A little closer, I wonder how far we are from making something a little more mundane like a Babylon 5 spinning habitat, or even a 2001 spinning wheel station. Are these just a matter of money, or is there some other fundamental technology challenges to getting those things built?
I bet future Asteroid miners wouldn't mind a cheap place (relative to going down then up a planetary gravity well) to R&R between digs.
Depends what you mean by "just a matter of money".
If you could enslave the entire population of Earth to work full-time on the project for a couple of decades or so then, yeah, you could do it easily. In a world of free will and competing priorities I don't think it'll be possible until we reduce our cost-to-orbit. Certainly there are no big technological show-stoppers though.
As a vague guesstimate, I've read 1km proposed as a minimum viable radius for one of these things. So you'll need a rim about 6km long. The International Space Station is about 100m long, so if you staple sixty of those end-to-end you'd have a minimum-viable 1g station, at a cost of about six trillion bucks. But of course it would basically just be a thin tube, not much living space.
As for asteroid miners: I can't possibly imagine that this is the sort of thing that we're ever going to send humans rather than robots to do.
Well in an age of $19billion chat app acquisitions, $6 trillion ain't what it used to be. That's only a one time cost of 8% of the Gross World Product. Spread that over a 20 year construction time-frame and that's $300billion per year globally.
Something of that scale could reasonably be covered if the U.S., Europe and China/Korea/Japan all agree to Iraq War level spending each for that time period.
I've wondered the same - why don't we make artificial gravity up there? The best answer I can find is experts saying, "What's the point, after all the trouble of getting to space?"
The point is, living in zero-g is destructive to humans. Living in even 1/3 g makes a lot of things a lot better ... and a space station with a zero-g part as well as a small-g part would have the best of both worlds.
I bet future Asteroid miners wouldn't mind a cheap place (relative to going down then up a planetary gravity well) to R&R between digs.