*http://news.bbc.co.uk/2/hi/science/nature/6917041.stm



US Army eyes truck-mounted laser*

(The laser is to be mounted on an eight-wheel-drive heavy truck)


The US Army is developing a truck-mounted laser weapon to destroy rockets,
artillery shells and mortars.

Aerospace giant Boeing has been awarded a contract to start on the first
phase of the project - designing a control system for the laser beam.

The solid state laser weapon would eventually be mounted on a 10-tonne,
eight-wheel-drive tactical truck.

The American military has several programmes underway to develop battlefield
lasers.

Under the Phase I contract, worth $7m (£3m), Boeing will develop a
preliminary design for a "rugged beam control system" to be used on a Heavy
Expanded Mobility Tactical Truck (HEMTT).

"We believe this is the next step for developing a weapon system that can
change the face of the battlefield" :Pat Shanahan, Boeing Missile Defense
Systems

The control system is needed to accurately point and focus a laser beam on
an enemy target.

The objective of the High Energy Laser Technology Demonstrator (HEL TD)
programme is to demonstrate that a mobile, solid state laser can effectively
counter rockets, shells and mortars.

Pat Shanahan, vice president and general manager of Boeing Missile Defense
Systems, said the contract was important because "it supports a cornerstone
of the Army's high-energy laser programme".

He added: "We believe this is the next step for developing a weapon system
that can change the face of the battlefield."

Directed energy

Solid state, electrically powered lasers are one of several "directed
energy" technologies being investigated by the US Army.

Chemically powered lasers have been able to achieve megawatts (one megawatt
equals one million watts) of power; but they are large and heavy, and
require a constant supply of chemical fuels.

A beam control system accurately points and focuses the laser

Solid state lasers may lack this power potential, but they tend to be
compact and lightweight, holding promise for the development of
vehicle-mounted weapons.

Massachusetts-based Textron Systems and Northrop Grumman are the only
companies currently working on solid state lasers for the US military. In
2005, they were selected to separately develop a 100 kilowatt (kW) solid
state laser by 2010.

A group at the Lawrence Livermore National Laboratory has hit 67 kilowatts
(kW) of average power in the laboratory with a pulsed solid state laser.

Pulsed laser beams switch on and off very rapidly. The US military is said
to favour a continuous wave (CW), or "always-on" laser.
The Airborne Laser will shoot down missiles in their "boost" phase

The lethality of a laser comes from more than just the power level.
Achieving good beam quality - a measure of how well-focused the laser beam
is - is paramount, as is the duration of the beam, or its "run time".

The Boeing contract contains options that, if exercised, will call for the
company to build and test part of the beam control system integrated on its
vehicle platform.

The options would increase the contract cost for the total programme to
approximately $50m (£24m).

Boeing is also one of several companies, including Northrop Grumman and
Lockheed Martin, building the Airborne Laser (ABL) for the US military.

The ABL consists of a high-energy, chemical oxygen iodine laser (COIL)
mounted on a modified 747 freighter aircraft. It is designed to shoot down
enemy ballistic missiles in their early boost phase, when they are most
vulnerable.


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