I'm guessing the casing would have to be hefty stuff and a lot of it to hold in all that mass under ~0.3g of outward centrifugal acceleration. Of course you mi

I'm guessing the casing would have to be hefty stuff and a lot of it to hold in all that mass under ~0.3g of outward centrifugal acceleration. Of course you might be able to do some stuff internally as you hollowed out the thing too like perfuse it with high tension wires kind of like steel reinforced concrete, but it seems like a huge job at least on par with building giant space stations. Still you might be onto something with the radiation shielding.