The Solar Spirit

摘要

Early on a June morning in Switzerland the next stage in the evolution of solar-powered flight took place. The second Solar Impulse aircraft (Si2) departed Payerne. near Lake Neuchatel. on its maiden flight. The aircraft, on the Swiss civil register as HB-SIB, was airborne for two hours and 17 minutes, reaching a top speed of 30kts (56km/h) and an altitude of 5.500ft (1,670m). The numbers may seem unimpressive compared with those recorded by new commercial airliners and military aircraft during their first flights. But speed and altitude isn't the point of Si2. Next year the aircraft will be flown by the Solar Impulse project's founders. Bertrand Piccard and Andre Borschberg. on the first round-the-world flight powered only by solar energy. Si2 is one of the most unmistakeable aircraft in modern aviation. Though it looks ungainly on the ground, it appears elegant in flight. Its long wing - wider than a Boeing 747 - and slender fuselage have thousands of solar cells. Its makers claim there's never been an aircraft of its size that is so light. It weighs about the same as a small van and does not use a drop of aviation fuel or produce emissions. The two Swiss hope to spread a message about the potential of solar energy by flying this machine.