At 06:51 this morning, 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.

"For 7 years now, the whole team has been passionately working to achieve this first decisive step of the project", said André Borschberg a few minutes before easing himself into the cockpit for a flight expected to last until next morning.

FLIGHT PROFILE

The whole day long, up to about 19:30, the prototype will be slowly ascending to an altitude of 8,500 metres, while at the same time charging its batteries in preparation for the night flight. When the sun's rays stop being strong enough to supply the solar cells (about two hours before sunset) with energy, the HB-SIA will start a slow descent, reaching an altitude of around 1,500 metres by 23:00. It should then carry on flying, using the energy stored in its batteries, until the next sunrise. The big question is whether the pilot can make efficient use of the battery energy to fly throughout the night. If this mission is successful, it will be the longest and highest flight ever made by a solar plane.

"The intention of this mission is to demonstrate the potential of renewable energy and clean technologies and to promote them amongst the public", explains Bertrand Piccard, initiator and President of Solar Impulse.

"After 4 space missions, I experience the same excitement being part of this revolutionary project!" declares Claude Nicollier, Head of the Solar Impulse test flight programme.

You will be informed when the HB-SIA has reached 8,500 metres and when it enters the night.

PRATICAL INFORMATION

If the afternoon sky is not affected by storm clouds, the suspense will reach its height in the early evening. That's when your presence at the Payerne airbase makes the most sense, with the flight then having a good chance of succeeding. If all goes well, the plane will land on Thursday, 8 July, in the morning.