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International Space Station



Zarya (Dawn) is the Russian-built, American-financed module that was the first-launched of numerous planned modules of the International Space Station (ISS), which is being assembled in earth orbit. The ISS orbit is approximately circular at 386 km, with an inclination of 52.6 degrees. Zarya, the initial control module, also known as the Functional Cargo Block (FGM when the Russian equivalent acronym is transliterated), was linked together with Unity, the American six-port habitable connection module, in the first assembly step of the ISS. Because Zarya was the first-orbited element of the ISS, its international spacecraft ID (1998-067A) will also be the ID used for the International Space Station, and the continually-evolving brief description of the ISS will also be maintained here. References to other information are given at the end of this description.

The International Space Station is a large multi-module earth-orbiting space station, intended to be a long-term manned station for various research and development uses. It will be constructed in earth orbit, using STS shuttle flights (U.S.A.) and Proton and Soyuz rocket flights (Russia) for ferrying components into orbit and for later resupply flights.

In 1984, President Ronald Reagan gave NASA the go-ahead to build a space station, and invited the participation of international partners. There was a series of proposed plans for a large manned earth-orbiting space station, at low inclination, to be coordinated with related platforms, such as the ESA Columbus Polar Platform, Columbus Attached Lab, and Columbus Free-flying Platform. Over time, each proposed station and alternative version in turn failed to gain acceptance and budget approval, and was dropped during re-scoping and down-sizing of the plan. Those rejected items included Space Station Alpha and Space Station Freedom, the last of the group. The ESA Columbus platforms underwent a similar re-scoping and down-sizing, and the principal ESA module will be the laboratory Columbus Orbital Facility (COF), to be flown after the year 2002.

Eventually the multi-nation US-led international station, named International Space Station, or ISS, was accepted and gained U.S. budget approval. By launch time the mission had evolved, due largely to financial constraints, to include a variety of levels of involvement by additional other nations. As of November, 1998 the global participants, in addition to the United States, included Russia, Canada, Japan, Brazil, and ESA (Belgium, Britain, Denmark, France, Germany, Italy, The Netherlands, Norway, Spain, Sweden, and Switzerland).

In the first phase of the project, seven U.S. astronauts spent almost 27 months aboard the Russian Mir, gaining technical, operational and risk management experience. In the next phase (November 1998 - January 2000) the station will expand from its first two sections to include labs, larger solar wings, a Soyuz return vehicle, communications systems and a robot arm. After that (March 2000 - January 2004), labs from Japan and ESA will be added, as well as a centrifuge module for experiments requiring gravity, and finally a U.S.-built habitation module big enough for a permanent crew of seven.

Once the station becomes habitable, perhaps early in 2000, three-person crews will begin living aboard and conducting long-term experiments. Anticipated projects for ISS include zero-gravity research in processing of materials and pharmaceuticals, and biological research.

The first two modules of the ISS, Zarya (1998-067A) and Unity (1998-069F, also called Node 1), were attached together in orbit at 02:49 GMT on December 7, 1998. Zarya, a 43,000-pound (~19,500 kg) control module launched November 20 by a Russian Proton rocket, and Unity, a 25,500-pound (~11,600 kg) six-port habitable connection module launched aboard the U.S. STS-88 Space Shuttle on December 3, were linked together by the international crew of STS-88. With the subsequent connection of various power, communication, and data cables, the International Space Station became operational. For further details of the component modules, see their separate descriptions in the NSSDC information system, and/or see the URLs below.

For more information, see the following NASA and ESA WWW pages:

(A search page)

Zarya (1998-067A)

Unity (1998-069F)



Alternate Names

  • 25544
  • FGB
  • ISS
  • InternationalSpaceStation
  • MKS
  • Space Station
  • Unity
  • Zarya

Facts in Brief

Launch Date: 1998-11-20
Launch Vehicle: Proton-K
Launch Site: Tyuratam (Baikonur Cosmodrome), Kazakhstan
Mass: 31100 kg

Funding Agencies

  • Russian Space Agency (Russia)
  • National Aeronautics and Space Administration (United States)


  • Engineering
  • Human Crew

Additional Information

Questions and comments about this spacecraft can be directed to: Coordinated Request and User Support Office



NameRoleOriginal AffiliationE-mail
Dr. Donald A. ThomasProgram ScientistNASA Johnson Space
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