U.S. Missile Hits Defective Satellite
The U.S struck a crippled spy satellite out of space using a Navy heat-seeking missile from a warship in the Pacific Ocean, said military officials, reported the BBC News. The satellite called USA 193 had stopped communciating and lost control hours after it was launched in 2006.
The Pentagon planed to hit the satellite before it re-enters Earth's atmosphere, minimizing the debris remaining in space, reported the Pioneer Press. The missile needed to strike a small fuel tank aboard the satellite in order to eliminate the toxic fuel that would injure or kill people if it reached the Earth, a Navy official said.
The fuel tank contains more than 450kg (1,000lbs) of toxic hydrazine, which if it was not released in space, would most likely survive re-entry through Earth's atmosphere and leak toxic gas over a wide area, reported the BBC News.
The military said it would destroy the satellite with an SM-3 missile fired from the crusier USS Lake Erie, which is posted on the western side of Hawaii. The fact that the satellite has no heat-generating propulsion system on board made it difficult for the Navy missile's heat-seeking systme to work, reported the Pioneer Press. However, software changes had been made to compensate for the lack of heat, an official said.
Left alone, the satellite would be expected to hit Earth during the first week of March scattering debris across the Earth's surface. Officials expect that debris from over half of the 5,000lb spacecraft will fall to Earth within the first 15 hours after the strike or within its first two revolutions of Earth, reported the BBC News.
It is unclear whether the missile has ruptured the tank. Tthe military hoped to disperse as much hydrazine as possible in space before the National Reconnaissance Office (NRO) "bird" falls to Earth.
Professor Richard Crowther, a space debris expert with the Science and Technology Facilities Council (STFC), said that if struck with the missile, about 25% of USA 193 is likely to survive the fall to Earth.
"The smaller the debris is the more likely you are to get burn-through. So if you fragment something before re-entry, less mass will survive to hit the Earth," he told BBC News.
The U.S. denied the operation was a response to the anti-satellite test carried out by China last year, which prompted fears of a space arms race. But Russia's defence ministry has effectively branded the U.S. operation a cover for testing an anti-satellite weapon.
Last year, China carried out a test using a ground-based ballistic missile to destroy a satellite in space, prompting international alarm and fears of a space arms race. The Russian defence ministry argued that various countries' spacecraft had crashed to Earth in the past, with many using toxic fuel on board, but that this had never before merited "extraordinary measures".
On Tuesday, a U.S. State Department spokesman stressed that the action was meant to protect people from the hazardous fuel and was not a weapons test. The U.S. government has also denied claims that the main aim of the operation was to destroy secret components on USA 193. Officials say classified parts would be burned up in the atmosphere and would not be a reason for shooting down the satellite.