'Next stop Hawaii' for Solar Impulse 2
Solar Impulse, a zero-fuel aeroplane piloted by Andre Borschberg, is on the most difficult leg of its mission to fly around the world.
It is expected to take six full days and nights to make the journey from China to Hawaii.
The journey is the seventh leg in the single-seat, propeller-driven aircraft's quest to circumnavigate the globe using just the energy of the Sun.
John Sudworth reports.