The U.S. Missile Defense Agency’s (MDA) Airborne Laser (ABL) has successfully engaged its first ballistic missile with its powerful chemical laser, shooting it down and demonstrating the concept of using high-powered lasers to destroy such threats in their boost phase of flight.

A series of flight tests included engagement of a single liquid-fueled ballistic missile and two solid-fueled Terrier Black Brant sounding rockets. Though not ballistic missiles, the rockets closely mimic a solid-fueled ballistic missile in the boost phase, the period in which ABL is expected to engage. And they offer a lower-cost alternative to launching actual short-range ballistic missile targets, according to Rick Lehner, an MDA spokesman.

During this long-awaited exercise Feb. 11, the 747-400F-based ABL testbed aircraft self-tracked a boosting liquid-fueled, short-range ballistic missile lofted from a mobile sea platform at 8:44 p.m. (PST) within seconds of launch. The onboard low-energy laser compensated for atmospheric disturbances and then the multimegawatt-class high-energy laser engaged the target, “heating the boosting ballistic missile to critical structural failure,” according to a statement from MDA officials. The engagement lasted about two minutes, the officials say.

Within one hour, MDA engaged the second target, a solid-fueled Terrier Black Brant, which was launched from a ground location. Lasing terminated prior to its destruction. MDA officials nonetheless say this demonstration “met all its test criteria,” but they do not cite a reason why the target was not fully lased to destruction.

The ABL did not land or reconstitute the chemicals used to form the laser between the two engagements.

This round, using the sounding rocket, was actually ABL’s third airborne target and its second airborne solid-fuel target engagement, according to MDA officials. The first was apparently quietly “destroyed” during a Feb. 3 flight test, according to MDA officials, though it is unclear why MDA is only just now acknowledging it.

ABL is designed to precisely lase the outer skin of a boosting missiles to prompt a failure in its structural integrity, destroying the target in flight.

These trials — previously expected last year — took place at a weapons range off of Point Mugu, Calif., and represent a leap forward for the ABL program. The Boeing-led effort has been challenged by numerous technical problems and cost overruns, although it has received much attention as the Pentagon’s flagship chemical laser program. As of last spring, about $4 billion had been spent on ABL. MDA is requesting another $99 million in Fiscal 2011 for directed energy projects, which includes funding for the ABL test bed, and for exploration of potential future applications.

This will be the last year MDA manages the system; following flight trials, it will be turned to the oversight of the Pentagon’s director of defense research and engineering to serve as a testbed for other laser projects.

These airborne shootdown tests were originally scheduled for 2002; most recently officials had hoped to execute it last fall.

Boeing officials noted the achievement, saying, “This experiment marks the first time a laser weapon has engaged and destroyed an in-flight ballistic missile, and the first time that any system has accomplished it in the missile’s boost phase of flight. ALTB [Airborne Laser Test Bed] has the highest-energy laser ever fired from an aircraft, and is the most powerful mobile laser device in the world.”

Northrop Grumman designed and built the high-energy chemical laser while Lockheed Martin supplied the beam control/fire control system for ABL.

There are no plans to produce this design, and as ABL has evolved Defense Dept. officials have become more interested in solid-state lasers. Still, MDA has left the door open to a possible operational system in the future that would build off the lessons learned from ABL.

Photo: MDA