Solar Impulse begins 90-hour Atlantic crossing

Having been on U.S. territory for almost a year since touching down in Hawaii in June 2015, the Solar Impulse 2 aircraft – kitted out with 17,000 solar cells and four batteries – this morning left New York to embark on a 90-hour journey across the Atlantic to Seville, Spain.

This leg will be the longest that the team has had to fly this year, and co-founder of the Solar Impulse project Bertrand Piccard is at the controls. Ahead of him are potentially tricky weather conditions and the prospect of just a few minutes’ rest each day as he mans the plane single-handedly.

Having begun their around-the-world attempt on March 9, 2015 from Abu Dhabi, Solar Impulse’s Piccard and Andre Borschberg have shared piloting duty, swapping in and out at various legs as the plane – and supportive ground crew – has inched eastwards.

The previous leg saw the Solar Impulse plane land at New York’s JFK Airport on June 11 following a five-hour flight from Pennsylvania. With an average speed of 70km/h, the Atlantic crossing could well be one of the most arduous yet for the team, but it is not the longest leg: that occurred last summer when Borschberg flew for four days, 21 hours and 52 minutes non-stop from Nagoya in Japan to Kalaeloa in Hawaii, breaking the world record for the longest uninterrupted flight in the process.

Speaking to ABC News, Piccard said: "The Atlantic is always the symbolic flight for all the means of transportation and today it becomes a symbolic flight for energy vision. It is the first time an airplane flying solar – that means with electric engines, zero emissions, zero fuel – is attempting to cross this ocean from America to Europe, so it is extremely exciting for all of us."

The final destination for the Solar Impulse 2 plane is Abu Dhabi this summer, returning to where the adventure began last March.