Kosmos 521
Encyclopedia
Kosmos 521 also known as DS-P1-M #4 is a satellite
which was intended for use as a target for tests of anti-satellite weapon
s. It was launched by the Soviet Union
in 1972 as part of the Dnepropetrovsk Sputnik
programme, and was to have been used as a target for an IS-A
interceptor, as part of the Istrebitel Sputnik
programme. A malfunction aboard the satellite rendered it useless, and the interceptor was not launched.
It was launched aboard a Kosmos-3M carrier rocket, from Site 132/2
at the Plesetsk Cosmodrome
. The launch occurred at 20:18:59 GMT on 29 September 1972.
Kosmos 521 was placed into a low Earth orbit
with a perigee
of 987 kilometres (613.3 mi), an apogee
of 992 kilometres (616.4 mi), 65.8 degrees of inclination
, and an orbital period
of 104.9 minutes. No attempt to intercept the satellite was made after its onboard telemetry system malfunctioned. As of 2009, it is still in orbit. 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, 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.
Satellite
In the context of spaceflight, a satellite is an object which has been placed into orbit by human endeavour. Such objects are sometimes called artificial satellites to distinguish them from natural satellites such as the Moon....
which was intended for use as a target for tests of anti-satellite weapon
Anti-satellite weapon
Anti-satellite weapons are designed to incapacitate or destroy satellites for strategic military purposes. Currently, only the United States, the former Soviet Union, and the People's Republic of China are known to have developed these weapons. On September 13, 1985, the United States destroyed US...
s. It was launched by the Soviet Union
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....
in 1972 as part of the Dnepropetrovsk Sputnik
Dnepropetrovsk Sputnik
Dnepropetrovsk Sputnik , also known as DS, was a series of satellites launched by the Soviet Union between 1961 and 1982. DS satellites were used for a number of missions, including technological and scientific research, and radar tracking targets for anti-satellite weapons and anti-ballistic...
programme, and was to have been used as a target for an IS-A
Is-a
In knowledge representation, object-oriented programming and design, is-a or is_a or is a is a relationship where one class D is a subclass of another class B ....
interceptor, as part of the Istrebitel Sputnik
Istrebitel Sputnik
Istrebitel Sputnik , or IS , was a Soviet anti-satellite weapons programme which led to the deployment of the IS-A or I2P system during the 1970s and 1980s...
programme. A malfunction aboard the satellite rendered it useless, and the interceptor was not launched.
It was launched aboard a Kosmos-3M carrier rocket, from Site 132/2
Plesetsk Cosmodrome Site 132
Site 132, also known as Chusovaya , is a launch complex at the Plesetsk Cosmodrome in Russia, used by Kosmos carrier rockets. It consists of a two launch pads, Site 133/1, which is active, and Site 133/2 which is not....
at the Plesetsk Cosmodrome
Plesetsk Cosmodrome
Plesetsk Cosmodrome is a Russian spaceport, located in Arkhangelsk Oblast, about 800 km north of Moscow and approximately 200 km south of Arkhangelsk.-Overview:...
. The launch occurred at 20:18:59 GMT on 29 September 1972.
Kosmos 521 was placed into a low Earth orbit
Low Earth orbit
A low Earth orbit is generally defined as an orbit within the locus extending from the Earth’s surface up to an altitude of 2,000 km...
with a perigee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 987 kilometres (613.3 mi), an apogee
Apsis
An apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of 992 kilometres (616.4 mi), 65.8 degrees of inclination
Inclination
Inclination in general is the angle between a reference plane and another plane or axis of direction.-Orbits:The inclination is one of the six orbital parameters describing the shape and orientation of a celestial orbit...
, and an orbital period
Orbital period
The orbital period is the time taken for a given object to make one complete orbit about another object.When mentioned without further qualification in astronomy this refers to the sidereal period of an astronomical object, which is calculated with respect to the stars.There are several kinds of...
of 104.9 minutes. No attempt to intercept the satellite was made after its onboard telemetry system malfunctioned. As of 2009, it is still in orbit. 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, 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.