Building ISS

The International Space Station (ISS0 is the largest human-made body in low Earth orbit and can often be seen with the naked eye from Earth. The first ISS component was launched in 1998. Since then, the station has been continuously built up for 19 years. Development and assembly of the station continue, with several major new elements scheduled for launch starting in 2020. The ISS consists of pressurized modules, structural trusses, solar arrays, radiators, docking ports, experiment bays, and robotic arms. Major ISS modules have been launched by Russian Proton and Soyuz rockets and US Space Shuttles.

Beginning in the mid-1990s, the U.S. components Destiny, Unity, the Integrated Truss Structure, and the solar arrays were fabricated at the Marshall Space Flight Center and the Michoud Assembly Facility.

The Russian modules, including Zarya and Zvezda, were manufactured at the Khrunichev State Research and Production Space Center in Moscow. Zvezda was initially manufactured in 1985 as a component for Mir-2, but was never launched and instead became the ISS Service Module.

The European Space Agency Columbus module was manufactured at the European Space Research and Technology Centre (ESTEC) in the Netherlands, along with many other contractors throughout Europe. The other ESA-built modules - Harmony, Tranquility, the Leonardo MPLM, and the Cupola - were initially manufactured at the Thales Alenia Space factory located at the Cannes Mandelieu Space Center. The structural steel hulls of the modules were transported by aircraft to the Kennedy Space Center SSPF for launch processing.

The Japanese Experiment Module Kibo, was fabricated in various technology manufacturing facilities in Japan, at the NASDA (now JAXA) Tanegashima Space Center, and the Institute of Space and Astronautical Science. The Kibo module was transported by ship and flown by aircraft to the KSC Space Station Processing Facility.

The Mobile Servicing System, consisting of the Canadarm-2 and the Dextre grapple fixture, was manufactured at various factories in Canada and the United States under contract by the Canadian Space Agency. The mobile base system, a connecting framework for Canadarm-2 mounted on rails, was built by Northrop Grumman. The Canadarm-2 and Dextre were built by MDA Space Missions.

The first module of the ISS, Zarya, was launched on 20 November 1998 on an autonomous Russian Proton rocket. It provided propulsion, attitude control, communications, electrical power, but lacked long-term life support functions. Two weeks later, a passive NASA module Unity was launched aboard Space Shuttle flight STS-88 and attached to Zarya by astronauts during EVAs. On 12 July 2000, Zvezda was launched into orbit. Preprogrammed commands onboard deployed its solar arrays and communications antenna. It then became the passive target for a rendezvous with Zarya and Unity: it maintained a station-keeping orbit while the Zarya-Unity vehicle performed the rendezvous and docking via ground control and the Russian automated rendezvous and docking system. Zarya's computer transferred control of the station to Zvezda's computer soon after docking. Zvezda added sleeping quarters, a toilet, kitchen, CO2 scrubbers, dehumidifier, oxygen generators, exercise equipment, plus data, voice and television communications with mission control. This enabled permanent habitation of the station.

Expedition 1 arrived midway between the flights of STS-92 and STS-97. These two Space Shuttle flights each added segments of the station's Integrated Truss Structure, which provided the station with Ku-band communication for US television, additional attitude support needed for the additional mass of the USOS, and substantial solar arrays supplementing the station's existing 4 solar arrays.

Over the next two years, the station continued to expand. A Soyuz-U rocket delivered the Pirs docking compartment. The Space Shuttles Discovery, Atlantis, and Endeavour delivered the Destiny laboratory and Quest airlock, in addition to the station's main robot arm, the Canadarm2, and several more segments of the Integrated Truss Structure.

In 2006 Atlantis delivered the station's second set of solar arrays. Several more truss segments and the third set of arrays were delivered on STS-116, STS-117, and STS-118. As a result of the major expansion of the station's power-generating capabilities, more pressurized modules could be accommodated, and the Harmony node and Columbus European laboratory were added. These were soon followed by the first two components of Kibō. In March 2009, STS-119 completed the Integrated Truss Structure with the installation of the fourth and final set of solar arrays. The final section of Kibō was delivered in July 2009 on STS-127, followed by the Russian Poisk module. The third node, Tranquility, was delivered in February 2010 during STS-130 by the Space Shuttle Endeavour, alongside the Cupola, followed in May 2010 by the penultimate Russian module, Rassvet. Rassvet was delivered by Space Shuttle Atlantis on STS-132 in exchange for the Russian Proton delivery of the US-funded Zarya module in 1998. The last pressurized module of the USOS, Leonardo, was brought to the station on February 2011 on the final flight of Discovery, STS-133. The Alpha Magnetic Spectrometer was delivered by Endeavour on STS-134 the same year.

As of June 2011, the station consisted of 15 pressurized modules and the Integrated Truss Structure. Five modules are still to be launched, including the Nauka with the European Robotic Arm, the Uzlovoy Module, and two power modules called NEM-1 and NEM-2. As of March 2019, Russia's future primary research module Nauka is set to launch in the summer of 2020, along with the European Robotic Arm which will be able to relocate itself to different parts of the Russian modules of the station.