>>12030969Claims like these are only backed by the wishful hope that Martian resources can be 3D printed into farms, city, and space elevator without needing "much" cargo from Earth.
It's as if simply being on a planet allow leap of logic were space-suit become heavy clothes, any soil become farmable and fully pressurized comfy habitat are built as easily as a log cabin in the previous new world.
They mock O'neill -endgame- station and needed robots while dreaming of thousand of city-sized green dome and glorified human-robot.
Mars "habitability" is grossly overrated.
Martian would be living in more costly liveable can, you'll need airlock and spacesuit/pressurized car to move between every place of importance, you'll need maintenance for the wear caused by the cold weather, the change in temperature, you'll be fighting gravity as you build, find reach and dig out the ore.
Btw, airplane won't be economical in a thin atmosphere.
Before you reach the million of colonist you'll require to lift as much if not more cargo out of a gravity well and down another than if you went for asteroid.
And here I'm assuming we will have enough biotech to negate every health problem caused by gravity, as well as food production.
Martian need to hope 0.3G is both acceptable and better than 0G.
Spacenoid can emulate 1G, if they must.
In short: If you had the technologies for Mars, asteroids would be easier to colonize.
Asteroid are often big enough to support all of mankind for years. Everything you build in 0G can be moved or discarded easily.
If you start close you won't need more propellant than Mars and have quicker growth while Earth make a profit of it.
Radiation will be a problem but we will always have that problem, rock can be used as shield and in 0G they can be moved with simple robotic arms.
If you think long term, the best choice is to learn to live entirely in orbit ASAP then move to Ceres or the Jovian system for resources.
