Solar Impulse 2 completed the first circumnavigation of Earth using only solar power in 2016.
The Swiss aircraft was piloted by Bertrand Piccard and André Borschberg, who shared the journey in alternating legs. Its wings carried thousands of photovoltaic cells that powered four electric motors and charged batteries for night flying.
The journey began in Abu Dhabi in March 2015 and ended there in July 2016. The longest and most demanding leg crossed the Pacific Ocean from Japan to Hawaii, with Piccard spending several days aboard the aircraft.
Solar Impulse 2 was a technology demonstrator rather than a commercial aircraft. Its flight showed that solar-electric propulsion could support long-distance aviation, although the aircraft's low speed and limited payload made it unsuitable for ordinary airline service.