If you like BRP, like I do, then you might want to consider the fan made publication New Horizon. It provides detailed rules as well as a setting for playing science fiction in a world most like that in Blade Runner or Total Recall. I haven't studied it in depth but the only thing it seems to lack are rules for creating starships (Use M-SPACE for that). Instead it just list a few ships and their stats. You can find it at https://gitlab.com/NHcthulhu/NewHorizon