By John McHale
ALBUQUERQUE, N.M. - Scientists at the U.S. Air Force Phillips Laboratory at Kirtland Air Force Base in Albuquerque, N.M., are making heavy use of commercial off-the-shelf (COTS) electronics in designing an airborne laser to track and destroy theater ballistic missiles shortly after launch.
The airborne laser, which is to be mounted on a Boeing 747 widebody jetliner and deployed early in the next century, has recently passed two technical checkpoints using a laser to track a theater ballistic missile in flight and compensating for the effects that the atmosphere could have on that laser beam.
The system`s primary mission is to destroy short-range ballistic missiles such as the Iraqi Scud used during the Persian Gulf War in boost phase to keep debris or unexploded warheads from falling on friendly forces or civilians.
The signal processing on this complex and formidable weapon uses virtually all off-the-shelf equipment, says Air Force Col. Michael W. Booen, airborne laser program director. About the only custom portions of the laser`s signal processing is software, he points out. "We`ve written about 800,000 lines of code."
The system will use approximately 100 digital signal processors. Suppliers for the processors have yet to be determined, says Kirtland spokesman Rich Garcia.
The executive control equipment for the airborne laser system is being designed at Raytheon Co. in Lexington, Mass. It will use four Alpha microprocessors from Digital Equipment Corp. in Maynard, Mass., Garcia says.
"Tracking missiles in the air is more difficult than from the ground because you`re looking horizontal rather than up," Booen says. The aircraft uses existing infrared sensors embedded in its skin, which enables operators to search for ballistic missiles over a 360-degree field of view, he says. "The sensors are the same as those used on the F-14" carrier-based jet fighter.
The airborne laser has three subsystems - laser generation, beam control, and battle manager. The beam-control subsystem houses the optics, steering, and deformable mirrors, while the battle manger communicates with other missile defense systems such as Patriot and THAAD, Booen says.
The system also uses three lasers: a targeting laser that illuminates the target, a beacon laser that helps steer the killer laser, and the killer laser that heats a point about the size of a basketball on the target to destroy it, Booen explains.
Steering the killer laser are "deformable" mirrors that can change their shapes, as well as computers that help neutralize the atmosphere`s effects. Atmospheric conditions distort the laser beam and weaken its effects on a target missile.
The deformable mirror, designed at TRW in Redondo Beach, Calif., uses actuators which adjust to atmospheric turbulence in the light collected from the beacon laser every few seconds to control the shape of the beam and ensure full laser effectiveness, Booen explains.
The killer laser takes two to ten seconds to destroy its target. "It will unzip the missile like a sardine can," Booen boasts.
Air Force scientists are supervising a project to mount a high-power laser aboard a wide-body jet such as a Boeing 747 in efforts to find, track, and destroy theater ballistic missiles shortly after launch.
