they’d put down an initial layer of moon dust and rocks in the shape of whatever they’re trying to build—say, the walls of a lunar habitat—then use a purpose-bu

they’d put down an initial layer of moon dust and rocks in the shape of whatever they’re trying to build—say, the walls of a lunar habitat—then use a purpose-built laser to melt the regolith so that it would be permanently stuck together. Once the first layer solidified, they’d add another; it’s not so different from the way their 3D printers work on Earth.