Installation of the

high-power chemical laser aboard the Pentagon’s Airborne Laser (ABL)

began Sept. 4 at Edwards Air Force Base in California, shortly after

completion of a round of

flight tests of the anti-missile aircraft’s

low-power targeting lasers, the

program director said during a Sept. 4 media conference call.

Greg Hyslop, ABL

vice president and project manager at Boeing Missile Defense of Huntsville, Ala.,

said all of the key ABL subsystems have been tested, and work to integrate the megawatt-class Chemical Oxygen-Iodine Laser (COIL)

will be going on through the beginning of next year. The high-power laser, which has been tested on the ground, was built by Northrop Grumman Space Technology of Redondo Beach, Calif.


to be powerful enough

to shoot down missiles in flight, the COIL laser

will be activated next


and ground testing of the fully integrated system will begin in fall 2008, Hyslop said. Flight tests will begin in early 2009, and an

attempt to shoot down a short-range ballistic missile is scheduled for

August 2009.

The ABL, based on a modified Boeing 747 aircraft platform, is the U.S. Missile Defense Agency’s primary weapon for boost-phase missile defense. The system being built today is a prototype intended to verify the concept, but it eventually could be pressed into service if needed, Missile Defense Agency officials say.

Hyslop noted that the schedule of the ABL’s first shoot-down test

is subject to

the whim of lawmakers, who will soon determine how much money the program

will get in 2008. U.S. President George W. Bush requested $498.1 million for the ABL in February. The U.S. House of Representatives passed a defense appropriations bill in August that cut

$50 million from the ABL request. The Senate has yet to pass its version of the defense appropriations bill; however, the Senate Armed Services Committee has recommended that the ABL budget request be cut by half.

Hyslop said a $50 million cut probably would not affect the test schedule, but that a $250 million cut likely would result in a two-year delay.

The ABL’s recent round of flight testing involved three low-power lasers, two for targeting and one that simulated the aircraft’s main weapon. During the final test, completed Aug. 23, all three worked together to

track and engage

a target aircraft at a distance similar to that of a real missile engagement

, the Missile Defense Agency and Boeing

said Aug. 31. The ABL’s effective range is classified, but program officials say it is in the hundreds rather than tens of kilometers.

The Tracking Illuminator Laser, built by Raytheon Space and Airborne Systems of El Segundo, Calif., tracked the target, which is a modified NC-135 aircraft called

Big Crow.

The Beacon Illuminator Laser, built by Northrop Grumman Space Technology, was used to compensate for atmospheric distortion. These two lasers are part of the beam control and fire control system built by Lockheed Martin Space Systems

of Sunnyvale, Calif.

The Surrogate High Energy Laser,

filling in for the COIL that now is being

installed, engaged the target. Cameras on board Big Crow verified all three lasers performed as specified

. Analysis of the test data shows ABL is ready for the next phase of testing, Boeing said.

This flight test mission was ABL’s 48th overall.

ABL will be the first combat aircraft to rely

solely on a directed energy device as a weapon. If it is approved for operations, it

will be a part of the nation’s layered ballistic missile defense system.

The 2009 shoot-down test will be a key factor in determining whether additional ABL platforms are built and deployed. Hyslop said the ABL also could be used against aircraft and ground targets, though there is currently no funding for these capabilities.

In February, the Congressional Budget Office issued a budget options report detailing the possibility of terminating the ABL program. It said ending the program would save $330 million in 2008,

$1.7 billion through 2011, and more than $10 billion between 2012 and 2017


plans to build seven more ABL aircraft at roughly $1.5 billion apiece. Hyslop said $1.5 billion per aircraft is probably a little high.

MDA spokesman Rick Lehner

said the budget for future ABL aircraft is unknown.