ELLSWORTH AIR FORCE BASE, S.D. -- Airman 1st Class Aaron Valdez, 28th Munitions Squadron conventional maintenance crew member, secures an aerosurface assembly on an inert Guided Bomb Unit-31, Dec. 8. The aerosurface assembly is designed to stabilize the GBU-31. (U.S. Air Force photo/Airman 1st Class Anthony Sanchelli)