> Plus, I don't think that anyone has built an autonomous robot for zero-g yet (I'm not counting satellites and Canada-arm).
https://www.theverge.com/2017/7/17/15981250/japan-space-came...
"Japan’s space agency has for the first time released photos and videos taken on the International Space Station by its resident robot drone..."
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.
While I disagree with your benchmark, I don't think we're going to be putting robotic factories in space in 3-4 years. Have we even built a 100% robotic factory on earth yet? Plus, I don't think that anyone has built an autonomous robot for zero-g yet (I'm not counting satellites and Canada-arm).