International Space Station (ISS)
At the control of Expedition Two Flight Engineer Susan B. Helms, the newly-installed Canadian-built Canadarm2, Space Station Remote Manipulator System (SSRMS) maneuvers the Quest Airlock into the proper position to be mated onto the starboard side of the Unity Node I during the first of three extravehicular activities (EVA) of the STS-104 mission. The Quest Airlock makes it easier to perform space walks, and allows both Russian and American spacesuits to be worn when the Shuttle is not docked with the International Space Station (ISS). American suits will not fit through Russion airlocks at the Station. The Boeing Company, the space station prime contractor, built the 6.5-ton (5.8 metric ton) airlock and several other key components at the Marshall Space Flight Center (MSFC), in the same building where the Saturn V rocket was built. Installation activities were supported by the development team from the Payload Operations Control Center (POCC) located at the MSFC and the Mission Control Center at NASA's Johnson Space Flight Center in Houston, Texas.
The International Space Station (ISS) is a habitable space station in low Earth orbit with an altitude of between 330 and 435 km (205 and 270 mi). It completes 15.54 orbits per day. Its first component launched into orbit in 1998, and the ISS is now the largest man-made body in low Earth orbit. The ISS consists of many pressurized modules, external trusses, solar arrays, and other components. ISS components have been launched by Russian Proton and Soyuz rockets, and American Space Shuttles. The ISS is a space research laboratory, the testing ground for technologies and systems required for missions to the Moon and Mars. The station has been continuously occupied for 16 years and 201 days since the arrival of Expedition 1 on 2 November 2000. This is the longest continuous human presence in low Earth orbit, having surpassed the previous record of 9 years and 357 days held by Mir. The station is serviced by a variety of visiting spacecraft: the Russian Soyuz and Progress, the American Dragon and Cygnus, the Japanese H-II Transfer Vehicle, and formerly the Space Shuttle and the European Automated Transfer Vehicle. It has been visited by astronauts, cosmonauts and space tourists from 17 different nations.