A solar powered plane has flown over San Francisco as part of a test run for a planned cross-country flight in May. Weighing just 3,500 pounds, Solar Impulse runs entirely through power drawn from the 12,000 cells on its 208 foot wingspan.
On its first big trip next month, the aircraft, which reaches a top speed of 43 mph, will travel from San Francisco to New York, stopping in Phoenix, Dallas and Atlanta, with its creators already planning a longer around-the-globe flight in 2015. Report by Sophie Foster.
