The analogy to the ISS would be a science base Mars. That does not get you interplanetary trade, or asteroid mining. Tourism is at least conceivable, but the n

The analogy to the ISS would be a science base Mars. That does not get you interplanetary trade, or asteroid mining. Tourism is at least conceivable, but the number of people who could plausibly afford a ticket is tiny; and the journey time would be hard to justify. The market for low earth tourism is already tiny; and exists only because everything needed was already built to support the science mission. For asteroid mining; just go to asteroids. It seems bonkers to set up your base at the bottom of a gravity well for no particular reason. For trade; there is nothing of particular value on Mars. If you are already there, then on site production makes sense. Otherwise, skip the trip and gravity well and find an asteroid to mine.