NASA, the National Aeronautics and Space Administration, was established in 1958 to lead the United States' civilian space program and aeronautics research. The agency conducts missions in space exploration, planetary science, astrophysics, and Earth observation, and has been responsible for landmark achievements such as the Apollo Moon landings, the Space Shuttle program, and the Mars rover missions. NASA also collaborates internationally on projects like the International Space Station and advances technology for both space and terrestrial applications.