How to build a plane that never needs to land

Solar power's the thing

The British military is reportedly set to purchase two planes that can fly for months on end without needing to land. These large solar-powered "Zephyr" drones would likely be sent to carry out long-term surveillance missions and could constantly monitor an area with high-quality imagery. They could also be used to provide mobile and internet communication signals in remote areas, to support ground missions, and even conduct long-term research projects."