110929-N-TT977-188 In his final full day as the 17th Chairman of the Joint Chiefs of Staff, Adm. Mike Mullen and his wife Deborah walk through Arlington National Cemetery's Section 60, Sept. 29, 2011. The Mullen's will retire after serving more than 40 years in uniform, handing the reins to U.S. Army Gen. Martin E. Dempsey during a ceremony at Ft. Meyer, Va. (DoD photo by Mass Communication Specialist 1st Class Chad J. McNeeley/Released)