A lunar base for six to twelve people, built into an inflatable spherical habitat. Proportions of interior volume devoted to different systems equipment is relatively accurate. The heaviest equipment such as for environmental control, and areas in which the crew spends the most time, such as their personal sleep quarters are lowest in the habitat. Work areas for lunar sample analysis, for hydroponics, and even for small animals are located in the middle areas. The top deck in this view is a running track on which the sloped surface permits the crew member to use centripetal force rather than gravity to permit running in 1/6 G. Concept: NASA (1989)