Solar Impulse, a solar-powered plane, completed the longest, transpacific leg of its round-the-world journey. The 72-metre-wide craft, powered by 17,000 photovoltaic cells on its wings and fuselage, has broken several solo- and long-flight records. It began its trek in Abu Dhabi in March 2015 but had been grounded in Hawaii for eight months of repairs after its batteries overheated.