The NASA – AeroVironment flight test team is reviewing data from the
first of several planned checkout flights of the Helios Prototype
solar-electric flying wing, now equipped with a revolutionary fuel
cell system for night time flight.

During the first shakedown flight last weekend from the U.S. Navy’s
Pacific Missile Range Facility (PMRF), the Helios Prototype was aloft
for about 15 hours at altitudes up to 52,000 feet while engineers
checked out modifications and upgrades made to the aircraft over the
past two years.

John Del Frate, NASA’s Helios project manager, said the fuel cell
system could not produce electrical power due to leakage in the
coolant system and feed air lines downstream of the system’s air
compressor while the Helios was flying at about 50,000 feet altitude.
He noted that all other objectives for the first flight were met,
including checking the integrity, performance and stability of
Helios, training of new crew members prior to much longer missions,
verifying all operational procedures and confirming integrity of the
fuel cell system’s thermal protection system.

The Helios flight test team is currently analyzing the flight data
and inspecting the aircraft to better understand the causes of the
leaks in order to correct them. The next possible check flight could
come as early as June 26, but could occur later depending on how long
modifications take and test range scheduling constraints.

The overall goal of the flight series is to demonstrate the ability
of the Helios Prototype to fly a long-endurance mission of about 40
hours, including at least 14 hours above 50,000 feet altitude. The
Helios flies on electrical power derived from solar arrays during the
day and from the experimental fuel cell system that combines oxygen
from the atmosphere with hydrogen stored on the aircraft at night.

NOTE TO EDITORS:

Still photos are available to support this release. Four new photos
in series ED03-0152 are available on the NASA Dryden Flight Research
Center internet website at:

http://www.dfrc.nasa.gov/Gallery/Photo/Helios/index.html

Video footage will also be available shortly. For photo prints or
video dubs, please call (661) 276-2665.