The upgraded solar-powered plane Solar Impulse 2 was unveiled on 13 April 2014 at Payerne Air Force Base of Switzerland. The solar plane will circumnavigate the world in March 2015. The solar plane can fly around the world for five consecutive days without using any fuel.
Swiss pilots Andre Borschberg and Bertrand Piccard have developed the solar powered aircraft. Solar Impulse 2 is a bigger and better version of the single-seater prototype that first took flight five years ago.
The entire airplane weight only 2.3 metric tons (2.54 tons). To maintain its weight budget, the materials in the updated plane are lighter than before, and it has more efficient electric motors.
The upgraded aircraft has a wingspan that is 72 meters longer than a Boeing 747 commercial jet. The wings are covered with 17000 solar cells that power the plane's various systems.
The maximum speed of aircraft is 140 kilometers per hour (87 mph).
The original plane demonstrated that a solar-powered plane can fly through the night, hop from Europe to Africa and cross the width of the United States.
The plane have an autopilot function, a toilet, a comfortable business-class seat and enough space in the ergonomic cockpit for the pilot to lie down and either exercise a little bit, or get some rest.
The purpose of the round-the-world flight is to showcase cutting-edge renewable technologies developed by some 80 companies involved in the project.
When: 13 April 2014