DELTA 2 R/B(1)

DELTA 2 R/B(1) is a spent rocket body associated with United States, launched on 1990-01-24 from Cape Canaveral, Florida on the Navstar GPS SVN 18 launch. With over 36 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 316 km and 402 km with an inclination of 35.6°. It travels at approximately 27,705 km/h (7.70 km/s), completing one full orbit every 92 minutes — that’s roughly 15.70 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is months to ~1 year. Spent rocket bodies like DELTA 2 R/B(1) are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

DELTA 2 R/B(1) orbits at an average altitude of 359 km in the lower reaches of Low Earth Orbit, where atmospheric drag is significant and orbital lifetimes are measured in months to a few years. This is the busiest corridor in space — home to crewed spacecraft, rapid-revisit imaging satellites and the densest part of the Starlink constellation. Within ±50 km of DELTA 2 R/B(1)’s average altitude, there are currently 1,195 active payloads and 53 tracked debris or rocket body fragments — notable neighbours include STARLINK-1020, STARLINK-1036, STARLINK-1042. This makes it one of the more crowded altitude bands, containing roughly 6.8% of all active satellites. With an inclination of 35.6°, DELTA 2 R/B(1) passes over latitudes between 35.6°N and 35.6°S, covering the tropical and temperate zones where most of the world’s population resides. Low-to-mid inclination orbits are efficient to reach from equatorial and mid-latitude launch sites. United States operates approximately 12,413 active satellites in total, of which 1,108 share a similar altitude band with DELTA 2 R/B(1).