Comment on Historic solar flight marks first round-the-world journey

ABU DHABI, United Arab Emirates (AP) — The world's first round-the-world flight to be powered solely by the sun's energy made history on Tuesday as it landed in Abu Dhabi, where it first took off on an epic 25,000-mile (40,000-kilometer) journey that began more than a year ago. Since its March 2015 take off, the Swiss-engineered Solar Impulse 2 has made 16 stops across the world without using a drop of fuel to demonstrate that using the plane's clean technologies on the ground can halve the world's energy consumption, save natural resources and improve quality of life. After landing the plane, pilot Bertrand Piccard was greeted outside the cockpit by his Solar Impulse partner and fellow pilot Andre Borschberg. The aircraft is uniquely powered by 17,248 solar cells that transfer energy to four electrical motors that power the plane's propellers. The plane's wingspan stretches 236 feet (72 meters) to catch the sun's energy. The carbon-fiber plane is a single-seater aircraft, meaning its two Swiss pilots — Piccard and Borschberg— had to take turns flying solo for long days and nights. Goggles worn over the pilot's eyes flashed lights to wake him up while armbands placed underneath their suits buzzed when the plane was not at flying level.