BARKING SANDS, Kauai >> The first check flight of the Helios, solar-powered flying wing, has been delayed at least until July 5, NASA officials at the Navy's Pacific Missile Range said yesterday.
Solar plane's Kauai
check flight delayed
By Anthony Sommer
The check flight originally was scheduled for late May, with an attempt to establish a new altitude record above 10,000 feet initially expected in early July. The check flight has been rescheduled repeatedly, with the most recent flight date set for today.
The delays have been caused by the need to redesign a critical subsystem, the flight termination program, which would allow Helios to be parachuted back to Earth in case of a major malfunction. The flight termination system is needed only on takeoff and landing when Helios will be over the Navy base; the remainder of the time, Helios will be over open ocean northwest of Kauai.
NASA also saw a need to provide additional training for the two five-member primary crews who will fly Helios in 2 1/2 hour shifts from a van near the missile range runway. The aircraft hasn't been flown since low-altitude tests using battery rather than solar power since 1999 at NASA's Dryden Flight Research Center at Edwards, Calif.
The two crews have been training for 10 hours a day, six days a week for more than a month at the missile range, said John Hicks, NASA project manager for the Environmental Research Aircraft and Technology Sensor program, which includes Helios and several other experimental aircraft.
"I decided they need a week's rest before they get really tired and do something wrong," said Hicks, who has the final say on the flight schedule.
The flight crews will fly to the mainland this weekend and return June 30. The three-day countdown for the first flight is now scheduled to begin July 1, which would put the first flight on Independence Day. Hicks said even though the Navy offered to bring in personnel on the holiday, he decided to wait one more day.
The Helios takeoffs will be open to the public. The gates at the missile range open at 6 a.m. and takeoffs will occur between 7:30 and 8:30 a.m. The flight crews will begin work at 3:30 a.m. on flight days and the aircraft is not scheduled to land until the following evening.
Once Helios is rolled out to the tarmac along the runway (it is too wide to take off and land on the runway itself), about two hours of ground testing will be required before takeoff.
NASA has set up a telephone line with recorded information that is updated frequently at 335-4027.
With a wingspan of 256 feet, Helios is wider than any conventional aircraft. Its designer and builder, AeroVironment Inc., calls it the "Eternal Airplane" and it is intended to eventually stay aloft above the weather and the jet stream for months at a time, providing communications relays that currently require far more expensive satellites.
The $10 million Helios is powered by 14 electric motors. It is covered from wingtip to wingtip with 62,450 solar cells that collectively will produce 40 kilowatts of electricity.
NASA has four flights scheduled for this summer, with a goal of topping 100,000 feet, higher than any aircraft except rocket-powered spacecraft have flown. At 100,000 feet, the air is only 1.5 percent as dense as at sea level.
Helios will be brought back to Kauai in two years with batteries still being designed that are too keep it aloft for several days.
NASA's previous solar airplane, Pathfinder Plus, set a world record in 1998 for propeller-driven aircraft flying just above 80,000 feet from Kauai. The only aircraft that has flown higher is the jet-powered SR-71 Blackbird spy plane, and even that airplane has not approached 100,000 feet.
Both Hicks and John Del Frate, NASA project manager for both Pathfinder and Helios, said this week that the initial Helios check flight could go higher than Pathfinder Plus and set another record for propeller-drive airplanes, even though NASA won't attempt a 100,000 foot flight the first time out.