CSS (TIANHE-1)

CSS (TIANHE-1) is an active satellite operated by China, launched on 2021-04-29 from Wenchang, China. It orbits in Low Earth Orbit (LEO) at altitudes between 374 km and 381 km with an inclination of 41.5°. It travels at approximately 27,667 km/h (7.69 km/s), completing one full orbit every 92 minutes — that’s roughly 15.64 orbits per day. Its near-circular orbit (eccentricity close to zero) means it maintains a very consistent altitude throughout each revolution. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is months to ~1 year. Orbital Radar tracks CSS (TIANHE-1) in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

CSS (TIANHE-1) orbits in the most densely populated region of Low Earth Orbit, between roughly 300 and 600 km altitude. This band is home to the International Space Station, most Earth observation satellites, and the bulk of the Starlink constellation. Objects here experience measurable atmospheric drag, which gradually lowers their orbit over months to years and eventually causes re-entry. The relatively short signal path makes this altitude ideal for low-latency communications and high-resolution imaging.