NASA satellite to crash back on Earth
21 Sep 2011
An old NASA satellite is expected to crash back on Earth any time from Thursday, 23 September onwards, NASA said Monday. The Upper Atmosphere Research Satellite (UARS), decommissioned in 2005, is expected to re-enter the Earth's atmosphere on 23 Sept, give or take a day or two.
"Although the spacecraft will break into pieces during re-entry, not all of it will burn up in the atmosphere," NASA said in a statement. It added that "the risk to public safety or property is extremely small."
According to various reports, about 26 pieces of the satellite are expected to survive re-entry and more than 450 kilograms of debris may finally crash back on Earth. The probability of hitting someone is estimated to be 1 in 3,200.
Experts estimate that the satellite most likely will come down over an ocean.
Launched from the Space Shuttle Discovery in 1991, the Upper Atmosphere Research Satellite has a mass of nearly six tonnes. It was launched to measure the ozone layer.
It is a little over 10 metres long, with a diameter of about 4.5 metres.
