Solar-powered planes? That's pure science fiction; here's a quote from John W. Campbell's 1930 novel The Black Star Passes:
"Dad, I believe that you have been trying to develop a successful solar engine. One that could be placed in the wings of a plane to generate power from the light falling on that surface..."
(Read more about Campbell's solar-powered airplane)
Amazingly, the solar-powered plane Solar Impulse has completed a crossing of the Mediterranean as well as (most recently) a transcontinental flight.
"It was perhaps the most beautiful flight of my life, I have dreamed since I was a child of flying without using fuel," said pilot Bertrand Piccard, who has already circumnavigated the world by balloon.
The single-seat aircraft is fitted with 12,000 solar cells across its immense wings and but only weighs just as much as the average family car, according to organizers.
The plane is the first of its kind to fly both during the night and day as the solar panels charge the batteries for night flying.