A handout picture taken and released by on May 12, 2016 by Solar Impulse 2 shows Swiss pilot Bertrand Piccard (L) speaking to the press before boarding the experimental solar-powered aircraft Solar Impulse 2 prior to taking off from Phoenix, Arizona, en route to Oklahoma, for the latest stage of its around-the-world flight aimed at drawing attention to clean energy technologies. The Solar Impulse 2 plane took off from Phoenix, Arizona en route to Oklahoma on May 12, resuming its record-breaking quest to circle the globe without consuming a drop of fuel. The flight to the city of Tulsa is expected to take about 18 hours. / AFP PHOTO / Solar Impulse 2 / Jean Revillard / RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / SOLAR IMPULSE 2 / CHRISTOPHE CHAMMARTIN" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS JEAN REVILLARD/AFP/Getty Images
