The National Aeronautics and Space Administration (NASA) is an agency of the United States government, responsible for the nation's public space program. NASA was established by the National Aeronautics and Space Act on July 29, 1958, replacing its predecessor, the National Advisory Committee for Aeronautics (NACA). The agency became operational on October 1, 1958. NASA has led U.S. efforts for space exploration ever since, resulting in the Apollo missions to the Moon, the Skylab space station, and later the Space Shuttle. Currently NASA is supporting the International Space Station and developing new Ares I and V launch vehicles.