WaterFirst of all: water can be found underground. There should be some frozen highly-preasurized lakes deep underground. In order to get that water you would only need to find it and drill it to the surface
using a combination of
water-pumps and heat injectors. It's an easy source of large amounts of water but they should be very rare.
Secondly: WAVAR. WAVAR is an equipement that drains water disolved in martian atmosphere. It uses practicly no power and no space, but in Mars conditions it needs some time to gather large amounts of it. Player would need to drail the tanks manually from time to time using water cans.
Thirdly: RWGS reactor. CO2 + H2 = CO + H2O
The H2O can be than electrolyzed more efficiently in-situ to H and O2.
http://www.lpi.usra.edu/meetings/ISRU-III-99/pdf/8004.pdfhttp://spot.colorado.edu/~meyertr/rwgs/rwgs.htmlI would also like to point-out that RWGS makes preasurized CO which can be stored in
gas tanks. Those gas tanks when full could than be replaced with empty ones, and the full ones are taken to
Air-Preasure Power Generator to store power.
Fourthly: Water Synthesis Reactor (WSR): 2 H2 + O2 = 2 H2O It may happen that you have much Hydrogen and Oxygen but you need desperatly water NOW. No problem - add hydrogen and oxygen to gain water almost instantly...and since this is exothermic proces that requires only a catalisator, you don't even need to power-up WSR, so that you could make water even when base is out of power.
Those are the main possibilities. There are more ways to make water...for instance by MMARS equipement, plant/air recuperator or bying it :-)
What can you do with water?
1) Drink it. In order for water to be drinkable you would first need to destilate it, using
distillizer.
2) Take it to
electrolyser (needs power). H2O = 2H2 + O2
3) Give them to plants/animals.
4) Add it to other reactions....like RWGS 2nd stage (it's more efficiently than simple electrolyser).
5) Use it to
extract P2O5 - which is later-on used for fertilizing. (NOTE: P2O5 and P4O10 is the same thing - check it out if you don't believe me)
P4 can be extracted from ores or from rocks.
P4 + 5 O2 → P4O10
P4O10 + 6H2O → 4H3PO4
4H3PO4 = Phosphoreus Fertilizer for plants
It can be like this: Player mines ore that contains P4, extracts it from the ground. Take's it to the furnace. He get's pure P4. He takes P4 and places it into
Phosporeus Fertilizer Synthesizer (PFS) [I just made that-up]. He add's water and oxygen. He presses start, and after some time he gets in return Phosporeus fertilizer, that he can add to the plants.