There's a great interview with my buddy Carleton Eastlake over at The Write Blog, talking about his experiences writing & producing shows like BURNING ZONE, SEAQUEST, FARSCAPE, and OUTER LIMITS. He says, in part:
I think good science fiction and fantasy, because they break some or many of the rules of the real world, require that the rules of the imagined world be interesting and consistently applied. So much more attention needs to be paid to the mythology.
At the same time, there’s more room, if done in a credible way, to keep things fresh by evolving those rules, making new discoveries…here come The Borg with all sorts of new moral and psychological issues – and very different spacecraft!
On the other hand, it’s a little harder to keep the dramatic, psychological side of a science-fiction show compelling. It’s easier to ignore those concerns or be distracted from them. But if the show is consistent about its rules, then the character side of the show can absolutely work. Crichton and Aeryn on Farscape were very much in love and very much troubled by the moral conflict between running away and having a life, or staying and fighting to save their societies.
It’s also important in a science fiction show that the plot issue of the day be motivated by the implications of the world the show is set in. Attempts to do actual medical or criminal or legal procedural shows in a science fiction setting are very, very hard to pull off – the science fiction side undermines the credibility of the procedural issue, and the procedural issue rarely delivers on the magic and wonder of the setting.