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 Impulses 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 Yorks 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.