Solar Impulse Unveils Fuel-Free Plane for Round-the-World Flight

Artist's conception of Solar Impulse 2

The Swiss team that flew a solar-powered airplane across America has unveiled the even bigger plane that they plan to take around the world a year from now.

"It's the most incredible airplane of its time," Bertrand Piccard, the president and co-pilot of the Solar Impulse venture, told VIPs who gathered at Switzerland's Payerne Air Field on Wednesday for the first public look at the 236-foot-wide (72-meter-wide) aircraft.

Like last year's Solar Impulse plane, the Solar Impulse 2 craft is festooned with solar cells that power the electric motors without a drop of fuel. But this time around, the plane's wingspan is more than 25 feet (8 meters) wider. It's built from carbon composite materials that are even lighter— and it's capable of going faster, up to 87 mph (140 kilometers per hour).

Image: Solar Impulse 2
The Solar Impulse 2 airplane is unveiled Wednesday during a VIP ceremony in Payerne, Switzerland. Solar Impulse

"The first airplane, for us, was a prototype — a flying test bench," said Andre Borschberg, Solar Impulse's other co-pilot and the venture's chief executive officer.

Piccard and Borschberg are expected to start test flights in the next month or so, with increasingly ambitious outings leading to the round-the-world attempt as early as next March. That timing is dictated by the weather they expect to encounter along the way: If they start out much later, they run the risk of encountering the monsoon season in India.

The itinerary calls for a starting-line takeoff from the Persian Gulf region. The plane will fly over the Arabian Sea, India, Burma, China, the Pacific Ocean, the United States, the Atlantic Ocean and then southern Europe or North Africa, leading back to the starting point. Maximum cruising altitude will be 27,000 feet, or 8,500 meters.

Image: Airplane comparison
This schematic compares the width of the Solar Impulse 2 airplane with that of a Boeing 747 jet. Solar Impulse

Batteries make up a quarter of the plane's 2.5-ton (2,300-kilogram) weight, and that's because the power generated by the more than 17,000 solar cells has to be stored up to keep Solar Impulse 2 flying through the night or through cloudy weather.

Landings will be made every few days so that Piccard and Borschberg can trade turns in the single-seat cockpit. But the flight plan calls for five days and five nights of continuous flight across the Pacific and the Atlantic — which poses one of the greatest challenges for the sustainable-energy project.

"We have to make the pilot sustainable as well," Borschberg observed.

The solution is to make the cockpit more comfortable, and create a sophisticated autopilot system that serves as a "virtual co-pilot." Borschberg said the accommodations for this second Solar Impulse plane have been upgraded from economy-class to "good business class."

Image: Reclining
Solar Impulse pilot Bertrand Piccard tries out the reclinable pilot's seat in a simulator. Solar Impulse

The pilot will be able to recline the cockpit seat fully to get some shut-eye, and set the autopilot to wake him up when necessary. And of course, mission controllers in Switzerland will monitor the flight continuously as well. As was the case for last year's "Across America" odyssey, video and flight data from Solar Impulse 2 will be beamed across the Internet.

Swiss and European industries have backed the project with $124 million (90 million euros) over the past decade, but Piccard suggested that even more backing was needed to follow through with Solar Impulse 2. "They brought the money," he said Wednesday. Last year, Google joined the project as a technology partner.

Solar Impulse and its backers say they took on the challenge of building a solar-powered, round-the-world airplane to promote sustainable technologies — ranging from the plane's solar cells, lithium polymer batteries and carbon composites to the high-tech foam materials that insulate the cockpit.

Image: Solar Impulse pilots
Solar Impulse's Bertrand Piccard and Andre Borschberg show off the round-the-world airplane. Solar Impulse

"In the next years, what we'll see is the same technology dropping into the automotive industry, dropping into the refrigeration industry, and everybody will be getting the benefit," said Richard Northcote, head of communications and public affairs for Bayer MaterialScience.

But the backers also acknowledged that the thrill of adventure was also part of the payoff.

"We're selling a dream," Stephen Urquhart, president of the Omega watchmaking company, told the VIPs in Payerne. "It may sound a bit corny, but it's true."

Piccard admitted as much as well.

"It's not the easiest way to fly around the world," he said, "but it's probably the most spectacular way we can achieve today to really attract the awareness of the political world, the media, the industries, the economy, to show what we can do with renewable energy."