Photo taken on May 31, 2015 shows the Swiss-made solar-powered plane Solar Impulse 2 at Nanjing Lukou International Airport in Nanjing, capital of east China's Jiangsu Province. The solar-powered plane left China for Hawaii on Sunday. It will fly across the United States and make several stops before finally reaching Abu Dhabi. (Photo: Xinhua/Xie Mingming)
