The Solar Impulse, an experimental solar-powered plane, completes a 26-hour flight in a major development for the alternative energy movement. The slender, long-winged plane, which was powered by 12,000 solar cells and sunlight-powered lithium batteries, flew through the night over Switzerland using just energy collected the day before.

In what may be the longest test flight of a piloted solar aircraft, the plane reached a height of 28,000 feet and flew at a top speed of 78 miles per hour. The experimental solar plane project, which was launched in 2003, was created under the guidance of Bertrand Piccard, who is the first person to successfully complete a non-stop balloon flight around the world.

The solar plane project was launched at the end of 2003 under the guidance of Bertrand Piccard, the first person to complete a nonstop balloon flight around the world.

The Solar Impulse, which was flown by Andre Borschberg, a former Swiss air force fighter pilot, took off and landed in the same place, Payerne, Switzerland.