The spectacular advances of science and engineering in the twentieth century established the basis for creating permanent human settlements in space in the twenty-first century. Since the Moon is our closest celestial neighbor and is in orbit around Earth, it will logically be the next principal focus of human exploration and settlement. The Moon is an excellent platform for astronomical and other scientific investigations, for technological development, and for human habitation. It also has access to the virtually unlimited energy and material resources of space, which can be applied to the development needs of both the Moon and Earth. These opportunities, combined with the universal desire of humankind to explore and settle new lands, assure that the global transformation of the Moon into an inhabited sister planet of Earth will become a reality in this century.
A major impediment to the exploration of space is the high cost of delivering cargoes from the surface of Earth into space. For example, the cost of launching a payload into low Earth orbit by the space shuttle is approximately $22,000 per kilogram ($10,000 per pound), and that figure will be higher for missions to the Moon. Thus, it appears that lunar projects will be prohibitively expensive, even if launch costs to low Earth orbit are reduced to less than $2,200 per kilogram ($1,000 per pound).
The exploration and development of the Moon, however, will be marked by a dramatic reduction in the cost of space exploration through the process known as in situ resource utilization, which means "living off the land." Industrial processes on Earth use energy, raw materials, labor, and machines to manufacture sophisticated products such as computers, medical imaging devices, rockets, and communication satellites. By the end of the first or second decade of the twenty-first century, it will become possible to use lunar materials to manufacture equally sophisticated products on the Moon.
The Moon has a reliable supply of energy in the form of sunlight, and the lunar regolith (Moon dirt) contains abundant supplies of iron, silicon, aluminum, and oxygen as well as traces of carbon, nitrogen, and other light elements. In addition, the U.S. Lunar Prospector satellite detected increased hydrogen concentrations in the polar areas of the Moon, suggesting the presence of water-ice in those regions. Thus a significant reduction in the cost of space projects can be achieved by simply transporting the basic components of Earth's industrial base, such as lathes, drills, ovens, and control devices, to the Moon. The lunar industrial base will then use solar energy and lunar materials to manufacture the products that are needed for the exploration and human habitation of the Moon. By this means, the high cost of transporting materials from Earth to the Moon will be eliminated, and large-scale space projects will become possible.
Initially, tele-operated robots that have been delivered to the Moon will serve as the "labor" component for lunar industrial processes. Tele-operation is the process by which robots are controlled by scientists or technicians at remote locations using radio links and television monitors. Tele-operation procedures are widely used on Earth for diverse applications such as mining, undersea projects, and certain forms of surgery. It is fortuitous that the Moon always has the same face directed to Earth and that the round-trip time for communications between Earth and the Moon is less than three seconds. These conditions will allow Earth-bound operators of lunar robots to have a virtual presence on the Moon twenty-four hours per day, 365 days per year.
Establishing a Lunar Base
The site for the first unmanned base will likely be on the Earth-facing side of the south polar region of the Moon. There are several sites in this region that always have Earth in view for continuous telecommunications and that receive as much as 340 days of sunlight per year for the generation of solar electric power. A south polar base would also have access to increased concentrations of hydrogen (possibly water-ice), which would be useful for industrial operations and eventual human habitation.
Many countries have rockets that can be modified to place useful payloads on the Moon. In one scenario for the establishment of a lunar base, one or more of these existing rocket systems will be used to transport solar panels, communication systems, scientific equipment, and robots from Earth to the south polar region of the Moon. When these components are in place, tele-operated rover vehicles will explore and analyze the lunar surface. Protocols for the preservation of unique features of the lunar environment will be observed, and scientific data will be obtained before local materials are used for experiments. When surveys and analyses have been completed, tele-operated robots will then begin experiments with the production of bricks, wires, transistors, and glass products from lunar dirt.
In the preceding scenario, priority will be given to the fabrication of solar cells for the generation of electric power. The demonstration that electric power can be produced on the Moon from the first lunar-made solar cell will be a milestone in space exploration because it will mean that human enterprises can be self-supporting in space. From that beginning, lunar-made solar cells will be added to the electric power system of the lunar base. As electric power levels grow, additional scientific and manufacturing equipment will be delivered from Earth, and the lunar base will expand in all of its capacities. Iron rails may then be made from lunar iron to construct a simple two-track rail line from the first base to other areas in the south polar region, including the geographic south pole. A "southern rail line" would greatly expand the ability to carry out exploratory missions and would facilitate the growth of lunar power and communication networks.
Humans Return to the Moon
Within a decade after the first unmanned base has been established, humans will return to the Moon. During the build-up of the first unmanned lunar base, controlled ecological life support systems will undergo continued research and development on Earth and the International Space Station. Work will also commence on the development of reusable rocket systems that can ferry people between Earth and the Moon. When a reliable lunar electric power system is in place and underground chambers (for protection from radiation, temperature extremes, and micrometeorites) have been constructed, life support systems and agricultural modules will be delivered to the lunar base. Humans will then return to the Moon for sixty-to ninety-day periods, and all aspects of lunar base activities will be expanded.
As experience with lunar operations increases, the scientific and industrial capability of the Moon will reach parity with Earth, perhaps within two to three decades after the founding of the first base. Widely separated, permanent human settlements will be established, and the only cargoes that will need to be transported from Earth will be humans—the scientists, engineers, tourists, and immigrants who will explore, develop, and inhabit the Moon.
Future Lunar Development
Geological expeditions will explore the mountain ranges, mares (plateaus), craters, and rills (narrow valleys) of the Moon, and investigate lava tubes that have been sealed for billions of years. Thousands of lunar-made telescopes will be placed at regular intervals on the Moon so that any object of interest in the universe may be observed continuously under ideal viewing conditions. People will live and work in large underground malls that have Earth-like living conditions. A rail system will provide high-speed access to all areas of the Moon and lunar tourism will be a growth industry. Millions of megawatts of low-cost environmentally sound electric energy will be beamed from the Moon to Earth and other locations in space by the lunar power system.
By the mid-twenty-first century, thousands of spacecraft will be manufactured on the Moon and launched by electromagnetic "mass drivers" to all points of interest in the solar system, and robotic missions to nearby stars will be underway. Communication, power, and transportation systems will be built on the Moon and launched to Mars in support of the global human exploration and development of that planet. Asteroids and "burned out" comets in Earth's orbital vicinity, especially those that pose a threat of collision with Earth or the Moon, will be maneuvered out of harm's way and mined for their hydrocarbon, water, and mineral contents, which will then be delivered to Earth or the Moon.
The transformation of the Moon into an inhabited sister planet of Earth is an achievable goal that will be highly beneficial to the people of Earth. It will provide the following:
- An expansion of scientific knowledge;
- The advancement of all engineering disciplines;
- Access to the virtually unlimited energy and material resources of space;
- Job and business opportunities;
- International cooperation;
- A greatly expanded program of solar system exploration; and
- The opening of endless frontiers.
The binary Earth-Moon planetary system will thus draw upon and benefit from the vast energy and material resources of space, and the spacefaring phase of humankind will be firmly established.
see also Lunar Bases (volume 4); Lunar Outposts (volume 4); Natural Resources (volume 4); Settlements (volume 4); Space Tourism, Evolution of (volume 4); Telepresence (volume 4); Tourism (volume 1).
David G. Schrunk
Harris, Philip R. Living and Working in Space: Human Behavior, Culture, and Organisation, 2nd ed. Chichester, UK: Wiley-Praxis, 1996.
McKay, Mary, David J. McKay, and Michael Duke, eds. Space Resources, 4 vols. National Aeronautics and Space Administration, SP-509. Washington, DC: U.S. Government Printing Office, 1992.
Mendell, Wendell. Lunar Bases and Space Activities of the 21st Century. Houston: Lunar and Planetary Institute, 1985.
Schrunk, David, Burton Sharpe, Bonnie Cooper, and Madhu Thangavelu. The Moon: Resources, Future Development, and Colonization. New York and Chichester, UK: Wiley-Praxis, 1999.