Are there any fantasy/sci-fi stories written since 1950 that assume Einstein's theory of Relativity is wrong?

What I mean here is that we could travel to the speed of light, and faster than the speed of light, with nothing much very exciting happening, at all. So, perhaps using a nuclear fusion pulse powered spacecraft, we would accelerate by simple Newtonian mechanics up to the speed of light, then, perhaps to five or ten times the speed of light, and reach some of the many earth-like planets we now know with near-certainty exist in accessible solar systems not too far from our own. Now I know the physicists will cry foul here. After all, we all know it's impossible to travel faster than the speed of light. After all, we have laboratory particle accelerator experiments consistent with relativity; possibly artifactual, but, we have them. We have GPS. It's done empirically, but, some aspects of it do seem consistent with Relativity theory. Still, this is fantasy fiction, you know. Surely, it would possible to consider the possibility that Einstein was wrong, in fantasy? And, the implications might be quite interesting from a sociological point of view. All kinds of human civilizations spread throughout the stars and communicating or trading with each other using nuclear powered spaceships. Now, I know we do have the speculated possibility of wormholes, warp drives or even black holes facilitating time travel, faster than light travel and travel to other universes in good old Relativity Theory. It's just, somehow, we don't seem to be making much real progress in those directions, despite the best efforts of the physicists. So, I was wondering if there are any fantasy/sci-fi stories that consider putting Einstein aside, for the moment, just for speculative purposes.