STS-104 was a Space Shuttle mission to the International Space Station (ISS) flown by Space Shuttle Atlantis. Its primary objectives were to install the Quest Joint Airlock and help perform maintenance on the International Space Station. It was successful and returned to Earth without incident, after a successful docking, equipment installation and three spacewalks.
The International Space Station programme is tied together by a complex set of legal, political and financial agreements between the sixteen nations involved in the project, governing ownership of the various components, rights to crewing and utilization, and responsibilities for crew rotation and resupply of the International Space Station. It was conceived in 1984 by President Ronald Reagan, during the Space Station Freedom project as it was originally called.