Two important factors have given rise to mankind's successful evolution into space: the first is that the possibilities are bounded only by our imaginations - if we can conceive it, historically it has been proved that we can do it, and in a predetermined timescale. The second factor is recognition of the evolving civilizations on the Moon and Mars as separate entities from Earth.

Space, whether we or our children live in it or on the Moon or Mars, will be important to all of us, not only to aerospace engineers and cosmologists, because of the new opportunities for freedom and limitless growth it offers. Our continued prosperity and survival as a species will in part depend upon space exploration and the resources it provides for our industrial societies and for the markets it will create. The expansion of Earth's success in science and culture to the Moon, then Mars, and eventually the Solar System, can only strengthen mankind's core positive achievements: democracy, individual rights and equal opportunities for all. The significant topic of returning to the Moon, this time to stay, is a central part of space exploration.

Concepts for lunar base structures have been proposed since long before the dawn of the space age. Suggestions made during the last 25 years are likely to form the pool from which eventual lunar base designs will evolve. Studies have intensified, both within NASA and outside national governments in industry and academe, since the days of the Apollo program, when it appeared likely that the Moon would become a second home to humans. Since then, science on the Moon, the economics of lunar development, and human physiology in space and on planetary bodies, as well as related policy issues have been studied as they are all needed to plant Man on the Moon in a sustainable and viable way.

Economics and politics will play a heavy if not deciding role in space and lunar settlement. The issues of pollution and related environmental matters, the question of ownership, and how these affect the investor communities, including governments, will be considered. Human exploration and colonization of the Moon and the planets appears far off but it is important to discuss the safeguarding of the integrity of these planetary bodies in advance of the economic development that will be explosive once it begins. For purposes of discussion, it will be assumed that by the year 2050 there will be a well-developed human colony of many hundreds of people on the Moon, created by several democratic Earth governments in partnership with numerous industrial concerns. Its purpose will be to learn survival on a non-terrestrial body naturally hostile to human life and to explore and use the resources of the Moon, leading eventually to self-sufficient large lunar cities that will survive economically by exporting lunar minerals and finished products to Earth, and by servicing transportation, both commercial and military, between Earth and emerging settlements on Mars, its moons, as well as early mining activity on the asteroids and the moons of the gas giants of the outer solar system.