A missile launched from a US navy ship in the North Pacific hit an out-of-control spy satellite late Wednesday, CNN reported.

"The missile has been launched and (it was) a successful intercept," a Pentagon source was quoted by CNN as saying.

"A network of land-, air-, sea- and space-based sensors confirms that the US military intercepted a non-functioning National Reconnaissance Office satellite which was in its final orbits before entering the earth's atmosphere," the Pentagon announced in a written statement midnight Wednesday.

At approximately 10:26 P.M. EST Wednesday (0326 GMT Thursday), a US Navy AEGIS warship, the USS Lake Erie (CG-70), fired a single modified tactical Standard Missile-3 (SM-3) hitting the satellite approximately 247 km over the Pacific Ocean as it traveled in space at more than 17,000 mph (about 27353 km per hour), said the Pentagon's statement.

USS Decatur (DDG-73) and USS Russell (DDG-59) were also part of the task force.

Although the dying satellite is the target, the Pentagon hopes the missile directly hit the tank carrying toxic fuel aboard the spacecraft. The tank is circular with a radius of 20 inches (about 50 cms).

"Confirmation that the fuel tank has been fragmented should be available within 24 hours," according to the statement.

US President George W. Bush authorized Defense Secretary Robert M. Gates to give the shoot-down order. The Navy has prepared for the mission by modifying three SM-3 missiles aboard Aegis ships to strike the bus-size satellite, according to the Pentagon action plan released earlier.

The satellite, called USA 193,was launched December 14, 2006. Shortly after it reached orbit, ground controllers lost contact with it. Left alone, the satellite would be expected to hit Earth during the first week of March. Approximately 1,134 kg of satellite mass would survive re-entry, including 453 kgs of propellant fuel hydrazine, a hazardous material, in the tank, according to the Pentagon.

Therefore, President Bush decided to take action to mitigate the risk to human life by shooting down the errant satellite.

"The likelihood of the satellite falling in a populated area is small. Nevertheless, if it did fall in a populated area, there was the possibility of death or injury to human beings," said James Jeffrey, deputy national security advisor at a Pentagon briefing last week.

In late January, the US government notified other nations that the satellite was unresponsive and would make an uncontrolled re-entry in late February or early March without intercept.

The US satellite shoot-down plan spurred significant concern around the world. US military and government officials have said at several news briefings that the mission is not designed to test US anti-satellite capabilities.

"This operation is designed to alleviate a threat to human beings on this planet. There is a large tank of hydrazine fuel onboard the satellite that would pose a significant threat to people within the immediate vicinity of it if it were to hit land, " Pentagon Press Secretary Geoff Morrell said Tuesday.

However, it was also said that the satellite has to be shot down because of its classified data. "The spy agency doesn't want some part of the satellite to fall into the wrong hands," Space.com quoted Philip Coyle as saying, who is former assistant secretary of defense, now a senior advisor to the Center for Defense Information.

Due to the relatively low altitude of the satellite at the time of the strike, debris will re-enter the earth's atmosphere immediately. Nearly all of the debris will burn up on re-entry within 24-48 hours and the remaining debris should re-enter within 40 days, the Pentagon said.

(Xinhua News Agency February 21, 2008)