Science fiction has both no role in promoting science and [yet] it often serves as a de facto introduction to science for the general public. For writers, I think it’s very rare for promoting science to even be considered when wrting sci-fi... In the case of science fiction movies and TV, I think that harm often results. Most of the general public wouldn’t consider the various CSI shows as science fiction, but that’s exactly what they are. One consequence is that people serving on juries often expect more than is actually possible from prosecutors and have little understanding of important details and caveats of scientific evidence – so, our legal system is suffering due to missunderstandings that often originate from TV shows.
Most science fiction is, from my limited and biased perspective, fantasy with chrome.
I don’t need my science fiction to be so-called “hard” science fiction. I just need it not to be blatantly stupid or fantasy without clearly being fantasy. I mean, too many space-based science fiction stories ignore the laws of physics, and common sense, as it is.... As for the harm, well, there has been a lot of discussion about that, too, following Buzz Aldrin’s comments that unrealistic and unscientific science fiction has dampened interest in the space program. I don’t think his case is overwhelming, but I agree that science fiction has an effect and it isn’t always positive, at least to the public at large that isn’t already a fan of science and discovery.
I don't think science fiction is particularly good at promoting science. (One word: Frankenstein.) An awful lot of science fiction seems to reveal a fear of the unknown, a fear of tampering with nature or with going too far in trying to understand something... Whether it harms the cause of science... well, honestly, I don't think that science should be a cause, really. Science is a sort of organized curiosity about the natural world, and it's sad to live amongst people who are uncurious and afraid of learning new things.