Well, you start with a Rock...

Space Colonization for the 21st Century

Authors: Turhan Herder, Stephen Shepherd, John Hirst

Table of Contents


One hundred years ago, the western frontier of America disappeared. Thirty years ago, we made a new frontier accessible to man -- space. Since then, one of the most consistent goals of science has been to find a way to colonize that new frontier. That is our goal with this project.

Our task has been to design, in as much detail as possible, a space colony. The format of the project is relatively unrestrained, and the end result shows that. It is, however, a good general model for space colonization, and includes in its description the most obvious flaws and possible alternatives available to science.

In the end, we concluded that a lot more specifics are necessary to be sure about the viability of this design. We need more information on specific attributes of certain molds and algaes, for example, that are impossible to attain through a standard library. There are a number of possible ideas that we've elected not to use in this model, listed in the Alternative Possibilities section of this report, which require much more in-depth work in order to evaluate.


The objective of this project was to create a model space colony. While resolving the living conditions and construction of the space shuttle as completely as possible and exploring new approaches to space colony design, we have attempted to use theoretical and concrete principles to design a complete and viable space colony.

In order to do this, we spent several days researching materials in the local library and in science-related periodicals in our homes. Additionally, we used several computerized resources in this report, including America On-line, the Usenet, the Internet, local bulletin boards, and several on-line university documents.

Review of Literature

Since Copernicus and Galileo's theories redefined our understanding of space, humanity has pursued its exploration, in our thoughts and fancies. In the last two centuries, the notion of space travel has moved from far-fetched space opera to mainstream science fiction, and then, in the last four decades, to a physical reality.

Throughout this time, ideas of how to survive in space have been numerous, diverse, and often far from the truth. Early scientists contemplated using hot air balloons to travel to the moon, perhaps making friends with the inhabitants thereof. Later, scientists wondered what kind of atmosphere the moon was surrounded by, and whether the use of Venusian jungles for agriculture would change the terrestrial produce market.

Since then, we have discovered that at extreme elevations, the atmosphere is too thin to support hot air balloons, and that the moon is neither inhabited nor hospitable. We have learned that Venus is not a dense jungle, nor is it a petroleum or carbonate ocean, but rather a stone wasteland covered with seas of lava, and with temperatures upwards of 900 degrees Fahrenheit.

With our increased knowledge comes an increased understanding of the risks we face in colonizing space. We not only need to bring our own food, but also our own air. We not only need to bring clean water, we may need to make it, letting some boil away each day to keep from burning to death. We not only need to worry about our whether we get enough light, but we may need to make sure that we are well enough insulated from it that it doesn't instantly blind us or punch holes in our DNA. The only thing that we can be certain of, is that in the vast and unexplored reaches of space, we must be prepared for everything.

The interest in humanity's habitation in space has been a source of fascination for decades. References to the habitation of space appeared as early as 1869 in popular magazines and adventure stories, and during the early portion of this century many of the progenitors of modern rocket and space science were influenced by these.

Early Russian rocket pioneer Konstantin Tsiolkovsky wrote Beyond the Planet Earth in 1920. One of the first serious works on space stations, this book contained many theories on what a space station would need in order to survive. Later in the 1950s rocket scientist Wernher von Braun wrote a series of articles concerning a fictional space station. His ideas concerning shuttles which traveled to and from space are still in use today. In 1951, famous science-fiction author Arthur C. Clarke wrote The Exploration of Space, which contained a chapter on space stations and colonies. Explorer I, the first U.S. satellite, was launched in 1958 and became the first observer of the Van Allen radiation belts.

A milestone was reached in !961 when Russian cosmonaut Yuri Gagarin spent 108 minutes in space, followed by Alan Shepard's ascent 116.5 miles into the Earth's atmosphere. Kicking off the race to the stars, these events were quickly topped by first Soviet cosmonauts and then American astronauts, among whose achievements was the 1962 free fall around the Earth by American John Glenn.

Records continued to be set with the increasing amount of time being spent in space. Until 1965, no flight had lasted more than 8 days, but in December of that year Frank Borman and James Lovell spent a record 13 days in orbit in the Gemini 7. Four years later Soviets surpassed this record with 18 days on the Soyuz 9. The year 1969 was also a record-setting year in another regard -- astronaut Neil Armstrong became the first man to walk upon the face of the moon on July 20 of that year.

The year 1971 marked the first launching of a space station. The Soviet Salyut 1 was launched into a low earth orbit, where it could be easily reached by spacecraft. The cosmonauts were aboard for 23 days, surviving throughout their stay on the shuttle, but dying on re-entry due to an air leak. Two years later, the Americans launched Skylab. After hosting three separate teams of astronauts, the last of which was in space for 84 days, Skylab's systems failed and it crashed to the earth in 1979. The Skylab astronauts showed signs of debilitating affects of weightlessness: their calcium was dissolving back into their blood stream, weakening their bones and creating threatening high levels of the dissolved element in the blood. Fortunately, these effects proved reversible.

Less fortunate was the Challenger disaster of 1986. After several extremely successful space shuttle missions, plans were made, for the first time ever, to take a civilian into space -- school teacher Christa McAuliffe. Mere seconds into the launch, however, the shuttle developed a fuel leak, caused by faulty seals, and was torn apart by an powerful explosion. There were no survivors. A subsequent investigation charged NASA with abandoning "good judgment and common sense." The Challenger disaster served as a warning of dangerous extraterrestrial travel could be.

The space station projects marched on, with new technology and longer habitation times. The Soviets launched Salyut 6 and 7, which incorporated a second docking bay among other innovations. First 96, then 185, and finally 237 days were spent living on these stations. The Mir station, launched in 1986, included six docking stations, making it the largest space station yet. Its crew spent a record of 366 days in space before returning in 1988.

The number of relevant experiments conducted during the last 20 years of the space program have been huge, but a few of the highlights will be mentioned here. Aeronautical and astronautical experiments have shown long term departure from Earth-normal conditions have serious implications to human health. For example, long term exposure to weightlessness results in calcium reabsorbtion, something that weakens bones and could poison the human body if allowed to progress.

Also common is a disorientation, first noticed in the early NASA, characterized by sensations of vertigo and motion sickness. These generally disappeared within hours or days, but were quite debilitating until the symptoms faded. One of the symptoms that never faded was the loss of positioning senses. The sense of body position was completely obliterated, and did not seem to return with time despite year-long stays in space. One astronaut complained that in trying to turn on a light switch, one often found their arm was more than 45 degrees away from where it should be. This number did not improve with practice.

More serious risks became apparent when the atmospheric pressure and chemistry changes. Exposure to low partial pressures of oxygen results in dizziness, headaches, hallucinations, and eventually death. Exposure to overall low pressures causes the blood to boil and severe damage to appear the internal organs.

Food and water pose special risks. Though bacteria and algae tend to grow well in zero-g conditions, plants are stunted and misshapen, and water and organic wastes are hard to collect, contain, and treat. While artificial gravity, cause by the rotation of an environment, helps correct this, it doesn't solve all problems. At the same time, though, it is clear from a Boeing study that the handicap of needing to import food from Earth costs more than 30 times more than growing it in space.

However, studies also tell us that artificial gravity has risks. Its effects on humans are devastating when the rotated environment is less than 300 meters in radius, because of Coriolis effects and a mock "tidal effect" resulting from the varied distance from the axis between head and feet.

Finally, NASA studies have produced a series of statistics related to life in space. These include food and water consumption based on the temperature and humidity of an environment, as well as vitamin, micro nutrient, and rest requirements. NASA's research tells us that approximately five tons of matter per square meter are needed to adequately shield astronauts from radiation, and that an human efficiency peaks during the first two hours of labor, and then falls to a slightly declining plateau in the hours after that.

The colonization of space will prove the true test of humanity's destiny. Earth, as limitless as it seems, may be likened to a time capsule. It has a definite life span, a maximum occupancy, and a set amount of damage it can sustain before it breaks. It has no back-up copy. Should mankind be relegated to the Earth, we are doomed to destruction, be it a matter of years by environmental disaster, or a matter of epochs by the death of the sun.

On the other hand, should humanity give up its Earth-tethered umbilical cord, it will have reached a kind of immortality and invulnerability. We would no longer be tied to the Earth -- by the time Sol dies and the Earth dies with it, humanity will have moved on. Far more immediately, no disaster could wipe out an interstellar civilization. The risks of overpopulation, pollution, and ozone depletion rapidly fade in importance, because humanity can afford to solve them at a leisurely pace, sure that the species will survive even if the Earth itself becomes inhospitable.

The true test of any civilization is how it uses its resources. From the Anasazi, who died out without ever learning how to use the iron ore they were surrounded by, to the Romans, who built hundred mile aqueducts to bring water to their cities, it is the way that a society uses its resources that determines how great it is. The question now becomes, how will humanity use the limitless resources of space?


Aerospace terms used in this report are

listed below, for purposes of clarification:

activated-carbon - coal that has been heated so that volatile chemicals are freed from the extra bonding electrons of carbon, allowing it to react with and filter impurities from air and water.

air-locks - a partitioned doorway designed to keep different atmospheres from mixing, as between a space colony and a vacuum or between a pure argon and pure nitrogen atmosphere.

Apollo group - a group of asteroids, generally less than two kilometers diameter but ranging up to sixteen kilometers, in a near earth orbit.

artificial gravity - simulated gravity; the most common method uses centrifugal forces to mimic gravity by rotating the living environment.

asteroid - an extremely large, interplanetary stone.

boiler - a mechanism for boiling off water to export large amounts of excess heat energy.

breeder reactor - a reactor that uses both U235 and U238 as fuel, efficiently producing a large amount of energy.

chemiluminescence - a chemical reaction that releases energy in the form of light.

Chlorella pyrenoidosa - a species of algae extremely well adapted for survival in space.

Coriolis forces - a illusory force caused by the rotation of an environment.

extraterrestrial - foreign to the Earth in origin or current location.

g-forces - pressure on body, caused by inertial forces or by gravity; usually expressed as a fractional equivalent of the Earth's gravitational pull.

genetic engineering - the process of altering an organism's DNA sequence to change its properties.

Lagrangian points - points in any system of massive bodies where gravitational forces are at an equilibrium.

light-rail - a light-weight, quickly moving electric trolley, similar to a train.

micro gravity - another name for "zero-g," a state where the absence of an overwhelming gravitational attraction reveals the minuscule attractions of small objects in space.

meteoroid - an interplanetary stone, smaller than an asteroid.

NASA - National Aeronautics and Space Association, organization in charge of United States space exploration effort.

solar wind - the constant stream of charged particles being spewed from every star; usually refers to Sol's solar wind.

terrestrial - related to the Earth by origin or current location.

tight-beam laser - a narrowly-focused beam of coherent light.

The Plan

Construction and Design

The first step is to select a two to three kilometer diameter asteroid from the Apollo group, a set of near-earth orbiting asteroids. Then place it in orbit around earth, and use explosives to roughly shape into a sphere. The asteroid will serve as the outer hull of the station, protecting it against solar radiation as well as minor collisions with meteoroids.

Once in orbit, work will progress out of lunar base to begin preliminary tunneling into the asteroid. In the end, the asteroid will have a hollowed out cylinder in the center, stretching out about 850 meters on either side of the central axis. It is wise to balance the mass of the asteroid so that it can by spun without a wobble, something that could potentially displace the colony or interfere with the artificial gravity created within it.

The workers, using terrestrial and lunar supplies in addition to raw materials mined from the asteroid itself, will construct a multistory series of tunnels in the asteroid, each residential area a nominal 3 meters tall. The main residential areas will be within between the radius 841 and radius 850 areas of the cylinder, a total of 3 floors. This will minimize difficulties caused by Coriolis effects once the asteroid is spun.

Close to this area will be the recreation area, designed to simulate outdoor conditions on earth and provide for high- and low-g recreation. These facilities will stretch both above (low-g) and below (high-g) the standard living area, and will provide exercise, recreation, and escape for the inhabitants. Schools, vendors, and other non-technical or service related jobs will probably be interspersed throughout this area.

Separated but near to these sections will be the food, air, water purification, and organic waste disposal area. This will basically consist of a series of "food vats" through which all organic wastes, including dissolved CO2, will be pumped. Chlorella pyrenoidosa algae will be used, both because they thrive in space and effectively photosynthesize. Among their benefits: they reproduce at a factor of up to 800% a day, can be engineered to serve as any one of a number of food types, and can be packed easily into a small space. As much as 45 kg per acre per day can be harvested, and as much as 8 billion cells can fit into one milliliter of water. Both water and oxygen-rich air will be collected after moving through the vats, and then run through activated-carbon filters for further purification.

There will also be a section devoted to industry and research. This will be as far from housing and recreation as possible. Several advantages come from this. First, the nuclear plant that will power the colony, probably modeled on the French breeder reactors, will be housed here, partitioning it from civilization as much as possible. Waste from this reactor would be minimal and could be dumped on the equator of the asteroid. Second, maintenance and research areas can be placed at any height within this area of the asteroid, allowing for variable gravity and environments within the complex. For instance, a welding process could be conducted in high-g to be certain that molten metal quickly falls away from the material being worked, and kept in an inert atmosphere, such as argon or neon gas, to insure a that side reactions do not interfere in the process.

In some central location between these two areas, which will continue to expand for a some time, will be a region for commercial interests, food services, educational facilities, nurseries, offices, systems monitors, and controls (staffed 24-hours-a-simulated-day). Workers will follow the standard 8 hours work, 8 hours recreation, 8 hours sleep formula considered optimal by NASA.

A series of elevator / light-rail routes will connect each division within the asteroid, pen ultimately connecting them all with the terminal at the axis of the asteroid. This end will face towards earth when in its final location, and will contain both a space port for interplanetary travel as well as a communications receptor for beaming information to and from the Earth via tight-beam lasers.

The opposite pole will be a disposal site for those things that must be jettisoned. For example, this is the ideal location for the boilers that may be necessary to eliminate waste heat from the colony. A preferable but somewhat less sound method of handling waste is chemiluminescent radiation, discussed in the Alternative Possibilities chapter.

Once the asteroid's structure is completed, sealed, and filled in with an atmosphere (namely, 79 parts nitrogen, 20 parts oxygen, 1 part argon, and a tiny bit of carbon dioxide), it will be ready to be transported to its final location. For the first attempt, this should be near enough to Earth that infrequent trade is possible, but far enough that the colony must be self-reliant.

An ideal location for this would be in one of Earth's Lagrangian points, located both 60 degrees in front of and 60 degrees behind the Earth in its orbit of the sun. At these points, equilibrium is reached between the sun's gravitational field and the Earth's gravitational field, resulting in a kind of plateau in space-time upon which an object can be delicately balanced. These points, cleared of the junk that commonly accumulates in them, are the perfect site for a near-earth independent colony.

Once transported, the colony would be set in rotation, spinning quickly enough (probably around 1.2 rotations per minute) to create 0.8 g of force at radius of 847 meters, the average level of habitation. This would minimize debilitating affects of zero-g life, such as muscle atrophy and bone decalcification, and also minimize the affects of rotation-based artificial gravity, such as gravity variation based on the direction of movement, and the misdirection characteristic of Coriolis forces.

Social Structures and Personnel

While much of the personnel hired would be based on special research and industrial programs funded either by separate government programs or by private industry, a number of essentials are required for the success of this program. The high level of automation in this colony means few blue collar jobs would travel to the Lagrange point with the asteroid, but engineers and maintenance workers would be an absolute necessity to the survival of the colony. While any estimation made is purely theoretical, it's safe to assume that a minimum of 3 astronomers, 3 ecologists, 5 biochemists, 5 mathematicians, 10 programmers, 25 engineers, and 10 doctors are necessary for any operations to continue.

Again, because of the long term nature of this project, it is necessary for this colony to be a functional society. For this reason, the standard signposts of civilization must be in evidence at this station. For example, a priest or minister of several different faiths should be invited, and all crew should be asked to bring their families. A gender balance would be ideal, but not mandatory as the second generation will naturally about balanced by gender.

Because of the isolated nature of this colony, and because the support of each individual is necessary for survival, a capitalistic society would at most be a nominal gesture. For example, competition for production would be fatally inefficient, this economy cannot support an overproduction of goods. While it seems like most goods could be shipped to Earth for export if overproduced, this is not the case -- the cost will be too prohibitive to have any shipped goods not unique to their source. Therefore, it is likely that administrative control would be needed to set the amounts of production, and while rationing may be in effect, money would not be used for basic necessities such as air, food, water, or energy consumption.

On the other hand, money could be used for luxury supplies. Food, water, and energy consumption beyond the rationed amount could be billed to the user, probably utilizing a computerized debit account. Though, by necessity, few luxury items would be available aboard the ship, information would be fairly easy to come by. A series of tight-beam laser transmitters would be focused at an Earth satellite from the axis of the asteroid, and a series of receivers would likewise gather laser pulses from Earth. These would exchange practical information, such as medical developments, scientific research, transport schedules, and industrial information, as well as more a more superfluous exchange of literature, music, and art, digitized and sent to a central mainframe that serves as the "library" of the station. This library would rent out to personnel as requested, and perhaps as paid for.

This leaves on the question of government. The government structure, again by necessity, would bear little resemblance to that of Earth. It seems logical that taxes would not be needed in such a comparatively moneyless economy. Any work taxes would accomplish would be part of the basic necessities for life in the colony. General direction of the colony would not require a vote although it seems logical that citizens of the colony could be called to vote on certain issues. The Administrator, whose entire job (and life) will depend on the success of the colony, will naturally attend to most such duties.

As far as justice goes, there are bound to be breaches of protocol. Most of these could be handled by the jury system, with the Administrator serving as magistrate until the population grows large enough to require a separate judicial position. Typical penalties would be either fines or loss of recreational time, and would not need to be very stiff. Violence (no weapons will be required on this station) or refusal to work will invoke an ultimate penalty, unavoidable in space -- being exiled from the ship. This would in almost all cases mean death.

Given enough space, and enough involvement in society, humans generally get along well. NASA has predicted that each civilian involved in a space colony would need somewhere around 270 cubic meters to insure their mental condition, however, military personnel survive long periods in as little as 20 cubic meters. Colony personnel will quickly adapt to an amount somewhere between these figures.


What we have been able to provide in this report is clearly not a blueprint. It's also not a complete building procedure, a study, a comprehensive research paper, or a ready-to-begin-construction proposal. However, it does serve as framework by which a long-term colony could be designed, and it does elucidate some of the most critical problems facing the aerospace industry. For the most part, the theory presented here is sound -- it could work, given money and resources to construct it. The experimental data available from such a station would be astounding, and the step would be a first critical move in the development of an interplanetary or perhaps even interstellar space program. Finally, the resources to which this would open the door could support humanity for centuries to come.

The first major hurdle that needs to be crossed is the capture and transportation of the asteroid. While we have the capabilities, especially in space, where there is little to no friction, sufficient thrust will be hard to attain for something as massive as this. Several alternatives are possible, such as hollowing the asteroid as much as possible before any movement is attempted. A possibly more useful method, discussed in the Alternative Possibilities section, would be to use a light sail to harness solar wind and pull the asteroid to Earth and later to the Lagrangian point. However, another problem awaits us when we get there. It may be similarly difficult to cause sufficient angular momentum to create artificial gravity.

Secondary hurdles are just as hindering. The basic design of the colony should be sufficient to support the colony, and the variable g-force levels are a distinct boon. However, the gravitational aberrations caused by Coriolis forces will be at the least mildly irritating, and balancing the colony may require much more integration of the different zones (recreational, residential, industrial, et cetera.) than would be preferred. Also, circulation of air and water may prove difficult to maintain, especially since mistakes will be extremely costly in this environment.

While air and water should be fairly easy to purify and recycle, using the "food vats" and activated-carbon filters mentioned above, there is always a risk of contamination. Much of this could be defended against through air-locks and frequent analysis of purity, but should a problem develop it may be difficult to track down from where it originated. Perhaps different parts of the ship could be fed by entirely separate systems of circulation and purification, giving at least marginal protection from contaminants.

Food poses a special problem. According to NASA studies, morale on a space colony bears some correlation with the variety of food served there. In this, variety basically amounts to: "Would you like your algae raw, fried, sautéed, or steamed?" Flavorings would help, so would small plots of land devoted to more mundane agriculture. Even this problem, though, pales by a comparison to one other -- Chlorella pyrenoidosa is digested only with difficulty in the human digestive tract. The simplest solution would be to find a similarly hardy algae, or to find a way of processing the algae so that it would be easier to digest. Should this fail, another possible route would be to genetically engineer more palatable algae or a bacterial assistant to digestion, discussed in the Alternative Possibilities section.

Our main defense against other disasters, such as fires and systems malfunctions, is dependent upon the control systems. The would be manned 24 hours a day to check for anomalies, and all computer systems would be double-verified, double-staffed, and could be manually overridden by workers at any one time.

There are other, more superficial difficulties as well. For example, transportation is a problem when we consider the Coriolis forces at work -- a light-rail traveling at half the speed of rotation, for example, would reduce or enhance the force of gravity by a factor of 4, depending on its direction. Likewise, communications with Earth are jeopardized by everything from stellar interference to cosmic dust, but would be protected by the nature of the beam (a receptor for a tight beam laser could filter by frequency and direction to error-correct communications).

Another problem is with the boiler method of heat removal. This method would be a constant release of water, and water is a precious commodity in space. While it could be replenished from the moon, or perhaps the other debris in the Lagrange points, it would be extremely inconvenient.

The very balancing of the colony in a Lagrange point is an unknown. It will either be extremely easy, in which case we need to worry about collecting debris, or extremely difficult, in which case we may need to fit the colony with thrusters in order to keep it centered in the Lagrange area. The points are normally fairly large, but any disturbance would grow geometrically, it may be difficult to correct any aberrations that appear.

The final concerns are either theoretical or unavoidable. Included as one of the theoretical problems is the social structure the community will take. Life on the colony will be distinctly different from the on Earth, and without much more focused research on this still hypothetical situation, it will be impossible to design any sort of fool-proof utopia.

The unavoidable problem is money. No matter what, the investment required to create this colony will be tremendous, and the returns at best unpredictable. The cost of a shuttle between the colony and Earth is almost unbearable, and while high-quality and perhaps unique equipment could be made on this colony, its cost would be ludicrously inflated by the distances of transportation. We cannot hope, yet, to make a profit on this endeavor. At best, we are paying for knowledge, and investing in our future as a race.

Alternative Possibilities

The Light Sail

Mentioned as a possible way of transporting the asteroid between its place in the Apollo group to Earth, and later to the Lagrange point. A light sail is a very thin sheet of durable fabric, anchored to the object to be moved an arrayed in a parachute- or clipper- ship like fashion. The sail would be propelled by the steady stream of particles in the solar wind, and could pull the asteroid for great distances with no expenditure of thrust. Unfortunately, all designs considered so far appear extremely fragile.

The Case for the Zero-G Colony

Traditional space stations have been designed based on the premise that humans would eventually be returning to Earth. For this reason, there has not been a real expenditure of effort to design a long term zero-g colony. Astronauts on Skylab, for example, exercised regularly to simulate a gravitational environment, and keep them in shape for the return home.

If humans are to truly adapt to space, we may find it more practical to adapt to micro gravity instead of trying to maintain an illusion of Earth-like conditions. This policy would allow much more effective use of space and revolutions in colony design. For example, corridors no longer need lay flat, and elevators are no longer at all necessary. Instead of relying on wall terminals, the entirety of the wall, ceiling, and floor could be used as display space. New varieties of plant could be bred for micro gravity environments, and they could by hydroponically watered and fertilized.

We could stop worrying about the size of colonies, or unpleasant side effect of rotation for artificial gravity. Instead of building in a shell around the perimeter of the station, we could build throughout it's entirety. We don't even need to START with a micro gravity environment to take advantage of this -- the colony describe in this report could easily be slowed down, gradually, to a micro gravity environment.

Our efficiency would increase, our comfort in space would increase, and we would truly adapt to the life of a spacefaring people. But we'll admit that we're not certain anyone will be sold on this concept, so...

...What About an Artificial-Gravity Ring?

Humans could continue to exercise in the portion of the shuttle that was rotated, and plants and processes that are ill-suited to micro gravity (such as the mechanics of a nuclear reactor) could be run out of this area. This would preserve humanity's Earth-legs, as it were, while still allowing the efficiency of a zero-gravity environment.

The difficulty now becomes human adaptation to this kind of "amphibian" gravity, where daily switches have to be made between micro gravity and 0.5 to 1 g environments. This kind of switching is hard on the human mind, causing disorientation, nausea, intense vertigo, and motion sickness.

While not as efficient, in our opinions, as either the artificial gravity or micro gravity environments, this is a kind of middle ground that may prove useful for future attempts at colony design.

Chemiluminescent Radiation and Waste Heat

One of the most frustrating things about a colony is the radiation of heat. Contrary to popular belief, space isn't this deep cold -- it's an insulator, and an extremely effective one. In order to cool off, we need to eject some of our more energetic mass. If we don't do this, we risk heating up due to waste heat until the environment is impossible to survive in.

The current plan it to cool off the complex with water, and then use pressure gates and diffusion rates to sort out the most energetic particles, and then boil them off for heat loss. However, there's another, much more user-friendly method -- if it works.

By concentrating the waste heat in conjunction (where necessary) with catalysts, we should be able to construct endothermic chemical compounds that release their energy in heat when they break down. Using the same principal as the one behind a glow-stick or chemical torch, we could convert the heat energy into light and radiate it into space. This would conserve water, and still protect us from a gradual heat death of the colony.

Genetic Engineering and the Chlorella pyrenoidosa Algae

Perhaps one of the most mundane ideas mentioned herein is the use of genetic engineering to help sort through the problem of Chlorella's hardiness in the digestive tract. The simplest solution would be to engineer Chlorella to have a simpler chemical structure, just as they currently engineer it to be either protein-rich or fat-rich. However, this could have the side effect of decreasing its hardiness in space, the reason why it was selected as the primary foodstuff on board the shuttle.

Perhaps a safer way of handling this would be to engineer a bacteria for our own digestive tracts. After the first few months of each of our lives, we are exposed to symbiotic bacteria that help us break down food in return for the energy and security our bodies can yield. It does not seem far fetched that a bacteria could be found or designed to help us digest Chlorella.

Direct Lighting of Chlorella pyrenoidosa Algae

One of the odder ideas we came up with while working on this project was horrifically impractical, yet strangely compelling. Instead of going to all the trouble of creating artificial light and hiding from the sun behind meters upon meters of opaque rock, why not simply wall one side of the asteroid with glass and place all the food and plant life we need behind that?

The purpose of the rock wall between the sun and the colony is, of course, to protect us from solar radiation. However, the meters and meters of glass will do this just as effectively as the meters of stone, and we would have the added benefit of saving energy and producing a perfect kind of light for photosynthesis. In much the same manner that modern lenses are made to be transparent to specific ranges of light, we could design a glass transparent mostly to the shades of light absorbed in photosynthesis. This would effectively use the resources at our disposal, provide natural and intense lighting for plant life, and... well, it just seems neat.

There are a series of prohibitions against this, however. Most critically, the cost of this glass would be phenomenal. Directly after that in importance, the installation of this glass wall would be nightmarishly complicated. However, it is certainly a compelling thought.

Solar Power

The final alternative we have to suggest, although it is not exactly a new concept to this field, is the use of solar power. While not as efficient as nuclear power, nor as easily controllable, it has no waste, little risk of accident, and requires no fuel and thus no dependence on a fuel source.

The negatives to solar power, however, are distressing. Most solar cells are expensive, delicate, and inefficient at high temperatures. In an environment where a piece of dust can leave a crater, they would be extremely hard to maintain. Also, either the same solar cells face the sun constantly, becoming hot and thus inefficient, or there is a rotation of cells and not all cells are in use at a given time -- also inefficient.

Should there be any improvement to the technology behind solar power, they would be an important option in the creation of a space colony. For the time being, however, they do not appear to be the best resource at our disposal.

Further Research

Several areas could use further research. Before the specific details of this colony could be addressed, there are certain pieces of information that still need to be attained. The following is a list of that missing research.

First: At what rate is CO2 exchanged for O2 by Chlorella? What alternative species of algae might be more applicable to space use, and more easily digested by humans? Would mats of algae growing on cloth slats be more effective a medium for their growth, or perhaps shallow tanks filled with carbonated, fertilized water?

Second: What nutrients is Chlorella unable to provide? The human body needs upwards of 30 chemicals and chemical compounds in order to survive, and a deficiency of any of these (even micronutrients such as zinc) can lead to painful and even deadly symptoms. What other plants, perhaps non-standard to the modern world, might be able to provide these nutrients in a space environment?

Third: Are there any alternatives to chemiluminescence and boiling off water as a means of keeping heat under control? Could this waste heat energy be recycled and concentrated, somehow?

Fourth: Are there practical ways of running a nuclear reactor in microgravity environments?

Fifth: What specific personnel would be needed to run this station, and how much space will we need to devote to each section? What possible social problems can we expect and try to diffuse?

Sixth: What are the concrete advantages of industry in space? Would modern corporations support a venture of this sort by sending employees along on the voyage?

Seventh: How stable are the Lagrangian points, and how much debris are collected there? Does any of it have raw material potential? What will the cost of processing and transport be?

Eight: How can we get the asteroid rotating with minimal stresses to the asteroid and minimal costs?

Nine: How much will this actually cost, and in what ways could it be simplified or cheapened?


1) Peter Smolders. Living in space Pub. 1986 by Airlife Pub.

2) Patrick Moore. Mission to the Planets Pub. 1990 by W.W. Norton and Co.

3) Time Life Books. Spacefarers Pub. 1989 by Time Life Books

4) G. Harry Stine. Handbook for Space Colonists Pub. 1985 by Holt, Rhinehart, and Winston

5) Time Life Books. How Things Work in Space Pub. 1991 by Time Life Books

6) Brian O'Leary. Project Space Station Pub. 1983 by Stackpole Books

Space settlement home page.

Curator: Al Globus
If you find any errors on this page contact Al Globus.
Space Settlement hompage

This site was hosted by the NASA Ames Research Center from 1994-2018 and is now hosted by:

National Space Society