|Mission type||Early warning|
|Mission duration||4 years |
|Launch mass||1,900 kilograms (4,200 lb)|
|Start of mission|
|Launch date||25 October 1988, 18:02UTC|
|Launch site||Plesetsk Cosmodrome|
|Perigee altitude||654 kilometres (406 mi)|
|Apogee altitude||39,703 kilometres (24,670 mi)|
Kosmos 1977 (Russian: Космос 1977 meaning Cosmos 1977) is a Soviet US-K missile early warning satellite which was launched in 1988 as part of the Soviet military's Oko programme. The satellite is designed to identify missile launches using optical telescopes and infrared sensors.
Kosmos 1977 was launched from Site 41/1 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 18:02 UTC on 25 October 1988. The launch successfully placed the satellite into a molniya orbit. It subsequently received its Kosmos designation, and the international designator 1988-096A. The United States Space Command assigned it the Satellite Catalog Number 19608.