Bob Simon: Has there ever been anything so light before?
Bertrand Piccard: No, I don't think so.
And the solar cells are light too. Other cells available were more efficient but weighed more, and the Solar Impulse team needed cells flexible enough to create the contour of the wings. There are 12,000 of them.
Andre Borschberg: These solar cells make the surface of the wing. So they are not glued on the surface. They are the surface.
Bertrand Piccard: And these cells capture the energy of the sun and transform it into electricity. And then this electricity goes simultaneously to the engines and to the batteries and then we will reach the next sunrise and capture the sun again. And we can continue theoretically forever.
Almost all of the energy created by the cells ends up being used by the engines. Compared to car engines that can waste 70 percent of the energy provided. During the day, excess energy is stored in batteries -- batteries that are unusually efficient. Piccard says all the materials can be used for more practical applications.
Bertrand Piccard: If we can fly in a solar airplane like Solar Impulse with no fuel, just on solar power, then all the technologies here can, of course, also be used in the daily life for cars, for houses, for heating systems, cooling systems and so on.
While the technology was being fine tuned, Andre spent months inside a simulator so he could learn how to fly the plane himself. Then short flights to and from a military air base in Switzerland. The Alps provided a breathtaking backdrop, but they weren't in it for the scenery. They wanted altitude and distance. They took it out of Switzerland to Belgium and Paris, where they created quite a stir flying by the Eiffel Tower. But for once the French didn't complain. Solar Impulse was so quiet and elegant.
But the biggest challenge was flying at night. Were they ready? "Yes," said Piccard and he announced to the team that Andre would be in the cockpit.
[Bertrand Piccard: Andre will stay up there now as long as we can.]
And off he went, into the night. For eight hours, Andre flew in darkness over Switzerland. Andre could see nothing so the team on the ground had to track winds, squalls, battery levels. Watching this creature in the air -- long after the sun has surrendered - is almost unreal. The plane emerges from the darkness like an apparition. Just before the sun peeked through the clouds, Bertrand counted Andre down to the dawn.
[Bertrand Piccard: Nine, eight, seven, six, five, four, three, two, one. We made it! We made it guys! Andre you should be with us right now.]
Andre made it with power to spare and, just think, he could have taken off again without refueling.
Bob Simon: It must be a pretty good sensation when that sun comes up in the morning.
Andre Borschberg: It is, well certainly because of the beauty, I mean the sunset is gorgeous but the sunrise of course brings us the next day there. It brings the hope again that you can continue.
Bertrand is continuing a family tradition --- visionaries, pioneers, adventurers. His father, Jacques, designed a new fangled submarine, squeezed himself inside, and went down seven miles beneath the surface of the Pacific and came up to talk about it. That was 50 years ago. His grandfather, Auguste, decided to go the other way - up. He'd heard the Earth was round, but wanted to see for himself. So, he designed a pressurized cabin, attached it to a balloon and flew it to an altitude of 10 miles.
Bertrand Piccard: It was considered by NASA as the first man in space. So in those days it was like going in another world.
Bob Simon: Was your grandfather in fact the first human being to see the curvature of the earth?