Solar Impulse passes the 'point of no return' over Pacific ocean

Tokyo

 A solar-powered plane has passed the "point of no return" in a bid to make a record-breaking flight for the second time, across the Pacific Ocean.

Solar Impulse took off from Japan's Nagoya Airfield at 18:03 GMT on Sunday.

The plane is expected to complete the journey to Hawaii in approximately 120 hours.

The team spent two months waiting for clear weather to cross the Pacific, and as the plane has developing cold front  it has been forced to make an unscheduled landing in Japan earlier in June.

"Andre Borschberg (Swiss pilot and co-founder of Solar Impulse) has passed the point of no return and must now see this 5 days 5 nights flight through to the end," Solar Impulse said on its website.

The pilot can no longer turn around and return to Japan, even if the weather forecast changes.

The first attempt to fly over the ocean was cut short after a change in the forecast forced an unscheduled landing.

And another attempt to take off last Tuesday was aborted at the last moment because of concerns about the conditions.

If the pilot 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.

 Andre Borschberg was initially supposed to begin his journey to Hawaii from Nanjing in China.

 The experimental craft - which has 17,000 solar cells - is powered only by the Sun.

 The plane has to later, cross North America, before attempting to fly over the Atlantic by August, before the hurricane season reaches its peak.