Solar-powered plane flies all day and all night

New York Times : Yesterday morning around 7am, Solar Impulse, a solar-powered airplane, took off from Payerne, Switzerland. The goal of the flight: to test whether the energy that fell on its solar-panel-covered wings during the day and stored in its batteries could sustain the plane during a night flight. The test was successful. On its 26-hour flight, Solar Impulse reached a maximum altitude of 8564 m and maintained an average speed of 40 km/h. The ultimate goal of the Solar Impulse Project is to fly nonstop around the world.