Oko (OldRussian:Око,lit. 'Eye')[a] is a Russian (previouslySoviet) missile defenceearly warning programme consisting ofsatellites inMolniya andgeosynchronous orbits. Oko satellites are used to identify launches ofballistic missiles by detection of their engines' exhaust plume ininfrared light, and complement other early warning facilities such asVoronezh,Daryal andDnepr radars. The information provided by these sensors can be used for theA-135 anti-ballistic missile system which defendsMoscow. The satellites are run by theRussian Aerospace Forces, and previously theRussian Aerospace Defence Forces andRussian Space Forces. Since November 2015, it is being replaced by the newEKS system.[1]
Development of the Oko system began in the early 1970s under the design bureau headed by AI Savin, which becameTsNII Kometa. The spacecraft element was designed byNPO Lavochkin.[2] The first satellite was launched in 1972[3] but it was not until 1978 that the overall system became operational and 1982 before it was placed on combat duty.[2] The system had amajor malfunction in 1983 when it mistakenly identified sunlight on high altitude clouds as a missile attack.Stanislav Petrov, on duty at the new control centre inSerpukhov-15,Moscow Oblast, discounted the warning due to the newness of the system and the lack of corroboration from ground-based radar.[4]
The vast majority of the satellites launched (86 out of 100 as of March 2012[5]) have been the first generationUS-K satellites which operate inmolniya orbits. Seven first generation satellites were launched into geosynchronous orbits, calledUS-KS, starting in 1975.[6] A decree of 3 September 1979 led to the creation of the second generation satellitesUS-KMO which had their first launch in 1991.[2] In total,101 satellites have been launched.
The US-K satellites, were launched byMolniya-Mlaunch vehicles withBlok 2BL upper stages fromPlesetsk Cosmodrome. The US-KS and US-KMO operate in geosynchronous orbits and were launched byProton withDM-2 upper stages fromBaikonur.[5][7]
The last US-KMO satellite (Kosmos 2479) was launched on 30 March 2012[8] and the last US-K satellite (Kosmos 2469) on 30 September 2010.[9] They are due to be replaced by a new system calledEKS.
The first generation Molniya-type orbit Oko satellites launched between 1976 and 1983 were prone to disintegration, resulting in extensivespace debris. The reason they broke up was because they each carried an on-board explosive charge that would be used to destroy the satellite in the case of a malfunction. Unfortunately, control of the explosive charge was itself unreliable and it would often explode, rendering the satellite inoperative, while it was still under control. The design was eventually changed, and the explosive charge inKosmos 1481 was the last to explode early.[10]
The system has two dedicated control centres. The western centre is atSerpukhov-15 (Russian:Серпухов-15) nearKurilovo outside Moscow[11] (55°04′06″N37°02′29″E / 55.06833°N 37.04139°E /55.06833; 37.04139 (Serpukhov-15 Oko satellites control centre)) and the eastern centre is atPivan-1 (Russian:Пивань-1)[12] (50°20′57″N137°11′22″E / 50.34917°N 137.18944°E /50.34917; 137.18944 (Pivan-1 Oko satellites control centre)) in the Russian Far East. The centre at Serpukhov-15 burned down in 2001[13][14] which caused the loss of contact with currently orbiting satellites.[15]
