The US 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 and Raytheon hardware "demonstrated the capability" of the first phase of a layered, multibillion-dollar antimissile shield, which is due to be in place in Europe by year-end.
The technology may also be adapted to defend against North Korea, another focus of US antimissile efforts, and ultimately to bolster existing ground-based defences.
The test west of Hawaii marked the first time Lockheed's shipboard Aegis combat system had been used to intercept a target with a range greater than 1 900 miles, said the Pentagon's Missile Defence Agency, or MDA.
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 counter an enemy ballistic missile "greatly increases the battle space and defended area" of the Standard Missile-3 interceptor built by Raytheon and used to destroy the target, MDA said.
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.
The last two intercept tests of a US ground-based antimissile bulwark, managed by Boeing and aimed at protecting US soil from even longer-range missiles, have failed.
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 the "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 on Friday, an intermediate-range ballistic missile target was launched in a north-easterly 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 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".
But unless such countermeasures are included, "MDA's tests simply cannot tell us whether the system would work in the real world," said Tom Collina, research director at the private Arms Control Association.
The US expects to meet its goal of putting an initial missile defence 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 defence, told the House of Representatives Armed Services subcommittee on strategic forces on 31 March.
Both North Korea and Iran have developed and deployed medium-range ballistic missiles, with a range of 625 to 1 875 miles.
Neither has successfully flight-tested either intermediate range or intercontinental-range ballistic missiles, said Greg Theilmann, an Arms Control Association missile expert who formerly assessed foreign ballistic missile threats in the US State Department's intelligence bureau.
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