It is literally two things connected by a rope. A tether-based spun spacecraft is trivial from an engineering perspective, and can have as large a radius as you need to avoid differential “gravity” effects.
- What material are you making the rope out of? What data do we have of that material's behaviour under tension in a vacuum?
- How is the craft connected to the rope? Is it a fixed bond or is there freedom to move? What are the tradeoffs?
- What happens when one of the two ends is accelerated? How do you reestablish a stable rotation?
- How do you manoeuvre it? Can you?
- What happens in the event of a catastrophic failure of the rope? What safeguards need to be in place?
And this is all on top of the fact that we're discussing two things connected by a rope under conditions that rope has never been tested in, doing something that's never been done. Space exploration isn't in the habit of trusting that our untested models are reliable, especially where human life is involved.
- What material are you making the rope out of? What data do we have of that material's behaviour under tension in a vacuum?
- How is the craft connected to the rope? Is it a fixed bond or is there freedom to move? What are the tradeoffs?
- What happens when one of the two ends is accelerated? How do you reestablish a stable rotation?
- How do you manoeuvre it? Can you?
- What happens in the event of a catastrophic failure of the rope? What safeguards need to be in place?
And this is all on top of the fact that we're discussing two things connected by a rope under conditions that rope has never been tested in, doing something that's never been done. Space exploration isn't in the habit of trusting that our untested models are reliable, especially where human life is involved.