Solar Impulse 2, the first ever fuel-free plane to successfully circumnavigate the globe, touched down in Abu Dhabi today. The solar-powered machine took off from the same city in March 2015. But despite a few setbacks, the plane and Swiss pilot Bertrand Piccard (who took shifts with fellow flyer André Borschberg) touched down without incident.
Solar Impulse 2 is a one of a kind. Its 236-foot wingspan makes it wider than a Boeing 747, but the thing is just 5,000 pounds. 17,000 rigid, photo-voltaic panels charge four uber-efficient batteries, which make up nearly a third of the weight. Its four 17.4-horsepower motors definitely aren’t the fastest: The plane tops out around 90 mph, and traveled at an average of 38 mph across the Pacific.
Though the pilots had a tough time with facing turbulent weather over the Pacific storms – which is particularly bad news for a solar-powered plane.
Then the Pacific leg also fried the plane’s batteries, leading to a nine-month delay. But the team sure made the best of that, raising an extra $20 million from sponsors and adding a battery cooling system. Then in May, another boo-boo: A power outage in Dayton, Ohio, deflated the plane’s bespoke hangar and slightly damaged the plane. In mid-July, Piccard’s upset stomach delayed the final leg between Cairo, Egypt, and Abu Dhabi. And in a final twist of irony, the sun tried sabotaging the mission. Super-hot temperatures (like, 119 degrees Fahrenheit hot) over the Saudi Arabian desert postponed the trip once again.