Boston.com's Big Picture photo blog covers the sun-powered Solar Impulse flight.

The experimental airplane Solar Impulse completed its first flight across the United States this week. The Swiss-made plane, powered only by the sun, is the first to make the trip both day and night without using conventional fuel. It started the journey on May 3 in California and ended on July 6 in New York. Pilots and creators Bertrand Piccard and Andre Borschberg took turns manning the single-seat flyer, which is powered by about 12,000 silicon solar cells and has a wingspan of a jumbo jet. The next step is a trip around the world in 2015.- Leanne Burden Seidel

Loads more photos at the link - boston.com/bigpicture

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