Space warfare

However, the mission has not gone without criticism, or speculation that the real purpose is to test missile capabilities.

The Chinese Communist party newspaper wrote: "The United States, the world's top space power, has often accused other countries of vigorously developing military space technology.

"But faced with the Chinese-Russian proposal to restrict space armaments, it runs in fear from what it claimed to love."

Last year, China was also criticised by the US and several of its allies which accused Beijing of risking a space arms race after it used a ballistic missile to destroy one of its own obsolete weather satellites.

Russia's defence ministry also said it feared the US plan was a veiled test of US anti-satellite capabilities and represented an "attempt to move the arms race into space".

The ministry said: "The decision to destroy the American satellite does not look harmless as they try to claim, especially at a time when the US has been evading negotiations on the limitation of an arms race in outer space."


Toxic target

Rogue satellite

Satellite code name USA-193 launched in December 2006 on a Delta II rocket from Vandenberg Air Force Base in California

 

Top secret military reconnaissance mission - otherwise known as a spy satellite

 

Controllers lost contact with satellite hours after it entered orbit

 

Carrying approximately 450kg of toxic hydrazine rocket fuel

 

Satellite itself weighs about two tonnes and is about the size of a bus

The SM-3 missile was fired from the USS Lake Erie in the Pacific Ocean at about 10:26 EST (0326 GMT Thursday), the Pentagon said.

 

There was no immediate word on whether the toxic fuel tank, had been shattered as officials had hoped.
 
But the Pentagon statement said that confirmation the fuel tank had been fragmented should be available within 24 hours.

"Nearly all of the debris will burn up on re-entry [of the Earth's atmosphere] within 24-48 hours and the remaining debris should re-enter within 40 days," it said.

 

Left alone, about half of the spacecraft was expected to survive its blazing descent through the atmosphere and would scatter debris over several hundred miles.

Highly classified

 

Critics have said the justification of health fears may be a cover for preventing highly classified spy satellite technology from falling into foreign hands.

Jing-Dong Yuan, from the non-proliferation programme at the James Martin Centre, told Al Jazeera that the toxic-spread argument is "not very credible according to scientists and other analysts".

 

"The chances of a spy satellite hitting a populated area are only very small. We know that only 30 per cent of the earth is populated, so the vast majority would be the ocean," he said.

Robert Massey, a scientist in London, told Al Jazeera that the US may want to shoot down the spy satellite because "if it landed in the wrong place ... some of their less favourable allies might decide to examine the contents".

Jing-Dong said: "Another reason is that the US has used this opportunity to test its own missile defence capabilities or anti-satellite capabilities."

 

The missile carries a non-explosive "kinetic kill vehicle" – designed essentially to destroy the satellite by smashing into it.

 

The technique is similar to the system employed in US anti-missile shields.

 

Initial delay

The project was initially delayed after weather forecasts on Wednesday in the Pacific, where the US warship was stationed for the mission, indicated that seas would not be calm enough for the ship to fire a missile.

 

But the Pentagon had to act before February 29, when the dead satellite, about 247km above the Pacific Ocean, was projected to re-enter the Earth's atmosphere.

 

On Wednesday, the space shuttle Atlantis landed in Florida, clearing the way for the military operation to proceed.

 

The Pentagon had been waiting for the shuttle to land to avoid contact with flying debris as the satellite returned to Earth.

 

Atlantis returned after completing a mission to deliver Europe's first permanent space laboratory to the International Space Station.