I know theres some really tantalizing ideas about using metal 3d printers which melt powdered metal with a laser in space. By varying the composition of the pow

I know theres some really tantalizing ideas about using metal 3d printers which melt powdered metal with a laser in space. By varying the composition of the powders, it's possible to make pieces which are gradient alloys- Imagine a pipe thats copper at one end, silver in the middle and gold on the other. Opens up a lot of possibilities for mining asteroids.