ISS Program Phases
Phase 1. Begun in 1994, completed in 1998. Comprised Space Shuttle dockings with Mir and 27 months of continuous stays by seven U.S. astronauts aboard the Russian spacecraft. Built invaluable knowledge and experience in international space operations and international coordination as applied to the International Space Station. Scientific experiments aboard Mir were valuable forerunners to research in the Station. Many technological "lessons learned" have been incorporated into the Station.
Phase 2. Initial on-orbit construction phase, completed in 2000. Following the Dec. 4, 1998 launch of Space Shuttle Endeavour, it began with the Control Module Zarya, launched Nov. 20, and the shuttle's cargo, U.S. Node 1 Unity, by the Endeavour crew.
The Russian-built Service Module was launched in 2000. It provided initial living quarters and life support systems. After two more Space Shuttle assembly flights, a three-person crew was sent there to reside for four months. This marked the beginning of permanent habitation of the ISS.
Phase 3. "Assembly complete" phase. Laboratory modules supplied by the U.S., Japan, Europe and Russia will be added. The Robotic arm supplied by Canada was attached. Crews will have up to six members. Due to the tragic loss of the Space Shuttle Columbia, completion of Phase 3 was postponed until the two Space Shuttle return to flight test missions were completed. The last of those test flight missions was completed in July 2006. See the "Gold-medal performance" (Adobe PDF) article in the August 2006 issue of Boeing Frontiers for details. With STS-115, resumption of ISS assembly resumed with delivery of the Boeing-built P3/P4 truss segment. Sixteen space shuttle assembly and logistics flights will be flown to complete the ISS by 2010.