DELTA 1 R/B(1)

DELTA 1 R/B(1) is a spent rocket body associated with United States, launched on 1978-04-07 from Cape Canaveral, Florida on the BSE launch. With over 48 years in orbit, it has far exceeded many satellites’ design lifetimes. It orbits in Low Earth Orbit (LEO) at altitudes between 567 km and 1,897 km with an inclination of 28.2°. It travels at approximately 26,066 km/h (7.24 km/s), completing one full orbit every 110 minutes — that’s roughly 13.08 orbits per day. At its current altitude, the estimated orbital lifetime before atmospheric re-entry is thousands of years. Spent rocket bodies like DELTA 1 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 1 R/B(1) orbits at an average altitude of 1,232 km in the uppermost reaches of Low Earth Orbit. At this altitude, orbital decay is effectively zero without active deorbiting, and coverage footprints are significantly larger than lower LEO, though at the cost of higher latency. Within ±50 km of DELTA 1 R/B(1)’s average altitude, there are currently 579 active payloads and 302 tracked debris or rocket body fragments — notable neighbours include ONEWEB-0012, ONEWEB-0010, ONEWEB-0008. With an inclination of 28.2°, DELTA 1 R/B(1) passes over latitudes between 28.2°N and 28.2°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 2 share a similar altitude band with DELTA 1 R/B(1).