OFFICIAL WELCOME Chairman of the Joint Chiefs of Staff Navy Adm. Mike Mullen salutes during the piping of the official party at the beginning of the North American Aerospace Defense Command and U.S. Northern Command Change of Command ceremony on Peterson Air Force Base, Colo., May 19, 2010. SHARE: Download: Full Size (0.06 MB) Credit: VIRIN: 122729-S-CKY02-715.jpg Photo Gallery