Solar plane in second last leg of world flight
Solar-powered plane Solar Impulse 2 on Monday took off from Spain and headed towards Egypt's Cairo, beginning the 16th and second last leg of the first ever fuel-free round-the-world flight. It is expected to reach Cairo in 50 hours and 30 minutes. It cruises at an average speed of 75 kmph and has over 17,000 solar cells on its wings.