The purpose of this paper is to explore a range of physiological, psychologi-cal, and social problems that occur in deep space.The physiological, psychological, and social well being of the inhabitants ofany extraterrestrial space environment in a location as foreign as a spacestation, the moon, Mars, or even deeper space, is of prime concern in theextraterrestrial design process. There are a multitude of human concerns tobe considered in the design of any extraterrestrial space habitat.First among them are basic human factors issues including both anthro-pometric and ergonomic issues.A number of physiological problems affect space design, chief among thembeing the effects of weightlessness and micro-Gravity often resulting instress. Sensory responses including vision, response to color, and responseto noise and temperature, must also be considered in the design of any close-fitting extraterrestrial environment.Because extraterrestrial environments necessitate a closed-system archi-tecture, _psychological problems can also occur, including __personal dis-orientation and way-findino difficulties Maintaining a highly productiveand interactive team in the face of stress is one of the most important con-cerns in both a safety and economic sense. Together, these psychologicalproblems can lead to complex, _multiple stressor effectsEconomic and resource constraints necessitate that designed extraterrestrialand space colony spaces serve multiple functions, perhaps resulting in aseries of social problems including boredom and _feelings of isolation a lossof privacy, the need for the ability to personalize space and make one's ownhome __territory the possibility of tension among workers, and the __interper-sonal dynamics of small groups.This paper explores these human factors, physiological, psychological, andsocial issues of long-term space travel and inhabited extraterrestrial colo-nies.