NaturalZero
Hero
I seem to remember plenty of the mods with futuristic stuff being released after the game came out.That point was prior to 1e. In 1e Gygax included those as options for the DM. He includes them as recommendations for other planes, but they don't exist as other planes by default.
Sci-fi was a basic theme employed by the creators of the game themselves. Only later did we have ironic claims that there was no place for it in the game.