Kosmos 123

Kosmos 123 (Космос 123 meaning Cosmos 123), also known as DS-P1-Yu No.5 was a Soviet satellite which was used as a radar calibration target for tests of anti-ballistic missiles. It was built by the Yuzhnoye Design Bureau, and launched in 1966 as part of the Dnepropetrovsk Sputnik programme.

A Kosmos-2I 63S1 carrier rocket was used to launch Kosmos 123. The launch occurred from Site 86/1 at Kapustin Yar, at 05:31 GMT on 8 July 1966. and following its successful arrival in orbit the spacecraft received its Kosmos designation; along with the International Designator 1966-061A and the Satellite Catalog Number 02295.

Kosmos 123 separated from the carrier rocket into a low Earth orbit with a perigee of 256 km, an apogee of 512 km, an inclination of 48.8°, and an orbital period of 92.2 minutes. It decayed from orbit on 10 December 1966. Kosmos 123 was the sixth of seventy-nine DS-P1-Yu satellites to be launched, and the fifth of seventy-two to successfully reach orbit.