Boeing plans to build a solar powered UAV capable of 5 years sustained flight challenging conventional notions about what goes up…
"Boeing has won an $89 million government contract to build and fly an unmanned solar-powered plane that can--eventually--stay aloft continuously for up to five years. Yes, that's five years.
The defense contractor will develop the SolarEagle aircraft for the Vulture II program run by the U.S. Defense Advanced Research Projects Agency, better known as DARPA. Scheduled to get off the ground for its first demo flight in 2014, the plane will likely serve as an electronic sensor and military communications platform. But it could eventually turn into a less expensive alternative to communications and reconnaissance satellites."
Although, I understand the DIY Drones community is already working on something much cooler: