It is a fairly undisputed fact that the genre of western fiction has had a declining audience for decades. The Western Writers Association still exists, but if I had never worked in a Border bookstore I wouldn't even know that the genre was still stocked (on an area spanning maybe 2 shelves?) in bookstores. A magazine which tried to focus on the genre and bring it back into more prominence in the 2000s folded after just two issues. The western's appeal - based in television and the cultural ethos of the time - seems to have faded.
Will the same thing ever happen to science fiction? For example in the United States the space shuttle program has ended. Does this mean the end of space-focused novels? Will the genre change to focus on new developments in science or even fade from the popular consciousness? Or is there something different about science fiction's appeal from the appeal of the western, something that makes it more like romance?