Going Beyond The Status Quo In Space, Dennis Wingo, Paul Spudis, and Gordon Woodcock
"Why the Moon? While appearing barren, the Moon has the resources upon which to build a prototype space civilization. It is a power-rich environment, permitting initial steps to be undertaken using proven, inexpensive solar power generation technology. The Moon is readily accessible from Earth at almost any time. This accessibility makes it a practical site for such a pioneering development - one that is convenient enough to Earth so as to enable trade, travel and telepresence operation. In contrast, Mars and the inner solar system asteroids have infrequent travel opportunities and comparatively long trip times. They won't work for first steps towards economic development of the solar system. With experience and technology from developing the Moon in hand, Mars can then be settled and the rest of the inner solar system can be developed in a cost effective manner."