A solar flight around the world.

• Position: THE BIG PICTURE - Solar Impulse 2 aircfaft - Brief article

Can a plane make it all the way around the world without using a drop of fuel? The Solar Impulse 2 (SI2), which recently took off from Abu Dhabi in the United Arab Emirates, is attempting the feat, long considered impossible. With more than 17,000 solar cells on its wings and tail, the 5,000-pound Swiss-made plane is powered entirely by the sun. The solar energy is used to run the engines and charge four lithium batteries that keep Si2 flying at night. The zero-emission, single-seat aircraft will fly for five months; it will make 12 stops along the way (see map) to allow two pilots to alternate, before finishing its journey back in Abu Dhabi in August. Although commercial solar-powered planes may still be a long way off, those involved in the project say their goal is to show what's possible using renewable technologies. "When the Apollo astronauts went to the moon, it wasn't to launch tourism on the moon and open hotels and make money," pilot Bertrand Piccard...