B-1B with laser

Ultimately, the Pentagon would like to cook up a much smaller laser weapons array -- just one-tenth the size and weight of existing lasers packing comparable power -- for tactical aircraft that would target threats on the ground. Enter DARPA's High Energy Liquid Laser Defense System (HELLADS) program, the goal of which is to develop a 150KW laser weapon that has a volume of 3 cubic meters for the system and a weight of no more than 5 kilograms per kilowatt (which, at 150KW, means a weight below 1,650 pounds). In June 2011, DARPA said it was looking to have the 150KW system, featuring twinned laser modules, completed by the end of 2012 and transported to the White Sands Missile Range in New Mexico in early 2013 for ground-testing against rockets, mortars, and surface-to-air missiles, and for simulations of air-to-ground targeting.

In July 2011, Predator drone maker General Atomics won the contract from DARPA to build the Demonstrator Laser Weapon System (DLWS) for HELLADS. General Atomics says it is pursuing a "new approach to electric lasers" that joins "the high storage density of solid-state with the efficient heat removal of flowing liquids."

Following the ground testing of the DLWS in 2013, the laser demonstrator looks likely to be integrated onto a B-1B Lancer aircraft. (See DARPA's illustration of that above.)