10,000 PEOPLE IN SPACE-SANITARY ENGINEERING
IN THE YEAR 2000
Harold J. Jebens, Associate Professor
Department of Civil Engineering
University of Wisconsin-Platteville
Platteville, Wisconsin 53818
INTRODUCTION
Establishing permanent human communities in space has often been proposed by science fiction authors [1-4].   Recently, however, serious proposals for constructing large
rotating space colonies with an earth-like interior have been presented [5] and have attracted considerable attention [6-9].   The National Aeronautics and Space Administration (NASA) has indicated interest in such a colony and during the summer of 1975
hosted a group of nineteen faculty members, six students and three volunteers to perform a system design study on space colonization [10].   Cosponsors of the project with
NASA were Stanford University and the American Society for Engineering Education.
This paper describes the life support system selected for the baseline design of the
colony.
The objective of the summer study was to design a space colony for permanent habitation by 10,000 people that would be physiologically safe, socially viable and economically justified while being accomplished with near-term technology.   The colony would
be constructed in space orbiting around L-5, a point in lunar orbit equidistant from the
earth and the moon that follows the moon as it revolves around the earth.   Raw materials from the moon would be transported to the colony site, refined and fabricated into
the toroidal-shaped habitat shown in schematic in Figure 1.   Physiological and aesthetic
constraints necessary for permanent human occupancy dictated the shape of the habitat
and its earth-like interior (Figure 2), thereby precluding the use of rotating cylinders as
proposed in Physics Today [5].   The inhabitants of the colony would construct and
service large (>5000 Mw) solar power stations utilizing photovoltaic [11] or thermal
methods [12] of solar conversion.   The power stations would collect solar energy and
transmit the energy to earth via microwaves, thereby producing sufficient revenue to
justify the expense of constructing the colony.
LIFE SUPPORT REQUIREMENTS
The life support system of the colony must meet the inhabitants' metabolic requirements for food, water and oxygen while removing their solid, liquid and gaseous waste.
Table I lists the quantities of materials required and produced by an individual astronaut
[13], a space shuttle crew member [14] and a space colonist.   Minor differences in the
table reflect the difference in size of the average individual supported by each system.
Women crew members will be in the shuttle and children will be present in the space
colony.   The difference in food and water requirements are indicative of the type of food
supplied-the astronauts and shuttle personnel dine on condensed or dehydrated foods
and thus must consume higher quantities of water; the space colonist enjoys an earth-like
diet where fruit juice is counted as food rather than as solids and reconstituting water.
To date, life support systems for space vehicles have been completely open systems.
Supplies for metabolic requirements were either stored expendables or resupplied from
earth or vented to space.   Failure to provide regeneration systems in space vehicles has
been due to the relatively short mission durations in past and scheduled missions.   As
missions have lengthened, the components needed for a life support system also increased
in complexity [15,16].   Figure 3 indicates the effect of mission duration on the weight
of the system for various degrees of life support loop closure.   As evident in the figure,
the closure of a subsystem (water, atmosphere or food) causes an increased initial weight
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