Kosmos 521 (russian: Космос 521 meaning ''Cosmos 521''), also known as DS-P1-M No.4 is a

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioi ...

which was intended for use as a target for tests of

anti-satellite weapon Anti-satellite weapons (ASAT) are space weapons designed to incapacitate or destroy satellites for strategic or tactical purposes. Several nations possess operational ASAT systems. Although no ASAT system has been utilised in warfare, a few ...

s. It was launched by the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a List of former transcontinental countries#Since 1700, transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, ...

in 1972 as part of the Dnepropetrovsk Sputnik programme, and was to have been used as a target for an

IS-A In knowledge representation, object-oriented programming and design (see object-oriented program architecture), is-a (is_a or is a) is a subsumption relationship between abstractions (e.g. types, classes), wherein one class ''A'' is a subclass ...

interceptor, as part of the Istrebitel Sputnikov programme. A malfunction aboard the satellite rendered it useless, and the interceptor was not launched. It was launched aboard a

Kosmos-3M The Kosmos-3M (russian: Космос-3М meaning "''Cosmos''", GRAU index 11K65M) was a Russian space launch vehicle, member of the Kosmos rocket family. It was a liquid-fueled two-stage launch vehicle, first launched in 1967 and with over 42 ...

carrier rocket, from Site 132/2 at the

Plesetsk Cosmodrome Plesetsk Cosmodrome ( rus, Космодром «Плесецк», r=Kosmodrom "Plesetsk", p=kəsmɐˈdrom plʲɪˈsʲet͡sk) is a Russian spaceport located in Mirny, Arkhangelsk Oblast, about 800 km north of Moscow and approximately 200 ...

. The launch occurred at 20:18:59 UTC on 29 September 1972. Kosmos 521 was placed into a

low Earth orbit A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never mor ...

with a

perigee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

of , an

apogee An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

of , 65.8 degrees of

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a reference plane and the orbital plane or axis of direction of the orbiting object. For a satellite orbiting the Eart ...

, and an

orbital period The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets ...

of 104.9 minutes. No attempt to intercept the satellite was made after its onboard

telemetry Telemetry is the in situ collection of measurements or other data at remote points and their automatic transmission to receiving equipment (telecommunication) for monitoring. The word is derived from the Greek roots ''tele'', "remote", an ...

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 First or 1st is the ordinal form of the number one (#1). First or 1st may also refer to: *World record, specifically the first instance of a particular achievement Arts and media Music * 1$T, American rapper, singer-songwriter, DJ, and rec ...

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.

References

Kosmos satellites Spacecraft launched in 1972 Dnepropetrovsk Sputnik program {{USSR-spacecraft-stub

See also

References