http://www.spacedaily.com/news/laser-03l.html'Ever since the dawn of powered flight, it has been necessary for all aircraft to carry onboard fuel - whether in the form of batteries, fuel, solar cells, or even a human "engine" - in order to stay aloft.
But a team of researchers from NASA's Marshall Space Flight Center in Huntsville, Ala., NASA's Dryden Flight Research Center at Edwards, Calif., and the University of Alabama in Huntsville is trying to change that.
They have now chalked up a major accomplishment... and a "first." The team has developed and demonstrated a small-scale aircraft that flies solely by means of propulsive power delivered by an invisible, ground-based laser. The laser tracks the aircraft in flight, directing its energy beam at specially designed photovoltaic cells carried onboard to power the plane's propeller.'
A plane that needs no fuel. Think of it!
Keep in mind that the plane tested in the article was very small (5 ft. wingspan) and very light (11 ounces). It would likely take more power to get, say, a passenger plane into the air, and to get it to go any sort of long distance you'd need arrays of lasers all over the place to ensure the plane got uninterrupted power.