SJ-5

SJ-5 is an active satellite operated by China, launched on 1999-05-10 from Taiyuan, China. With over 27 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 837 km and 861 km with an inclination of 98.7°. It travels at approximately 26,749 km/h (7.43 km/s), completing one full orbit every 102 minutes — that’s roughly 14.13 orbits per day. Its near-polar, sun-synchronous orbit means it passes over any given point on Earth at approximately the same local solar time, ideal for consistent Earth observation lighting conditions. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is ~100–500 years. Orbital Radar tracks SJ-5 in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

SJ-5 orbits at an average altitude of 849 km in a sun-synchronous orbit (SSO), a specialised subset of LEO where the orbital plane precesses to maintain a constant angle relative to the Sun. This provides consistent lighting conditions on every pass — essential for Earth observation, weather monitoring and environmental science. Within ±50 km of SJ-5’s average altitude, there are currently 249 active payloads and 2,064 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 98.7°, SJ-5 passes over latitudes between 98.7°N and 98.7°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. China operates approximately 1,218 active satellites in total, of which 119 share a similar altitude band with SJ-5.