A U.S. Air Force C-17 Globemaster III taxis before take off during the delivery of a Negatively Pressurized Conex prototype at Joint Base Charleston, S.C., April 21, 2020. The NPC will be tested for potential use as a transport module for individuals infected with the COVID-19 virus and other highly infectious diseases. (U.S. Air Force photo by Staff Sgt. Chris Drzazgowski)