reentry
ROSAT uncontrolled reentry (October 2011)
October 23, 2011
Germany's ROSAT X-ray observatory re-entered uncontrolled over the Bay of Bengal; its heat-resistant mirror was expected to survive to the surface.
On 23 October 2011, Germany's ROSAT X-ray observatory — launched in 1990 and retired in 1999 — made an uncontrolled re-entry over the Bay of Bengal. The roughly 2.4-tonne satellite could not be commanded down.
Why ROSAT was watched closely ROSAT carried a large, heat-resistant X-ray mirror assembly built to survive extreme conditions — and analysts expected that dense optics could survive re-entry and reach the surface. That made the spacecraft a particular focus among the 2011 wave of high-profile re-entries.
Outcome As with UARS a month earlier, ROSAT's exact splashdown couldn't be predicted until the end, and any surviving pieces are believed to have fallen into the ocean. No casualties were reported. Together the two re-entries became a touchstone in the argument for end-of-life disposal planning.
Sources & further reading
Professional tracking & space domain awareness
- LeoLabs — commercial radar tracking & orbital intelligence
- Space-Track.org — US Space Force public catalogue
- CelesTrak — orbital element sets & analysis
LowEarth shows the public catalogue for curiosity and education. For operational tracking, conjunction screening, or threat assessment, the organisations above provide authoritative, higher-precision data.