But that factory won't do any good unless it gets input, and can put its output somewhere. The input would supposedly be from the local regolith which has a lo

But that factory won't do any good unless it gets input, and can put its output somewhere. The input would supposedly be from the local regolith which has a lot of the same problems that the example roomba would face. Now a factory on Mars that takes in sunlight and atmosphere, and fills a tank with rocket fuel, could be possible. But in that case I would call it a specialized machine, not a factory or a robot.