Solar Plane Circumnavigation

Prep for launch! A team of Swiss adventurers start the first leg of their around the world journey in a plane fueled only by sunlight...

Two Swiss adventurers, Borschberg and Piccard, hope to fly around the world in an airplane fueled only by sunlight. Their five month journey, or quest to 'Fly Forever' will break the fuel barrier; crossing immense distances, flying day and night (wait a sec...), without consuming a drop of gasoline.

"This is the future," said Piccard, a psychiatrist and adventurer who in 1999 was the first to fly around the world in a gas balloon. "It's another way to think, to fly, to promote sustainability. We've come a long way since the Wright brothers."

Piccard, who had made two previous, unsuccessful bids at the balloon record, said he became obsessed with fuel as the possibility of a third failure crept closer. He said he began to see fuel as an obstacle-in his own adventure and also in terms of human progress. "We are addicted to fuel," he said. "But we have clean technologies now that can change that, and change the world."

The Swiss Federal Institute of Technology became intrigued with Piccard's plan for a solar-powered circumnavigation and commissioned a feasibility study and chose Borschberg to lead it. At the time, Borschberg was an entrepreneur with experience in tech start-ups. He had also for years flown jets in the Swiss air reserves. His team concluded that Piccard's idea was possible...though just beyond reach of the day's technology. But those limitations only fired Borschberg's imagination, and in 2004 he joined Piccard in order to found the Solar Impulse project. "Many people told us they didn't think our project would be possible," Borschberg said.

While many solar aircraft have flown successfully before, including small piloted models and massive remote-controlled drones, all have been relatively fragile and none has ever attempted the multi-day transoceanic journey awaiting Piccard and Borschberg.

Designing the plane wasn't easy. In order to accomplish such long flights, it needed to be both very big, and very light. Solar technology is still not a very efficient way of converting energy, so the plane would need a lot of solar panels. The designers' answer was to line every sun-facing surface of the plane with more than 17,000 solar cells, each about as thick as a human hair. Carrying most of this photovoltaic assembly, the Solar Impulse 2's wings reach 236 feet (72 meters) across-wider than the wingspan of a Boeing 787-8, an airliner built for more than 460 passengers. To save weight, Borschberg said his team searched for the lightest materials possible, paying close attention to notoriously dense parts, like the plane's four batteries, which at 519 pounds (235 kilograms) apice, are among its heaviest components. Engineers spent years fine-tuning and test-flying. They trimmed every unnecessary kilo, turned the cockpit into a cell smaller than a car trunk, and composed the plane's skeleton from custom-made carbon fiber. Even the pilot's seat was reconfigured for efficiency: it doubles as a toilet and reclines into a short bed.

As it lifted off (Monday in Abu Dhabi, Sunday night in the United States), after years of refinement and experimentation, the Solar Impulse 2 weighed just over 5,000 pounds (2,268 kilograms), similar to some large SUVs. No featherweight, Borschberg admitted. But still, not bad. Most of the legs of the journey ahead will require a dozen or more hours of flying, during which the pilot will guide the aircraft up to 28,000 feet to gather the day's maximum load of sunlight. While at altitude, he will face extreme cold, and even possibility of altitude sickness, similar to climbers on Mt. Everest. 

With the plane finally airborne, the most trying and potentially dangerous part of the two Swiss adventurers journey awaits. Will the Solar Impulse 2 achieve it's round the world quest, or end up like Malaysia Airlines Flight 370? Only time will tell...man this got dark.