3-D printing may be more advanced than I had thought:
I am a little bit skeptical. For example, how does the optical scanner determine the dimensions and configuration of individual internal parts, for which there is no line of sight? That is not explained in the video, though perhaps it’s a simplification for the casual viewer.
Nonetheless, what a great technology for off-world travel. No need for spare parts. Of course, you need a feed stock for the process that will meet the specifications for the end product, and it helps if that feedstock can be manufactured at your destination. We already know that we can make breathing air and rocket propellant from elements readily available on Mars, so why not other compounds?