ELLSWORTH AIR FORCE BASE, S.D. – Airman 1st Class Alejandro Sanchez, 28th Munitions Squadron weapons loader, straps down guided bomb unit-38s during the phase II operational readiness exercise, July 21. The GBU-38 is a 500-pound bomb commonly used with the B-1B Lancer. (U.S. Air Force photo/Airman 1st Class Corey Hook)