CZ-4 DEB

CZ-4 DEB is a tracked piece of space debris attributed to China, launched on 1999-10-14 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 652 km and 1,049 km with an inclination of 99.1°. It travels at approximately 26,746 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. As orbital debris, CZ-4 DEB poses a potential collision risk to operational satellites in nearby orbits and is continuously monitored by the U.S. Space Surveillance Network and other tracking systems.

CZ-4 DEB orbits at an average altitude of 851 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 CZ-4 DEB’s average altitude, there are currently 252 active payloads and 2,052 tracked debris or rocket body fragments — notable neighbours include NOAA 20, ONEWEB-0179, ONEWEB-0455. With an inclination of 99.1°, CZ-4 DEB passes over latitudes between 99.1°N and 99.1°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 1,194 active satellites in total, of which 121 share a similar altitude band with CZ-4 DEB.