Flight Global just announced in this article that DARPA is close to awarding a contract to build an unmanned aircraft that can stay in the air for up to 5 years. But again, the main issue is how are they going to power the aircraft for such period. The design of the aircraft is aimed at being able to hover over a single area, narcing, communicating, or surveying for years at a time. Oops, did I forgot to mention it will have to do it while carrying a 1000 pound payload in the fearsome winds at a 60,000—90,000 feet? No brainer right? Now I wonder if I’m going to be able to see the aircraft built before I turn 80.