US Orbital Segment

The US Orbital Segment (USOS) is the name given to the components of the International Space Station (ISS) constructed and operated by the United States National Aeronautics and Space Administration (NASA), European Space Agency (ESA), Canadian Space Agency (CSA) and Japan Aerospace Exploration Agency (JAXA). The segment consists of eleven pressurized components and various external elements, almost all of which were delivered by the Space Shuttle. The segment is monitored and controlled from various mission control centers around the world including Johnson Space Center in Houston, Texas, Columbus Control Centre in Oberpfaffenhofen, Germany, and Tsukuba Space Center in Tsukuba, Japan. It depends on the Russian Orbital Segment for essential flight control, orbital station-keeping and life support systems.