The Solar Impulse 2 took off from New York City on Monday for a sun-powered flight across the Atlantic Ocean expected to take 90 hours, beginning the next leg of its pilots' attempt to circumnavigate the world.
The single-seat aircraft began the 15th leg of its round-the-world journey a little more than a half hour behind schedule at 2:33 am (0633 GMT), beginning a four-day, non-stop journey from JFK airport in New York to Seville, Spain.
"Bertrand Piccard takes off from NYC to attempt the crossing of the Atlantic & prove that future is clean," the project's organizers tweeted as the plane took off.
Piccard, piloting what the Solar Impulse 2 team says will be the first trans-Atlantic solar and electric crossing with zero fuel and zero emissions, is expected to arrive in Seville in the early hours of Friday.
Piccard and Andre Borschberg, both Swiss, co-founded the project to promote fuel-free flight and clean-energy technology. They launched their first flight in March 2015.
The single-seat plane, with a wingspan of 72 metres, began with flights over India and China before stopping in Hawaii for nine months due to battery damage.