QUOTE (JTN @ Nov 7 2006, 10:56 PM)
The Space Review has recently posted a summary
of observations to date, by Paul D. Spudis.
That's a very nice article. It's worth working out some of the first approximation process issues involved assuming 2% water content in the upper regolith.
That is 20kg of water per tonne or, at a density of 2, 40 kg (or L, if you prefer) per cubic metre of regolith.
A commonly used figure is a ration of 30 kg of water per person per day in space. Assuming 90% recycling, as on the ISS, that is 3 kg per person per day, 12kg for a four person crew.
A station with a crew of four would need to process 600 kg of regolith to supply the daily requirements, or 0.3 cubic metres.
Before we could start utilisng the water we would need to know it distribution, grade, and water other ices (CO, CO2, CH4, NH4, SO2 etc.) occur along with it. Plus the mechanical properties of the ice bearing regolith (essential for extractive system design).
With this we could decide whether the ice were best extracted in situ, or excavated and processed somewhere else,
Then we would need a suitable plant to extract the water. I suggest a low pressure, solar heated, and shade cooled fractional distillation process would be best.
So a lot of basic field science, engineering, and mineral processing research is needed before an operational system could be set up.