The National Aeronautics and Space Administration (NASA ) is an independent agency of the U.S. federal government responsible for the United States' civil space program and for research in aeronautics and space. Headquartered in Washington, D.C., NASA operates ten field centers across the U.S. and is organized into three mission directorates: Human Spaceflight, Research and Technology, and Science. Established in 1958, NASA succeeded the National Advisory Committee for Aeronautics (NACA) to give the U.S. space program a distinct civilian orientation focused on peaceful applications.