Airman 1st Class Jesse Knappen, 28th Munitions Squadron conventional maintenance technician, assembles a GBU-31 during an operation readiness exercise at Ellsworth Air Force Base, S.D., March 30, 2015. The 28th MUNS goal during the ORE was to evaluate the effectiveness, maintainability, suitability and accuracy of precision guided munitions and other advanced air to ground weapons. (U.S. Air Force photo by Senior Airman Anania Tekurio/Released)