|Mission type||Solar imaging|
|Mission duration||131 days|
|Launch mass||400 kg |
|Start of mission|
|Launch date||16 June 1967, 04:44:00 GMT|
|Launch site||Kapustin Yar, 86/1|
|End of mission|
|Decay date||25 October 1967|
|Reference system||Geocentric |
|Perigee altitude||281 km|
|Apogee altitude||553 km|
|Epoch||16 June 1967|
Kosmos 166 (Russian: Космос 166 meaning Cosmos 166), also known as DS-U3-S No.1, was a satellite which was launched by the Soviet Union in 1967 as part of the Dnepropetrovsk Sputnik programme. It was a 400 kilograms (880 lb) spacecraft, which was built by the Yuzhnoye Design Office, and was used to conduct multispectral imaging of the Sun.
Kosmos 166 was launched from Site 86/1 at Kapustin Yar, aboard a Kosmos-2I 63SM carrier rocket. The launch occurred at 04:44:00 GMT on 16 June 1967, and resulted in the successful insertion of the satellite into a low Earth orbit. Upon reaching orbit, the satellite was assigned its Kosmos designation, and received the International Designator 1967-061A. The North American Air Defense Command assigned it the catalogue number 02848.
Kosmos 166 was the first of two DS-U3-S satellites to be launched, the other being Kosmos 230. It was operated in an orbit with a perigee of 281 kilometres (175 mi), an apogee of 553 kilometres (344 mi), an inclination of 48.4°, and an orbital period of 92.6 minutes. It completed operations on 26 September 1967, before decaying from orbit and reentering the atmosphere on 25 October.