ORBCOMM FM 21

ORBCOMM FM 21 is an active satellite operated by ORBCOMM Inc. (ORBCOMM), launched on 1998-09-23 from Esrange, Sweden. With over 28 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 763 km and 766 km with an inclination of 45.0°. It travels at approximately 26,907 km/h (7.47 km/s), completing one full orbit every 100 minutes — that’s roughly 14.38 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. It is part of the Orbcomm constellation group. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. Orbital Radar tracks ORBCOMM FM 21 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ORBCOMM FM 21 orbits at an average altitude of 765 km in the mid-LEO band, where atmospheric drag is minimal but radiation exposure remains manageable. Objects at this altitude persist for decades to centuries, making debris mitigation critical. This regime is popular for remote sensing constellations and scientific instruments that need stable, long-duration orbits. Within ±50 km of ORBCOMM FM 21’s average altitude, there are currently 383 active payloads and 2,076 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0179, ONEWEB-0455. With an inclination of 45.0°, ORBCOMM FM 21 passes over latitudes between 45.0°N and 45.0°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. ORBCOMM operates approximately 58 active satellites in total, of which 34 share a similar altitude band with ORBCOMM FM 21.