Senior Airman Zachary Rogers, a 28th Aircraft Maintenance Squadron aerospace propulsion journeyman, smiles as he performs maintenance on a grounded B-1B Lancer at Ellsworth Air Force Base, S.D., Dec. 4, 2018. Aerospace propulsion, hydraulic systems, crew chiefs and avionics all work together in their area of expertise to ensure the aircraft is properly maintained and ready to fly. (U.S. Air Force photo by Senior Airman Denise Jenson)