by ERIC LIMER

Next week, pilot André Borschberg will take off in the solar-powered plane Solar Impulse 2. After he does, he’ll be in the air for five days, traversing the Pacific Ocean on his way from Nanjing, China, to Honolulu, Hawaii alone. It only gets crazier from there.
This hop from China to Hawaii is just one leg in a much longer 12-jump trip that’s taking the solar-powered plane and its two pilots around the globe. Shortly after Solar Impulse 2 touches down in Hawaii, its other pilot, Bertrand Piccard, will be taking it back up and across the rest of the Pacific on a four-day flight to Phoenix, Arizona.
Each leg has been a challenge, but these oversea flights are especially grueling. The pair have been preparing for them for years.
Five days is a long time—a commercial jet could make the same trek in some 12 hours—and it takes so long because the Solar Impulse 2 is slow. Its cruising speed is around 25 to 30 knots (roughly 30 miles per hour), Piccard tells The Verge. That is positively pokey, an order of magnitude slower than your average jet.
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