Mars Colonization in our lifetime is fantasy. Not necessarily from technical but from purely economic perspective. You can't make near time colony self sufficient and maintaining it would require billions in subsidies year after year.
At this point it’s pretty clear that with low enough launch costs orbital industry will be a big thing. All sorts of high performance materials can only be made in microgravity:
* Better optical fibers with ZBLAN (happening today) and better optics in general with zero-g glass forming
* whole new alloys which can’t be made in normal g due to density separation. Think better nickel superalloys, and guess what the price per kg could be
* much larger, purer, more perfect crystals of all sorts for semiconductors, drug development, etc
* artificial tissues and organs grow better when not under their own weight
Launch costs are dropping fast today, but will eventually probably plateau someplace north of $50/kg until we can move past chemical rockets, which IMO is fantasy in our lifetime.
As long as launch costs stay that high, it’s strong incentive to develop mining and refining capacity on Mars. The gravity well is so much shallower than Earth that for any destination past LEO, you’re saving money launching from Mars.
Martian materials won’t be used on Earth for centuries, if ever. But $50,000 / ton Martian steel + Martian launch costs will be cheaper than ~free Earth steel + Earth launch costs within our lifetimes, imo.
Everything you say is argument for not going to Mars but develop industry in the Moon, close Earth asteroids or in the Earth orbit. Mars is in the bottom of big and expensive delta-v well just like Earth.
If asteroid mining becomes profitable, Mars can never compete. It has no microgravity, no enough sunlight, corrosive soil and dust everywhere. It's just a lifeless desert in deep delta-v.
Having small economic settlement inside near earth asteroid could be economically sound idea. Most of the work would be done by semi-automatic robots and people on Earth but maybe there is need for on-site crews as well.
I don’t have the expertise to really compare asteroid mining to Mars, but I’m suspicious of the fixed infrastructure costs. Mining and refining takes a lot of mass. Replicating that mass for each object you want to mine or flying it from rock to rock both seem like significant costs. Perhaps we’ll find a big Goldilocks rock that’s near Earth, will stay near Earth for a long time without insanely expensive capture maneuvers, and contains all the materials we want, but I think Mars has a better shot.
Mars also has much friendlier conditions for propellant manufacturing, which is an important factor in these cheap launches.
Metals on asteroids are easier to extract. Some asteroids, like 16 Psyche are almost solid chunks of metal. Asteroid ice (oxygen and hydrogen) can be turned into rocket fuel with electricity from solar panels.
Single asteroid close to the Earth can supply all the needs on earth for centuries.
16 psyche is one of the 10 most massive objects in the belt. The belt is more than twice as far away, and transfers to it are much more variable over the years than the fairly regular Mars windows.
Finding the “Goldilocks” object that supplies all our needs, can be regularly reached economically, etc etc isn’t an easy problem.
Also, water gets you hydralox propellant, which is a bit of a pain in the ass. You really want organic compounds too so you can do methalox, which is one more constraint on Goldilocks.
[0] https://m.phys.org/news/2013-05-curiosity-mars-rover-drills....
And then to sustain this massive operation you need a massive demand. You'd need millions of tons of steel of demand to make the colossal investments (of perhaps billions/year) viable. And then the demand for the primary applications needs to be even larger. I don't know much about the applications you've cited, but I'd find it hard to believe you could get demand in tens or hundreds of billions per year. They look essentially like niche applications that can be fulfilled by a low-cost launch system. Remember that the FH costs about $1700/kg (and cost probably be cut in half or better with several billions in annual demand).
I.e. I'm not convinced. That said, I think under a very long term (perhaps by the end of the century), the objective of a self-sustaining colony is worthwhile.
Before economic viability of any enterprise, a massive amount of systems will need to be developed enabling manufacturing basic tools and materials in situ. It's basically reinvention of industry from scratch but with much more strict requirements and much thinner margins for sustenance. A first step would be probably local production of solar panels, food, structural materials, habitats. The basic elements of self-sustenance. Then gradually moving up the technology ladder until import dependence from Earth would be at a minimum. Only then it starts to become viable and thinkable to have small martian exports for orbital systems, tourism, culture and media (I imagine showcasing life on Mars would get quite an audience on Earth), perhaps low-bandwidth scientific computing. This will probably take centuries but is an important step for humanity. Sooner or later we have to get off this rock, there's an entire universe out there waiting for life...
That's why colonization must start on the first mission. Flags and footprints missions are self-defeating.
>You can't make near time colony self sufficient and maintaining it would require billions in subsidies year after year.
The US alone already spends $5 billion per year on ISS.
ISS has crew of 6 located 400 km from the surface of the Earth. In the emergency they can leave the station in minutes (in two Soyuz capsules). Time between the decision to leave and landing in Kazakhstan is 3.5 hours or less.
What's the relevance to cost here, anyway?
Economically speaking Mars would not achieve economies of scale needed for becoming self sustaining.
Manufacturing every component for higher safety standards than commercial aircraft or nuclear submarine is expensive. Building whole society that works in safety critical environment 24/7, starting from daycare and ending with microprocessor and chemical plants is just fantasy in the near future.
Maybe in 100 or 150 years we can start dreaming.