Kosmos 521


Kosmos 521
Mission typeASAT target
COSPAR ID1972-074A
SATCAT no.06206Edit this on Wikidata
Spacecraft properties
Spacecraft typeDS-P1-M
Launch mass650 kilograms (1,430 lb)
Start of mission
Launch date29 September 1972, 20:18:59 (1972-09-29UTC20:18:59Z) UTC
Launch sitePlesetsk 132/2
Orbital parameters
Reference systemGeocentric
RegimeLow Earth
Perigee altitude987 kilometres (613 mi)
Apogee altitude992 kilometres (616 mi)
Inclination65.8 degrees
Period104.9 minutes

Kosmos 521 (Russian: Космос 521 meaning Cosmos 521), also known as DS-P1-M No.4 is a satellite which was intended for use as a target for tests of anti-satellite weapons. It was launched by the Soviet Union in 1972 as part of the Dnepropetrovsk Sputnik programme,[1] and was to have been used as a target for an IS-A interceptor, as part of the Istrebitel Sputnikov programme. A malfunction aboard the satellite rendered it useless, and the interceptor was not launched.[2]

It was launched aboard a Kosmos-3M carrier rocket,[3] from Site 132/2 at the Plesetsk Cosmodrome. The launch occurred at 20:18:59 UTC on 29 September 1972.[4]

Kosmos 521 was placed into a low Earth orbit with a perigee of 987 kilometres (613 mi), an apogee of 992 kilometres (616 mi), 65.8 degrees of inclination, and an orbital period of 104.9 minutes.[1] No attempt to intercept the satellite was made after its onboard telemetry system malfunctioned. As of 2009, it is still in orbit.[2][5] Western analysts did not identify Kosmos 521 as being associated with the Soviet ASAT programme until records were declassified.

Kosmos 521 was the last of the five original DS-P1-M satellites to be launched,[1] of which all but the first were successfully reached orbit. Despite its successful launch, the satellite malfunctioned shortly after reaching orbit, and was unusable. Subsequent launches used a modified version of the DS-P1-M, known as Lira.[6]

See also


  1. ^ a b c Wade, Mark. "DS-P1-I". Encyclopedia Astronautica. Archived from the original on 5 January 2009. Retrieved 29 May 2009.
  2. ^ a b Wade, Mark. "IS-A". Encyclopedia Astronautica. Archived from the original on 21 April 2012. Retrieved 29 May 2009.
  3. ^ McDowell, Jonathan. "Launch Log". Jonathan's Space Page. Retrieved 29 May 2009.
  4. ^ Wade, Mark. "Kosmos 3". Encyclopedia Astronautica. Retrieved 29 May 2009.
  5. ^ McDowell, Jonathan. "Satellite Catalog". Jonathan's Space Page. Retrieved 29 May 2009.
  6. ^ Wade, Mark. "DS". Encyclopedia Astronautica. Archived from the original on 31 March 2009. Retrieved 29 May 2009.