The Solar Impulse 2 plane is currently tackling the most ambitious leg of its round-the-world journey, after taking off from China bound for Hawaii.
Swiss pilot Andre Borschberg left Nanjing in eastern China overnight on Saturday, after weeks of delays waiting for good weather conditions. Later he described the flight as “unbelievable”, saying he felt both physically and mentally prepared for the first night.
The entirely solar-powered aircraft needs plenty of sunlight to make the trip across the Pacific Ocean.
The distance of 8,500 kilometres is expected to last six days and six nights, which could set a duration record for a single pilot.
There were cheers from the ground crew as the plane took off.
Although its wingspan of over 70 metres is that of the largest passenger airliner, the aircraft weighs no more than a family car.
The journey which began in Abu Dhabi in March is an attempt to promote green energy.