Solar wing becomes highest flying plane

Helios soars into the record books over Hawaii

By Richard Stenger
CNN

(CNN) -- The prototype of an aircraft that could compete with terrestrial satellites and lead to unmanned flights on Mars shattered altitude records during an aerial marathon that ended Tuesday.

The solar-powered plane soared to as high as 96,500 feet during a marathon flight that squeezed as much sunlight as possible from the long summer Hawaiian day.

The NASA craft, known as Helios, easily overtook the 80,200-foot record for propeller-powered aircraft and the 85,068-foot mark for all non-rocket planes.

"It's kind of fun for us because people are well aware of NASA's space shuttle [program], and we are not as well known," said Fred Johnsen, spokesperson for NASA's Dryden Flight Research Center, which oversees the program. "We're pretty proud."

The high point was just short of the 100,000-foot goal that NASA had set for the remote-controlled craft. The plane took off at 8:48 a.m. local time Monday and landed at 1:43 a.m. Tuesday, according to AeroVironment, the California builder of the craft.

The plane boasts a wingspan longer than a Boeing 747, weighs less than many automobiles and uses solar-powered motors to power 14 propellers. During the record-breaking flight, it flew at speeds ranging from 20 mph to 170 mph.

Thinning air and waning sunlight slowed and eventually stopped the plane's climb as it approached 100,000 feet, convincing NASA managers to bring it home to the island of Kauai.

Eventually fleets of such aircraft could remain aloft for months, offering inexpensive alternatives to low-orbit communications and environmental monitoring satellites, according to Dryden.

Moreover, test flights with the $15 million Helios should provide valuable information about how to design airplanes that can navigate martian skies, said Johnsen. Helios, approaching the boundaries of the terrestrial atmosphere, encountered thin air pressure thought to resemble conditions near the surface of Mars.

The flying wing operates on solar panels linked to a regenerative fuel cell that produces enough power during the day to remain in flight for hours into the night. The 247-foot-long, eight-foot-wide structure gently flexes and bends as it flies, similar to a kite instead of a conventional aircraft.

CNN's Patricia Coughlin contributed to this report.