When I was in Australia a few years ago, I bought the first book of the Greatwinter series. It was one of the best sci-fi books I've read. The characters are wonderfully complex and they exist in a future Australia that is original and exciting. When I got to the end and discovered that it was only one of a series, I started a long search for the second book, Mirrorsun Rising.
It took a long time, but it was worth the wait. Despite my plan to make it last, I read it through in one day, but definitely plan to reread it before sending it back through the interlibrary loan system. If you like sci-fi that doesn't require people to have learned the secrets of interstellar travel, this series is for you. I never felt cheated by having the action confined to terra firma.
I highly recommend trying to find this series. It's well worth the trouble.