Laser gun zaps missile

An infrared detector capture the explosion

A laser gun, described as "the world's first high-energy laser weapon system designed for operational use", has shot down a missile in a test in the US desert.

We've just turned science fiction into reality

Lieutenant General John Costello, US Army Space and Missile Defense Command

The $250m system was built by TRW Corporation for the US and Israeli governments and was tried out at the White Sands missile range, New Mexico, on Tuesday

During the test of the Tactical High Energy Laser (THEL), it tracked a Katyusha rocket with its radar and then destroyed it with its high-powered laser beam.

The system will be delivered to Israel by the autumn and could be used to intercept Katyusha rockets, which have in the past been fired by guerrillas from the Islamic group Hezbollah, based in southern Lebanon.

Israeli pull-out

The need for protection in northern Israel gained added urgency this month when Israeli troops withdrew from the so-called "security zone" they controlled in southern Lebanon.

The laser gun uses radar to track targets

The THEL system stems in part from a commitment President Clinton made in April 1996 to then-Israeli Prime Minister Shimon Peres to aid Israel in developing a security system against rockets.

"This compelling demonstration of THEL's defensive capabilities proves that directed energy weapon systems have the potential to play a significant role in defending US national security interests world-wide," said Lieutenant General John Costello.

Israeli Major General Isaac Ben-Israel said the weapon was "the crucial first step to help protect the communities along our northern border against the kind of devastating rocket attacks we've suffered recently."

Big beam

A laser is an intense, beam of light, carefully corralled so that the beam does not diverge and weaken. In THEL, the energy is supplied by a controlled chemical reaction.

The laser is a potentially potent weapon as the beam travels literally at the speed of light and can cross great distances with minimal loss of intensity. Such a beam could knock out targets at distances ranging from tens of kilometres to, in theory, thousands of kilometres.

Lasers were behind the space-based missile defence shield idea, labelled "Star Wars", first suggested by US President Ronald Reagan in 1983.

Israel has not said how and when it might deploy THEL and the US Defense Department has said it has no immediate plan to use it with US forces.

The Pentagon is working on a variety of other laser weapon technologies that could be used to shoot down ballistic missiles in flight, although deployment of such weapons is at least a decade away.

The Katyusha missiles are Soviet-designed