The Centurion solar-electric flying wing, one of several remotely piloted aircraft being developed under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program, touches down on a Rogers Dry Lake runway following a test flight at NASA's Dryden Flight Research Center, Edwards, Calif. The 206-foot-wingspan lightweight aircraft demonstrated its flying qualities during an initial series of three low-altitude test flights under battery power in late 1998. The Centurion was developed by AeroVironment, Inc., under NASA's ERAST program, managed by NASA Dryden. The Centurion is a prototype technology demonstrator designed to reach altitudes of 90,000 to 100,000 feet, powered entirely by the Sun. Solar cells will eventually cover most of the wing's upper surface, providing power to its 14 electric motors, flight controls and communications systems. Centurion is helping to validate technology for the Helios, a planned high-altitude solar-powered aircraft which could fly for days or weeks at a time on atmospheric sampling, telecommunications or imaging missions, using rechargeable fuel cells to maintain flight at night.