Solar powered autonomous flight completes full day/night cycle; 28 hrs w/o fuel!

Hallie Siegel writes: Researchers have long worked on building a solar powered aircraft capable of continuous flight. The general idea seems achievable enough: during the day, with the help of the solar cells that cover its wings, the aircraft collects energy from the sun in order to power the propulsion and control systems while any surplus power charges the battery. During the night, the batteries take over powering the propulsion and control systems, slowly discharging until the next morning when a new cycle begins.

To actually pull it off has required a fair bit of innovation in flexible solar cells, high energy density batteries, miniaturized MEMS and CMOS sensors, and powerful processors ... but researchers at ETH Zurich have just recently managed to keep their unmanned UAV aloft for 28 hours without any fuel, building on their previous record by over an hour. Having more than 24 hours of endurance is important because overcast skies can inhibit recharging and poor weather or high winds can effect power consumption.

Really nice accomplishment from the folks at the AtlantikSolar project — we're looking forward to their next goal, which is to achieve 80 hours of endurance flight. Now that would be something.