COSMOS 1661

COSMOS 1661 is an active satellite operated by Russia (CIS), launched on 1985-06-18 from PKMTR. With over 41 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 4,611 km and 35,729 km with an inclination of 67.8°. It travels at approximately 13,951 km/h (3.88 km/s), completing one full orbit every 11 hours 57 minutes — that’s roughly 2.01 orbits per day. Its orbital eccentricity of 0.5862 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks COSMOS 1661 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 1661 orbits at an average altitude of 20,170 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 1661’s average altitude, there are currently 102 active payloads and 14 tracked debris or rocket body fragments — notable neighbours include GPS BIIR-5 (PRN 22), GPS BIIR-8 (PRN 16), GPS BIIR-11 (PRN 19). With an inclination of 67.8°, COSMOS 1661 passes over latitudes between 67.8°N and 67.8°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 1,285 active satellites in total, of which 55 share a similar altitude band with COSMOS 1661.