Twenty-eight feet long and fourteen in diameter, the habitation module will provide additional living quarters, for a space station complement of seven crew members. NASA is currently considering replacing this element with an inflatable, three-story version called the TransHab module, which includes, besides crew quarters, a wardroom, galley, mechanical room, and equipment for health, exercise, and hygiene.
Note: The main image shows the habitation module in an earlier configuration; current models have it sitting horizontally off Node 3, which will hang off Unity.
The U.S. habitation module will be the last component added to the space station.