U.S. service members arrive at the Langley Transit Center at Langley Air Force Base, Va., Nov. 13, 2014. Ninety service members from multiple branches of the armed forces will undergo a 21-day controlled monitoring period at the transit center after returning from fighting the spread of Ebola in West Africa in support of Operation United Assistance. (U.S. Air Force photo by Staff Sgt. Jason J. Brown/Released)