COSMOS 977

COSMOS 977 is an active satellite operated by Russia (CIS), launched on 1978-01-10 from PKMTR. With over 48 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 1,400 km and 1,463 km with an inclination of 74.0°. It travels at approximately 25,731 km/h (7.15 km/s), completing one full orbit every 114 minutes — that’s roughly 12.58 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Orbital Radar tracks COSMOS 977 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 977 orbits at an average altitude of 1,432 km in the uppermost reaches of Low Earth Orbit. At this altitude, orbital decay is effectively zero without active deorbiting, and coverage footprints are significantly larger than lower LEO, though at the cost of higher latency. Within ±50 km of COSMOS 977’s average altitude, there are currently 344 active payloads and 171 tracked debris or rocket body fragments. With an inclination of 74.0°, COSMOS 977 passes over latitudes between 74.0°N and 74.0°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. Russia (CIS) operates approximately 1,286 active satellites in total, of which 309 share a similar altitude band with COSMOS 977.