Next, We have to develop Tripods

From Space Daily :

The U.S. Missile Defense Agency has successfully test-fired the megawatt-class laser built by Northrop Grumman for the Airborne Laser (ABL) system, marking the first time such a powerful directed energy weapon suitable for use in an airborne environment has been demonstrated.

The ground-based test, referred to as "First Light," took place Nov. 10 on ABL's laser testbed at the Systems Integration Laboratory, a special building at Edwards Air Force Base, Calif., which houses a modified Boeing 747 freighter fuselage where all elements of the laser system are being assembled and tested.

The test involved the simultaneous firing of all six laser modules and the associated optics that comprise the Chemical Oxygen Iodine Laser (COIL). The laser systems produced an amount of infrared laser energy that was within pre-test expectations.

It's a genuine honest-to-God Martian-War-Machine-type Heat Ray. But to be mounted on a 747. Object? To shoot down things like ballistic missiles, other aircraft etc. At a 747's cruising altitude there's no effective cloud - but of course an aircraft flying entirely below any cloudbase would be relatively safe. I say "relatively" because even at low efficiencies, a Megawatt is a lot of power to be pumping out, even in fractional-second bursts.