If we're ever going to colonize space or even do automated manufacturing in space on any scale we need to build a system which can manufacture "anything" that can be sent in a small number of launches and watched over by just a few people.

Eric Drexler's "assembler" concept has been stuck for the last 25 years, but biological systems are a good model because if they can build you out of a cell they could build just about anything else out of a cell. This kind of mycelium network is running fast compared to the neurons in your brain.