BB4

BB4 is an active satellite operated by United States, launched on 2023-09-02 from Vandenberg SFB, California on the SDA-0B launch. It orbits in Low Earth Orbit (LEO) at altitudes between 663 km and 677 km with an inclination of 81.0°. It travels at approximately 27,087 km/h (7.52 km/s), completing one full orbit every 98 minutes — that’s roughly 14.68 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~10–25 years. Orbital Radar tracks BB4 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

BB4 orbits at an average altitude of 670 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 BB4’s average altitude, there are currently 634 active payloads and 1,198 tracked debris or rocket body fragments — notable neighbours include TERRA, AQUA, LANDSAT 9. With an inclination of 81.0°, BB4 passes over latitudes between 81.0°N and 81.0°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 12,671 active satellites in total, of which 340 share a similar altitude band with BB4.