COSMOS 1687

COSMOS 1687 is an active satellite operated by PVO (Russia (CIS)), launched on 1985-09-30 from Plesetsk Cosmodrome, Russia on the Oko launch. With over 41 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Medium Earth Orbit (MEO) at altitudes between 5,531 km and 34,808 km with an inclination of 72.1°. 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 0.5516 gives it a noticeably elliptical path, with significant altitude variation between perigee and apogee. Orbital Radar tracks COSMOS 1687 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 1687 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 1687’s average altitude, there are currently 103 active payloads and 14 tracked debris or rocket body fragments. With an inclination of 72.1°, COSMOS 1687 passes over latitudes between 72.1°N and 72.1°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 1,536 active satellites in total, of which 54 share a similar altitude band with COSMOS 1687.