OPS 4988 (GREB 6)

OPS 4988 (GREB 6) is an active satellite operated by NRO / NRL (United States), launched on 1965-03-09 from Vandenberg Space Force Base, United States on the Secor Type II S/N 1 launch. After more than 61 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 888 km and 923 km with an inclination of 70.1°. It travels at approximately 26,645 km/h (7.40 km/s), completing one full orbit every 103 minutes — that’s roughly 13.97 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks OPS 4988 (GREB 6) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

OPS 4988 (GREB 6) orbits at an average altitude of 906 km in the upper LEO band, where atmospheric drag is negligible and objects can persist for centuries to millennia. This altitude is used by broadband constellations like OneWeb and by scientific missions requiring stable orbits far from the densest debris bands. Within ±50 km of OPS 4988 (GREB 6)’s average altitude, there are currently 307 active payloads and 1,574 tracked debris or rocket body fragments. With an inclination of 70.1°, OPS 4988 (GREB 6) passes over latitudes between 70.1°N and 70.1°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. United States operates approximately 13,279 active satellites in total, of which 147 share a similar altitude band with OPS 4988 (GREB 6).