The National Advisory Committee for Aeronautics (NACA) was a United States federal agency founded on March 3, 1915, to undertake, promote, and institutionalize aeronautical research. On October 1, 1958, the agency was dissolved and its assets and personnel were transferred to the newly created National Aeronautics and Space Administration (NASA). NACA is an initialism, i.e., pronounced as individual letters, rather than as a whole word.

The National Aeronautics and Space Administration is an independent agency of the U.S. federal government responsible for the civil space program, aeronautics research, and space research. Established in 1958, it succeeded the National Advisory Committee for Aeronautics (NACA) to give the U.S. space development effort a distinct civilian orientation, emphasizing peaceful applications in space science. It has since led most of America's space exploration programs, including Project Mercury, Project Gemini, the 1968–1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. Currently, NASA supports the International Space Station along with the Commercial Crew Program, and oversees the development of the Orion spacecraft and the Space Launch System for the lunar Artemis program.