>>374
>I don't know much about the pioneers or well established authors of the genre.
This is going to sound weird, but Tolkien was an inflection point for science-fiction just as he was for fantasy. Much like in the fantasy genre, authors before Tolkien focused on exploring an idea or making a point rather than building an open world just for the sake of doing it. So bear in mind that those pioneers were nothing like 40k or really any of the modern sci-fi franchises, which have more in common with Tolkien than with Phillip K. Dick and such.
H. G. Wells is a good starting point, I read almost a third of his bibliography when I was in high school and from what I remember, I liked his earlier work from "The Time Machine" to "Kipps", his later stuff was badly written, preachy
and so optimistic and utopian that I couldn't take it seriously. I think it is completely valid to prefer modern, Tolkien influenced sci-fi over the old guys, so don't feel obligated to read Asimov or Wells if you don't like them.