International Space Station's (ISS) Structure

As the largest facility ever assembled in space, the International Space Station has been in the construction process since 1998. ISS represents a truly international project, joining efforts space agencies around the world. Along with NASA, the following space agencies are also major players in the creation and development of ISS:
  • CSA, the Canadian Space Agency
  • ESA, the European Space Agency
  • JAXA, the Japan Aerospace Exploration Agency
  • RKA, the Russian Aviation and Space Agency.
 
Given the enormity of ISS, construction of this facility takes place in phases, with each phase representing the assembly of a new module to the International Space Station. In the context of ISS, a module refers to a self-contained, independently operated unit. Modules can specifically be labs, living quarters, docking compartments, etc.
 
Pressurized versus Unpressurized Modules
Atmospheric pressure refers to the weight of the Earth's atmosphere at any given point. The higher you travel from the surface of the Earth, the lower the pressure, due to the fact that there are less atmospheric particles weighing down on you.
 
For survival, humans require specific environments, which must have a distinct natural or artificial atmospheric pressure. Because there is no atmosphere in space, spacecraft need to be pressurized to sustain life. As a result, ISS contains both pressurized and unpressurized modules (areas of ISS that humans don't occupy are not pressurized).
 
In total, ISS will consist of 14 pressurized modules (at a total of 1,000 cubic meters) when it is complete. Ultimately, these modules will be able to sustain a crew of six astronauts on a permanent basis. While half of the modules have already been assembled, the remaining seven are projected to be part of ISS by 2010. As a result, ISS can currently only sustain three crewmembers.
 
Launch Vehicles for ISS Modules
Before a module can be added to ISS, it has to be launched into space. ISS modules can be launched with the:
  • proton rocket, the Russian launch vehicle for unmanned missions
  • Space Shuttle, the United States' primary spacecraft for manned (human) missions
  • Soyuz rocket, the Russian spacecraft for both manned and unmanned missions.
 
Consult the following table for an outline of the various modules that currently or will soon make up the structure of ISS. These are listed in order of first to last that have been (or will be) connected to ISS.
 
Module Name
Launch Date
Launch Vehicle Used
Purpose of Module
Zarya
November 1998
Proton rocket
To supply power and storage room for ISS.
Unity
December 1998
Space Shuttle
To connect the American side of ISS to the Russian side.
Zvezda
December 2000
Proton rocket
To provide ISS with environmental systems and serve as primary living quarters for crew. Once Zvezda was assembled, ISS was capable of being permanently habitable.
Quest
July 2001
Space Shuttle
To provide ISS with an airlock that would make spacewalks possible.
Pirs
September 2001
Soyuz rocket
To enhance spacewalking capabilities and provide further storage area.
Destiny
February 2007
Space Shuttle
To add permanent research modules, as well as more living quarters and environmental systems.
Harmony
October 2007
Space Shuttle
To serve as a common docking station for other research labs, such as ESA's Columbus.
Columbus
February 2008
Space Shuttle
To serve as Europe's primary research module on ISS.
Experiment Logistics Module
March 2008
Space Shuttle
To provide Kibo, the primary Japanese research module, with storage space.
Japanese Pressurized Module
April 2008
Space Shuttle
To serve as the central part of Kibo.
Multipurpose Lab Module
December 2008
Proton rocket
To serve as Russia's primary research facility and crew living quarters.
Docking Cargo Module
2010
Space Shuttle
To provide the Russians with a docking area and storage space.
Node 3
2010
Space Shuttle
To provide ISS with the most advanced life support and recycling systems. This is the last U.S. module.
Cupola
2010
Space Shuttle
To serve as an observation point for ISS operations and the docking process. Cupola will also allow crew to observe space.
 
Resource
 
NASA (updated February 7, 2008). NASA: International Space Station. Retrieved February 7, 2008 from the NASA Web site.