PHOENIX, AZ - The wingspan, at more than 200 feet, is equal to that of an Airbus A320 - but this aircraft is lightweight in comparison.
The world's most advanced solar-powered airplane is crossing the country to get attention and show off its technology.
The site for the HB-SIA prototype says the plane's physical and aerodynamic features are new to the world.
The features of the plane, including flight instrumentation and carbon fiber structure, have been designed to save energy.
The site explains, "It was not built to fly round the world. Its purpose was rather to demonstrate the feasibility of the program by making the first ever whole day-and-night flight without fuel, a task that it accomplished brilliantly in July 2010. The lessons learned by the team are now being applied to the construction of Solar Impulse HB-SIB, which is due to circumnavigate the Earth in 2015."
On the trip from San Francisco to New York, the plane is making several stops so its pilot, Bertrand Piccard, can show off the aircraft.
After 18 hours in the air, it made a stop in Phoenix, having used about three-quarters of its battery power on the first leg of the trip.