The U.S. military said it shot down an intermediate-range ballistic missile target over the Pacific on Friday in the most challenging test yet of its work on a planned antimissile shield for Europe against Iran.

The Pentagon said the successful test of Lockheed Martin Corp and Raytheon Co hardware showed it is on track to wrap up this year the first phase of a layered, multibillion-dollar antimissile defense in Europe.

It also may be adapted to defend against North Korea, another focus of U.S. antimissile efforts, and ultimately to add to the existing U.S. ground-based defenses.

The test west of Hawaii marked the first time that Lockheed's shipboard Aegis combat system had been used to intercept a target with a range greater than 3,000 kms (1,864 miles), the Pentagon's Missile Defense Agency said.

Dubbed Flight Test Standard Missile-15, it was also the first Aegis test to rely on missile tracking data gathered by a powerful on-shore radar station.

The ability to use remote radar data to engage a threat ballistic missile greatly increases the battle space and defended area of the SM-3 interceptor missile built by Raytheon and used to destroy the target, the Pentagon's Missile Defense Agency said in a statement.

Previous sea-based Aegis intercept tests have featured shorter-range targets.

This was the 21st successful intercept in 25 attempts for the Aegis program since flight testing began in 2002, the agency said. Of all elements of the layered antimissile shield, it was the 45th successful intercept in 58 flight tests since 2001, the statement said.

The last two intercept tests of a U.S. ground-based antimissile bulwark, managed by Boeing Co and aimed at protecting U.S. soil from even longer-range missiles, have failed.

FLEXIBLE TECHNOLOGY

President Barack Obama in September 2009 scrapped a George W. Bush-era plan to build in Poland and the Czech Republic a European version of the ground-based shield already deployed in California and Alaska.

Instead, Obama's Pentagon turned to the more flexible Aegis technology to adapt more readily to evolving threats and geography of each region, Navy Rear Admiral Archer Macy, head of the joint military staff's antimissile office, said in congressional testimony on Wednesday.

In the test Friday, an intermediate-range ballistic missile target was launched in a northeasterly direction from Kwajalein Atoll in the Republic of the Marshall Islands, about 2,300 miles southwest of Hawaii.

A Raytheon-built, forward-based AN/TPY-2 X-band transportable radar, located on Wake Island, detected and tracked the target, MDA said.

The radar sent information to a battle management system that relayed cues to the destroyer O'Kane, which was to the west of Hawaii. The ship aimed and launched Raytheon's SM-3 Block IA missile 11 minutes after the target was launched, MDA said.

Initial indications are that all components performed as designed, it said. Richard Lehner, an MDA spokesman, declined to say whether the test included any countermeasures, such as decoys that an enemy likely would use. He cited security requirements.

The United States expects to meet its goal of putting an initial missile defense capability in Europe by the end of this year even though efforts to find a host nation for the Raytheon-built X-band radar station are still under way, Brad Roberts, a deputy assistant secretary of defense, told the House of Representatives Armed Services subcommittee on strategic forces on March 31.

A Lockheed-Raytheon team is seeking to oust Boeing as manager of future work on the ground-based midcourse system that is the sole U.S. shield against intercontinental ballistic missiles.

(Editing by Jackie Frank)