A plane that flies at night. What's wrong? We spend thousands over our head when the sun sets. But this is a very special night flight and worthy of note: it was made ​​from an airplane powered only by solar energy, the Solar Impulse HB-SIA.

The plane, designed by a Swiss working group composed of Bertrand Piccard, André Borschberg, Luigi Torrigiani, and Brian Jones, is made ​​by the time the prototype stage.

The Solar Impulse HB-SIA is the first commercial solar power designed to stay in the air day and night, without fuel, with a scheduled average speed of about 70 miles an hour. The plane, made ​​of carbon fiber, has 12 000 solar cells, which power the four engines. The wingspan is 63.4 meters, similar to that of an Airbus A-340. Its weight is about 1600 kilograms, comparable to that of a car. The ultimate goal of this project is to travel around the world by 2013 in 5 stages.