Dronefag reports..

An Airbus' Zephyr S solar-powered, very-high-altitude unmanned aircraft is in the midst of a long-duration test flight and has already been aloft for 17 days so far. The drone, sometimes described as a pseudo-satellite in terms of potential capabilities, took off from the U.S. Army's Yuma Proving Ground in Arizona last month for what the service says is a test of its highly efficient long-endurance flight characteristics as part of broader work to demonstrate its ability to serve as a persistent sensor platform. The current world record is 26 days so they may be going for that.