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Comment by drzaiusapelord | Hacker News Reader

I wonder if these water deposits are near craters that are in permanent shadow and always below freezing. You could send a relatively small robotic setup that would melt the deep ice into water and use it to form structures on the crater. Now you have a permanent moonbase without bringing in tons of material via rockets.

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The craters full of permanent shadow are at lunar poles and we had already discovered water in one of them[1]. This discovery is that there is probably a lot more water in other places on the moon, but probably far under ground if it hasn't boiled off during the harsh lunar day.

[1]https://www.space.com/16222-moon-water-ice-shackleton-crater...

It would be a far better use of the water to save it for life support or crack it into hydrogen and oxygen. Regolith can be used to create structures without having to haul everything up out of Earth's gravity well. It's also chock full of aluminum, so that would be easy to make with a nuclear or solar smelter. But water would never be used as a structural material, that would be a tremendous waste.

...until you try to heat it to a reasonable temperature, the walls melt, and all your atmosphere off gases in to space.

Water is a pretty useful resource. It is also more weight to bring into space. Having it already available at a location would be tremendously helpful. Using that water to build space igloos would appear to be a poor use of a valuable resource.

You'd have to lay insulation against the ice so you can have a warmer interior, but that's still a pretty good mass savings. You'd use ice for the heavy structural elements and then only lift the lighter stuff.

The more pressure you put on ice, the more it wants to turn into liquid. So your "heavy structural elements" can't be bearing too much weight.

On the moon, it could bear six times the mass it would bear on Earth.

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