Solar Impulse on Wednesday unveiled an airplane that is scheduled to fly around the world, powered only by the sun. Co-founders and pilots Bertrand Piccard and Andre Borschber announced the Solar Impulse 2 at a press event at Payerne Air Force Base in Switzerland.
The company says the Solar Impulse 1 -- which flew across the United States last summer and across Europe to Morocco in 2012 -- was a flying laboratory, and added that the Solar Impulse 2 is built for a journey.
Borschber says the new airplane's updates include wider wingspan, lighter materials, more efficient engine and an upgraded cabin.
The Solar Impulse 2 weighs 2.3 tons. At 72 meters, the airplane's wings are 15 percent wider than Solar Impulse 1, which is about 63 meters long. For comparison, a Boeing 747's wings are 64 meters long. Borschber says the wings are made with a material that is one-third the weight of printer paper. The wings are fitted with about 17,000 solar cells that are 135 microns thick.
Piccard and Borschber rotated 24-hour shifts for the flight across the United States. The trip around the world will be done in four- to six-day shifts. The updated cabin will now have business class seats and include a virtual co-pilot that will alert the pilot of issues.
"This airplane is really sustainable in terms of energy," Borschber said, "we have to make the pilot sustainable as well."
The company aims to raise awareness of sustainable technologies that can be applied in the real world, and hopes to inspire innovation.
"We believe if we can demonstrate this in the air, where it is the most difficult to do, people will understand that they can also use the same technologies for their daily lives," Piccard told CBS News in an interview last summer.
The Solar Impulse 2 is scheduled to fly through several countries, including India, Burma, China and the United States. Test flights are scheduled to start in the spring, with a round-the-world flight planned between April and July 2015. Borschberg says the trip will take 20 days, spread out over several months.