I’m currently running an RPG set in a world based on the classic Golden-Age science fiction of R.A. Heinlein, H. Beam Piper and others. It takes place in the year 2103, but the 2103 imagined in 1960 rather than the 2103 we expect. Men with slide-rules navigate atomic rockets on expeditions to scout strange new worlds for colonization under the aegis of the Solar Guard. I’ve taken pains to make the science and engineering as realistic as possible, with the exception of the frantic handwaving necessary for FTL, not to mention primitive computers in the 22nd century.
I’m maintaining a website that covers the basics of the game here. My in-person players are cast as officers of the Solar Guard exploration cruiser Avalon, while I have two remote players who respectively take the role of the Solar Guard’s secretly self-aware mainframe computer, Astrovac, and the leadership of a genocidal alien race called the “Chlor.” The first arc of the plot ended with a surprise orbital bombardment attack by the Chlor upon several peripheral human colony worlds. The current arc focuses on the crew’s assignments during the resultant war.
In keeping with my nature, I’ve worked up a topical analysis of Avalon’s engineering aspects, as well as a CAD model to illustrate the players’ home-away-from-home to them. The site also has some fun filk pieces very much in the space-opera spirit.
The system is pretty loose, with a very general basis in the mechanics of Sufficiently Advanced but with the scale brought down to a more human level and less dice rolling.