A solar airplane. Neat.
The Solar Impulse is a prototype airplane that made its first real flight today. The plane runs entirely on solar energy, deriving said energy from 12,000 solar cellsthat power four 10-horsepower motors. This new machine has a wingspan of 208 feet and weighs only 3,500 pounds. The flying time was 87 minutes at an altitude of just under 4,000 feet. The ultimate goal is to circumnavigate the globe, but this is a good first step, especially considering that it only got 3 feet off the ground for 1/4 of a mile back in December. Future testing will include night flights -- fly to higher altitudes during the day, trading altitude for airspeed, and supplementing with battery power. These night flights will hopefully help the plane make its trip around the world in 2012.
Read the story and see more pictures here: http://www.wired.com/autopia/2010/04/solar-airplane-completes-maiden-voyage/