Aviones a Pedal y Alas Solar

8/7/2019 Aviones a Pedal y Alas Solar

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REPBLICA BOLIVARIANA DE VENEZUELAMINISTERIO DEL PODER POPULAR PARA LA DEFENSA

UNIVERSIDAD NACIONAL EXPERIMENTAL POLITCNICADE LA FUERZA ARMADANCLEO MARACAY EDO. ARAGUA

ASIGNATURA: Termodinmica

TITULO: Avin a Pedal y Ala Solar.

REALIZADO POR:Solini Paul

PROFESORA: Willson

SECCIN::AER - 602

Boca de Ro, 08/03/10.


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Paul B. MacCready, Jr. (September 25, 1925 - August 28, 2007), During his

adolescence he was a serious model airplane enthusiast, who set many records for

experimental craft. At age 16, he soloed in powered planes. In World War II, he flew

in the U.S. Navy flight training program. Was an American aeronautical engineer. He

was the founder of AeroVironment and the inventor of the first practical flying

machine powered by a human being. He devoted his life to developing more efficient

transportation vehicles that could "Do more with less".

In 1943 MacCready graduated from Hopkins School in New Haven. In 1947

he received his Bachelor of Science in physics from Yale University. His interest inflight grew to include gliders. He won the 1948, 1949 and 1953 U.S. National

Soaring Championships, pioneered high-altitude wave soaring in the United States;

and in 1947 was the first American in 14 years to establish an international soaring

record. (The 1999 National Soaring Convention of the Soaring Society of America

was dedicated to him.) He represented the United States at contests in Europe four

times, becoming International Champion in France in 1956, the first American to

achieve this goal.

During the decade 1946-56, MacCready worked on sailplane development,

soaring techniques, meteorology, and invented the Speed Ring Airspeed Selector that

is used by glider pilots worldwide to select the optimum flight speed between

thermals (commonly called the "MacCready Speed"). Concurrently, he earned a

master's degree in physics in 1948 and a Ph.D. in aeronautics in 1952 from the

California Institute of Technology, and in 1950-51 managed a weather modification

program in Arizona. He founded Meteorology Research Inc., that became a leading

firm in weather modification and atmospheric science research. He pioneered the use

of small instrumented aircraft to study storm interiors and performed many of the

piloting duties.


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In 1971, MacCready started AeroVironment, Inc., a diversified company

headquartered in Monrovia, California. The company provides services,

developments, and products in the fields of alternative energy, power electronics, and

energy efficient vehicles for operation on land and in air and water. Products include

environmental instrumentation, surveillance aircraft, and power electronic systems

for stationary and mobile uses. MacCready is Chairman of the Board of

AeroVironment, and active in all the technology areas.

MacCready became internationally known in 1977 as the "father of human-

powered flight" when his Gossamer Condor made the first sustained, controlled flightby a heavier-than-air craft powered solely by its pilot's muscles. For the feat he

received the $95,000 Henry Kremer Prize. Two years later, his team created the

Gossamer Albatross, another 70-pound craft with a 96-foot wingspan that, with

DuPont sponsorship, achieved a human-powered flight across the English Channel.

That flight, made by "pilot-engine" Bryan Allen, took almost three hours. It

won the new Kremer prize of $213,000, at the time the largest cash prize in aviation

history.

Subsequently, the AeroVironment team led by MacCready developed, under

DuPont sponsorship, two more aircraft, this time powered by the sun. In 1980, the

Gossamer Penguin made the first climbing flight powered solely by sunbeams. In

1981, the rugged Solar Challenger was piloted 163 miles from Paris, France to

England, at an altitude of 11,000 feet. These solar-powered aircraft were built and

flown to draw world attention to photovoltaic cells as a renewable and non-polluting

energy source for home and industry and to demonstrate the use of DuPont's

advanced materials for lightweight structures.

In 1983, his team built the 70-pound, human-powered (with on-board battery

energy storage) Bionic Bat, partly to vie for new Kremer speed prizes and partly to


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explore new technologies leading toward practical, long-duration, unmanned vehicles

and quiet, slow-speed, piloted aircraft. In 1984, the Bionic Bat won two of the speed

prizes.

Starting in 1984, the team developed a large radio-controlled, wing-flapping,

flying replica of the largest animal that ever flew: the long-extinct pterodactyl

Quetzalcoatlus northropi, whose giant wings spanned 36 feet. This QN replica

became the lead "actor" in a 1986 wide-screen IMAX film titled "On the Wing", a

film depicting the interrelation between the developments of biological flight and

aircraft. The film and the QN replica were sponsored by Johnson Wax and theNational Air and Space Museum.

Recent "cover story" type aircraft of his AeroVironment groups start with the

100 foot remotely-piloted solar powered Pathfinder that, in 1997, reached the

stratospheric altitude of 71,500'. In 1998, the 120 foot Pathfinder Plus reached over

80,000 feet (the highest any powered airplane has maintained level flight), and the

206 foot Centurion, designed for 100,000 feet, started low altitude tests. The

Centurion then evolved into the 247 foot prototype Helios. This underwent low

altitude tests in 1999 as a step toward "near-eternal" (6 month) flights when the solar

cells and the regenerative fuel cell system power the final Helios. These NASA-

supported developments are steps toward non-polluting flights in the stratosphere for

environmental studies and surveillance. The largest potential is for Helios to serve as

an 11-mile-high "SkyTower" that relays multichannel wide bandwidth

communications. Other widely publicized pioneering aircraft are at the other end of

the size range: tiny (6" span) surveillance drones, microplanes with on-board video

cameras, featuring gross weight under 2 ounces.

His team's first land vehicle was the GM Sunraycer, for which AeroVironment

provided project management, systems engineering, aerodynamics and structural


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design, power electronics development, as well as construction and testing for

General Motors and Hughes Aircraft. In November 1987, this solar-powered car won

the 1,867 mile race across Australia, averaging 41.6 mph (50 percent faster than the

second place vehicle in the field of 24 contestants). The goal of the Sunraycer, in

addition to winning the race, was to advance transportation technology that makes

fewer demands on the earth's resources and environment, and to inspire students to

become engineers. AeroVironment also helped with the GM-sponsored educational

tour of the Sunraycer, spearheaded a course at Caltech on the Sunraycer engineering

design (course notes were distributed in book form by SAE), and helped manage, for

GM, the Sunrayce, in which solar-powered cars from 32 university groups raced fromFlorida to Michigan in July 1990. In January 1990, the GM Impact was introduced, a

battery-powered sports car with snappy "0 to 60 mph in 8 seconds" performance. GM

later turned the Impact into the production vehicle EV-1. The AV team provided the

initial concept for the Impact; performed program management, systems engineering,

and design of the electrical and mechanical elements; and built the vehicle,

integrating the participation of a dozen GM divisions. This pioneering car became a

catalyst for the present intense global developments of battery-powered and

alternatively-fueled vehicles.

The unique vehicles produced by MacCready's teams have received

international attention through exhibits, books, television documentaries, and

innumerable articles and cover stories in magazines and newspapers. They,

MacCready, and AeroVironment have become symbols for creativity. The Gossamer

Condor is on permanent display at the Smithsonian's National Air and Space Museum

in Washington, D.C., adjacent to the Wright Brothers' 1903 airplane and Lindbergh's

Spirit of St. Louis. A film about it, "The Flight of the Gossamer Condor", won the

Academy Award for Best Documentary - Short Subject in 1978. The Gossamer

Albatross, after touring U.S. science museums, was for some years hung in the central

atrium of the London Science Museum. Now in storage, it is slated for a forthcoming


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NASM facility at Dulles. The almost-identical backup vehicle, Gossamer Albatross

II, was flown in the Houston Astrodome, and on a NASA research project. It now

hangs at the Museum of Flight in Seattle. The Gossamer Penguin was exhibited in the

U.S. Pavilion of the 1982 World's Fair in Knoxville, Tennessee. The Solar Challenger

was displayed at the National Air and Space Museum, and at Expo '86, and is now at

the Science Museum of Virginia in Richmond. The QN flight replica, after being on

display at the National Air and Space Museum in conjunction with showing the "On

the Wing" film, now rests at the Smithsonian Zoo. A full size static display version is

at the Museum of Flying at Santa Monica airport. The Sunraycer is stored at the

Smithsonian American History Museum, and is displayed occasionally.

MacCready's achievements have brought him many recent honors, including:

Distinguished Alumni Award, 1978, California Institute of Technology Collier Trophy, 1979, by the National Aeronautics Association ("awarded

annually for the greatest achievement in Aeronautics and Astronautics inAmerica"

Reed Aeronautical Award, 1979, by the American Institute of Aeronautics andAstronautics ("the most notable achievement in the field of aeronautical

science and engineering" Edward Longstreth Medal, 1979, by the Franklin Institute Ingenieur of the Century Gold Medal, 1980, by the American Society of

Mechanical Engineers; also the Spirit of St. Louis Medal, 1980 Inventor of the Year Award, 1981, by the Association for the Advancement of

Invention and Innovation Klemperer Award, 1981, OSTIV, Paderborn, Germany I.B. Laskowitz Award, 1981, New York Academy of Science The Lindbergh Award, 1982, by the Lindbergh Foundation ("to a person who

contributes significantly to achieving a balance between technology and theenvironment")

Golden Plate Award, 1982, American Academy of Achievement Gold Air Medal, by the Federation Aeronautique Internationale Distinguished Service Award, Federal Aviation Administration Public Service Grand Achievement Award, NASA Frontiers of Science and Technology Award, 1986, first award in this category

given by the Committee for the Scientific Investigation of Claims of the


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Paranormal The "Lipper Award", 1986, for outstanding contribution to creativity, by the

O-M Association (Odyssey of the Mind) Guggenheim Medal, 1987, jointly by the American Institute of Aeronautics

and Astronautics, the Society of Automotive Engineers, and the AmericanSociety of Mechanical Engineers

National Air and Space Museum Trophy for Current Achievement, 1988 Enshrinement in The National Aviation Hall of Fame, July 1991, Dayton,

Ohio SAE Edward N. Cole Award for Automotive Engineering Innovation,

September 1991 Scientist of the Year, 1992 ARCS (Achievement Rewards for College

Scientists), San Diego Chapter Pioneer of Invention, 1992, United Inventors Association Chrysler Award for Innovation in Design, 1993 Honorary Member designation, American Meteorological Society, 1995 American Society of Mechanical Engineers, Ralph Coats Roe Medal,

November 1998 Howard Hughes Memorial Award, Aero Club of Southern California, January

1999 Calstarts 1998 Blue Sky Merit Award, February 1999 1999 National Convention of the Soaring Society of America, dedicated to

Paul MacCready, Feb. 1999

Special Achievement Award, Design News, March 1999 Included in Time magazines "The Centurys Greatest Minds" (March 29,

1999) series "on the 100 most influential people of the century" Lifetime Achievement Aviation Week Laureate Award, April 1999 Commemorated in Palau stamp, 1 of 16 "Environmental Heroes of the 20th

Century", Jan. 2000 Institute for the Advancement of Engineering William B. Johnson Memorial

Award, Feb. 2000

In 1999, MacCready directed prize money from the Design News Special

Achievement Award to Harvey Mudd College, initiating an industry/studentdevelopment of a two-legged walking robot.

MacCready has many professional affiliations, including the National

Academy of Engineering and the American Academy of Arts and Sciences, and


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Fellow status in the American Institute of Aeronautics and Astronautics, the American

Meteorological Society (he is also an AMS Certified Consulting Meteorologist and a

member of the AMS Council), and the Committee for the Scientific Investigation of

Claims of the Paranormal. He is a Humanist Laureate of the Academy of Humanism.

For two decades he has been International President of the International Human-

Powered Vehicle Association; and in 1999 helped create the Dempsey-MacCready

One Hour Distance Prize He has served on many technical advisory committees and

Boards of Directors for government, industry (public and private corporations),

educational institutions, and foundations; and is at present a Director of the Lindbergh

Foundation and the Society for Amateur Scientists. He has a dozen patents.He has been awarded five honorary degrees (including Yale 1983) and made

numerous commencement addresses. He has written many popular articles, and

authored or co-authored over one hundred formal papers and reports in the fields of

aeronautics; soaring and ultralight aircraft; biological flight; drag reduction; surface

transportation; wind energy; weather modification; cloud physics; turbulence,

diffusion, and wakes; equipment and measurement techniques; and perspectives on

technology, efficiency, and global consequences and opportunities. He lectures widely

for industry and educational institutions, emphasizing creativity and the development

of broad thinking skills, and also treating issues such as future paths for energy and

transportation, and the changing relationship between nature and technology.

MacCready lives in Pasadena, California, with his wife Judy. Their three sons,

all of whom were involved in the early human- and solar-powered aircraft

developments, are now following their independent career paths.

The Gossamer Condor

The Gossamer Condor was the first human-powered aircraft capable of

controlled and sustained flight, able to win the Kremer prize.


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The Kremer prize had been set up in 1959 by Henry Kremer, a British

industrialist, and offered 50,000 pounds ($100,000) in prize money to the first group

that could fly a human-powered aircraft over a figure-eight course covering a total of

a mile (1.6 kilometers). The course also included a ten-foot pole that the aircraft had

to fly over at the start and end. Early attempts to build human-powered aircraft had

focused on wooden designs, which proved too heavy. Very early attempts notably

the HV-1 Mufli and Pedaliante used catapult launches.

In 1961, the Hatfield Puffin, which took off under human power, managed a

maximum flight of 908 metres but it was difficult to turn. The Jupiter managed 1,239

m in June 1972. The Nihon Stork B achieved over 2 kilomters in 1976.

In the early 1970s, Dr Paul B. MacCready and Dr Peter B. S. Lissaman, both

of AeroVironment Inc., took a fresh look at the challenge and came up with an

unorthodox aircraft, the Gossamer Condor. He took his inspiration from hang gliders,increasing wing area so that the drag of the wire bracing needed would be reduced.

The Gossamer Condor is built around a large wing with a gondola for the pilot

underneath and a canard control surface on a fuselage extension in front, and is

mostly built of lightweight plastics with aluminium spars.

The aircraft, piloted by amateur cyclist and hang-glider pilot Bryan Allen,

won the first Kremer prize on August 23, 1977 by completing a figure-eight coursespecified by the Royal Aeronautical Society, at Minter Field in Shafter, California. It

was capable of taking off under human power.


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The aircraft is preserved at the Smithsonian National Air and Space Museum.

The success led Paul MacCready and AeroVironment to carry on with experimental

aircraft:

the Gossamer Albatross, which crossed the English Channel,

the Solar Challenger, a solar electric-powered version that also made anEnglish Channel crossing.

NASA's Pathfinder/Helios series of unmanned solar-powered aircraft.


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The Gossamer Conder was firstly plane stimulated by capable human being offlight controlled and supported, capable of gaining Kremer's Prize. It he has one;

Importance: 29.25m (96 feet), Length: 9.14 m (30 feet), Height: 5.49 m (18 feet) and

a Weight: 31.75 kilograms (70 pounds.)

The Gossamer Albatross

The Gossamer Albatross was a human-powered aircraft built by American

aeronautical engineer Dr. Paul B. MacCready's AeroVironment. On June 12, 1979 it

completed a successful crossing of the English Channel to win the second Kremer

prize. The 70-lb aircraft completed the 26-mile flight in 2 hours, 49 minutes,

clinching the second prestigious Kremer Prize for Dr. Paul MacCready.

The aircraft was designed and built by a team led by Paul B. MacCready, a

noted US aeronautics engineer, designer, and world soaring champion. Gossamer

Albatross was his second human-powered aircraft, the first being the Gossamer

Condor, which had won the first Kremer prize on August 23, 1977 by completing a

mile-long figure-eight course. The second Kremer challenge was then announced as a

flight across the Channel recalling Louis Blriot's crossing of 1909.

The Albatross was powered using pedals to drive a large two-bladed propeller.


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Piloted by amateur cyclist Bryan Allen, it completed the 35.8 km (22.2 mi) crossing

in 2 hours and 49 minutes, achieving a top speed of 29 km/h (18 mph) and an average

altitude of 1.5 metres (5 feet).

The aircraft is of unusual "canard" configuration, using a large horizontal

stabilizer forward of the wing in a manner similar to the Wright brothers' successful

"Flyer" aircraft. The Gossamer Albatross was constructed using a carbon fiber frame,

with the ribs of the wings made with expanded polystyrene; the entire structure was

then wrapped in a thin, transparent plastic (mylar aka PET film). The empty mass of

the structure was only 32 kg (71 lb), although the gross mass for the Channel flightwas almost 100 kg (220 lb). To maintain the craft in the air it was designed with very

long tapering wings (high aspect ratio), like those of a glider, allowing the flight to be

undertaken with a minimum of power. In still air the required power was of the order

of 0.4 horsepower (300 W), though even mild turbulence made this figure rise

rapidly.

A follow-up to 1977s Kremer Prize winning Gossamer Condor (first

sustained, controlled, human-powered flight), the Albatross came about after two

years of human-powered flight experiments. The main differences between the two

aircraft were a reduced wing area and shorter wing chord on the Albatross, along with

the switch from an aluminum main structure to carbon fiber-reinforced plastics.

The initial construction and load-testing of the Albatross components was

particularly interesting, since carbon fiber was at that time a somewhat exotic

material and there was very little practical knowledge of how to craft parts out of it,

said Albatross pilot Bryan Allen. There was a lot of camaraderie in the team,

amusing stories of past experiences, and a fair amount of brainstorming about how to

solve particular problems on the airplanes and come up with better and lighter and

more-reliable solutions.


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Albatross test-flights began in the summer of 1978. Early flights at Shafter

airport near Bakersfield, CA, yielded positive results; however, flying near the ocean

at Long Beach proved more challenging, with a series of malfunctions requiring

repairs and improvements. Eventually, the Albatross became able to make 15-minute

flights, twice the length of previous attempts. Following further improvements,

including a new propeller design, Allen piloted the Albatross for a 13-mile, 69-minute

flight over Harper Lake in April 1979. The one-hour, nine-minute, three-second

flight at Harper Lake was my favorite single flight, Allen said.

As a long-time long-distance cyclist, Allen was built for the kind of challenge

presented by the Gossamer aircraft. In order to prepare for the Albatrosss English

Channel flight, Allen trained both on the road (40-80 miles per day) and using an

ergometer (stationary) training bike. The ergometer training enabled Allen to quantify

his performance and improvement.

The years of development and months of training came to a head very early on

the morning of June 12, 1979. The media began to gather around Paul MacCready at

around 2:30 a.m., where the Albatross was being assembled in the dark. Without

hesitation, Paul calmly and slowly explained the progress of the preparations.

According to Allen, He said that shortly, the plane would take off and fly from

England to France. There was no drama or uncertainty. Paul always had a

fundamental grasp of what is possible and what is not.

Just before 6 a.m., with Allen pedaling at the rehearsed 75 rpm, the Albatross

lifted off the make-shift runway at The Warrens near Folkestone, Kent, and headed

out over the English Channel. Calm seas and lack of wind foretold a potentially

worry-free flight, but soon after take-off, the trouble began. I got a triple-whammy

of failures, Allen said. First, the transmit button on the radio failed, leaving Allen


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unable to talk to control personnel in the chaser boats. He was still able to receive

communications from them, however, and could communicate with them using hand

and head motions.

Second, Allens water supply ran out. Due to unexpected headwinds, the flight

took 49 minutes longer than planned. Without adequate water later in the flight, Allen

suffered leg cramps from dehydration. Finally, the airspeed instruments and acoustic

altimeter failed when their batteries expired. Again, this was due to the flight taking

longer than predicted. Without these instruments, Allen could not know his height

above the water or his speed.

As the headwind increased, so did uncertainty among onlookers that the flight

would be successful. With the far shore nowhere in sight and turbulence taking its

toll, the trailing Zodiac pulled into position to hook onto the aircraft and abort the

flight. When he increased the aircrafts altitude to allow the Zodiac to pull underneath

the Albatross, Allen discovered the air was less turbulent higher up. As the Zodiac got

closer to the plane, Bryan kept moving away. Bryan requested another five minutes,

and then another five minutes, and then another five minutes. This went on for over

an hour.

The surface wind calmed slightly and the Albatross continued toward Cap

Gris-Nez, France. Persisting through equipment failures, exhaustion, and careful

negotiation of the rocky French coastline, Allen landed the Albatross on the beach at

Cap Gris-Nez. There were so many unknowns on that flight that I could not be

certain wed make it, but I was certain Id use every resource in trying, Allen said.

Beyond the pouring of champagne and the Kremer prize, the flight of the Gossamer

Albatross remains a story of ingenuity and heart, 30 years later.

When the Kremer prize was originally announced, it was assumed that 20


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years would pass before it was won. Pauls optimism was what kept the project

moving at such a momentous pace. He kept saying, Well win it next week. The

Condor and Albatross were dealing with fundamental physics, right at the edge of the

possible. So it seemed to me they would be remembered and written about for a good

long while said Allen. He went on to say, I am very pleased to see that finally some

of the things about efficiency and quality of life that Dr. MacCready was talking

about and advocating 30 years ago are making it into our societal discourse.

The Gossamer Albatross is currently on display at the National Air and Space

Museum in Washington, DC. and the Gossamer Albatross II is on display at the TheMuseum of Flight in Seattle, WA. Gossamer Albatross images are courtesy of Donald

Monroe.

AeroVironment, the company that Dr. Paul MacCready founded, remains

committed to his philosophy of doing more with much less, and today is the leader

in unmanned aircraft systems and efficient energy systems.


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Manufacturer: Engineer Paul MacCready. Date: 1979Country of origin: United States

Dimensions:

Wingspan: 28.6 m (93 ft 10 in)

Length: 15.4 m (50 ft 6 in)

Height: 5 m (16 ft 4 in)

Weight, empty: 31.8 kg (70 pounds)

Weight off: 97.5 kilograms (215

pounds)

Maximum speed: 24 km / h (15 mph)

Cover: Mylar Structural: balsa wood, carbon fiber, Kevlar, Cable, Foam

Physical Description:

The pedal pushed the plane, mylar and composite construction.


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On the left, the Gossamer Penguin. At right, the Solar Challenger. A new

meaning to cut up when it is cloudy.

Solar-Power Research and Dryden

Since 1980 AeroVironment, Inc. (founded in 1971 by the ultra-light airplane

innovator - Dr. Paul MacCready) has been experimenting with solar-powered aircraft,

often in conjunction with NASA's Dryden Flight Research Center, Edwards,

California. Thus far, AeroVironment, now headquartered in Monrovia, Calif., has

achieved several altitude records with its Solar Challenger, Pathfinder, and

Pathfinder-Plus aircraft. It expects to exceed them with the newer and larger solar-powered Centurion and its successors in NASA's Environmental Research Aircraft

and Sensor Technology (ERAST) program, the Centelios and Helios vehicles.

Solar Challenger set an initial altitude record of 14,300 feet. More

spectacularly, on July 7, 1981, the solar-powered aircraft flew 163 miles from

Corneille-en-Verin Airport north of Paris across the English Channel to Manston

Royal Air Force Base south of London, staying aloft 5 hours and 23 minutes.

At the time, AeroVironment was headquartered in Pasadena, Calif. Dr.

MacCready, a former gliding champion, whose Gossamer Albatross crossed the

English Channel using human power in 1979, saw solar power as a way to "help


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business and government recognize and meet their environmental and energy

objectives." MacCready remains the Chairman of the Board at AeroVironment.

1981 from the U.S. government for a classified program to look into the

feasibility of long-duration, solar-electric flight above 65,000 feet. The firm designed

an airplane designated HALSOL (High-Altitude Solar Energy), built and test flew

three subscale models and a final prototype. The HALSOL proved the aerodynamics

and structures for the approach, but subsystem technologies, principally for energy

storage, were inadequate for the intended mission. The HALSOL was mothballed for

ten years but later evolved into Pathfinder, which first flew at Dryden in 1993 under

the auspices of the Ballistic Missile Defense Office for potential use in an anti-

ballistic-missile defense role.

When funding for this program ended, Pathfinder became part of NASA's

ERAST program to develop remotely piloted, long-duration aircraft for

environmental sampling and sensing at altitudes above 60,000 feet. On September 11,1995, Pathfinder exceeded Solar Challenger's altitude record for solar-powered

aircraft by a long margin when it reached 50,500 feet at Dryden.

After moving its flight operations to the U.S. Navy's Pacific Missile Range

Facility (PMRF) on Kauai, Hawaii, in April 1997, an upgraded Pathfinder took

advantage of the improved angle of sunlight to set a new record of 71,530 feet for

solar-powered aircraft on July 7, 1997.

Further modified with longer wings, improved motors, and more efficient

solar array, Pathfinder-Plus (as it was now called) flew to still another record of


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80,201 feet at the PMRF on August 6, 1998. In the process, it stayed above 70,000

feet for almost three and a half hours while carrying 68 pounds of test instrumentation

and other payload.

Background

The first flight of a solar-powered aircraft took place on November 4, 1974,

when the remotely controlled Sunrise II, designed by Robert J. Boucher of

AstroFlight, Inc., flew following a launch from a catapult.

Following this event, AeroVironment took on a more ambitious project to

design a human-piloted, solar-powered aircraft. The firm initially took the human-

powered Gossamer Albatross II and scaled it down to three-quarters of its previous

size for solar-powered flight with a human pilot controlling it. This was more easily

done because in early 1980 the Gossamer Albatross had participated in a flight

research program at NASA Dryden in a program conducted jointly by the Langley

and Dryden research centers. Some of the flights were conducted using a small

electric motor for power.

Alas Solares

Gossamer Penguin

The scaled-down aircraft was designated the Gossamer Penguin. It had a 71-

foot wingspan compared with the 96-foot span of the Gossamer Albatross. Weighing

only 68 pounds without a pilot, it had a low power requirement and thus was an

excellent test bed for solar power.

AstroFlight, Inc., of Venice, Calif., provided the power plant for the

Gossamer, Penguin, an Astro-40 electric motor. Robert Boucher, designer of the


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Sunrise II, served as a key consultant for both this aircraft and the Solar Challenger.

The power source for the initial flights of the Gossamer Penguin consisted of 28

nickel-cadmium batteries, replaced for the solar-powered flights by a panel of 3,920

solar cells capable of producing 541 Watts of power.

The battery-powered flights took place at Shafter Airport near Bakersfield,

Calif. Dr. MacCready's son Marshall, who was 13 years old and weighed roughly 80

pounds, served as the initial pilot for these flights to determine the power required to

fly the airplane, optimize the airframe/propulsion system, and train the pilot. He made

the first flights on April 7, 1980, and made a brief solar-powered flight on May 18.

The official project pilot was Janice Brown, a Bakersfield school teacher who

weighed in at slightly under 100 pounds and was a charter pilot with commercial,

instrument, and glider ratings. She checked out in the plane at Shafter and made about

40 flights under battery and solar power there. Wind direction, turbulence,

convection, temperature and radiation at Shafter in mid-summer proved to be lessthan ideal for Gossamer Penguin because takeoffs required no crosswind and

increases in temperature reduced the power output from the solar cells.

Consequently, the project moved to Dryden in late July, although conditions

there also were not ideal. Nevertheless, Janice finished the testing, and on August 7,

1980, she flew a public demonstration of the aircraft at Dryden in which it went

roughly 1.95 miles in 14 minutes and 21 seconds.

This was significant as the first sustained flight of an aircraft relying solely on

direct solar power rather than batteries. It provided the designers with practical

experience for developing a more advanced, solar-powered aircraft, since the


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Gossamer Penguin was fragile and had limited controllability. This necessitated its

flying early in the day when there were minimal wind and turbulence levels, but the

angle of the sun was also low, requiring a panel for the solar cells that could be tilted

toward the sun.

Gossamer Penguin en vuelo encima de Rogers Lakebed Seco en Eduardo,

California, mostrando al perpendicular de panel solar al ala y afrontando el sol.

Solar Challenger

Using the specific conclusions derived from their experience with Gossamer

Penguin, the AeroVironment engineers designed Solar Challenger, a piloted, solar-

powered aircraft strong enough to handle both long and high flights when

encountering normal turbulence. As compared with the Penguin's 71-foot wingspan,

Solar Challenger had only a 46.5-foot wingspan, but it had a huge horizontal

stabilizer and a large enough wing area to accommodate 16,128 solar cells.

Using in-house computer programs, AeroVironment engineers Peter Lissaman

and Bart Hibbs designed the unusual wings and stabilizers, which they made flat on

top to hold the solar cells. Hibbs developed the aerodynamic design for the propeller


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with another in-house computer program. The result was a "smooth and docile"

aircraft that dropped in a steady, wing-level attitude when stalled and rapidly regained

unstalled flight.

AstroFlight, Inc., again provided the motor, and the DuPont Company, which

produced many of the advanced materials for the Gossamer Albatross, Gossamer

Penguin, and Solar Challenger, sponsored the project. Janice Brown remained one of

the pilots, but she was joined by the slightly heavier Stephen R. Ptacek (almost 150

pounds), who brought to the project over 4,600 hours of flight in a variety of aircraft.

The pilots flew the aircraft, first with batteries and then under solar power, at

the Santa Susana, Shafter, and El Mirage airports in California before moving to

Marana Airpark northwest of Tucson, Arizona, in late 1980 and early 1981. With

some modifications, the Solar Challenger showed itself to be an effective aircraft.

This was proved to the world during the cross-Channel flight on July 7, 1981, with

Ptacek at the controls.

Pathfinder

Growing out of the post-1983 development of HALSOL, Pathfinder was


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modified with additional solar arrays and other upgrades. It was then brought back to

Dryden for another series of developmental flights in 1995. On Sept. 11, 1995,

Pathfinder reached an altitude of 50,500 feet, setting a new altitude record for solar-

powered aircraft. The National Aeronautic Association presented the NASA-industry

team with an award for one of the "10 Most Memorable Record Flights" of 1995.

After additional upgrades and one checkout flight at Dryden in late 1996,

Pathfinder was transferred to the U.S. Navy's Pacific Missile Range Facility (PMRF)

at Barking Sands, Kauai, Hawaii, in April, 1997. Kauai was chosen as an optimum

location for testing the solar-powered Pathfinder due to the high levels of sunlight,

available airspace and radio frequencies and the diversity of terrestrial and coastal

ecosystems for validating scientific imaging applications. While in Hawaii,

Pathfinder flew seven high-altitude flights from PMRF, one of which reached a world

altitude record for propeller-driven as well as solar-powered aircraft of 71,530 feet.

Pathfinder "Plus"During 1998, the Pathfinder was modified into the longer-winged Pathfinder-

Plus configuration. On Aug. 6, 1998, the modified aircraft was flown to a record

altitude for propeller-driven aircraft of 80,201 feet on the third of a series of

developmental test flights from PMRF on Kauai. The goal of the flights was to


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validate new solar, aerodynamic, propulsion and systems technology developed for

the Pathfinder's successor, the Centurion, which is designed to reach and sustain

altitudes in the 100,000-foot range.

Essentially a transitional vehicle between the Pathfinder and the follow-on

Centurion, the Pathfinder-Plus is a hybrid of the technology that was employed on

Pathfinder and developed for Centurion.

The most noticeable change is the installation of a new 44-foot-long centerwing section that incorporates a high-altitude airfoil designed for Centurion. The new

section is twice as long as the original Pathfinder center section and increases the

overall wingspan of the craft from 98.4 feet to 121 feet. The new center section is

topped by more-efficient silicon solar cells developed by SunPower Corp.,

Sunnyvale, Calif.; they can convert 19 percent of the solar energy they receive to

useful electrical energy to power the craft's motors, avionics and communication

systems. That compares with about 14 percent efficiency for the older solar arrays

that cover most of the surface of the middle and outer wing panels from the original

Pathfinder. Maximum potential power was boosted from about 7,500 Watts on

Pathfinder to about 12,500 Watts on Pathfinder-Plus.

In addition, the Pathfinder-Plus was powered by eight electric motors, two

more than had powered the previous version of Pathfinder. Designed for Centurion,

the motors are slightly more efficient than the original Pathfinder motors.


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Pathfinder "Plus" flight in Hawaii June 2002

Centurion

Centurion, like its immediate predecessors Pathfinder and Pathfinder-Plus, is a

lightweight, solar-powered, remotely piloted flying wing aircraft that is

demonstrating the technology of applying solar power for long-duration, high-altitude

flight. It is considered to be a prototype technology demonstrator for a future fleet of

solar-powered aircraft that could stay airborne for weeks or months on scientific

sampling and imaging missions or while serving as telecommunications relay

platforms.

Although it shares much of the design concepts of the Pathfinder, the

Centurion has a wingspan of 206 feet, more than twice the 98-foot span of the

original Pathfinder and 70 percent longer than the Pathfinder-Plus' 121-foot span. At

the same time, it maintains the eight-foot chord (front to rear distance) of the

Pathfinder wing, giving the Centurion wing an aspect ratio (length-to-chord) of 26 to

1.

Other visible changes from its predecessor include a modified wing airfoil

designed for flight at extreme altitude and four underwing pods to support its landing

gear and electronic systems, compared with two such pods on the Pathfinder. The


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flexible wing is primarily fabricated from carbon fiber and graphite epoxy composites

and kevlar. It is built in five sections, a 44-foot-long center section and middle and

outer sections just over 40 feet long. All five sections have an identical thickness that

is 12 percent of the chord, or about 11.5 inches, with no taper or sweep.

Solar arrays that will cover most of the upper wing surface will provide up to

31 kilowatts of power at high noon on a summer day to power the aircraft's 14

electric motors, avionics, communications and other electronic systems. Centurion

also has a backup lithium battery system that can provide power for between two and

five hours to allow limited-duration flight after dark. Initial low-altitude test flights at

Dryden in 1998 are being conducted on battery power alone, prior to installation of

the solar cell arrays.

Centurion flies at an airspeed of only 17 to 21 mph, or about 15 to 18 knots.

Although pitch control is maintained by the use of a full-span 60-segment elevator on

the trailing edge of the wing, turns and yaw control are accomplished by applyingdifferential power-slowing down or speeding up the motors-on the outboard sections

of the wing.

The slow-flying Centurion solar-electric flying wing, one of several remotely

piloted aircraft developed under NASA's Environmental Research Aircraft and


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Sensor Technology (ERAST) program, glides in for a landing on Rogers Dry Lake

following a test flight at NASA's Dryden Flight Research Center.

Helios

AeroVironment envisions Helios as the ultimate solar aircraft that can offer

virtually eternal flights in the stratosphere. It will build upon the technologies

developed by Pathfinder and Centurion but will add an energy storage system for

nighttime flying. From 25 to 50 percent larger than Centurion, the Helios will store

up to two-thirds of the energy received by its solar array during the day and will use

this stored energy to maintain its altitude overnight. Because it will renew its energy

every day from the sun, the Helios will have flight endurance limited only by the

reliability of its systems, meaning a practical limit of perhaps six months on station.

Because of this long duration of flight, the Helios will be extremely economic

in operation. However, it will have to be perhaps the most reliable aircraft ever built,

with each flight lasting longer than the time between overhaul for a typical, generalaviation aircraft. As a consequence, much of the Helios design will involve a

minimum of moving parts, high redundancy, low temperatures, and solid-state control

systems. The Helios will also be able to diagnose degradation of its control systems

and reconfigure the autopilot while in flight. As a result, AeroVironment expects the

Helios to perform as a non-polluting, re-configurable "atmospheric satellite" in the

new millenium.


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The solar-electric Helios Prototype flying wing is shown near the Hawaiian

islands of Niihau and Lehua during its first test flight on solar power from the U.S.

Navy's Pacific Missile Range Facility on Kauai, Hawaii, July 14, 2001

El Programa ERAST

Centurion is and Helios will be one of a number of remotely piloted aircraft

being evaluated under NASA's Environmental Research Aircraft and Sensor

Technology (ERAST) program. The ERAST program is one of NASA's initiatives

designed to develop the new technologies needed to continue America's leadership in

the highly competitive aerospace industry.

The primary focus of ERAST is on the development of slow-flying, remotely-

operated aircraft that can perform long-duration science missions at very high

altitudes above 60,000 feet. These missions could include in-situ atmospheric

sampling, tracking of severe storms, remote sensing for earth sciences studies,

hyperspectral imaging for agriculture monitoring, and serving as telecommunicationsrelay platforms. The most extreme mission envisioned for solar-powered aircraft such

as the Centurion, Centelios and Helios would reach altitudes of 100,000 feet.


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A parallel effort is developing lightweight, microminiaturized sensors that can

be carried by these aircraft. Additional technologies considered by the joint NASA-

industry ERAST Alliance include lightweight materials, avionics, aerodynamics, and

other forms of propulsion suitable for extreme altitudes and duration.

The ERAST program is sponsored by the Office of Aeronautics and Space

Transportation Technology at NASA Headquarters, and is managed by the NASA

Dryden Flight Research Center. Sensor technology development is headed by NASA

Ames Research Center, Moffett Field, Calif.

Specific featurings

Wingspan: Solar Challenger, 46.5 feet (14.8 meters); Pathfinder, 98.4 feet (29.5

meters); Pathfinder-Plus, 121 feet (36.3 meters) Centurion, 206 feet (61.8 meters)

Length: Solar Challenger, 30.3 feet (9.22 meters); Pathfinder, Pathfinder-Plus, and

Centurion, 12 feet (3.6 meters)

Wing chord: Solar Challenger, 5.8 feet (1.78 meters); Pathfinder, Pathfinder-Plus,


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and Centurion, 8 feet (2.4 meters)

Gross weight: Solar Challenger, about 336 pounds (152.8 kg); Pathfinder, about

560 pounds (252 kg.); Pathfinder-Plus, about 700 pounds (315 kg.) Centurion, varies

depending on power availability and mission profile; approximately 1,900 pounds

for a mission to 80,000 feet altitude.

Payload: Solar Challenger, weight of pilot, up to 150 pounds Pathfinder, up to 100

pounds (45 kg.); Pathfinder-Plus, up to 150 pounds (67.5 kg.) Centurion, varies

depending on altitude; about 100 pounds. to 100,000 ft., 600 pounds. to 80,000 feet.

Airspeed: Solar Challenger, approx. 25-34 mph cruise Pathfinder, Pathfinder -Plus.

approx. 17-20 mph cruise Centurion, approx. 17-21 mph cruisePower: Arrays of solar cells, max. output: Solar Challenger, 2,700 Watts Pathfinder,

about 7,500 Watts; Pathfinder-Plus, about 12,500 Watts Centurion, 31,000 Watts

Motors: Solar Challenger, one electric motor, 2.7 kW Pathfinder, six electric

motors, 1.25 kW each Pathfinder-Plus, eight electric motors, 1.5 kW maximum each

Centurion, 14 electric motors, 2.2 kW each

Manufacturer: AeroVironment, Inc.

Primary materials: Composites, plastic, foam.

Aviones a Pedal y Alas Solar

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