Chinese satellite kill challenges U.S.

A large U.S. spy satellite has lost power and could hit the Earth in late February or March, government officials said Saturday. The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where on the planet it might come down, they said. The officials spoke on condition of anonymity because the information is classified as secret.

"Appropriate government agencies are monitoring the situation," said Gordon Johndroe, a spokesman for the National Security Council, when asked about the situation after it was disclosed by other officials. "Numerous satellites over the years have come out of orbit and fallen harmlessly. We are looking at potential options to mitigate any possible damage this satellite may cause." He would not comment on whether it is possible for the satellite to be perhaps shot down by a missile. He said it would be inappropriate to discuss any specifics at this time.

A senior government official said that lawmakers and other nations are being kept apprised of the situation. Such an uncontrolled re-entry could risk exposure of U.S. secrets, said John Pike, a defense and intelligence expert. Spy satellites typically are disposed of through a controlled re-entry into the ocean so that no one else can access the spacecraft, he said. Pike also said it's not likely the threat from the satellite could be eliminated by shooting it down with a missile, because that would create debris that would then re-enter the atmosphere and burn up or hit the ground.

Air Force Gen. Gene Renuart, who heads of U.S. Northern Command, told The Associated Press on Tuesday that the size of the satellite suggests that some number of pieces will not burn up as the orbiting vehicle re-enters the Earth's atmosphere and will hit the ground. "We're aware that this satellite is out there," Renuart said. "We're aware it is a fairly substantial size. And we know there is at least some percentage that it could land on ground as opposed to in the water."

A U.S. official confirmed that the spy satellite is designated by the military as US 193. It was launched in December 2006 but almost immediately lost power and cannot be controlled. It carried a sophisticated and secret imaging sensor but the satellite's central computer failed shortly after launch. The official spoke on condition of anonymity because the information is classified as secret. Renuart added that, "As it looks like it might re-enter into the North American area," then the U.S. military along with the Homeland Security Department and the Federal Emergency Management Agency will either have to deal with the impact or assist Canadian or Mexican authorities.

Military agencies, he said, are doing an analysis to determine which pieces most likely would survive re-entry. But he cautioned that officials won't have much detail on where or when it will crash until it begins to move through the atmosphere and break up. Renuart added that there does not as yet appear to be much concern about sensitive technologies on the satellite falling into enemy hands. "I'm not aware that we have a security issue," he said. "It's really just a big thing falling on the ground that we want to make sure we're prepared for."

The satellite includes some small engines that contain a toxic chemical called hydrazine - which is rocket fuel. But Renuart said they are not large booster engines with substantial amounts of fuel. Video images of the satellite captured by John Locker, a British amateur satellite watcher, show it to be about 13 feet to 16.5 feet across. He believes it weighs a maximum of 10,000 pounds. Locker calculated its size with data on its altitude and location provided by other amateur satellite watchers, using the International Space Station as a yardstick.

Satellite watchers - a worldwide network of hobbyists who track satellites for fun - have been plotting the satellite's degradation for a year. They estimate it is now at an altitude of about 173 miles, and Locker believes it is dropping about 1,640 feet a day. Where it lands will be difficult to predict until the satellite falls to about 59 miles above the Earth and enters the atmosphere. It will then begin to burn up, with flares visible from the ground, said Ted Molczan, a Canadian satellite tracker. From that point on, he said, it will take about 30 minutes to fall. In the past 50 years of monitoring space, 17,000 manmade objects have re-entered the Earth's atmosphere.