Strela military communications satellite family
Soviet Strela (an "arrow") satellites were designed for the so-called "store-and-dump" communications. The spacecraft of this type records a piece of communication, such as a fax, a telex or an e-mail, in its onboard recorder as it overflies a sender and when the satellite reaches a range of receiving antennas of an addressee, it downlinks the message. The method was intended primarily for communications in very remote areas lacking more traditional ground-based communications channels.
Strela served Soviet security and military intelligence services -- KGB and the army intelligence known as GRU. Soviet intelligence officials and staff at Soviet embassies overseas reportedly used Strela satellites to transmit highly sensitive and urgent information, such as documents and images to Moscow. In 1980s, the Soviet government also decided deploy a "civilian" version of the spacecraft named Gonets ("messenger"). (501)
On Oct. 30, 1961, the Soviet government issued a Decree No. 984-425 authorizing several military space projects including a small-satellite communication network. The development of the Pchela ("a bee") and Strela systems was first assigned to OKB-586 in Dnepropetrovsk, Ukraine. Engineers at KB Yuzhnoe planned to use existing manufacturing base for the spacecraft, fashioning them out of a pair of 400-millimeter hemispheres. One hemisphere was carrying an external radiator and another -- a ring-shaped solar panel. Four 75-kilogram satellites would be launched by a single 65S3 (Kosmos) rocket into a 1,500-kilometer circular orbit, where they were expected to function for at least three months.
By 1962, work on Pchela and Strela projects was transferred to OKB-10 in Zheleznogorsk (later renamed NPO PM and now known as ISS Reshetnev). Although OKB-10 clearly retained basic features of the Strela satellite proposed in Dnepropetrovsk, engineers in Zheleznogorsk apparently merged the inherited hardware with the KAUR-1 standard satellite platform developed at OKB-10. Along with OKB-10, the design bureau at the Krasnoyarsk Radio Plant led by V. G. Taranenko and the MNIIRS MPSS center led by Yu. S. Bykov, participated in the Strela project. By 1964, the spacecraft reached the launch pad. A trio of satellite mockups was lifted into orbit onboard a Kosmos-3 rocket from Baikonur on August 18. These prototypes (equipped only with radio transmitters) were officially identified as Kosmos-38, -39 and -40. (389)
Four days later, on August 22, 1964, the first pair of experimental satellites was launched from Kapustin Yar. They were identified as Kosmos-42 and -43. A month later, another mockup of the Strela satellite remaining on the ground became a part of an exhibit of space assets in Tyuratam attended by the head of the Soviet rocket forces Marshall Krylov on September 24 and 25. From the outset, Soviet military officials, who approved the development of two initial Strela networks, recognized limited capabilities of these small satellites, and, therefore, designated the constellation as experimental. (70)
Operational Strela-1 satellites had to be launched in groups of five, prompting KB PM to develop a specialized release mechanism for the purpose. Ground testing of the spacecraft was conducted at Site 2 of the KB PM campus and at a custom-built test site near the town of Chapaevsk.
At least one satellite of this type used a radioisotope thermal generator, RTG, as a source of power. First cluster of five 75-kilogram satellites was launched on Sept. 3, 1965. With the launch of a second cluster, the experimental Strela network was declared functional. A fully operational network was to include 24 satellites.
An initial upgraded satellite in the Strela family became known as Strela-1M. From April 25, 1970, and until June 3, 1992, a total of 45 satellites of this type were launched from Plesetsk by Kosmos-3M rockets in groups of eight into a 1,500-kilometer orbit with an inclination 82.5 degrees toward the Equator. According to ISS Reshetnev, a group of eight satellites reportedly covered all areas with potential users of the network. By mid-1970s, the Strela network reportedly covered not only the Soviet territory but also a large portion of the Earth's surface.
Strela-1M was also became a basis for the first Soviet flight experiment testing a nickel-hydrogen battery, which was conducted in January 1978. The same platform also became a basis for several amateur radio satellites built at NPO PM.
The second-generation Strela-2 network was reportedly under development since 1973. The flight testing of the system started at the beginning of the 1980s, apparently after delays caused by the lack of funding. The State Commission led by Lt. General Yu. F. Kravtsov oversaw the deployment of the network.
The development of the third-generation Strela network was authorized by a government decree on March 11, 1976. The Strela-3 revision of the family was also designated 17F13 and its upgrade -- Strela-3M -- 14F132. The completed Strela-3 constellation was to include 12-18 spacecraft each in two orbital planes, orbiting the Earth in a 1,500-kilometer circular orbit with an inclination 82.6 degrees toward the Equator. The Strela-3 satellite was heavier than its predecessors and provided more effective use of its communication signal. New spiral antennas and their deployment mechanism were specifically designed for the satellite. The spacecraft architecture probably resembled that of their civilian siblings, known as Gonets.
Even a partial completion of the network (apparently with as many as six satellites) reportedly enabled its use with direct communications available within limited areas. One cited advantage of the constellation was its capability to pick up signals from very weak transmitters thanks to the satellites' low orbit.
Batches of six satellites were originally launched by a single Tsyklon-3 rocket. During the orbital insertion, the Strela payloads would be separated from the upper stage of the launch vehicle, while the rocket's propulsion unit would be still operating (under low thrust), resulting in slightly different orbital parameters for each satellite. (383)
Strela-3 satellites officially remained in testing phase during 1992-1996. In 1996, a decision was made to launch Strela-3 satellites on the Rockot launch vehicle from Plesetsk, instead of relying on the Ukrainian-built Tsyklon-3 rocket. The Strela-3 network reportedly included two groups of satellites, one of which remained operational as late as 2012. By that time, 30 launches with Strela-3 had taken place successfully delivering 134 satellites of this type into orbit. Two failed missions resulted in the loss of nine Strela-3 birds.
Strela project overview:
Early concept of the Pchela spacecraft designed by KB Yuzhnoe in Dnepropetrovsk for military communications. Credit: KB Yuzhnoe
Clusters of five Strela-1 satellites tested a military personal communications system. Strela-1M apparently had similar appearance. Credit: ISS Reshetnev
The Strela-1M spacecraft was used for military communications. It was also a basis for Radio-ROSTO, Zeya and Mozhaets satellites. Copyright © 2001 Anatoly Zak
Strela-2 satellite. Credit: ISS Reshetnev
Artist renderings reportedly depicting Strela-2M satellite. Credit: ISS Reshetnev
Arrow hits the target: Russia's defunct Strela-2M ("Arrow") satellite collided with a US Iridium communications spacecraft on Feb. 10, 2009. Both vehicles were reportedly pulverized into a cloud of debris. In the aftermath of the incident, Western press was full of inaccurate depictions and wild speculations about the design of the Russian satellite, including a ludicrous claim by the Wall Street Journal about a nuclear reactor onboard the spacecraft. In reality, Strela-2M was powered by drum-shaped solar panels. This was apparently the first instance in the history of space exploration, when two satellites have collided in space. Click to enlarge. Copyright © 2009 Anatoly Zak