BD-21

BD-21 is an active satellite operated by China, launched on 2016-02-01 from Xichang, China. After 10 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Medium Earth Orbit (MEO) at altitudes between 21,517 km and 21,539 km with an inclination of 56.7°. It travels at approximately 13,607 km/h (3.78 km/s), completing one full orbit every 12 hours 53 minutes — that’s roughly 1.86 orbits per day. Orbital Radar tracks BD-21 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

BD-21 orbits at an average altitude of 21,528 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of BD-21’s average altitude, there are currently 38 active payloads and 9 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 56.7°, BD-21 passes over latitudes between 56.7°N and 56.7°S, covering most populated land masses in both hemispheres. This mid-inclination band balances global coverage with efficient launch energy requirements. China operates approximately 1,218 active satellites in total, of which 35 share a similar altitude band with BD-21.