Solar Impulse 2 at the finish line after historic world journey [Video timeline]

Solar Impulse 2, the world's largest solar-powered aircraft, which is currently flying on its last leg of its round-the-world tour has left the Egyptian capital, Cairo. The aircraft is expected to reach Abu Dhabi within 24 hrs, the place it began the circumnavigation in March 2015.

Bertrand Piccard and his friend and business partner Andre Borschberg have alternatively piloted the plane and covered more than 30,000 km, making it the first plane to circle the world using no fuel, but just the energy from the Sun.

Even after completing treacherous routes including crossings over the Pacific and Atlantic oceans. the 17th and final segment of the journey is expected to be difficult. The warmer, thinner air above the Saudi desert will require more energy from the plane's lithium polymer batteries to power up the propeller.

Apart from being the first solar powered plane to circumnavigate the globe, Solar Impulse broke many other aviation records. The records  include the first night flight, first intercontinental flight, first ocean crossing, and longest distance and duration for a solar flight and the longest ever solo flight that required the pilot to endure in the cockpit for more than 117 hours.

Click here to watch the live stream of the historic final leg of the world record breaking flight.