After the hubbub caused by the recent re-entry of the UARS satellite over the Pacific Ocean, another spacecraft called ROSAT seems to have escaped much of the media’s attention so far. ROSAT is a X-Ray telescope with a mass of around 2.4 tonnes, which is due to re-enter the Earth’s atmosphere in an uncontrolled manner in late October 2011.
The telescope payload is around 1.6 tonnes, but it is unlikely to remain in one lump during the destructive process of descent through the atmosphere. However, items with masses in the region of 100’s of kg may reach the ground (or more likely the ocean). A re-entry prediction done by a colleague at Southampton University UK, Dr Hugh Lewis, suggests that the re-entry may occur around the morning of 23 October 2011. However, the exact time is difficult to predict at this distance away from the event. I’m sure more refined estimates will be forth-coming when the media wake up to this