Staff Sgt. Joshua Feekes, left, and Airman 1st Class

Staff Sgt. Joshua Feekes, left, and Airman 1st Class Gabriel Stone, both assigned to the 388th Maintenance Squadron Munitions Flight, build a GBU-31 bomb at Hill Air Force Base, Aug. 1. The 2,000-pound bomb will be dropped by a Hill AFB F-35A Lightning II aircraft at the Utah Test and Training Range during Combat Hammer, an evaluation which determines the effectiveness, maintainability, suitability, and accuracy of precision-guided munitions and other high technology air-to-ground weapons. (Paul Holcomb/U.S. Air Force)