President Barack Obama and first lady Michelle prepare to depart Joint Base Andrews, Md., for Johannesburg, South Africa, to attend a national memorial service for former South African president and anti-apartheid icon Nelson Mandela on Dec. 9, 2013. Former President George W. Bush, along with former first lLadies Laura Bush and Hillary Clinton, will be accompanying the first couple during the trip. (U.S. Air Force photo/ Airman 1st Class Nesha Humes)