Laser weapon ‘milestone’

But the Pentagon’s former top weapons tester poured doubt on the project, saying it faced major technical hurdles and might be defeated by a simple countermeasure.

The Airborne Laser has been developed at a cost so far of about US$3.5 billion (A$4.59 billion) with the aim of destroying, at the speed of light, all classes of ballistic missiles shortly after their launch.

If successful in flight testing and deployed, it would become part of an emerging US anti-missile shield that also includes land- and sea-based interceptor missiles.

“You’ve demonstrated capability on the ground,” Air Force Lieutenant General Henry Obering said at a ceremony at which the aircraft was rolled out of a Wichita, Kansas, hangar where it has been undergoing modifications.

“Not since that time nearly twenty-two hundred years ago, when Archimedes reflected the sun’s rays to set the Roman fleet on fire off Syracuse, has the world seen a weapon that puts fresh meaning into the phrase ‘in real time’.”

“Let’s do it now in flight,” Mr Obering told employees of Boeing, the prime contractor, and chief subcontractors Lockheed Martin and Northrop Grumman at the event.

Effectivenss doubted

Philip Coyle, the Pentagon’s chief weapons tester under former president Bill Clinton and now at the private Centre for Defence Information, said the ABL’s effectiveness appeared doubtful.

“If a laser can be developed with enough power to penetrate the atmosphere and still be lethal once it reaches a target, an enemy would only need to put a reflective coating on the outside of its missiles to bounce off the laser beam, making it harmless,” he said.

Missile Defence Agency spokesman Richard Lehner said that “abrasion” during the early stage of a missile’s launch would erase the reflective capabilities of any such coating.

He added that the project currently involved a single “developmental” aircraft, with no others to be purchased until officials were satisfied the system would be successful.

Engineers are to start installing a high-energy chemical oxygen iodine laser on the modified jumbo jet next year, with the first missile intercept test to take place in late 2008.