ARLINGTON, VA - APRIL 22:  U.S. Secretary of Defense Chuck Hagel is shown the ATLAS Robot that has recently completed testing at the DARPA Robotics Challenge at the Pentagon on April 22, 2014 in Arlington, Virginia. Secretary Hagel visited Defense Advanced Research Projects Agency (DARPA) exhibits to see cutting edge technology first hand and how they contribute to U.S. national security. (Photo by Mark Wilson/Getty Images)