Oko satellite early-warning system
오코 조기경보위성
Oko was a Soviet-developed satellite system for early detection of ballistic-missile launches, using satellites in Molniya-type highly elliptical and geosynchronous orbits. It detected infrared emissions from missile engines and supplied data to the Soviet missile-attack warning network; in 1983, it falsely interpreted sunlight reflected from high-altitude clouds as launches.
In depth
System and operation
The Oko constellation was designed to monitor launches from U.S. intercontinental ballistic-missile fields. Early US-K satellites used Molniya orbits, while US-KS and later US-KMO satellites used geosynchronous orbits, providing different viewing angles. The first satellite was launched in 1972, and the system entered combat duty in 1982.
The 1983 false alarm
On 26 September 1983, an alignment of the Sun, satellite, and U.S. missile fields caused Oko to mistake sunlight reflected from high-altitude clouds for missile exhaust. At the Serpukhov-15 command centre, duty officer Stanislav Petrov did not pass the warning to higher command, citing the absence of confirmation from ground radar among other considerations.
Sources
- Wikipedia (RU) (Око의 구성, 운용 시기, 1983년 오경보 지원)
- Wikipedia (EN) (오코의 임무, 궤도, 적외선 미사일 발사 탐지, 1983년 오작동 지원)
- pbs.org (1983년 오추의 원인인 고고도 구름의 햇빛 반사와 몰니야 궤도 설명)