Davis Monthan Air Force Base, AZ--The U.S. Missile Defense Agency (MDA) announced this week that the Airborne Laser Test Bed -- a megawatt-class 1.3 µm chemical oxygen-iodine laser (COIL) mounted in a modified Boeing 747 and intended to shoot down ballistic missiles in their boost phase -- has been put into "long-term storage" at the 309th Aerospace Maintenance and Regeneration Group at Davis Monthan Air Force Base. This location, also known as the "Boneyard," is where excess and unused military aircraft are taken for preservation.

The Airborne Laser achieved high-power "first light" in ground testing in 2008, then was tested in flight several times over the next few years with varying success; however, it never reached the couple-hundred-kilometer range required to make the system useful in practice. In addition, its messy and bulky chemical-based technology is being superseded by electrically pumped lasers such as the alkali-vapor laser and, more importantly, diode-pumped solid-state lasers and fiber lasers, which are far higher in efficiency and require only a source of electrical power to operate.

Indeed, the MDA notes that it is "continuing efforts to develop highly efficient electric lasers in support of missile defense to significantly reduce the complexity and cost of future directed-energy weapons."