Lockheed Martin has demonstrated technology in partnership with LaserMotive which can extend the flight time of their “Stalker” drone by 2,400 percent using a ground-based laser and potentially allow the drone to stay in the air indefinitely.
http://lasermotive.com/2012/07/11/successful-48-hour-laser-powered-uas-demonstration/
Comments
Canada's Communications Research Centre accomplished the same and more in the '80s with power beamed with microwaves.
I talked to the guys at laser motive about a year ago when they were searching for uav partners. Fun fact, for an early demonstration the auto-tracking wasn't ready yet. So they got a kid who was good at video games to aim the laser! Now it's all automated, pretty cool system.