COSMOS 921

COSMOS 921 is an active satellite operated by Russia (CIS), launched on 1977-06-24 from PKMTR. With over 49 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 552 km and 602 km with an inclination of 75.8°. It travels at approximately 27,267 km/h (7.57 km/s), completing one full orbit every 96 minutes — that’s roughly 14.97 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~3–10 years. Orbital Radar tracks COSMOS 921 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

COSMOS 921 orbits at an average altitude of 577 km in the core of Low Earth Orbit, the most heavily utilised altitude band. The balance of moderate drag (limiting debris accumulation) and short signal path (enabling low-latency links and high-resolution imaging) makes this regime the default for most commercial and government missions. Within ±50 km of COSMOS 921’s average altitude, there are currently 3,133 active payloads and 516 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0050, STARLINK-2112, STARLINK-2722. This makes it one of the more crowded altitude bands, containing roughly 18% of all active satellites. With an inclination of 75.8°, COSMOS 921 passes over latitudes between 75.8°N and 75.8°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 32 share a similar altitude band with COSMOS 921.