(CNN) The Solar Impulse 2 took off Monday from New York’s John F. Kennedy International Airport in the first attempt to get a solar-powered aircraft across the Atlantic Ocean.
The flight is set to be one of the most grueling legs in the aircraft’s ambitious around-the-world journey, devised to raise awareness of the power and potential of clean-energy technologies.
Weather conditions over the Atlantic are notoriously unstable, with fast-changing winds a pilot’s greatest enemy.
Swiss psychiatrist and balloonist Bertrand Piccard is at the helm of the fixed-wing aircraft and is expected to fly between 90 and 110 consecutive hours, destined for Seville, Spain. He is prepared to land in various French cities if the weather takes him that way.
Piccard sent a series of Tweets after takeoff, including one just as he hit the Atlantic.
The project is the brainchild of Piccard and Andre Borschberg, a Swiss engineer and businessman.
The plane — powered 100% by the sun — has so far completed 14 legs of the journey, starting with a flight from Abu Dhabi, United Arab Emirates, to Muscat, Oman, then hopping through Asia before a lengthy leg through the Pacific Ocean and finally reaching the United States.
Borschberg flew the plane across the Pacific from Nagoya, Japan, to Hawaii in July in a leg that took just under 118 hours. That flight marked the first oceanic crossing for a solar-powered plane.
The plane is built with a wingspan wider than a Boeing 747, but it moves about the speed of an average car.
It doesn’t rely on fossil fuel, and its four electric engines are powered by more than 17,000 solar cells built into its lightweight, super-strong carbon fiber wings.
The journey so far has not been easy. It began in March 2015 in Abu Dhabi, and the project’s team has encountered several problems. The plane faced a series of weather delays in China that slowed progress for weeks, a hiccup followed by an unexpected diversion to Japan, where a storm damaged the aircraft on the tarmac.
The Solar Impulse 2 team eventually plans to return to the Middle East by late summer, completing a 43,000-kilometer (27,000-mile) world trip.