Kosmos 917

Kosmos 917 (Космос 917 meaning Cosmos 917) was a Soviet US-K missile early warning satellite which was launched in 1977 as part of the Soviet military's Oko programme. The satellite was designed to identify missile launches using optical telescopes and infrared sensors.

Kosmos 917 was launched from Site 43/4 at Plesetsk Cosmodrome in the Russian SSR. A Molniya-M carrier rocket with a 2BL upper stage was used to perform the launch, which took place at 04:44 UTC on 16 June 1977. The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1977-047A. The United States Space Command assigned it the Satellite Catalog Number 10059.

It self-destructed on 8 June 1978.

The primary portion of it re-entered on 4 January 2023, but several pieces of its debris still remain in orbit.