No longer [is science fiction presenting] iron-jawed heroes blasting away at ugly, many-tentacled aliens in an attempt to save a screaming but beautiful heroine from a fate worse than. . . .  Well, sometimes we do still find that plot, but more often, young readers are being asked to look at an aspect of themselves and their own culture made more clear by its extrapolation into the science fiction future where it can be highlighted--for good or ill.

In the end, this is what good science fiction does.  The good science part, even when it relies on the "soft" sciences, provides a believable extrapolation; the good fiction part puts that extrapolation into a setting with characters and the rest that compel the reader's attention and, hopefully, consideration.  In the best sense, then, to paraphrase [Robert A.] Heinlein, science fiction is the literature that can best prepare readers for the future by exposing them to a variety of possible futures and by giving them some fictional experience in dealing with the new, the unusual, and the challenging.  Science fiction readers are the least likely to become "calcified adults."