The prototype first flew over Western Switzerland (“Swiss Plateau”) and now heads in the direction of the Thuner Lake.


At 06:51 this morning (07/07/2010), the Solar Impulse HB-SIA took off from the Payerne airbase with André Borscherg, CEO and co-founder of the Solar Impulse project, at the controls. The flight, powered only by solar energy, has already been airborne for almost fifteen hours!

Around 16h40, the prototype even exceeded the 8’500 meters that were intended and reached an altitude of 8,700 meters. With the help of its 12,000 solar panels built into its enormous 63.4 meter wing, its 400kg of batteries were fully charged during this long ascent.

The prototype first flew over Western Switzerland (“Swiss Plateau”) and now heads in the direction of the Thuner Lake.

“The prototype is ready to begin its journey through the night! It is now going to start a slow descent, which will bring it down to an altitude of 1,500 meters at around 23:00. From then on, the energy stored in the batteries is going to have to keep it up in the air until tomorrow morning”, said a confident Claude Nicollier, head of the Solar Impulse test flight programme.

“During the whole of the flight, I just sat there and watched the battery charge level rise and rise! Sitting in a plane producing more energy than it consumes is a fantastic feeling”, said André Borschberg , CEO and co-founder of the Solar Impulse project from the cockpit.

“This is a highly symbolic moment: flying by night using solely solar power is a stunning manifestation of the potential that clean technologies offer today to reduce the dependency of our society on fossil fuels!” added Bertrand Piccard, Initiator and President of Solar Impulse.

“After 17,500 hours flying commercial aircraft, for the first time I am finding myself on the side of the air controllers, in charge of flights…. And I’m just loving it”, said Raymond Clerc, Head of Solar Impulse flight mission.

You will be informed when the HB-SIA has successfully flown through the night. More info on

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