Solar plane takes off in 'moment of truth' for longest solo flight in history

Solar Impulse 2 sets off on Pacific crossing from Japan to Hawaii, expected to last five days and nights in most difficult leg yet of Andre Borschberg's attempt

A solar plane took off for what could be the longest solo flight in history on Monday, with its Swiss pilot confronting the "moment of truth" of a journey around the Pacific Ocean and around the world.

The Solar Impulse 2 set off about 3am from Nagoya, Japan, en route to Hawaii, a trip expected to take five days and nights of continuous flight.