Kosmos 521

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, 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.

Kosmos 521

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, 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.