Yes, it was possible but did not happen. Somebody(s) has to be the person/people that does it. Nuclear powered rocket engines existed in the 1960's, but little to no work has been done on that problem since then. If someone develops one in 2361, proclaiming, "not big deal, we could have done that four hundred years ago" is a bit silly.

Musk went to NASA's website back in 2000 or so looking for the man to Mars plans and found nothing so he started a rocket company to bring down launch costs by a factor of 100. Ten years later reuse of rockets is happening. Amazing isn't it. Let's see what the next twenty bring.

I just don't think that anything SpaceX or Tesla have done is science fiction material the way you wrote. They are really good at commercializing and streamlining existing ideas and they have the courage to do something first.

Why mentioning sci-fi can be a bit hyperbole, the fact is that rocket reusability was considered a pipe dream a decade ago. Nobody thought it could be done commercially. SpaceX sticked with it and prevailed in the face of all skepticism. It's just not "commercializing" and "streamlining" as you trivially dismissed

Science fiction is part of the spectrum of: Idea --> Actually Economically Viable Product. Your "existing ideas" is not very different from science fiction compared to the amount of work needed to get to viable product from existing ideas.