Tech. Sgt. Leslee Williams (left) goes hand over hand on the rope while hanging over water at the Assault Course as Staff Sgt. Alex Andriyanov (right) reaches the end of his rope during a practice run on the Assault Course at the U.S. Air Force Academy, Colo., May 18, 2010. Both are Guardian Challenge 2010 competitors from the Space and Missile Systems Center's 61st Security Forces Squadron at Los Angeles Air Force Base. (Photo by Lou Hernandez)