Airbus has created a revolutionary family of drones called Zephyr, consisting of two models: the Zephyr S and T, that are supposed to “fill the capability gap between satellites and UAVs,” by flying higher than weather and commercial air traffic, but not quite in space. Both models run exclusively on solar power, with the wings covered in solar panels. According to Airbus’s website, replacing one UAV with one Zephyr would save approximately 2,000 tons of fuel per year. The craft are uniquely designed to accommodate both military and civilian uses.  The webpage lists many uses for the Zephyr S, including surveillance and reconnaissance, missile detection, navigation, among others. The Zephyr T, standing for “twin,” as it has two fuselages, is meant for larger payloads and including intelligence gathering systems such as RADAR, LIDAR, and ESM/ELINT.  Zephyr drones are High Altitude Pseudo Satellites meaning they “endure[] like a satellite, focus[] like an aircraft, and [are] cheaper than both of them.”

http://www.airbus.com/defence/uav/zephyr.html