The U.S. built Habitation Module was scheduled to be the International Space Station's main living quarters. About the size of a bus, it was to have sleeping quarters for four people. Astronauts and visiting researchers would be able to shower, cook food in the galley and relax in the wardroom.

At various points in the design, an inflatable "TransHab" module with several times the space of the initial design was part of the plans. Currently, the Habitation Module has been put on hold pending further developments as to plans for the International Space Station. In order to accommodate more than three people on the ISS, a lifeboat craft other than a single Soyuz TMA would be needed. The Crew Return Vehicle has been canceled and it is uncertain when the replacement Crew Exploration Vehicle will be ready.