DELTA 1 DEB

DELTA 1 DEB is a tracked piece of space debris attributed to United States, launched on 1975-06-12 from Vandenberg SFB, California on the Nimbus F launch. After more than 51 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Low Earth Orbit (LEO) at altitudes between 672 km and 836 km with an inclination of 100.0°. It travels at approximately 26,926 km/h (7.48 km/s), completing one full orbit every 100 minutes — that’s roughly 14.41 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 ~25–100 years. As orbital debris, DELTA 1 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.

DELTA 1 DEB orbits at an average altitude of 754 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 DELTA 1 DEB’s average altitude, there are currently 370 active payloads and 1,999 tracked debris or rocket body fragments. With an inclination of 100.0°, DELTA 1 DEB passes over latitudes between 100.0°N and 100.0°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. United States operates approximately 12,550 active satellites in total, of which 145 share a similar altitude band with DELTA 1 DEB.