COSMOS 1977

COSMOS 1977 is an active satellite operated by PVO (Russia (CIS)), launched on 1988-10-25 from Plesetsk Cosmodrome, Russia on the Oko launch. With over 38 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 5,360 km and 34,999 km with an inclination of 69.1°. It travels at approximately 13,949 km/h (3.87 km/s), completing one full orbit every 11 hours 58 minutes — that’s roughly 2.01 orbits per day. Its orbital eccentricity of 0.5582 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks COSMOS 1977 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 1977 orbits at an average altitude of 20,180 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of COSMOS 1977’s average altitude, there are currently 101 active payloads and 15 tracked debris or rocket body fragments — notable neighbours include GPS BIII-8 (PRN 21), GPS BIII-10 (PRN 13). With an inclination of 69.1°, COSMOS 1977 passes over latitudes between 69.1°N and 69.1°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 1,525 active satellites in total, of which 52 share a similar altitude band with COSMOS 1977.