Jonathan Kodman, right, Arcs Group manager, shows Dr. Richard Joseph, left, Air Force chief scientist, a component of an arc heater during Joseph's visit to Arnold Engineering Development Complex facilities at Arnold Air Force Base, Tenn., Nov. 18, 2020. Also pictured is Dr. Thomas Fetterhoff, technical advisor for aerodynamic, propulsion and ground test and evaluation, Air Force Test Center. (U.S. Air Force photo by Jill Pickett)