Switzerland has unveiled a solar-powered plane that could potentially stay in the air indefinitely. The newly finished aircraft will undergo its first tests in May and June, and plans to fly around the world in 20 days, spread out over three months.
The Solar Impulse 2 is an improvement over a small prototype that first flew five years ago. It weighs about as much as a car, and has a wingspan larger than a Boeing 747. The aircraft features 17,000 solar cells on its 72-meter wings, one seat, a toilet, and space in the cockpit for the pilot to lie down. To keep its weight down, engineers chose lighter materials and more efficient electric motors compared with the first prototype.
The new plane overcomes some of the limitations of the earlier prototype, which required ideal weather conditions to recharge its batteries. Solar Impulse 2 can fly across small cloud layers, but won't be able to traverse through thunderstorms. Pilots are training on flight simulators to fly long periods with short resting breaks, sleeping for about two hours a day in 20-minute periods.
"What we really wanted to demonstrate is how many incredible things we can make with renewable energies, with clean technologies," Andre Borschberg, cofounder of the Solar Impulse project, told the Associated Press. "Because so often we believe that clean technologies is a limit, for comfort, for mobility, for prosperity. And it's the opposite."