As I said I've been fiddling around with Traveller and trying to adapt it to a dieselpunk setting. As a side note I was also wondering about how far I could take the Mongoose Traveller system. Could you for example run a supers game with it?
The answer after a little thought is a cautious yes. No new rules needed in fact. Think about it. three possible origins for supers can already be handled with the RAW: power armor, cybernetics, and psionics for starters. Add to this the rules for creating aliens and you have genetic experiments as well. depending on what tech level you set the supers' tech to they could be gritty street level types or world beaters (assuming most of the world is TL 7.) Instead of the tech tree becoming a timeline it would become a measure of an individual's brilliance (maybe TL = Intelligence as a rough guide.)
Supers would be less freak accidents (although I guess some mutants and spontaneous psi's could creep in) and more national or corporate created. Captured or discovered alien tech could also play a part in 'unplanned' supers. A base tech level for supers of TL 10 works well to create people who are pretty tough but not impossible to kill (God didn't make all men equal, the RAM grenade launcher did.)
If I actually got you thinking about using Mongoose Traveller to run a supers game you might find the following supplements useful: Supplement 5-6: Vehicles (everyone wants to build a helicarrier), Supplement 4: Central Supply Catalogue, and Attack Squadron Roswell (excellent look at additional effects for grav drives: forcefields, invisibility etc. plus alien adversaries.) I haven't gotten Psion yet but that probably bears looking at as well.