According to NASA, the Upper Atmosphere Research Satellite (UARS) is expected to fall to Earth tomorrow (Friday, September 23, 2011) after using up all its fuel. It’s not entirely certain where on Earth the 6.5-ton satellite (or rather, pieces of it) will land when that happens. Much of the satellite will be burned upon reentering the Earth’s atmosphere. An expected 1,170 pounds of the remaining satellite parts will fall to Earth in roughly 26 large pieces. NASA predicts that the landing site will be somewhere between southern South America and northern Canada. NASA stressed that it’s unlikely the satellite will hit any towns or cities, and there’s only a 1 in 3,200 chance that any of the pieces will hit a human being.
UARS has been in space since 1991. The spacecraft was made using $750 million of titanium, aluminum, steel, and beryllium. Supposedly it contains no hazardous materials. Even so, FEMA has prepared a response in case it hits the United States, there’s a warning to not touch any of its parts after it lands, and the Air Force is monitoring the landing. In the past, satellites carrying toxic chemicals have had to be shot out of the sky with missiles!
(Sources: 1, 2)