The U.S. Ambassador to the United Nations, Samantha Powers, boards a U.S. Marine Corps MV-22B Osprey assigned with SPMAGTF-Crisis Response-Africa after conducting a site survey in support of Operation United Assistance in Gbarnga, Liberia, Oct 28, 2014. United Assistance is a Department of Defense operation to provide command and control, logistics, training, and engineering support to U.S. Agency for International Development- led efforts to contain the Ebola virus outbreak in West African nations. (U.S. Marine Corps photo by Lance Cpl. Andre Dakis/SP-MAGTF Crisis Response Africa Combat Camera/Released)