Kosmos 1261

Summary

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.[2]

Kosmos 1261
Mission typeEarly warning
COSPAR ID1981-031A Edit this at Wikidata
SATCAT no.12376
Mission duration4 years [1]
Spacecraft properties
Spacecraft typeUS-K[2]
Launch mass1,900 kilograms (4,200 lb)
Start of mission
Launch date31 March 1981, 09:40 (1981-03-31UTC09:40Z) UTC
RocketMolniya-M/2BL[2]
Launch sitePlesetsk Cosmodrome[2][3]
End of mission
Deactivated1 May 1981[1]
Orbital parameters
Reference systemGeocentric
RegimeMolniya [2]
Perigee altitude637 kilometres (396 mi)[4]
Apogee altitude39,747 kilometres (24,698 mi)[4]
Inclination63.0 degrees[4]
Period718.39 minutes[4]
 

Kosmos 1261 was launched from Site 41/1 at Plesetsk Cosmodrome in the Russian SSR.[3] 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.[3] The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1981-031A.[4] The United States Space Command assigned it the Satellite Catalog Number 12376.[4]

Kosmos 1261 was a US-K satellite like Kosmos 862 that self-destructed in orbit, NASA believe deliberately. The spacecraft attempted to maneuver from its transfer orbit to an operational orbit 3 days after launch, but it appears that the maneuver was unsuccessful, and the spacecraft never became ground track-stabilized. Immediately after the maneuver some debris was detected, while additional debris were discovered in mid-May. There may have been more than one debris event. All of the resultant debris is still in orbit.[5]

See also edit

References edit

  1. ^ a b Podvig, Pavel (2002). "History and the Current Status of the Russian Early-Warning System" (PDF). Science and Global Security. 10 (1): 21–60. Bibcode:2002S&GS...10...21P. CiteSeerX 10.1.1.692.6127. doi:10.1080/08929880212328. ISSN 0892-9882. S2CID 122901563. Archived from the original (PDF) on 2012-03-15.
  2. ^ a b c d e "US-K (73D6)". Gunter's Space Page. 2012-03-08. Retrieved 2012-04-21.
  3. ^ a b c McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 2 May 2012.
  4. ^ a b c d e f McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 30 April 2012.
  5. ^ Anz-Meador, Phillip (December 2022). History of On-orbit Satellite Fragmentations, 16th edition (PDF). NASA. p. 194. Retrieved 23 May 2023.