Preliminary indications are that the so-called Airborne Laser Test Bed tracked the target's exhaust plume but did not hand off to a second, "active tracking" system as a prelude to firing the high-powered chemical laser, said Richard Lehner, an MDA spokesman. "The transition didn't happen," he said. "Therefore, the high-energy lasing did not occur." Boeing produces the airframe and is the project's prime contractor, while Northrop Grumman supplies the high-energy laser and Lockheed Martin Corp has been developing the beam- and fire-control systems. Defense Secretary Robert Gates scaled back the program into a research experiment last year. About $4 billion...