An airborne intercept of a liquid-rocket target failed on September 1, 2010 when the megawatt power airborne laser (ABL) veered away from the target a split second before the planned engagement. Despite this problem, the Missile Defense Agency (MDA) plans to resume flight experiments this week, testing the performance of the software fixes, leading to a lethal shoot-down experiment involving a solid-fuel target missile by the end of September 2010. Another test, scheduled for mid-October will involve lasing another solid-fuel missile at a distance three times the range of the last successful intercept of a liquid-fuel missile performed on February 11, this year. The recent failure came after repeated aborted test attempts in August, where issues attributed to calibration and component cooling prevented tests completion. Prior to these tests, the aircraft set idle for several months until minor damage to its optics, caused during a May 2010 test flight are repaired. Test range availability have also limited further flights since May this year.
The recent intercept was the second failed attempt to shoot down a liquid-fuel missile during its boost phase. The first took place after the successful first intercept on February 11, 2010. While the February failure was caused by the megawatt laser shutting down prematurely, the recent mission terminated early, when corrupted beam control software steered the high energy laser slightly off center. preliminary indications are that a communication software error within the system that controls the laser beam caused misalignment of the beam. The on board safety system detected this shift and immediately shut down the high energy laser.
Airborne Laser Demonstrates First Ballistic Missile Intercept (Defense-Update)
Airborne Laser Gears Up for Next Shoot-down Test (Space News)