DELTA 4 R/B

DELTA 4 R/B is a spent rocket body associated with United States, launched on 2007-11-11 from Cape Canaveral, Florida on the DSP F23 launch. After 19 years in orbit, it continues to be tracked by global surveillance networks. It orbits in Geostationary Orbit (GEO) at altitudes between 36,010 km and 38,125 km with an inclination of 11.5°. It travels at approximately 10,905 km/h (3.03 km/s), completing one full orbit every 25.0 hours — that’s roughly 0.96 orbits per day. At geostationary altitude, there is no meaningful atmospheric drag — this object will remain in orbit indefinitely unless actively deorbited. Spent rocket bodies like DELTA 4 R/B are among the largest pieces of uncontrolled space debris and are priority targets for collision avoidance manoeuvres and future active debris removal efforts.

DELTA 4 R/B occupies geostationary orbit at approximately 35,786 km above the equator, where its orbital period matches the Earth’s 24-hour rotation. From the ground, it appears to hover over a fixed point — ideal for broadcast television, weather monitoring and wideband communications. With an inclination of 11.5°, it traces a small figure-of-eight pattern relative to the equator rather than remaining perfectly stationary, which can indicate aging stationkeeping fuel or a deliberate inclined-orbit strategy. Within ±50 km of DELTA 4 R/B’s average altitude, there are currently 4 active payloads and 1 tracked debris or rocket body fragment. United States operates approximately 12,413 active satellites in total.