U.S. to blast satellite after space shuttle leaves

WASHINGTON (Reuters) - The United States will have the chance to shoot down a disabled U.S. spy satellite from next Wednesday, after the space shuttle Atlantis ends its current mission, a U.S. general said on Friday.

"The window will open when the shuttle is on the ground," said Army Lt. Gen. Carter Ham, director of operations for the Pentagon's Joint Staff.

"All those who have a vested interest in this will then apply their best judgment as to when the best opportunity is to intercept the satellite," he told reporters.

The Pentagon said on Thursday the Navy would try to shoot down the satellite before it enters the atmosphere, using a modified tactical missile from a ship in the Pacific, to avert a potentially deadly leak of toxic gas from its fuel tank.

Each missile costs about $10 million but the U.S. government did not yet have an estimate of the cost of the shootdown operation, Ham said.

The space shuttle is scheduled to land on Wednesday at 9:06 a.m EST at the Kennedy Space Center in Florida.

Ham said the opportunity to shoot down the satellite would last until early March.

Some space experts have criticized the decision to shoot down the satellite, saying the risk of it causing any damage on the ground was remote.

They suggested the United States wanted to test its ability to hit other states' satellites. But U.S. officials insist their sole aim is to minimize the risk to human life.

Washington strongly criticized China for shooting down an old weather satellite in a test in January 2007.

Neither the United States nor Russia have conducted an anti-satellite operation since the 1980s, analysts said.

The State Department said it would try to reassure other nations the operation was not a statement of intentions about international arms treaties or anti-satellite weapons.

State Department spokesman Sean McCormack said the U.S. operation was "quite different" from China's test.

The Pentagon's mission would be "to try to protect populations on the ground" and take place when the satellite is about 155 miles from earth, he said.

China's operation was designed specifically as a test against a satellite and left a large amount of debris in orbit at a higher altitude that could affect the ability of others to put satellites into space, McCormack said. (Additional reporting by Susan Cornwell, editing by Alan Elsner)