The Solar Impulse, a solar-powered HB-SIA prototype airplane, takes off for its first night flight attempt at Payerne airport July 7, 2010. The propeller plane, piloted by Solar Impulse Chief Executive Andre Borschberg, has a 61-metre (200-foot) wingspan and is powered by four electric motors. It is designed to fly day and night by saving surplus energy from its 12,000 solar cells in high-performance batteries. REUTERS/Fabrice Coffrini/Pool (SWITZERLAND - Tags: TRANSPORT ENERGY ENVIRONMENT SCI TECH)