SOLAR-powered flying wing breaks all records but fails to reach its altitude goal

Tuesday, August 14th 2001, 12:00 am
By: News On 6

BARKING SANDS, Hawaii (AP) _ NASA's giant propeller-driven flying machine began its slow descent to Earth after setting altitude records for non-rocket powered aircraft but missing its goal by 3,500 feet.

Looking more like something out of the early days of aviation than a NASA project, the remote-control Helios Prototype hit an altitude of more than 96,500 feet Monday, just shy of its 100,000-foot goal.

By that point, the Helios had surpassed the 80,200-foot altitude record for propeller-driven aircraft and the 85,068-foot record for all non-rocket craft.

``We cracked that old record by 10,000 feet and that's a feat worth celebrating,'' said John Del Frate, NASA's project manager for solar powered aircraft.

The $15 million aircraft, with a wingspan longer than that of Boeing 747, is run by small, 2-horsepower electric engines attached to each of its 14 propellers. It was expected to land Tuesday on the island of Kauai.

When the Helios reached 96,500 feet _ three times higher than normal altitude for commercial jets _ NASA officials made the decision to bring it down.

With thinning air and slanting sunlight, the remotely controlled Helios had reached a ``zero climb rate,'' NASA spokesman Alan Brown said. ``As the sun angle gets lower, the amount of radiation you can absorb gets less and less and less.''

Designers believe the Helios can reach 103,000 feet under ideal weather conditions and eventually may be used to fly above Mars. Its rate of climb is determined by the amount of sunlight and air, as well as weather conditions.

Brown said the machine's latest records will be considered unofficial until they are certified by the National Aeronautics Association, the official record-keeping agency.

Moving more like a kite than an airplane, the flying wing was developed with AeroVironment Inc., of Monrovia, Calif. The craft gets its electricity from 65,000 solar cells covering the wing.

``It's a real milestone of flight,'' Brown said. ``It's a landmark achievement, and especially to do it with a solar aircraft that is nonpolluting. It is a triumph of technology in this area.''

Since the atmosphere at 100,000 feet is expected to be similar to the Martian atmosphere, the data collected from the Helios at high altitudes also will help engineers plan for future Mars aircraft designs, officials said.

Kevin Petersen, director of NASA's Dryden Flight Research Center at Edwards Air Force Base in California, said a solar-powered aircraft flying over Mars could survey a lot more area than a vehicle on the ground.

The Helios _ potentially capable of staying at high altitudes for months at a time _ also is envisioned as a surrogate satellite, or low-cost telecommunications relay platform capable of providing more efficient broadcast feeds, high speed Internet access and wireless communications.