|Mission type||ABM radar target|
|Mission duration||117 days|
|Launch mass||325 kg|
|Start of mission|
|Launch date||24 August 1967, 04:59:49 GMT|
|Launch site||Plesetsk, 133/1|
|End of mission|
|Decay date||17 December 1967|
|Perigee altitude||277 km|
|Apogee altitude||480 km|
|Epoch||24 August 1967|
Kosmos 173 (Russian: Космос 173 meaning Cosmos 173), also known as DS-P1-Yu No.8 was a Soviet satellite which was used as a radar calibration target for tests of anti-ballistic missiles. It was a 325 kilograms (717 lb) spacecraft, was built by the Yuzhnoye, and launched in 1967 as part of the Dnepropetrovsk Sputnik programme.
A Kosmos-2I 63SM carrier rocket was used to launch Kosmos 173 from Site 133/1 at Plesetsk Cosmodrome. The launch occurred at 04:59:49 GMT on 24 August 1967, and resulted in Kosmos 173's successful deployment into low Earth orbit.
Kosmos 173 was operated in an orbit with a perigee of 277 kilometres (172 mi), an apogee of 480 kilometres (300 mi), an inclination of 71.0°, and an orbital period of 92.3 minutes. It remained in orbit until it decayed and reentered the atmosphere on 17 December 1967. It was the ninth of seventy nine DS-P1-Yu satellites to be launched, and the eighth of seventy two to successfully reach orbit.