. 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. The YeSSS radio rebroadcast system was developed by MNIIRS Minradioprom, followed by Minpromsvyaz (M R Kaplanov) and KBPM Minobshchemash (M F Reshetnev - Reshetnev's bureau had been spun off from Korolev's Filial 2 in the 1960's. It specialized in communications, television, navigation, and geodetic satellites). Development of Molniya-2 was dogged by the issue of what on-board radio equipment to use. The final version used the retransmitter Segment-2, A G Orlov General Designer. The previous LBV Shunt traveling wave tube was initially to be used, but the final technical solution was an unpressurised satellite and a new type had to be found. Finally the LBV Shunt TWT was only applied to Ekran, where it was used in place of a cascading klystron TWT. Flight trials of the Molniya-2 were conducted in 1971-1974. Major General N F Shlikov was in charge of the state trials commission, and took a methodical approach to achieving reliability. For example, three trials launches took place at short (2 to 4 month) intervals. Chief Designer was Gregori Markelovich Chrenyavskiy. But he was also a Soviet Minister. The motto 'never test for operations a system that you've developed' was followed. Operational flights came in 1974-1977. Molniya-2, like Molniya-1, consisted of four pairs of spacecraft with orbits at ninety degrees to one another. A total of 19 flights were made. Molniya-2 was used in the Orbita television system and also for the military Korund communications system. New ground segment components included systems by Chief designer at MNIIRS MPSS, M R Kaplanov, for the communication systems from military units to the center, and the on-board retransmitter. The ground control system was by Ryazanskiy, based on a modernized KIS Saturn. The control system at the center was by NIIT MOM (O N Shishkin). Typical orbit: 490 x 34397 km, 63.2 deg inclinaton. Length: 4.40 m (14.40 ft). Maximum Diameter: 1.40 m (4.50 ft). Span: 8.20 m (26.90 ft). Mass: 1,600 kg (3,500 lb). Associated Launch Vehicle: Molniya 8K78M. Molniya-2 Chronology
Bibliography and Further Reading
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