Global Policy Forum

System is designed to counter possible North Korea threat.

The first test in nearly two years of a multibillion-dollar U.S. antimissile shield failed on Wednesday when the interceptor missile shut down as it prepared to launch in the central Pacific, the Defense Department said. About 16 minutes earlier, a target missile carrying a mock warhead had been successfully fired from Kodiak Island, Alaska, according to a statement from the Missile Defense Agency.

An "anomaly" of unknown origin caused the interceptor to shut down automatically in its silo at the Kwajalein Test Range in the Marshall Islands, said Richard Lehner, a spokesman for the Pentagon's missile agency. The aborted $85 million test appeared likely to set back plans for activation of a rudimentary bulwark against long-range ballistic missiles that could be fired by countries like North Korea.

Pentagon officials had hoped the test would set the stage for any decision by President George W. Bush to put the system on alert in coming weeks. Initially, the system is designed to counter North Korean missiles that could be tipped with nuclear, chemical or germ weapons. On Dec. 8, in reply to a question about switching the system on, Michael Wynne, the Pentagon's chief weapons buyer, said the plan was "not constrained by timing, exactly." But he said officials would await the test and "then we'll see from there."

In 2002, Bush pledged to have initial elements of the program up and running by the end of 2004 while testing and development continued. The system is a scaled-down version of a ballistic missile shield first outlined in March 1983 by President Ronald Reagan. The test followed a week of delays caused by weather and technical glitches, including malfunction of an internal battery aboard the target missile on Tuesday, Lehner said. In an e-mail exchange, Philip Coyle, the Pentagon's chief weapons tester under Reagan, called the failed test "a serious setback for a program that had not attempted a flight intercept test for two years."

Because the mission was to have tested new hardware, software and engagement scenarios, it was termed a "flyby," not an attempted intercept. This meant gathering data was the primary goal, not downing the target, according to the Missile Defense Agency. When a shoot-down has been the chief test objective, the system so far has succeeded five out of eight times in highly scripted conditions.

The last test, attempted in December 2002, misfired when the warhead - a 120-pound, or 55-kilogram, "kill vehicle" of sensors, chips and thrusters designed to pulverize its target on collision - failed to separate from its booster rocket. Boeing, as prime contractor, put together the ground-based shield, which is to be folded into a system involving airborne, sea- and space-based elements. The Pentagon is spending $10 billion a year on the project.