The ongoing obsession with a manned mission to the Red Planet is misguided. Habitation would be expensive, and worthless. Terra-forming would take too long. And, we have better options, closer to home: Mercury and Venus.
Mars is Depleted. Mercury is Ripe.
There simply isn’t a lot of stuff that we need on Mars. Carbon, silicon, iron — we have plenty of those things here on Earth! If we just need extra space to inhabit, an orbital platform in the Goldilocks Zone would let us grow food and live comfortably. In any supposed ‘planet-wide disaster’ scenarios, an orbital platform would be far superior to a Martian colony, as well: we would have a much easier time returning to Earth, to repair and repopulate. Heck, a Moon base makes much more sense than a Mars base! With all the literature on those three options, I have not heard a single argument showing that ‘Mars base > Moon or orbital platform’. Have you?
Meanwhile, our treasure troves go unnoticed: Mercury and Venus, by virtue of being closer to our sun, have a VAST reserve of heavy metals, rare minerals. Mercury is our solar system’s Fort Knox! And Venus, with its dense atmosphere (>90 times ours!) allows simple construction of massive floating cities, high enough above the lead-boiling surface, so that they inhabit a comfortable 80degF zone. That sounds much better than a potato farm on a cold, dim rock.
No Man’s Land…
If we plan to mine Mercury, it will be with semi-autonomous robots. And, we will need to pelt areas with icy globs at regular intervals, to cool and crumble the mantle and ease spectrography-based prospecting from an orbital hub. (Your orbital platform zaps the surface with a lazer, and watches the colors that the targeted rock makes, as it vaporizes and cools… that’s how we’ll do mineral prospecting on Mercury, and any other rocks without atmospheres. Wanna bet on it?) I offer Saturn’s ice moons (Rhea?) as fodder to the task of mining Mercury and gently cooling Venus. With even a gentle nudge, Saturn’s moon Rhea could be tumbled and sling-shot into an orbit closer to the sun, and robots on its surface could drill and lob chunks of ice, ferrying them into orbits that collide with Mercury or Venus.
Mercury has a super-abundance of fissile materials, which should make the job of launching exports from the planet’s surface that much easier. It also has significantly lower surface gravity than Mars — easier, still. And, if we persistently aim our icy chunks at the planet’s edges (steep-angled impacts, not bull’s eyed impacts), we could induce rotation. By spinning Mercury even a little bit, a space elevator there would be cheaper and lift a greater percentage of its mass as payload per hour, than on any other planet in our solar system. That would make mining Mercury MUCH easier.
Venus is Lovely:
I cannot understate the logistical advantages of Venus’s dense atmosphere! You could float there, with a blimp-backpack the size of a manta ray. City-sized floating platforms would be cheap to maintain. If you have a boulder that you want to hoist, then a blimp would do that work easily, with less capital material, at lower cost, and almost no power requirements, compared to a digger on Mars.
The atmosphere on Venus is also continuously circulating in a planet-wide single Hadley cycle. That means your floating city would naturally migrate across the planet’s surface, at NO COST. Gliders could easily launch from these migratory platforms, to land payloads thousands of miles from their launch-position, for free. Inflate a blimp-bladder, which tugs the glider and materials back up, to be grabbed by another floating city! Coordinating the movement of materials was never easier. Mars, meanwhile, would rely entirely on rovers trudging over rugged terrain. Sad!
Venus, by slow and gentle addition of ice-moons (one should be plenty, really), would begin cooling and chemically weathering surface rocks. Once the surface became damp and cool enough for robots, we could begin prospecting. I recommend using some of that Mercury-mined fissile material to drill and blast volcanic pools, then adding frit from surface rocks, to create magma mixtures that slow-cool and separate into valued minerals. You could call it ‘controlled igneous materials processing’? Also, blasting a micro-volcano, pouring a bunch of sifted dust on top (from the safety of your buoyant platform!), and waiting for it to cool into minerals is less labor and capital-intensive than drilling and refining on a cold rock like Mars.
Finally, with a moist atmosphere drawing down Venus’s high sulfur clouds and locking that sulfur in chemical reactions with surface rocks, your high floating platforms would be ideal gardens and solar farms. Massive arrays of gardens could be constructed and deployed far above the surface, and the sunlight captured by those high-altitude gardens would simultaneously create vast shaded zones beneath them. We could safely harvest from our bubble-cities, while cooling the planetary surface. It’s a virtuous cycle!
So, what was your reason for going to Mars?