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About Space Colonies
Space colonies are hypothetical permanent living and working environments away from Earth. They may be orbital colonies that orbit Earth or other planets or moons, or they may actually be colonies on other planets or moons. Colonies are intended to be settlements, cities in space where families live, work, and play.
Why space colonies?
One reason for space colonies is that they will enable us to explore other planets in our solar system — and eventually explore beyond our solar system. Colonies would be one way to ensure the survival of humans should Earth become uninhabitable because of environmental change, climate change, or because of threats from near-Earth objects such as asteroids. Space colonies offer business opportunities as well; there may be resources we can acquire on other planets, such as mining metals on the Moon, that are not as available on Earth. Research could be enhanced. Microgravity offers many opportunities for creating near-perfect crystals for pharmaceutical and computer applications. Experiments that might involve risks to the environment or population could be undertaken. Being away from the light pollution and atmosphere of Earth allows advanced astronomical observations from telescopes. The reduced gravity of space colonies could also offer wonderful opportunities for people with physical handicaps, as the need for walkers and wheelchairs might be nearly eliminated.
"Space settlers … would be the natural pioneers. They, not we, would be the Vikings, the Phoenicians, and the Polynesians of the future. They would make the long trips to Mars and the asteroids and learn how to mine the asteroids. They could travel out into the solar system and make plans to reach the stars someday. All we can do here on Earth, maybe, is reach the Moon. From worlds in orbit around the Earth, we can reach all the rest."
— Isaac Asimov
What do people need in order to colonize space or another planet?
If humans are to live in space or on the Moon or Mars, even for brief periods, they are going to need a wide range of support systems. They'll need a place to work, rest, and live that protects them from the cold and dangerous radiation of the space environment. They will need power, light, air, food, water, and heat. They'll need robust transportation and equipment able to operate in low temperatures and the hostile environment of space. They will need to be able to communicate with Earth, other colonies, and shuttles.
Lunar Base of the Future
Image by Pat Rawlings
They will also need to deal with health issues. Reduced gravity is a challenge to people living on smaller planets, like Mars with one-third Earth's gravity, and moons, like our Moon with one-sixth Earth's gravity. Under reduced gravity conditions, there is less “load” on bones and muscles, so living organisms lose bone mass, muscle tissue, and fluids. Even the heart — a muscle — loses mass because it does not have to work as hard. Humans in space must exercise to maintain their bone and tissue mass so that they can return to Earth's gravity and function well. More research is needed to understand the effects of reduced gravity on the human body — and how to counter these effects. These effects will be especially pronounced on humans living in orbiting colonies. Such colonies will have to rotate to produce a gravity field.
Where might the colonies be located?
The International Space Station could be viewed as the first step to a colony. It is designed to be a long-term living and working environment for astronauts. NASA will learn many valuable lessons from the space station about what is necessary for even longer-term colonization and its effects on humans.
The Moon is one of the first targets for colonization, mainly because it is close and scientists know more about it than other planetary bodies because of the Apollo missions to the Moon. Its closeness means that people and materials can be transported faster and at lower costs than for a planet farther away; a one-way trip to the Moon takes about three days. The Moon may have water ice trapped in the craters around its poles, which could serve as a water supply to the colonies. The Moon has no atmosphere and extreme temperatures: 130°C (265°F) during the day and –110°C (–170°F) at night. Any habitat would have to provide shelter from the extreme temperatures and from incoming radiation. Moon bases may include subsurface buildings to increase protection from radiation and micrometeorites. A lunar outpost could provide valuable information on the long-term physiological and psychological effects on humans living in space. This information could prove invaluable in the eventual planning for a manned Mars mission that would require years of travel. Also, the Moon could serve as a source for the large quantities of oxygen needed to fuel a spacecraft to Mars and back.
Future Mars Base
Image from NASA
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Mars is also a target for colonization. Some researchers suggest that future exploration should focus on Mars rather than the Moon. Others believe that the Moon should be the first step, and that it should be a staging area for building a Mars colony. A Mars mission from Earth takes about 180 days with today's technology. Mars has large water reserves and probably had a geologic history similar to Earth's in terms of volcanism; there may be valuable minerals on Mars. Mars has a very thin atmosphere, composed primarily of carbon dioxide. Its surface is not protected from incoming solar radiation and the average surface temperature of –62°C (–81°F) is cold. In addition, Mars has frequent dust storms that cover large portions of its surface. Any habitat must protect its colonists from these conditions.
What features would a colony have?
There would be three basic types of modules: habitation, laboratory, and support modules. The habitat would have sleeping quarters, a kitchen (or galley), and bathroom facilities. Any windows (if any) would have to be small and made of multiple thick glass sheets to block cosmic radiation. Laboratory modules would be used for conducting experiments. A colony would also need several types of support modules and facilities, including a greenhouse to grow food; a power plant — either solar or nuclear; a place to store construction equipment and do maintenance; a central control, life support, and communications center; resource utilization facilities for processing mined materials; and a landing/launch pad. Accidents or fires could occur or meteorites might strike the base. If an accident occurs in a large structure, it might be necessary to abandon the entire building. However, in a module system, a damaged module could simply be isolated from the rest by closing the hatches shared with other modules, similar to the plan currently onboard the International Space Station. The colonists will need some type of evacuation strategy, such as emergency escape transportation in the event of a severe accident.
How would a colony provide people with the things they need to live?
Modules will have to be filled with air to enable the crew to breathe, and pressurized like an airplane cabin at a pressure of one Earth atmosphere. Energy, oxygen, food, and water necessary to maintain life in the colony initially would have to be transported from Earth. Research and experiments would be conducted to find ways of producing or recycling some of these essentials on location.
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Water?
On the Moon, frozen soil and ice at the poles may contain as much as 1–10 billion tons of water locked into deeply shaded craters, according to data from the Lunar Prospector spacecraft. That is an amount equal to what is consumed by U.S. cities in 10 days. It would be enough to supply the population of a lunar base for a long time. In addition to sustaining life in a colony, water can be used for rocket fuel and for air by breaking it into its separate chemicals of hydrogen and oxygen. On Mars, the frozen water trapped at the poles and under the surface can be harvested.
Air?
Humans breathe in oxygen and expel carbon dioxide. Just like in Earth's system, carbon dioxide and oxygen probably will be recycled in the colony. If the colony has a greenhouse, the plants can help with the recycling. Plants take in carbon dioxide and, with sunlight, produce oxygen and food. Oxygen can also be released from the breakdown of some types of rocks or by removing it from water.
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Solar-powered enclosed colony at the Moon's pole. Water is obtained from ice deposits near the poles.
Image by Pat Rawlings, from NASA
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Solar power will be a fundamental energy source for bases and vehicles on Mars and the Moon. The Mars Pathfinder and Lander collected solar energy using the flat blue-tiled panels shown in this picture.
Image by Pat Rawlings, from NASA |
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Power?
Sunlight is available for near planets and moons — like Mars and Earth's Moon. Sunlight, captured by solar panels, is converted into energy that can be stored. The International Space Station gets its power from solar panels. The challenge to storing sufficient solar energy on the Moon is its long night — equivalent to two Earth weeks. On Mars, the prolonged dust storms may inhibit solar energy collection. For planets and moons far from the Sun, and for transportation between these planets, other energy sources will be necessary. Nuclear power is probably the most efficient power source for transporation to distant planets.
Food?
Settlers can grow plants such as wheat, soybeans, and other vegetables in extensive greenhouses. Plants can be grown hydroponically — using nutrient-rich water rather than soil. Colonists may be able to breed fish and other seafood in enclosed tanks. |
What kinds of skills would a team of people in a colony need?
The colony team would initially include scientists and engineers. These individuals would probably have many other capabilities, such as medical training and construction training. As the colony grew, other personnel would to be added. They would conduct research and experiments in the laboratories, work on colony construction, maintain the base, and mine resources. Medical specialists, cooks, safety specialists, administrative staff, and cleaning crews would be needed to support the efforts. These crews would be replaced on a regular basis in the same way as teams who work at Antarctic bases on Earth.
Do we have any experiments that help us understand what is needed to make a planet habitable?
NASA's Advanced Life Support (ALS) program has explored growing plants for food and oxygen regeneration, as well as the use of chemical and biological methods to process waste into usable resources. Several experiments have sealed humans in self-sustaining environments for periods of several months at the Johnson Space Center.
The NASA Haughton-Mars Project is an international field project on Devon Island in the High Arctic that models activities of a Mars colony. The geology and biology of this polar desert setting offer possible analogs for the evolution of the martian climate and hydrosphere as well as possibilities and limits of life in extreme environments. These environments can be studied as scientists would expect to study environments on other planets. New exploration technologies and strategies are being tested in this “Mars-like” environment to provide information for future exploration of the Moon, Mars, and other planets by robots and humans. The field base includes living and research quarters and an enclosed greenhouse. All terrain rover vehicles are used for transport, and solar panels provide much of the power needed.
Biosphere 2 (Biosphere 1 is Earth) is an experimental complex with an enclosed, air-sealed ecological system, designed as a precursor to future self-contained space colonies. The complex contains separate desert, ocean, and forest ecosystems, an extensive greenhouse, and living and research facilities. Eight individuals were sealed into Biosphere 2 from 1991 to 1993. The experiment was a partial success; periodic infusions of oxygen were necessary, and the greenhouse crops did not flourish. However, considerable data were acquired to help with future designs of colonies. |
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Scientists, doctors, librarians, engineers, and cooks will all be necessary to support working and living in colonies on other planets and moons.
Image by Pat Rawlings, from NASA |
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Last updated
January 21, 2005
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