Washington - The US military has opened a window beginning at 10:30 pm Wednesday (0330 GMT Thursday) to launch a missile to shoot down a failed spy satellite, a military source said. The Navy plans to launch a missile from a cruiser near Hawaii to destroy the satellite carrying fuel that defence officials believe could be hazardous to humans. A senior defence official said the window of opportunity to launch the missile is "tens of seconds."
The satellite is in low orbit and estimates show it will re-enter the Earth's atmosphere by the first week of March. The Pentagon hopes to destroy the fuel tank before re-entry to minimize the possibility the fuel, called hydrazine, can harm people.
Pentagon officials had said that poor weather and rough waters in the Pacific might have forced a delay in carrying out the strike on Wednesday and there was still no guarantee the launch would go forward.
The Pentagon has estimated that it has until the end of February to carry out a successful launch. The senior defence official said once the satellite begins re-entry it will be impossible to track.
The Navy plans to launch a Standard Missile-3 from a the Lake Erie cruiser stationed off Hawaii using the same system that forms the backbone of the sea-based missile-defence system, prompting speculation that the real reason for conducting the shoot-down was test the adaptability of missile defence for taking out enemy satellites.
President George W Bush's decision to proceed with the intercept has prompted complaints from China and Russia, who worry it marks a step toward the weaponization of space.
China last year used a missile to shoot down one of its old weather satellites that was in much deeper orbit than the US satellite, generating strong international criticism, including from the United States.
Thousands of pieces of debris from the destroyed Chinese satellite remain in orbit and have to be monitored. The US military hopes that by hitting its satellite in low orbit will send most of the debris to burn up while falling into the atmosphere.
