NASA's Dead Satellite Falls, Starting Over Pacific

WASHINGTON — NASA's dead six-ton satellite fell to Earth early Saturday morning, starting its fiery death plunge somewhere over the vast Pacific Ocean.

Details were still sketchy, but the U.S. Air Force's Joint Space Operations Center and NASA say that the bus-sized satellite first penetrated Earth's atmosphere somewhere over the Pacific Ocean. That doesn't necessarily mean it all fell into the sea. NASA's calculations had predicted that the former climate research satellite would fall over a 500-mile swath.

The two government agencies say the 35-foot satellite fell sometime between 11:23 p.m. EDT and 1:09 a.m. EDT. NASA said it didn't know the precise time or location yet.

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

The Upper Atmosphere Research Satellite is 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.

Before UARS fell, no one had ever been hit by falling space junk and NASA expected that not to change. 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.