ZK-1A / RB

ZK-1A / RB is an active satellite operated by China, launched on 2026-09-21 from Jiuquan Satellite Launch Center, 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 234 km and 539 km with an inclination of 97.6°. It travels at approximately 27,649 km/h (7.68 km/s), completing one full orbit every 92 minutes — that’s roughly 15.61 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 months to ~1 year. Orbital Radar tracks ZK-1A / RB in real time using the latest two-line element set (TLE) data, providing live position, altitude, speed and orbital path updated continuously.

ZK-1A / RB orbits at an average altitude of 387 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 ZK-1A / RB’s average altitude, there are currently 1,391 active payloads and 77 tracked debris or rocket body fragments — notable neighbours include ISS (ZARYA), STARLINK-1008, STARLINK-1012. This makes it one of the more crowded altitude bands, containing roughly 7.4% of all active satellites. With an inclination of 97.6°, ZK-1A / RB passes over latitudes between 97.6°N and 97.6°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 1,291 active satellites in total, of which 37 share a similar altitude band with ZK-1A / RB.