I had a discussion about SpaceMaster and Serenity some month ago. We agreed both, that it would be an interessting thing to play Serenity-setting with SM rules, because the system looks really weird. On the other side, I never played with the Serenity system and got some infos from a one-shot-team, about their feelings with the system.
finally I believe it would not be so hard to transform the setting into SM rules, but there will be one thing missing: The story-point-system of Serenity. Firefly/Serenity has its own kind of jokes, and I think it will be hard to play with them in a pure SM environment.
So I would like to give it a try, but I am not shure if it is the right way.
And finally you are right, shnar, the complete tech-setting has to be described.