GENEVA (AP) -- The pilot at the helm of the world's most advanced solar-powered plane said Sunday he hopes to take the prototype across the Mediterranean next year before attempting a round-the-world flight in 2014.
Andre Borschberg said the plane's recent round trip to Belgium and France had encouraged the Solar Impulse team to consider flying the aircraft to Morocco in 2012.
"We'd like to be able to do flights of a duration of two days, two nights, which is a big challenge for only one person on board," he told The Associated Press by satellite linkup while flying back from Paris to the plane's home base in Payerne, Switzerland.
Last year, Borschberg completed a marathon 26-hour nonstop test to demonstrate that the 12,000 solar cells attached to its 63-meter (207-foot) wingspan can soak up enough sunlight to keep the four-engine plane airborne through the night.
The Mediterranean flights will be a major challenge for the engineers and the pilot, as the lightweight design is very sensitive to air turbulence. If the 1,200-mile (1931-kilometer) journey from Switzerland to Morocco is successful, the team will attempt to fly the prototype onward to Turkey before returning home, Borschberg said.
Meanwhile, a second, sturdier aircraft is already in the works.
The second plane will begin flight testing in 2013 in preparation for its planned circumnavigation of the globe a year later.
Again, there will be no passengers on board, Borschberg said. The ultra-efficient design of the aircraft, which has a top speed of only 75 mph (120 kph), means all additional ballast needs to be avoided.
"People understand that we are not going to fly solar and be able to transport passengers using solar energy collected by the airplane anytime soon," said Borschberg, as he circled Lake Neuchatel and the Jura mountains on the French-Swiss border before his descent to Payerne.
Still, the insights gained from designing and flying an aircraft that could stay in the air indefinitely — were it not for the needs of its human pilot -- are significant, Borschberg said. "There is definitely a need for the technology to reduce the energy consumption" of planes, cars and other means of transportation, he said.