I never understood the appeal of Mars colonization. Venus is closer than Mars, and while its surface is harsher than inside a pressure-cooker, at ~50km altitude air pressure is equal to Earth at sea-level and the temperature a comfy 20-30C. Plus because Venus has a dense, mostly CO2 atmosphere, the breathable-air reserve required for a human habitat would be buoyant enough to float a colony permanently in the clouds. I for one would prefer to live in a bright Venusian cloud city than a dry, dusty, cold, dark underground cave on Mars.
Although future Venusian cloud cities might want to keep their operations small enough not to be noticed, you know, to stay out of the jurisdiction of the Empire. 😛