I finished studying some new Mars ISRU methodes on the internet and I must say I like your ideas Geoff. :-)
I just wanted to post some new ideas, when suddenly I realized "Wait...I remember geoff typing a similar topic!" and that's how I ended up here. :)
I just wanted to elaborate some new ideas....mainly the "zirconia electrolysis". It's important! As far as I read it's possibly the most important reaction in Permanent Mars Colonisation!
2CO2 --> 2CO + O2
Martian air has ~95% CO2. All you have to do to gather it is to just compress it, and it will liquify (and cleaned out off pollution!). The next stepp is to just take that CO2, pass it through the zirconia reaction and *PUFF*
YOU HAVE OXYGEN to breathe and to use as a fuel in various reactions. And all that out off martian air! No constant search for watter that could be electrolyzed. Only electric power.
But why isn't the zirconia reaction very popullar? Well.....there is a good reason for this.
You see....to operate a typical "Zircon electrolyser" in Mars condition you would need a large power supply (much larger that those you can archieve i Mars Colony right now). You would need a better power source - more solar cells, small nuclear reactor or something like that.
Let me Quote something about it:
" Oxygen can be produced by passing CO2 through a zirconia electrolysis cell at 800 to 1000deg C. Twenty to thirty percent of the CO2 dissociates into oxygen and carbon monoxide. Separation is accomplished by electrochemical transport of oxide ion through a membrane. A prototype reactor using this chemistry has been run for over 1000 hours. Using such a scheme, we could bring a small unit to the surface of Mars which would then continuously make oxygen for life support, propellant use, or further processing. The only additional item we would need to supply is the power to run it: a 12kW unit would produce about one metric ton of oxygen per month.
This oxygen can be converted into water if we also bring a small supply of hydrogen. Since the molecular weight of hydrogen is 2 and the molecular weight of water is 18, we can leverage 2 kilograms of hydrogen into 18 kilograms of water. The mass savings would, at some manufacturing rate, pay back the mass of the oxygen production unit. After that, we would get water for only the price of getting the hydrogen to Mars.
2CO2 --> 2CO + O2
zirconia electrolysis"
NASA is doying great research on that reaction for first Mars flight. They see a bright future in this technology. As far as I know, they mannaged to minimalyse the equipement so that it may be carried by a space vessel, but the low efficiency, and high energy consumptions are still a problem. Mars Colony game is set in some near future. It is therefore possible to assume that those problems are goying to be resolved.
As far as I can see it, in Mars Colony players have an ultimate goal
to be independant of Earth support.
And what can be more independant here that beying able to produce your own air for a large scale settlement?
Players goal would be to archieve proffit by mining, discovering and reasearching, and use that money to buy "Zircon electrolyser" and a reactor or solar panners that would power-it up.
It's even possible that one base could sell liquid oxygen to other, near-by bases.