Kosmos 668 (Russian: Космос 668 meaning Cosmos 668), also known as DS-P1-Yu No.74, was a Soviet satellite which was launched in 1974 as part of the Dnepropetrovsk Sputnik programme.

It was a 400-kilogram (880 lb) spacecraft, which was built by the Yuzhnoye Design Bureau, and was used as a radar calibration target for anti-ballistic missile tests.

[1] The launch of Kosmos 668 took place from Site 133/1 at the Plesetsk Cosmodrome,[2] and used a Kosmos-2I 63SM carrier rocket.

It occurred at 12:00 UTC on 25 July 1974, and resulted in the satellite successfully reaching low Earth orbit.

[4] The North American Aerospace Defense Command assigned it the catalogue number 07385.