U.S. Army Col. Chesley Thigpen, 733d Mission Support Group commander, signs the Ground Zero Flag Team log book at Joint Base Langley-Eustis, Virginia, Sept. 11, 2020. The Ground Zero Flag was flown in between the North and South Towers of the World Trade Centers after the 9/11 attacks. (U.S. Air Force photo by Staff Sgt. Donald Hudson)