NASA, or the National Aeronautics and Space Administration, is an independent agency of the U.S. federal government responsible for the nation's civilian space program and for aeronautics and aerospace research. It is known for its significant contributions to space exploration, including manned missions to the moon and robotic explorations of other planets. The term 'NASA' itself is an acronym, demonstrating a word formation process where the initial letters of a phrase are used to create a new word.