Some time, very likely within the lifetimes of most people reading this, people will live on the Moon. At first, the lunar settlers will be scientists, uncovering the geological and geophysical secrets of the Moon, and perhaps operating an astronautical observatory on the far side of the Moon. Later, the scientists will be joined by businessmen and entrepreneurs, mining the Moon for its resources and building and operating solar power stations that will beam the sun’s energy back to Earth. Finally, the Moon will be visited be tourists, visiting a hot, new destination that, for most of human history, has been beyond the reach of human beings.The Moon is a most inhospitable place. It has no atmosphere to speak of. Most places on the Moon are so arid that it makes the hottest desert on Earth seem garden-like by comparison. Temperatures can reach 123 degrees centigrade in the day and minus 233 degrees centigrade at night. A person standing unprotected on the surface of the Moon would die almost instantly.In order to live on the Moon, future lunar settlers will need oxygen, water, food, power, and building materials. As it turns out, most of these can be either gotten or produced on the Moon with a minimal need for imports from Earth.
Lunar soil is a mixture of a number of materials, nearly all of which contain oxygen, at about 45 percent. Ilmenite is one of the most common lunar minerals. It is a mixture of iron, titanium, and oxygen. In order to extract the oxygen one would develop a plant, usually called a LUNOX plant, to process the lunar soil using a combination of heat and chemical processes. Not only will the oxygen be extracted, but other useful materials such as titanium, iron, and silicon. Oxygen will not only be useful for breathing, but also for producing rocket fuel. Other components that make up a breathable atmosphere, such as nitrogen and carbon, have not yet been discovered on the Moon. Some scientists believe that such might exist in deep pockets underneath the lunar surface. However, in the near term, these elements will likely have to be imported from Earth.
Most of the lunar surface, as previously mentioned, is dryer than the proverbial bone. The exception may be permanently shadowed craters, where the sun has never shined, around the lunar south and north poles. Scientists have, for a long time, theorized that over billions of years, comets have impacted on the lunar surface, releasing tons of water and other materials. Most of these have cooked off the lunar surface and dissipated into space. Some, though, may have found its way to these shadowed areas of the Moon where they have frozen in the form of ice crystals mixed in with lunar soil. Both the Clementine and Lunar Prospector space proves have uncovered indications of ice permanently frozen in these shadowed craters at the lunar north and south poles. Future planned space probes should verify the existence of this ice. Extracting the water ice from the lunar soil should be an easy matter. The probable existence of water ice at the lunar poles make those areas prime candidates for building lunar settlements.
The big problem with growing food on the Moon is that lunar soil does not contain any of the nutrients that are required for plant growth. Much of those nutrients, such as nitrogen,l carbon, and ammonia, will have to be imported either from the Earth, by mining asteroids, or by processing human and animal waste. On the last subject, Dr. Robert Zubrin, a space exploration and settlement expert, famously said that bodily waste would be more valuable than gold at a lunar settlement.A lunar farm would likely be established underneath a domed covered area, with air, power, and water strictly regulated to enhance maximum yields. Since the Moon has a four week day and night cycle, lamps would have to be used to sustain food plants during the two week long lunar night. A hydroponics system is also a possibility for growing food on the Moon. In a hydroponics system, the physiological requirements of plants are met without the use of soil or natural sunlight. Plants are rooted, and thus supported, in an inert medium and nutrition is provided by water soluble mineral elements. Suitable livestock for lunar agriculture might include goats, sheep, pigs, and poultry. Cattle are probably too resource intensive an animal to try to raise on the Moon. Of course, the long term effects of one sixth gravity on generations of livestock have yet to be determined. Other products useful for a lunar settlement beside food can be extracted produced by lunar agriculture. These would include cloth, bamboo, certain plastics, and plant derived alcohol and oils. Lunar agriculture would also be a large component in the recycling systems that will be necessary to sustain a lunar settlement. Lunar plants would process carbon dioxide exhaled by humans and animals back into oxygen.
Lunar settlement would likely be powered by a small, nuclear power plant. Power would be supplemented by solar collectors, built in part with silicon that exists in lunar soil. There is a place near the lunar south pole, called the “Peak of Eternal Light”, which by virtue of its height and location is nearly entirely in sunlight and would thus be perfect as allocation for a solar power station. Hydrogen fuel cells and batteries will also supplement power for a lunar settlement.Lunar Building Materials Iron, aluminum, and titanium exists in a certain abundance on the Moon and would likely be used as building materials. Also, some researchers have been experimenting with a substance known as “lunar concrete.” Dr. Lin of Construction Technology Laboratories first explored the concept of using lunar concrete as a building material. The use of lunar concrete to build a lunar base and other support structures would eliminate much of the need to bring materials from earth. Research has indicated that lunar soils can be used to make Portland cement, but this approach has one major drawback. It requires water. Even if water is confirmed to exist at the lunar poles, making lunar concrete may not be the best application for it.Another possibility is mixing lunar soil with a polymer, which consist in part of hydrogen and carbon. But those elements do not exist in abundance on the Moon. Yet another possibility is using silicates as a binder. Current research is focusing on the use of a sodium silicate type adhesive mixed with fibers to serve as a concrete binder or cement. The lunar concrete properties can be tailored with the amount of fibers in the cement. The fibers can be silica, aluminum, iron or magnesium. This type of cement can be made with materials found on the moon.Lunar Recycling Recycling systems will be an important component for sustaining life on the Moon. Bodily waste will be used for lunar agriculture. Urine will be recycled into potable water. Carbon dioxide will be turned into breathable oxygen. The Future of Lunar Settlement People have not been back to the Moon for over three decades. Several countries, including the United States, have plans at various stages of seriousness to return people to the Moon. When human beings do return to the Moon, it is inevitable that some will want to stay permanently, just as the first settlers in the Americas. The first community of humans beyond the Earth, residing on a world that is seen from the Earth on most nights, will be a center of science and commerce