by new scientific knowledge for radically new weapons systems. The original membership of the Board, totaling twenty-five, consisted of the chairman of the eleven technical advisory panels in the Office of the Assistant Secretary of Defense (Research and Development), the chairmen of the senior advisory committees of the Army, Navy, and Air Force, the Directors of the National Science Foundation, the National Bureau of Standards, and the National Advisory Committee for Aeronautics (predecessor of the National Aeronautics and Space Administration), the President of the National Academy of Sciences, and seven members-at-large drawn from the scientific and technical community. The Board met for the first time on September 20, 1956. Its initial assignment concerned the program and administration of basic research, component research, and the advancement of technology in areas of interest to the Department of Defense. On December 31, 1956, a charter was issued specifying the Board as advisory to the Assistant Secretary of Defense (Research and Development). Following the consolidation of the offices of the Assistant Secretaries of Defense for R&D and Applications Engineering in 1957, the Board reconstituted as advisory to the Secretary of Defense through the Assistant Secretary of Defense (Research and Engineering). Its membership was increased to 28, including as ex officio members, the Chairmen of the President's Science Advisory Committee and the Scientific Advisory Committee in the Office of Guided Missiles, Office of the Secretary of Defense (OSD). A revised Board charter was issued on October 30, 1957. In accordance with the Department of Defense Reorganization Act of 1958, which stipulated the responsibilities, functions, and authority of the Director of Defense Research and Engineering (DDR&E), the Board's charter was revised on November 23, 1959. This revision harmonized the role and mission of the Defense Science Board with DDR&D's responsibilities, prescribing eight members-at-large and modifying ex officio membership to conform with the establishment or dissolution of advisory panels in the office of the DDR&E. In the course of organizing his staff, the DDR&E appointed Assistant Directors for several types of warfare systems. Following this action in late 1959, the Board made a study of the structure of scientific and engineering advisory bodies. Its report on this study was implemented by DoD Directive 5129.22, "Defense Science Board Charter," dated April 10, 1961. This directive was revised and reissued on February 17, 1971. In 1978, the title, Director of Defense Research and Engineering, was changed to Under Secretary