An evolutionary approach to settling the inner solar system would begin with an outpost on the Moon. Here, just three days away from Earth, we could become experienced in living and working on another planetary body. The explorer in the foreground, wearing a constant-volume, hard space suit with rotating joints, is a representative of a commerical enterprise that intends to develop and exploit extraterrestrial resources. A lunar oxygen production plant, set between the two large solar panels, is generating a supply of rocket fuel that will be used for later journeys to Mars. The lunar base can be seen in the distance.