On a bright blue day in December the Solar Challenger, the world's most expensive dirt-cheap airplane, took off from the Marana Air Park on the outskirts of Tucson. After circling the strip five times to gain altitude, the pilot of the Solar Challenger, a pert, petite schoolmarm named Janice Brown who holds commercial, instrument and glider ratings, headed across the cotton fields, arroyos and cactus-pocked desert. With the large propeller of her plane whirring slowly, making barely more sound than the beating wings of a goose, Brown flew for 22 minutes. In that time she reached an altitude of 500 feet and traveled slightly more than six miles. In so doing, she had in effect brought the history of aviation full circle, back to the legendary Icarus. It was because of the sun that Icarus crashed in a mess of melted wax and feathers. It was the power of the same sun that lifted the Solar Challenger and kept it flying, without any sweat on Brown's part, or a drop of gas, or any other source of power.
Compared to the super aircraft of the red-hot present, the Solar Challenger is not much for looks. Because of its big propeller, its broad wing and its stabilizers affixed to a thin boom, it resembles the rubber-band-powered "stick" model planes that kids build. The tough gossamer stuff of which it is made—Mylar, Kevlar, Delrin, Lucite, Teflon, Nomex, carbon fiber and piano wire—does cost a bit, but because the plane, without the 98-pound Brown aboard, weighs only 193 pounds, it didn't use much of anything. Structurally speaking, it's a bargain-basement item.
Its power plant—there's the rub. The propeller of the Challenger is driven by an electric motor, which, although the size and shape of a can of spray deodorant, costs $500. The 16,128 voltaic cells spread across the upper wing and horizontal stabilizer to convert sunlight into electricity are valued at $130,000.
Because the power derived from this bank of converters isn't enough to drive a large chain saw, the Challenger isn't a practical machine. It came to be largely because of the enthusiasm it generated in the Du Pont Company of Delaware and in the National Aeronautics and Space Administration. Du Pont contributed $400,000 to the project, in part because the Challenger is made largely of synthetics the company produces. NASA lent the costly solar cells after sticking its own neck out to borrow them from the Air Force. Neither Du Pont nor NASA makes a habit of contributing lavishly to far-out ventures, but both could easily do so in this case, reassured by the fact that the designer of the Challenger was Dr. Paul MacCready, a Pasadena physicist whose reputation for getting improbable machines to fly recently earned him the title Inventor of the Year.
The 55-year-old MacCready has spent his life studying and using the God-given atmosphere that swaddles this earth and contending with the manmade stink that is spoiling it. His cerebration in behalf of human welfare ranges from the practical to the highly speculative. At one extreme, AeroVironment, the company he now heads, makes drag-reduction devices that save large trucks about 2¢ a mile. At the other extreme, MacCready has served on a national panel investigating flying objects from outer space. The fact that, even in this day of climbing fuel prices, only about a fourth of the trucks in the U.S. use drag-reduction devices forces MacCready to believe that the bosses of the industry aren't particularly patriotic or smart. As a result of being a member of the panel investigating unidentified flying objects, MacCready concludes that "there will always be UFOs as long as there are people who believe in UFOs." Between these extremes, his company, AeroVironment, has been involved in projects making the most of geophysical functions—notably windmills and turbines to derive power from the air and the principal currents of the sea. The company also studies air pollution, using equipment that can trace noxious vapors and instruments that can determine the particular contaminants that are making people gasp and turn blue.
Getting something for nothing is a dream that dies hard. Alchemists of yore tried making gold out of base metals and never did. Today there are still well-educated noodlers who believe in perpetual motion. After graduating from Yale in 1947 with a degree in physics and a Phi Beta Kappa key, MacCready took a masters in physics and a doctorate in aeronautics at Cal Tech. Although he's too well disciplined academically ever to believe in something for nothing, when it comes to making a great deal out of almost nothing, he's a master.
Twenty years ago a retiring but ever curious English industrialist named Henry Kremer offered a £5,000 prize for the first successful man-powered flight. At Kitty Hawk back in 1903, to win its niche in history, the gas-powered Flyer I with Orville Wright at the controls spent a mere 12 seconds in the air and traveled only 120 feet The criteria laid down for the Kremer prize were much stiffer. To win, the pilot would have to lift off under his own power and complete a figure eight around two pylons half a mile apart. He could cover the course at any altitude, provided he cleared a 10-foot barrier at the start and at the finish.
The original prize was open only to subjects of the United Kingdom, but because by 1967 it was still unclaimed, Kremer doubled the purse and offered it to the whole world. Since the principal bugaboo seemed to be getting machines to execute a 180-degree turn, at the same time he offered £5,000 to the first three pilots of the U.K. who could fly a simpler course, simply weaving, slalom-style, around three pylons on a half-mile straight. In 1973 Kremer upped the figure-eight award to £50,000 and doubled the money for the simpler slalom test. As if in desperation to get somebody to win something, three years later he offered £1,000 to the first Commonwealth pilot who could even keep his machine in the air for three minutes.
Between 1960 and 1977 more than two dozen planes were designed to win Kremer money. Some never got off the drawing board: others never got off the ground. Canadians designed one super-sized eight-man machine and another for two men. Neither was completed, because of flagging interest and lack of funds. One dainty English beauty called Mayfly had a life even shorter than its name foretold. Before Mayfly was hauled out for its first test flight, the hangar roof collapsed, demolishing it.
Most of the Kremer-inspired craft did fly. Thirteen of them traveled farther than Flyer I did on its epic first hop at Kitty Hawk, but because the Kremer competition had become the recognized standard, all were deemed failures. Low-powered aircraft are necessarily light and large-winged, and consequently hard to turn. The best of the Kremer planes, Stork B, built at Nihon University in Japan, flew for nearly five minutes, but could never turn tightly enough to complete the figure eight.