From VOA Learning English, this is the Technology Report.In 2012, a team of pilots and engineers from Switzerland successfully flew a plane powered by sun light from Spain to Morocco.The same team flew the aircraft across the United States in 2013.Now, the Swiss team is preparing for a flight around the world in 2015.The new, improved version of the plane, named Solar Impulse 2, was recently shown in Switzerland.Solar Impulse 2 is a very light, single-seat airplane. Its wings are 63 meters across.This large wingspan provides 200 square meters of space for energy cells that charge lithium-ion batteries.These special batteries are needed to keep the plane flying at night.Four electric motors permit the plane to cruise at a speed of up to 140 kilometers per hour, at an average height of 8,500 meters above sea level.
