Laser beam powers flying machine.

A NASA-led engineering team announced on Oct. 9 that it has flown a lightweight, remote-controlled aircraft that receives power in flight from a ground-based laser. Theoretically, such a plane would never have to land for refueling. Such drones may someday serve as cheap alternatives to satellites for applications ranging from military surveillance to telecommunications (SN: 8/23/03, p. 125).

The team, led by David M. Bushman of NASA Dryden Flight Research Center in Edwards, Calif., built the drone from balsa wood, carbon-fiber-strengthened tubes, and colorful Mylar skin. Beneath the 1.5-meter wingspan, hangs a solar panel that's wired to the vehicle's electric motor.

Using an infrared laser such as those that cut steel in auto manufacturing, the researchers beamed enough energy into the plane's photovoltaic cells to drive a propeller and keep the vehicle airborne.

Last year, scientists in Japan used a laser's power to launch a paper plane (SN: 7/20/02, p. 46). Nevertheless, the recent NASA demonstration is the "first unfueled, sustainable flight" driven by laser, Bushman says.

Future aircraft could carry batteries and rely on the laser only for periodic recharging during long missions, Bushman says. This laser-driving technology should work at distances up to 30 kilometers, he adds.--P.W.