TRANSIT 4B

TRANSIT 4B is an active satellite operated by USN BuWeps (United States), launched on 1961-11-15 from Cape Canaveral Space Force Station, United States. After more than 65 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 948 km and 1,096 km with an inclination of 32.4°. It travels at approximately 26,434 km/h (7.34 km/s), completing one full orbit every 106 minutes — that’s roughly 13.64 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~500–1,000 years. Orbital Radar tracks TRANSIT 4B in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

TRANSIT 4B orbits at an average altitude of 1,022 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 TRANSIT 4B’s average altitude, there are currently 441 active payloads and 919 tracked debris or rocket body fragments. With an inclination of 32.4°, TRANSIT 4B passes over latitudes between 32.4°N and 32.4°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. United States operates approximately 13,279 active satellites in total, of which 42 share a similar altitude band with TRANSIT 4B.