by Jos Heyman, Tiros Space Information
In much the same way as the U.S. military forces use communications satellites, the USSR/ Russian military forces are a heavy user of communications satellites. A detailed analysis of the nature of the satellites used by the USSR/Russia indicates, however, that a different approach is taken to meet what essentially is the same objective, taking into account the local requirements.
In addition, it is believed the military forces of USSR/Russia also make extensive use of communications satellites which provide principally civilian services, such as the Molniya system. The three generations of Molniya satellites were placed in a highly eccentric orbit so that ground stations at high northern latitudes had access to the satellites. In these orbits the Molniya satellites were, for about 9 hours, over the USSR/Russias continental mass. An operational system consisted of at least three satellites.
The USSR was an early extensive user of the so called store-dump satellites, where a received signal is stored on board the spacecraft until the signal is downloaded as it nears a convenient ground station. This approach can be effective if there are multiple satellites in orbit.
The USSRs Strela system used satellites designated in the Kosmos multi-objective series. The Strela 1 series was essential a series of technology satellites to demonstrate the feasibility of placing multiple satellites in orbit and they had a mass of 50 kg.
The operational satellites were known as Strela 1M. The 61 kg satellites were launched in batches of eight and it is believed that the operational system used 24 to 30 satellites. The satellites, while retaining the store-sump approach, provided a near real time communications facility for the USSR military forces and were more or less randomly distributed in orbits of about 1500 km.
The Strela 2 series of store-dump communications satellites had a mass of about 750 kg and were built by NPO PM. The satellites transmissions have been observed in the 153 MHz and 204 MHz bands, although other frequencies may also have been used. No separate generations have been identified but it is highly likely that the spacecraft have been modified over the years. An operational system consisted of three satellites in a typical 780 x 810 km orbit with an inclination of 74 degrees. The three spacecraft were spaced 120 degrees apart.
The final store-dump series of communications satellites was designated as Strela 3. The satellites were built by NPO PM and had a mass of 230 kg. They were launched in groups of six by means of a Tsyklon 3 launch vehicle. The operational system consisted of 12 satellites. At some launches two of the six satellites were believed to have been larger than the remaining four. From 2002, the satellites were launched in pairs by Kosmos 3M launch vehicles.
The Raduga 1 series of geostationary satellites is based on the civilian Raduga series built by NPO PM using the KAUR-3 platform. Also known as Globus, the 2000 kg satellites are equipped with Tor transponders operating in the 4/6 GHz band and are optimized for telephone and telegraph communications. The first of these satellites was launched on June 21, 1989. From 2002, the satellites were launched in pairs by Kosmos 3M launch vehicles.
About the author
Jos Heyman is the Managing Director of Tiros Space Information, a Western Australian consultancy specializing in the dissemination of information on the scientific exploration and commercial application of space for use by educational as well as commercial organizations. An accountant by profession, Jos is the editor of the TSI News Bulletin and is also a regular contributor to the British Interplanetary Societys Spaceflight journal.