th th Mars, the Red Planet, fourth planet from the Sun, forever linked with 19 and 20 Century fantasy of a bellicose, intelligent Martian civilization. The romance and excitement of that fiction remains today, even as technologically sophisticated - botic orbiters, landers, and rovers seek to unveil Mars' secrets; but so far, they have yet to find evidence of life. The aura of excitement, though, is justified for another reason: Mars is a very special place. It is the only planetary surface in the Solar System where humans, once free from the bounds of Earth, might hope to establish habitable, self-sufficient colonies. Endowed with an insatiable drive, focused motivation, and a keen sense of - ploration and adventure, humans will undergo the extremes of physical hardship and danger to push the envelope, to do what has not yet been done. Because of their very nature, there is little doubt that humans will in fact conquer Mars. But even earth-bound extremes, such those experienced by the early polar explorers, may seem like a walk in the park compared to future experiences on Mars.