SZ-21 MODULE

SZ-21 MODULE is an active satellite operated by China, launched on 2025-10-31 from Jiuquan, China. As a relatively recent addition to the catalogue, its orbital elements are well-characterised. It orbits in Low Earth Orbit (LEO) at altitudes between 336 km and 345 km with an inclination of 41.5°. It travels at approximately 27,744 km/h (7.71 km/s), completing one full orbit every 91 minutes — that’s roughly 15.77 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 SZ-21 MODULE in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SZ-21 MODULE orbits at an average altitude of 341 km in the lower reaches of Low Earth Orbit, where atmospheric drag is significant and orbital lifetimes are measured in months to a few years. This is the busiest corridor in space — home to crewed spacecraft, rapid-revisit imaging satellites and the densest part of the Starlink constellation. Within ±50 km of SZ-21 MODULE’s average altitude, there are currently 1,107 active payloads and 31 tracked debris or rocket body fragments — notable neighbours include STARLINK-1036, STARLINK-1043, STARLINK-1048. This makes it one of the more crowded altitude bands, containing roughly 6.4% of all active satellites. With an inclination of 41.5°, SZ-21 MODULE passes over latitudes between 41.5°N and 41.5°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. China operates approximately 1,219 active satellites in total, of which 19 share a similar altitude band with SZ-21 MODULE.