athomasflynn t1_j2egtpu wrote on December 31, 2022 at 5:40 PM

Reply to comment by MyTurntableAccount in Want to Build Structures on the Moon? Just Blast the Regolith With Microwaves - Microwaves are useful for more than just heating up leftovers. They can also make landing pads on other worlds - Universe Today by vibrunazo

I completely agree. I thought about it for the first time 5 or 6 years ago when they were talking about 3D printing habs. I had a giant 3D printer (100x100x150cm) that I would run nylon through and it used more power than the rest of the building it was in. I couldn't see the practicality of 3D printing with local materials in an environment where energy efficiency was key. It didn't make sense. But if the energy was essentially free, instead of 3D printing they could essentially build a solar powered CNC machine.

Living underground makes more sense anyway. They need all the radiation shielding that they can get. Put the water supply on the roof above the living spaces and they'd be even safer.

There's a reason Musk started his boring company.

greenmachine11235 t1_j2eimzz wrote on December 31, 2022 at 5:52 PM

The benefits of 3d printing is you can take raw materials to orbit and create a structure that couldn't exist in 1g conditions with no or little waste. CNC milling creates lots of waste as shavings and chips that are hard to reform into usable materials.

athomasflynn t1_j2eks2s wrote on December 31, 2022 at 6:06 PM

You're missing the point.

The RFP was for 3D printing ground based habitats. Nothing that NASA or the ESA has actually pushed forward in terms of habitats involved 3D printing in low g. The competitions that they actually spent money on were for surface structures.

We're not talking about an actual CNC. The "wasted material" you're talking about is vaporized lunar rock. There's plenty to go around and you get a couple orders of magnitude more volume for your energy input by cutting down into it rather than building up with it. And that's before you even run the math on radiation shielding. Nobody is living off Earth without several meters of mass between them and the outside for any length of time any time soon

I like 3D printing, I've spent half a million on it over the last 10 years or so, but it's overhyped and it gets dropped in as a magic solution for every problem these days.