WASHINGTON — The Pentagon's missile defense program has long been as contentious as it is pricey. But a small part of that system, ship-mounted missiles designed to track and destroy enemy warheads, has proved more affordable and successful.
The Navy will activate that system as soon as today when the window opens for an unusual Pentagon attempt to shoot down a failing spy satellite that is hurtling toward Earth with 1,000 pounds of toxic rocket fuel aboard.
In eight years of testing, warships equipped with Aegis radar systems have hit 12 targets in 14 Pacific Ocean attempts, compiling a better record than the costlier land-based system of interceptor missiles in Alaska and California.
But the task of bringing down the satellite will be much harder, Navy officials warned. The satellite is traveling faster, higher and, perhaps most important, colder than the enemy missiles the system was built to hit.
"We're looking at a cold body in space, a body that has been shut down for some time, and so it doesn't have the traditional heating that a ballistic missile has," said a Navy official, noting that heat is one of the primary ways an interceptor finds its target.
"The typical clues that both the interceptors and the combat system look for have to be changed. That's the difficulty," the official said, speaking on condition of anonymity because he was not authorized to discuss the effort publicly.
Pentagon officials said today's scheduled landing of the space shuttle Atlantis in Florida marks the beginning of a nearly weeklong window to shoot down the satellite. There were signals that the attempt could come just hours after the shuttle's touchdown.
Ships and aircraft were issued a notice Tuesday by federal officials to avoid the north Pacific test area today, said Pentagon Press Secretary Geoff Morrell. But Morrell emphasized that no final decision had been made about when to take the shot.
"If a shot is not taken within the 24 hours after that notice went out, there will likely be another [notice] that goes out," he said.
According to a Web posting by Ted Molczan, a well-known amateur satellite tracker in Canada, the federal notice warns ships and planes to avoid a restricted zone just west of Hawaii for 2 1/2 hours beginning at 7:30 Pacific time tonight.
The 5,000-pound spy satellite went bad soon after its 2006 launch and has been orbiting out of control. The Bush administration's decision last week to shoot it down marks the first such attempt since Cold War-era tests in the 1980s.
