In practical terms the rotating space station makes little sense--in today's terms. If you choose to be in a 1 g environment and be comfortable(no nausea, side effects, or adaptations) The station needs to be -at minimum--about 750 ft in radius. That's almost 2 revolutions per minute at a speed of around 105 mph. 1 rotation per minute makes the ring 2900+ ft in radius at 209 mph. And to get really comfortable at 1/2 rotation per minute the darn thing needs to be 11,735 ft in radius and rotating at 418 mph! On top of that the whole thing needs to be balanced! That includes the folks on board moving around. Technically it's well within our grasp but financially and just from a practical point of view it's a pipe dream! It would have to be a robust /heavy structure. Just rotating it to those speeds would put tremendous stress on the structure--although this could be done slowly.Plus the whole thing will want to fly apart. A ring solves this problem somewhat from a structural point of view A spoked structure,( no ring) presents it's own set of problems and minimizes usable space. The simple task of lofting all this weight into space at several hundreds of thousands of dollars/lbs and then assembly makes it a fantasy! Once you did get it built , just maneuvering the giant gyroscope would be interesting at best. Having tethered habitats has it's own set of problems on top of the ones already mentioned. Yea, I guess until we learn to manipulate gravity or at best design a ship that can accelerate at somewhere near 1 g( by the way, you have to decelerate at 1 g when you get where your going) we are stuck with what we have. But, it's cool to think about!