Kosmos 2261


Kosmos 2261
Mission typeEarly warning
COSPAR ID1993-051A
SATCAT no.22741
Mission duration4 years [1]
Spacecraft properties
Spacecraft typeUS-K[2]
Launch mass1,900 kilograms (4,200 lb)[3]
Start of mission
Launch date10 August 1993, 14:53 (1993-08-10UTC14:53Z) UTC
Launch sitePlesetsk Cosmodrome[2][3]
Orbital parameters
Reference systemGeocentric
RegimeMolniya [2]
Perigee altitude625 kilometres (388 mi)[4]
Apogee altitude39,725 kilometres (24,684 mi)[4]
Inclination62.9 degrees[4]
Period717.70 minutes[4]

Kosmos 2261 (Russian: Космос 2261 meaning Cosmos 2261) is a Russian US-K missile early warning satellite which was launched in 1993 as part of the Russian Space Forces' Oko programme. The satellite is designed to identify missile launches using optical telescopes and infrared sensors.[2] It was estimated in the west that it stopped functioning in March 1998,[5] and reentered destructively on December 31, 2012.[6] (the early morning of January 1, 2013 in some time zones)

Kosmos 2261 was launched from Site 16/2 at Plesetsk Cosmodrome in Russia.[7] A Molniya-M carrier rocket with a 2BL upper stage was used to perform the launch, which took place at 14:53 UTC on 10 August 1993.[3] The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1993-051A.[3] The United States Space Command assigned it the Satellite Catalog Number 22741.[3]

Its predicted re-entry time was December 31, 2012 at 11:29 UTC ± 2 hours.[6]

See also


  1. ^ Podvig, Pavel (2002). "History and the Current Status of the Russian Early-Warning System" (PDF). Science and Global Security. 10: 21–60. CiteSeerX doi:10.1080/08929880212328. ISSN 0892-9882. 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 d e "Cosmos 2261". National Space Science Data Centre. 2012-04-20. Retrieved 2012-04-25.
  4. ^ a b c d McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 30 April 2012.
  5. ^ N. Busch (2004). No End in Sight: The Continuing Menace of Nuclear Proliferation. University Press of Kentucky. p. 97. ISBN 978-0-8131-2676-0.
  6. ^ a b "Aerospace.org - Cosmos 2261". Archived from the original on 2017-03-10. Retrieved 2013-08-29.
  7. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 2 May 2012.