Solar Impulse Takes First Successful Test Flight

Biofuels may be the most mainstream option for powering the airplanes of the future, but solar power shouldn't be completely overlooked--just take a look at the Solar Impulse, a completely solar-powered plane that just finished its first test flight, a 1.5 hour trip above Switzerland. The Boeing 747-sized plane, which features 12,000 solar cells on its wings, reached an altitude of 3,937 feet and an average speed of 44 mph during its 87-minute flight.

This wasn't technically the first test...