ESSA 3 (TOS-A)

ESSA 3 (TOS-A) is an active satellite operated by ESSA (United States), launched on 1966-10-02 from Vandenberg Space Force Base, United States on the TOS A launch. After more than 60 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Low Earth Orbit (LEO) at altitudes between 1,386 km and 1,486 km with an inclination of 101.1°. It travels at approximately 25,723 km/h (7.15 km/s), completing one full orbit every 115 minutes — that’s roughly 12.57 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Orbital Radar tracks ESSA 3 (TOS-A) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ESSA 3 (TOS-A) orbits at an average altitude of 1,436 km in the uppermost reaches of Low Earth Orbit. At this altitude, orbital decay is effectively zero without active deorbiting, and coverage footprints are significantly larger than lower LEO, though at the cost of higher latency. Within ±50 km of ESSA 3 (TOS-A)’s average altitude, there are currently 495 active payloads and 308 tracked debris or rocket body fragments. With an inclination of 101.1°, ESSA 3 (TOS-A) passes over latitudes between 101.1°N and 101.1°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 13,279 active satellites in total, of which 20 share a similar altitude band with ESSA 3 (TOS-A).