I have been itching to run a Mars campaign since I read the Barsoom books a few years back in my quest to learn more about D&D's literary roots, and I have been wanting to run a Traveller campaign for some time. I am loving the idea of a campaign set in an alternate 1990 or so, 4 years after the first manned Mars mission revealed vast underground complexes left behind (apparently) by an ancient Martian civilization. I want to hork Travellers character generation mini-game (modified for alternate history 1980's, obviously) but use modded B/X D&D for the ruleset. Setting it in 1990 would mean that the Soviet Union was still there, and I would propose that the alternate history would provide a new space race that would keep the Soviet Union together. Gawd I am getting excited about this! Megadungeon meets Mars meets Traveller meets Cold War!
I love this level of tech for a sci-fi space game. I could use our real life tech levels of the campaign years, with the internet being a rich and never ending resource in that regard.
I am not 100% sure if I am going to abandon the sci-fi fantasy Polynesian Islander-analog campaign that I have been working on or possibly try to do both, but I am definitely going to be putting some more thought into this idea.