Unmanned aircraft are flying right now in the National Airspace System (NAS). Since the early 1990s, unmanned aircraft systems (UAS) have operated on a limited basis in the National Airspace System (NAS). Until recently, UAS mainly supported public operations, such as military and border security operations, but is now rapidly expanding to encompass a broad range of other activities, including aerial photography, surveying land and crops, communications, monitoring forest fires, and environmental conditions. Integrating UAS into the NAS is challenging, and to do so safely and effectively requires help from NASA. The agency is providing research to reduce technical barriers associated with integrating these vehicles into our national airspace system.