Swiss zero-fuel plane, Solar Impulse 2 begins final flight
The Swiss solar-powered plane, Solar Impulse 2, has left Cairo on the last leg of its journey to become the first plane to circle the world using no fuel, just the energy from the Sun.
The zero-fuel aerocraft should take about 48 hours to reach Abu Dhabi, UAE, where it began the circumnavigation in March 2015.
The plane has covered around 30,000km in crossing Asia, the Pacific,the United States, Spain and Egypt.
The single-seat aircraft is covered in 17,000 solar cells and during night it runs on battery-stored power.
Traveling at 30 miles (48 kilometers) per hour, its flight speed can double when exposed to full sunlight.
It's pilot Bertrand Piccard's final flight and although it should be straightforward, there are some concerns about how the heat in the Middle East may affect the plane.
Mr Piccard has alternated pilot duties with Swiss entrepreneur Andre Borschberg.