yes, the Robinson Mars trilogy really set the pace for serious hard science fiction novels about terraforming. I like LeGuin as well, I notice some of the 'hard science' folks don't. When I read Leguin, I have to put on a different hat so to speak, and read it differently than I would read say Larry Niven, or Poul Anderson. Her works set in that fantastic future universe, seem to touch the fringes of fantasy.