The experimental plane powered solely by the sun has been forced to abort the most challenging part of its round-the-world trip due to bad weather and will land in Japan this evening.
Solar Impulse, a project of Swiss adventurers André Borschberg and Bertrand Piccard, took off for its scheduled five-day trans-Pacific flight on Saturday evening from Nanjing, east China, after weeks of delays.
The hold-ups were caused by less than optimal weather over the Pacific Ocean, a critical factor for the success of the pioneering mission, during which the one-seater plane was supposed to cover the 9,132km distance to Hawaii in one go without a drop of fuel.
“It’s one of the strange moments of life between elation and disappointment,” Bertrand Piccard said in an interview on YouTube.
“Elation because the flight has gone extremely well. It’s the longest flight ever of a solar aeroplane. On the other side, the weather window to reach Hawaii has closed, the front is too dangerous to cross and we have decided to land in Nagoya and wait until the weather conditions are better in order to continue.”
At controls of the lightweight plane with a wingspan similar to that of an Airbus A340 is André Borschberg, who will now have to perform the challenging landing manoeuvre against strong western winds.
“We were never planning to stop in Japan, we planned to take the plane directly to Hawaii and when we took off from China it seemed we would be able to cross the front easily,” said Piccard.
“But it’s always difficult to forecast the weather five days in advance. The front has gotten too thick and the plane would have to go through thick layers of clouds,” he explained, adding that safety of the pilot has always been the number one consideration for the team.
Despite the unplanned stopover, the more than 36-hour flight has already entered history books and proven the plane can safely fly on batteries during the night.
Solar Impulse took off from Abu Dhabi in March this year. The plane, powered by 17,248 solar cells, travels at speeds between 50 and 100km/h. At times it flies higher than the altitude of Mount Everest to provide optimum conditions to the solar panels covering its wings to charge the batteries.
The round-the-world journey was expected to span approximately 25 flight days broken up into 12 legs. The trans-Pacific leg was arguably the most difficult as it required the single crew member to stay in command for at least five consecutive days.
Video interview with Bertrand Piccard
Solar Impulse 2 infographic