Rather than a one off mission, why isn't NASA operating a permanent base there along those lines? Locate it reasonably close to mcmurdo so they can get help in

Rather than a one off mission, why isn't NASA operating a permanent base there along those lines? Locate it reasonably close to mcmurdo so they can get help in an emergency. I realize we have the ISS but there's probably still a lot to be learned about keeping a fully self contained system running in a hostile environment.