- Associated Press - Friday, September 23, 2011

CAPE CANAVERAL, FLA. (AP) - A 6-ton NASA satellite on a collision course with Earth clung to space Friday, apparently flipping position in its ever-lower orbit and stalling its death plunge.

The old research spacecraft was targeted to crash through the atmosphere sometime Friday night or early Saturday, putting Canada, Africa and Australia in the potential crosshairs, although most of the satellite should burn up during re-entry. The United States wasn’t entirely out of the woods; the possible strike zone skirted Washington state.

“It just doesn’t want to come down,” said Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics.

McDowell said the satellite’s delayed demise demonstrates how unreliable predictions can be. That said, “the best guess is that it will still splash in the ocean, just because there’s more ocean out there.”


Until Friday, increased solar activity was causing the atmosphere to expand and the 35-foot, bus-size satellite to free fall more quickly. But late Friday morning, NASA said the sun was no longer the major factor in the rate of descent and that the satellite’s position, shape or both had changed by the time it slipped down to a 100-mile orbit.

“In the last 24 hours, something has happened to the spacecraft,” said NASA orbital debris scientist Mark Matney.

On Friday night, NASA said it expected the satellite to come crashing down between 11 p.m. and 3 a.m. EDT. It was going to be passing over the Atlantic, Pacific and Indian oceans at that time, as well as Canada, Africa and Australia.

“The risk to public safety is very remote,” NASA said in a statement.

The Aerospace Corp., which tracks space debris, also estimated the strike would happen sometime between about 11 p.m. and 3 a.m. EDT, which would make a huge difference in where the debris falls. Its projections also put almost all of the U.S. in the clear _ with Washington state the lone holdout.

Any surviving wreckage is expected to be limited to a 500-mile swath.

The Upper Atmosphere Research Satellite, or UARS, will be the biggest NASA spacecraft to crash back to Earth, uncontrolled, since the post-Apollo 75-ton Skylab space station and the more than 10-ton Pegasus 2 satellite, both in 1979.

Russia’s 135-ton Mir space station slammed through the atmosphere in 2001, but it was a controlled dive into the Pacific.

Some 26 pieces of the UARS satellite _ representing 1,200 pounds of heavy metal _ are expected to rain down somewhere. The biggest surviving chunk should be no more than 300 pounds.

Earthlings can take comfort in the fact that no one has ever been hurt by falling space junk _ to anyone’s knowledge _ and there has been no serious property damage. NASA put the chances that somebody somewhere on Earth would get hurt at 1-in-3,200. But any one person’s odds of being struck were estimated at 1-in-22 trillion, given there are 7 billion people on the planet.

“Keep in mind that we have bits of debris re-entering the atmosphere every single day,” Matney said in brief remarks broadcast on NASA TV.

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