Internet sensation, singing Justin Bieber hits. Hello. A swiss plane has taken off from abu dhabi on the firstever attempt to fly around the world using only the energy of the sun. The Solar Impulse ii could take five months to complete the 12 stages of the flight. It will be crisscrossing continents while spreading the word about clean technology. Now, this is a pretty impressive project with some even more impressive figures. Lets show you. Two pilots will take turns to fly the singleseater plane on this 35,000 kilometer journey. The Solar Impulse ii has a wingspan of 72 meters. Now, this is larger than that of a boeing 747, although a jumbo is almost 80 times heavier. Built into the wings, this is the key, more than 17,000 ultraefficient solar cells, which transfer energy to four electrical motors powering the planes propellers. The pilots will have to stay awake for most of their time in the air. Theyre allowed nap times of just 20 minutes, confined in a cockpit not much bigger tha