Following the first take-off last December, the Solar Impulse HB-SIA prototype starts today, on March 30, a new test phase at Payerne airfield. These will lead up to the first night flights by a plane powered solely by solar energy this summer. These test flights (first short circuit flight, first altitude flight, etc.) will enable Markus Scherdel, the test pilot of Solar Impulse, to verify the aircraft’s controllability and behaviour. Bertrand Piccard and André Borschberg will then take turns at the controls to familiarize themselves also with the airplane and carry out the series of missions that should lead to the first night flights. Technical and weather constraints make it impossible for us to draw up a precise calendar of test flights. However, we will endeavour to inform you 24 hours in advance of the next flight – though without any guarantee that it will actually take place. You can follow each crucial test phase on our website (www.solarimpulse.com), where a blog is regularly updated and where the latest videos are available.