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. After more than 51 years in orbit, it is one of the longest-surviving objects in the space catalogue. It orbits in Medium Earth Orbit (MEO) at altitudes between 1,111 km and 2,127 km with an inclination of 99.4°. It travels at approximately 25,427 km/h (7.06 km/s), completing one full orbit every 119 minutes — that’s roughly 12.14 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of 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 1,619 km in Medium Earth Orbit, the region between LEO and GEO (2,000–35,786 km). MEO’s higher altitude gives each satellite a much larger ground footprint than LEO, meaning fewer spacecraft are needed for global coverage — but signal latency is higher and radiation from the Van Allen belts is a significant design constraint. Within ±50 km of DELTA 1 DEB’s average altitude, there are currently 28 active payloads and 174 tracked debris or rocket body fragments. This is a relatively sparse altitude band, containing less than 1% of all active satellites. With an inclination of 99.4°, DELTA 1 DEB passes over latitudes between 99.4°N and 99.4°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 12,261 active satellites in total.