Patrick Pasierb, Joint Direct Attack Munitions Systems Program Office engineer, assembles a GBU-31 Laser Joint Direct Attack Munition at Ellsworth Air Force Base, S.D., Feb. 11, 2014. Pasierb assisted Airmen of the 28th Munitions Squadron with building munitions during the exercise, designed 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 Zachary Hada/Released)