People have flown in planes for over 100 years, but many engineers are still trying to improve on their design. Airplanes are powered by fuel, which causes pollution and is also very expensive. To try and solve that problem, two engineers from Switzerland designed a plane that runs on solar power instead of fuel. They built really long solar panels, which harvest the sun's energy, and put those on the plane's wings. The engineers gave the plane a small, light-weight body, so it would need less energy than a traditional, heavy plane. But, that meant the solar plane could only carry a few passengers.
The engineers tested their plane prototype with a flight around the world! The plane used so little energy, it could fly for almost five days before it had to stop and recharge. The journey took about five months to complete - what a trip! The engineers learned a lot about how to improve their plane, and hope someday its solar power could replace fuel on passenger airplanes.
Click here to watch a video about the plane's first flight in 2013.
How would YOU redesign a vehicle, so it causes less pollution? Show us your ideas in the design section.
(Image credit: Inhabitat.com)