XPost: sci.space.policy, sci.physics   
   From: fjmccall@gmail.com   
      
   jimp@specsol.spam.sux.com wrote:   
      
   >In sci.physics Vaughn Simon  wrote:   
   >> On 10/17/2016 10:07 AM, Serigo wrote:   
   >>> Mars does not have any O2.   
   >>   
   >> Wrong!  There is more oxygen on Mars than we are ever likely to need.   
   >> It's just that there isn't much free oxygen floating around in the   
   >> atmosphere.   
   >>   
   >   
   >Which means you have to have a huge pile of machinery and energy to   
   >get it.   
   >   
      
   I'd like to point out before I go into Jimp's water wall that one   
   needn't get oxygen from water.  It's perfectly possible to get it from   
   CO2 and all you need at that point is a pump and power to run the   
   'reverse fuel cell' that produces the oxygen.   
      
   >   
   >Excavators to dig the ice out of the ground, assuming it is there.   
   >   
      
   It's just mass.   
      
   >   
   >Trucks to haul the ice to the water plant.   
   >   
      
   Put the water plant near the ice.  DOH!   
      
   >   
   >Conveyor system to haul the ice from the trucks to the melting pot.   
   >   
      
   Gravity.   
      
   >   
   >Melting pots to melt the ice.   
   >   
      
   Concrete or just rock.  Easily made on Mars.   
      
   >   
   >Filtering system to purify the water.   
   >   
   >If the ice is the remains of an ancient sea, then it is likely saline,   
   >so a desalination system.   
   >   
      
   If you use flash desalinization, you don't need to filter much (if   
   any(, since you're condensing pure water out.  And you're going to   
   have to do this, because a lot of the water ice on Mars that isn't at   
   the poles is subsurface brines.   
      
   Then subsurface pipes (more concrete) to take the pure water to the   
   colony for use.   
      
   >   
   >Tanks to hold the final product.   
   >   
      
   Because tanks are SO difficult...   
      
   >   
   >All of this needs lots of power to operate plus everything needs to   
   >be heavily insulated and heated so the water does not freeze in the   
   >-100 F Martian night and burst all the pipes and tanks.   
   >   
      
   Well, it's not like you just let the stuff lie about on the surface.   
   But yes, you'll need some insulation and heating.  Nuclear power is   
   kind of handy for producing heat.   
      
   >   
   >Then you can think about building the electrolysis plant and the tanks   
   >to store the hydrogen and oxygen you've generated, but these at least   
   >don't need to be heated.   
   >   
      
   If you bother to produce O2 from water.  See MOXIE, which produces it   
   from atmosphere.  The rover experiment will need around 30 watts of   
   power to get 1-2 grams of O2.  Scale up.   
      
   >   
   >It is easy to arm wave that there is lots of oxygen on Mars and another   
   >thing to actually produce it.   
   >   
      
   And it's even easier to handwave about how impossible it is to do.   
      
   >   
   >Where do the thousands of tons of steel come from to build all this   
   >stuff?   
   >   
      
   "Thousands of tons of steel"?  You really do think we're going from   
   zero to Pittsburgh in a week, don't you?   
      
      
   --   
   "Some people get lost in thought because it's such unfamiliar   
    territory."   
                                         --G. Behn   
      
   --- SoupGate-Win32 v1.05   
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