IRIDIUM 39

IRIDIUM 39 is an active satellite operated by Iridium Communications (United States), launched on 1997-11-09 from Vandenberg SFB, California. With over 29 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 713 km and 739 km with an inclination of 86.4°. It travels at approximately 26,980 km/h (7.49 km/s), completing one full orbit every 99 minutes — that’s roughly 14.50 orbits per day. It is part of the Iridium constellation group. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~25–100 years. Orbital Radar tracks IRIDIUM 39 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

IRIDIUM 39 orbits at an average altitude of 726 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 IRIDIUM 39’s average altitude, there are currently 293 active payloads and 1,756 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, LANDSAT 9. With an inclination of 86.4°, IRIDIUM 39 passes over latitudes between 86.4°N and 86.4°S, providing near-global coverage including the polar regions. Polar and near-polar orbits are used for reconnaissance, weather monitoring and Earth-observation missions that need to image every part of the planet. United States operates approximately 12,339 active satellites in total, of which 75 share a similar altitude band with IRIDIUM 39.