October 23, 2011 in Nation/World

Satellite fragments soon to hit Earth

Vessel’s re-entry difficult to locate
Juergen Baetz Associated Press
 
Chance of human injury

The German Aerospace Center puts the odds of somebody somewhere on Earth being hurt by its defunct ROSAT scientific research satellite at 1 in 2,000. But any one individual’s odds of being struck were 1 in 14 trillion.

BERLIN – A defunct satellite entered the atmosphere early today and pieces of it were expected to crash into the earth, the German Aerospace Center said.

There was no immediate solid evidence to determine above which continent or country the ROSAT scientific research satellite entered the atmosphere, agency spokesman Andreas Schuetz said.

Most parts of the minivan-size satellite were expected to burn up during re-entry, but up to 30 fragments could crash into Earth at speeds up to 280 mph.

Scientists were no longer able to communicate with the dead satellite and it must have traveled about 12,500 miles in the last 30 minutes before entering the atmosphere, Schuetz said.

Experts were waiting for “observations from around the world,” he added.

Scientists said hours before the re-entry into the atmosphere that the satellite was not expected to hit over Europe, Africa or Australia. According to a precalculated path it could have been above Asia, possibly China, at the time of its re-entry, but Schuetz said he could not confirm whether the satellite actually entered above that area.

The 2.69-ton scientific ROSAT satellite was launched in 1990 and retired in 1999 after being used for research on black holes and neutron stars and performing the first all-sky survey of X-ray sources with an imaging telescope.

The largest single fragment of ROSAT that could plow into the earth is the telescope’s heat-resistant mirror.

During its mission, the satellite orbited about 370 miles above Earth’s surface.

Even in the last days, the satellite still circled the planet every 90 minutes, making it hard to predict where on Earth it would eventually come down.

A dead NASA satellite fell into the southern Pacific Ocean last month, causing no damage, despite fears it would hit a populated area and cause damage or kill people.

Experts believe about two dozen metal pieces from the bus-size satellite fell over a 500-mile span of uninhabited portion of the world.

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