>3D printing up a robot smelter that collects iron from dust in the wind, and spits out I-beams that are a special Martian alloy that makes shipping them back t

>3D printing up a robot smelter that collects iron from dust in the wind, and spits out I-beams that are a special Martian alloy that makes shipping them back to Earth via a railgun cost effective Just picturing this is great, sounds like a winning proposal to me.