Solar Impulse passes ‘no-return’ point in Pacific crossing

Dress rehearsal: Pilot André Borschberg in the cockpit shortly before last week’s attempt was called off Keystone

The Swiss solar-powered plane, Solar Impulse 2, is past the point of no return in its attempt to cross the Pacific Ocean, expected to be the toughest part of its round-the-world trip.

On Sunday night, the Si2 crew quietly prepared the plane and pilot André Borschberg for the journey from Nagoya, Japan, to Hawaii, USA. Twelve hours into the flight, they declared that the Si2 was past the point of no return – meaning that it cannot fly back to Asia, but must either proceed or, worst-case scenario, make an emergency landing if the weather changes.

Initially, the plane left Nanjing, China, on May 31 for Hawaii but was forced to cut short its bid a day later due to what Borschberg termed “a wall of clouds” over the Pacific and land in the central Japanese city of Nagoya. Its departure was postponed several times due to poor weather, once last week with the plane – which bears 17,000 solar cells across its wingspan – on standby at the end of a runway.

“This is a one-way ticket to Hawaii,” organisers said on their website on Monday, eight hours after the plane’s pre-dawn departure. Unlike previous times, the team kept quiet until the plane was well on its way. “André Borschberg … must now see this five-days-five-nights flight through to the end.”

The past 10 hours have been very difficult. We did not communicate because we did not know what to say pic.twitter.com/5OJpALDxBCExternal link

— Bertrand PICCARD (@bertrandpiccard) June 29, 2015External link

The plane took off from Abu Dhabi in March on the 35,000-km global journey. Overall, the trip was expected to span approximately 25 flight days broken up into 12 legs at speeds of between 50 and 100 kph. 

The plane is only as heavy a family car but has a wingspan as wide as the largest passenger airliner. Studies, design and construction took 12 years and a first version of the craft rolled out in 2009 broke records for heights and distances travelled by a manned solar plane.