|Mission type||Early warning|
|Mission duration||4 years |
|Spacecraft type||US-K |
|Launch mass||1,900 kilograms (4,200 lb)|
|Start of mission|
|Launch date||31 March 1981, 09:40UTC|
|Launch site||Plesetsk Cosmodrome|
|End of mission|
|Deactivated||1 May 1981|
|Perigee altitude||637 kilometres (396 mi)|
|Apogee altitude||39,747 kilometres (24,698 mi)|
Kosmos 1261 (Russian: Космос 1261 meaning Cosmos 1261) was a Soviet US-K missile early warning satellite which was launched in 1981 as part of the Soviet military's Oko programme. The satellite was designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 1261 was launched from Site 41/1 at Plesetsk Cosmodrome in the Russian SSR. A Molniya-M carrier rocket with a 2BL upper stage was used to perform the launch, which took place at 09:40 UTC on 31 March 1981. The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1981-031A. The United States Space Command assigned it the Satellite Catalog Number 12376.