Pilots to Fly Plane Around the World Using Only the Power of the Sun

Two Swiss pilots will attempt to become the first people to circumnavigate the globe in a solar-powered plane.
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Two Swiss pilots will attempt to become the first people to circumnavigate the globe in a solar-powered plane.

Bertrand Piccard and André Borschberg are tentatively scheduled to take off on March 7 in an experimental plane for a flight around the world. If human endurance were as advanced as the plane, they might never have to land.

The Solar Impulse 2 aircraft, which they will fly around the world in several legs between their possible departure on Saturday and the end of their journey in July or August, could, in theory, fly nearly indefinitely because it never has to refuel.

The plane is fueled directly by sunlight during the daytime and stores solar energy in batteries for continued flying at night. If their flight is a success, Piccard and Borschberg will become the first pilots to circumnavigate the globe in a plane powered only by the sun.

The two Swiss adventurers and plane designers were making last minute preparations this week for their scheduled takeoff from Abu Dhabi in the United Arab Emirates. Their round-the-world journey will be flown in pieces over the next several months. It will take so long because the sunlight-powered plane flies only about the speed of a car, between roughly 20 mph and 90 mph.

Because it doesn't need to refuel, individual legs of the flight are limited mainly by the need for the pilots to get out and recharge after spending days inside a relatively small cockpit. The shortest flight legs on the upcoming journey will be about 20 hours, which, as Piccard noted last Tuesday on his Twitter feed, is much longer than passenger jets normally fly.

The idea — and the realization of a need — for such a flight has its beginning in an earlier round-the-world flying experience that Piccard, a noted adventurer, had several years ago.

In 1999, Piccard and Brian Jones completed the first-ever non-stop balloon flight around the world, completing the trip in 20 days. And as he stared out at the vast expanse of the Pacific Ocean below, Piccard began to worry that the balloon might not have enough fuel to finish the trip — or even get the two men back over land where they could survive an early ending to the flight.

They did make it, but when he and Jones landed, Piccard was struck even more by how his life had depended so much on how much fuel the balloon could carry and quickly began to see the balloon and its finite amount of fuel as a metaphor for humankind’s reliance on fossil fuel.

“We took off with 3.7 tons of liquid propane, we landed with 40 kilos,” Piccard recalled in a 2009 TED Talk. “When I saw that, I made a promise to myself. I made the promise that the next time I would fly around the world, it would be with no fuel ... not to be threatened by the fuel gauge.”

But in a larger sense, Piccard was struck by the thought, expressed by so many, that the world’s dependence on fossil fuels was an impossible problem to solve.

But then, so was flying around the world on solar power alone.

“I want to inspire others to also achieve the impossible,” Piccard said on a video from the Solar Impulse team announcing the planned flight.

For the Solar Impulse 2, Piccard says, the only fuel shortage threat now is darkness. Flying through the night on stored up battery power from the previous day’s sunshine, “there will be just one goal, just one,” Piccard said in that 2009 TED talk. “Reach the next sunrise before the batteries are empty.”

An earlier prototype for the plane, known as the Solar Impulse, set several records for experimental planes, including one for longest solar powered flight during a nearly 1,400 km flight from Phoenix, Arizona, to Dallas, Texas, in 2013.

The Solar Impulse 2 weighs just over 5,000 pounds and has more than 17,000 solar cells along its fuselage, wings and tail. The energy collected by the panels powers the plane’s four electric motors, with some stored in lithium batteries to be used during night flying. The plane is awkward looking — because the fuselage is relatively small, but the wingspan is about the same as the biggest passenger 747.

“Why? Because with this size we get more lift and less drag ... we have a higher efficiency,” Borschberg said in a BBC News report last year after announcing the planned flight.

Both pilots see the flight as one of inspiration.

Borschberg said last year that time he spent living in the tech hub of Boston, while a student at the Massachusetts Institute of Technology, instilled in him a belief in discovery and entrepreneurship.

“I know that dreams fuel innovation,” Borschberg said when the team announced the plan to circumnavigate the world with no fuel. “And I also know that human commitment in new technologies can really change the world.”

Piccard brings serious adventure bona fides to the project, along with his experience in pioneering around-the-world flights. He comes from an exploring family — Piccard's father, Jacques Piccard, was on the first team of human beings to descend to the bottom of the Mariana Trench. Bertrand Piccard's grandfather, Auguste Piccard, was an early pioneer of altitude records in balloon flight.

After takeoff from Abu Dhabi, the carbon-fiber plane will stop in Oman, and then make two stops in India, one in Myanmar and two in China before crossing the Pacific via Hawaii. The Solar Impulse 2 will then stop in Phoenix, somewhere in the American Midwest to be determined by weather conditions and then in New York. Then it’s back across the sea, heading out over the Atlantic toward another undetermined landing site in Europe or North Africa before heading back to Abu Dhabi this summer.

The pilots and other members of the Solar Impulse 2 team will also try to make the flight educational along the way. Engineering and other students will get to meet with the pilots during some stops, and the crew plans to make the plane viewable by the public during layovers as well.

While Piccard and Borschberg are on a mission to inspire and push scientific boundaries, there are obvious every day, practical applications that could come out of the development of the Solar Impulse 2. The most evident immediate application for many of us could be solar-powered cars that don’t need to recharge in any way other than just sitting out in the sun.

Those everyday applications are also part of the duo’s inspirational hopes.

“The idea,” Piccard said in that 2009 speech, “is that if we fly around the world in a solar-powered airplane, using absolutely no fuel, nobody ever could say in the future that it's impossible to do it for cars, for heating systems, for computers and so on and so on ...

“This airplane is more a symbol,” Piccard continued. “I don’t think it will transport 200 people in the next years. (But) this is not an airplane. This is a symbol of what we can achieve when we believe in the impossible.”

Learn more about the Solar Impulse 2’s flight at its website and by watching the video below:

Editor’s Note: This story has been updated to reflect that the first possible departure date for the Solar Impulse 2 has been changed to March 7.

Top photo caption: The Solar Impulse 2 during its maiden flight in Switzerland on June 2, 2014. (Photo courtesy of Solar Impulse)