The National Aeronautics and Space Administration is an independent agency of the US federal government responsible for the United States civil space program, aeronautics research, and space research. The International Space Station (ISS) is a large space station that was assembled and is maintained in low Earth orbit by a collaboration of five space agencies and their contractors: NASA (United States), Roscosmos (Russia), ESA (Europe), JAXA (Japan), and CSA (Canada).