The machine to end all machines — Towards self-replicating machines on the moon

We present the notion of a self-replicating machine for deployment on the Moon to leverage space colonization by exploiting its resources. The utility of self-replication cannot be understated - it offers the means to create an exponentially increasing general productive capacity on the Moon unconstrained by launch costs. Initially, we review the idea of physical self-replicating machines, emphasizing the universal constructor. The key to the universal construction mechanism necessary to realise self-replication is, we hypothesise, 3D printing. To date, 3D printing has been demonstrating its versatility in manufacturing structures, albeit of great sophistication. We briefly review 3D printing methods to date and suggest that fused deposition modeling and electron beam additive manufacturing offer a complete 3D printing capability suitable for deployment on the Moon. In our pursuit of a self-replicating machine, we have been working on 3D printing mechatronic components - electric motors, and to a lesser extent, electronics - as necessary steps to realizing 3D printing entire robotic machines in general (universal constructor) and 3D printers in particular (self-replicating machine). This 3D printer is essentially a core part of the payload for a rover vehicle which scours the lunar environment for the basic materials required for its own construction.