Building large space stations in space would be a huge challenge and it would have to be done differently to the way we build things now. You couldn’t build the components on earth and send them into orbit as we have done with the ISS. In a high technology factory there is a production line of machines and robots that are relatively fixed in place and the construction of something like car progresses as the chassis moves through different workstations. In space the robots that build the space station will have to be able to move independently and in concert with other robots. They would need to process metal structures, cut and bend the steel and weld the parts together, effectively in zero gravity. One of the most important things would be to be able to mine ores and refine the metals in the space environment into suitable alloys. It would all have to be solar powered with solar collector satellites and the coordination of the robotics could only be through software and control systems. Some of the fiddly work would need to be done by humans, so the design to keep as much as possible of the construction work in space so that it could be done by robots would be important.
In such a construction environment a moon base would be where the robots could be maintained and repaired by people and easily returned back to the construction site in space. Some of the finer components for the space station – or perhaps even for a large spaceship the size of a naval vessel for a trip to Mars – could also be fashioned in factories on earth so that they can be put in place on a space construction site by robots. The robots would be specialised machines that could be moved around on the construction site and they would not be anything as functional as humanoid Hollywood robots. There is nothing new about these kinds of ideas, plenty of people have thought about this kind of thing already.