I do not think that there is even a small possibility to find some ice sheets on the moon (tought I'll be very happy to be wrong).Aero wrote:As for using a heated drill, as put forth by Giorgio above, yes, that could work if we find ice sheets under the surface that are not very deep.
In reality we will be happy if the concentration of water in the moon regolith is few part per thousand...
In case water is indeed found in much bigger quantities than few part per thousand (say 5-10 %) but deep in the ground, than one of the way to exctract it would be drill some holes in the ground and inject (or induce) heath in the underground to recover the volatile steam. In vacuum the boiling point of water is around -60C if I remeber correctly.
In case the water is evenly mixed with the moon regolith on the surface or immediate sub-surface, than a processing machine that exctract water in a batch or continuos process can be easyly designed. Just imagine a big boiler that you fill with moon regolith, add heath to it, recover volatile water and discharge it for the next batch.
If, in the worst possible scenario, the water is mixed with the moon regolith in few part per thousand and only deep in the ground, than it might not be economical at all to process it to recover it.
Needless to say that the ideas above are just examples and extreme exemplifications of how a real system to exctract water from the moon regolith might work.