SUNNYVALE, Calif., April 13 -- Lockheed Martin Space Systems, a member of Team Airborne Laser, has commenced fabrication of the turret assembly for the high-energy laser weapon system at its facility in Sunnyvale, Calif.The turret assembly, which will be located on the nose of the system's modified 747-400 Freighter aircraft, will house a rotating 1.5-m telescope designed to locate hostile missiles while the missiles are still in their boost phase. The turret is one component of Lockheed Martin's overall Beam Control/Fire Control system that ensures that the laser is accurately aligned and aimed at its target. The assembly is housed in a roll shell that allows it to rotate 150 degrees in order to track a moving missile; the complete roll shell is scheduled for delivery to Boeing in the spring of 2001 for integration into the modified 747.