One should make one with centrifugal gravity, so that one can test out how good it works, if the materials are holding, how much energy/rocket-fuel it takes to keep it spinning, if the crew likes it, and so on. It cant be a full-circle "donut" Kubrick-style perhaps, but a solution where forexample the living-quarters are hanging in the end of one cable, and the television-room and exercise-room is hanging from the other shouldnt be to difficult. (The cables must be hollow so that one can walk from the one to the other without taking a EVA offcourse, storagerooms in the midle) Also, making such a space-station would give a feeling of progress that might boost fundings for NASA, ESA and the rest. The ISS is kind of boring, just a bigger version of MIR. I have heard that they where not intrested in making a centrifugal spacestation when they made MIR because they wanted to do cero-gravity experiments, but when they are done it might be possible to re-arrange it into a centrifugal one. Does annyone know if there are anny plans for a centrifugal spacestation?