The BBC reports that Solar Impulse has resumed its 'round-the-world attempt, having taken off today from Nagoya, Japan for what is intended to be a 120-hour voyage to Hawaii. [If pilot Andre Borschberg] succeeds, it will be the longest-duration solo flight in aviation history, as well as the furthest distance flown by a craft that is powered only by the Sun. The Pacific crossing is the eighth leg of Solar Impulse's journey around the world. But this stage has proven to be the most difficult, and has been hit by weeks of delays." The circumnavigation attempt began earlier this year.