“3D printing offers a potential means of facilitating lunar settlement with reduced logistics from Earth.” -Scott Hovland of ESA’s human spaceflight team.
Phase One: Survivable. This addresses the basics needed to allow a small crew to survive on the Moon, like living quarters.
Phase Two: Sustainable. This sees the Moon base being expanded to include more crew quarters, fabrication areas, and research facilities.
Phase Three: Operational. In this phase, the Moon base is fully operational and built for long-term habitation.
3D Bio-Printing
"We’re asking what astronauts would need in the short, medium and long term, and what steps are needed to mature 3D bioprinting to a level where it can be useful in space." - Tommaso Ghidini, head of ESA’s Structures, Mechanisms and Materials Division.
Moon Base Enthusiasm
Sources:
ESA Press Release: Future Moon Base
ESA Press Release: Pangaea-X Moon base
ESA Press Release: 3D Printing Skin, Bone, and Body Parts Under Study for Future Astronauts
ESA Press Release: Building a Lunar Base With 3D Printing