Space Shuttle program: Space Shuttle Atlantis is launched on mission STS-104, carrying the Quest Joint Airlock to the International Space Station.

The Space Shuttle program was the fourth human spaceflight program carried out by the U.S. National Aeronautics and Space Administration (NASA), which accomplished routine transportation for Earth-to-orbit crew and cargo from 1981 to 2011. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development, as a proposed nuclear shuttle in the plan was cancelled in 1972. It flew 135 missions and carried 355 astronauts from 16 countries, many on multiple trips.

Space Shuttle Atlantis is a retired Space Shuttle orbiter vehicle which belongs to NASA, the spaceflight and space exploration agency of the United States. Atlantis was manufactured by the Rockwell International company in Southern California and was delivered to the Kennedy Space Center in Eastern Florida in April 1985. Atlantis is the fourth operational and the second-to-last Space Shuttle built. Its maiden flight was STS-51-J made from October 3 to 7, 1985.

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 launched on 12 July 2001 at 09:04 UTC, and returned to Earth without incident after successful docking, equipment installation, and three spacewalks.

The Quest Joint Airlock is the primary airlock for the International Space Station. Quest was designed to host spacewalks with both Extravehicular Mobility Unit (EMU) spacesuits and Orlan space suits. The airlock was launched on STS-104 on July 14, 2001.