Arthur E. Smith 
Mars The Next Step [PDF ebook] 

The conquest of Earth’s moon was merely a precursor to a more dramatic step forward, which will take men and women to an outpost that might eventually become a second home for the human race.Mars: The Next Step illustrates how the only feasible colonization of another planet in our solar system will be on Mars. The author addresses the various questions surrounding this theory with frank scientific caution that in no way obscures his vigorous enthusiasm and, above all, optimism for mankind’s future in space.This vivid and entertaining book explores "terraforming" (planetary engineering), which could turn Mars into a more congenial environment for humans, both in terms of changing the harsh climate of the planet and the production of plants able to thrive there by means of genetic engineering. The book includes numerous diagrams of possible manned spacecraft, along with color pictures of Mars taken on previous unmanned missions.