Solar Impulse 2, the first solar-powered plane with the ability to fly several days and nights, launched from Abu Dhabi on March 5, 2015. On what was supposed to be a five-month journey, its goal was to complete a round-the-world voyage fueled by its 17,248 monocrystalline silicon cells.
But it ran into some trouble during its Pacific leg, and was grounded in Hawaii for nine months.
SI2 is resuming its round-the-world voyage this April, after vital repairs have been completed and the sunny season has returned. It suffered battery damage during the 8,900 km (5,530 mi) journey from Japan to the Hawaiian Islands, and was grounded on July 2015.
The battery damage was due to overheating, with certain parts of the four 70-liter, lithium polymer batteries attached to the plane’s wings heating up due to temperature fluctuations. During the break, the SI2 team replaced the batteries with similar ones, installed new cooling systems, and conducted maintenance flights on the wing.
The next leg of their journey will take them to North America, with the specific destinations still being chosen between Phoenix, the San Francisco area, Los Angeles and Vancouver.