Piccard, a Swiss psychiatrist and aviator, comes from a family of adventurers who don't back down from challenges: In 1960, his father, Jacques, made the first voyage to the ocean's deepest point; in 1931, his grandfather, Auguste, was the first balloonist to reach the stratosphere. Piccard continued to promote his solar-powered plane concept, and the Swiss Federal Institute of Technology in Lausanne (EPFL) agreed to conduct a formal feasibility study in 2003. It concluded that an ultralight plane with a long wingspan to reduce drag and support solar cells could conceivably work. André Borschberg, the pilot and engineer who led the EPFL study, joined Piccard to officially found Solar Impulse, and they began recruiting corporate and individual donors to help finance the $130-million, 10-year project.
The two men immediately ran into problems finding an aviation contractor to build the plane. None thought it was possible, so they assembled their own motley team of engineers. "I think we have more people from outside the field of aviation than inside," says Borschberg. Solar Impulse's head of airplane development, Robert Fraefel, has a background in Formula One racing. Others come from industries such as photovoltaic manufacturing and die casting. "In some ways, it was a big asset not to be too experienced," Borschberg says. "When you are experienced, you go back to the solution you know."
The team decided to construct the frame's ribs and wing spar entirely from carbon fiber (manufactured by a company that builds yachts) joined by high-performance plastic screws and bolts. The materials are light yet strong enough to give HB-SIA a wingspan of 69 yards—almost exactly that of an Airbus A340-500 passenger jet. Yet the plane weighs just over 3,500 pounds, less than 1 percent of the weight of an Airbus and about 2,000 pounds less than a typical SUV.
To power the plane, engineers laminated nearly 12,000 silicon solar cells over the main wing and horizontal stabilizer. The cells generate an average of 50 kilowatts over a 24-hour period, sending electricity directly to the motors when the plane is in flight and directing any excess to four lithium-polymer batteries. A battery management system ensures the batteries don't get too cold, reducing their efficiency, or dangerously overheat.
The Piccards. Now there's a PopSci dynasty. I am curious though; because this isn't at all like the ballooning achievements, because that was actual high technology in that day. This is not. Difficult feat-yes, high tech-no. We won't see common personal aircraft of this size or anything close. Too fragile. Full hangar expense to park indoors in winter. Nor is solar as robust as need be for general aviation. Can't really power out of an emergency. I imagine this is more aimed at the sailplane crowd. Civil Air Patrol does use them for flight training and firewatch and the like.
Where is the bathroom!
Ok. Now try that with a B747. Then I'll applaude.