| Web posted Wednesday,
May 8, 2002
|
The Helios Prototype begins a northerly climb over Ni'ihua Island, Hawaii.
NASA Photo / Carla Thomas
|
Helios Prototype Team aims to 'Conquer the Night'
Jay Levine
X-Press Editor
The Helios Prototype set an altitude record at 96,863 feet and made a run as a candidate for one of aviation's greatest prizes, the Collier Trophy.
So what does a project team do for an encore? That's what the Helios Prototype Team began to answer even before the record flight - to again demonstrate new abilities by initiating activities toward a duration flight that will exceed a day and night cycle above 50,000 feet during Summer 2003.
"Technically it's a very challenging mission. We will probably set up well before the summer. We fully expect to see some problems that require us to go back to the shop and test facilities and fix them and come back and fly. For that reason, it would be good to be close to test stands and suppliers to maximize our opportunities to meet our mission goals," said John Del Frate, solar-powered aircraft project manager.
|
The Helios Prototype was stored in a hangar at the U.S. Navy's Pacific Missile Range Facility in Kauai, Hawaii before its record flight.
NASA Photo
|
The Helios Prototype spent about seven hours above 50,000 feet on its record
breaking high-altitude flight Aug. 13, 2001. However, the mission in 2003 is expected
to see the aircraft for at least 14 hours above 50,000 feet with different systems
and procedures.
"This is a whole new ballgame for us because we are trying to conquer
the night. The longer mission will require multiple shifts and therefore a much
larger team. This mission also has more hazards associated with it. We will be
looking at issues we have not had to deal with before, like charging flammable
gases to high pressure before we launch," Del Frate said.
The Helios Prototype is a solar wing that resembles a yardstick with a wing
span of 247 feet, or larger than that of NASA's 747 and will demonstrate a fuel
cell-based power system to permit the aircraft to fly at night.
AeroVironment, NASA's partner and the aircraft's builder, is developing the
fuel-cell-based power system. The fuel- cell based power system is a step toward
flying an eternal airplane that could be sent on missions spanning months, said
Del Frate.
These capabilities are developed as part of Dryden's Environmental Research
Aircraft and Sensor Technology (ERAST) Program that began in 1994.
Because the mission does not require the aircraft to fly as high as the mission
in 2001 did, the Helios Prototype will be modified to run with about 8 to 10 motors versus the 14 motors it flew with on the record altitude
flight.
The Helios Prototype team opted to remove some of the solar cells on the forward
portion of the wing to reduce drag. A single pod replacing the existing center
pod will contain the new power system."We have to provide power to systems
and motors all the time. At night time, where are you going to get that power?
When the sun goes down, you carry batteries or you carry something else. What
we are doing is something else. Batteries are so heavy that we deter-mined a long
time ago that even with the best batteries we could barely get off the ground.
The fuel-cell-based power system will be incorporated into one pod to provide
the power," Del Frate said.
The team also will take on a new configuration. Rather than two main flight
teams that switch about every three hours, the duration flight probably will require
two 12-hour shifts each with two teams that alternate. Each flight crew could
be twice as large because in addition to monitoring the basic aircraft, the flight
crews also will be monitoring the power system.
In addition to training people for the Helios Prototype mission, AeroVironment
currently is training people for work on another of the company's family of high
flying solar wings, the Pathfinder Plus, in Kauai, Hawaii. Scheduled for two commercial
demonstration missions outside of the ERAST Program, the Pathfinder Plus will
provide a flight platform for a Japanese agency that wants to test some of their
communications payloads in the stratosphere. The aircraft also will carry a remote
sensing instrument for Clark University, Worchester, Mass., to monitor coffee
crops. That mission is funded byNASA's Code Y.
"It's gratifying to see commercial use of the solar flying wings. Ultimately
the real commercialization of the airplane will blossom when it can routinely
fly extreme duration flights be-cause that's how you get the costs down. If you
launch an airplane to the stratosphere for a single day and come back down after
dark, it's going to be cost prohibitive unless you have a very high-value mission.
But once you are able to fly an airplane for two weeks to several months at a
time, your life cycle costs come way down and so do the costs per flight hour.
All of a sudden it becomes very attractive," Del Frate said.
An aircraft with multi-week to multi-month flight capability opens the door
to a new way of Earth monitoring. Helios could serve as a platform for disaster
relief and crop monitoring, or follow the eye of a hurricane.
|
