A crew chief assigned to the 28th Aircraft Maintenance Squadron at Ellsworth Air Force Base, S.D., conducts pre-flight maintenance on a B-1B Lancer prior to a Bomber Task Force mission to the U.S. European Command area of responsibility May 10, 2020. BTF missions enhance the readiness and training necessary for bomber forces to respond to any contingency or challenge across the globe. (U.S. Air Force photo by Senior Airman Michael Jones)