ELLSWORTH AIR FORCE BASE, S.D. -- Airman 1st Class Michael DiRienzo, 28th munitions Squadron conventional maintenance crew member, hold an inert Guided Bomb unit-31 as it is hoisted onto a bomb trailer, Dec. 8. Airman DiRienzo, along with others, put together several inert GBU-31 bombs for training missions on the B-1B Lancer. (U.S. Air Force photo/Airman 1st Class Anthony Sanchelli)