The Defense Department requires security clearances for service members and civilians, allowing them to be mission ready for deployment around the globe for DoD missions. Here, Navy Seaman Aaron Mason signals to an SA 330 Puma helicopter, assigned to the dry cargo and ammunition ship USNS Wally Schirra, during flight operations aboard the forward-deployed guided-missile destroyer USS Stethem, Oct. 17, 2017, on patrol in the U.S. 7th Fleet area of operations. Navy photo by Petty Officer 2nd Class Jeremy Graham