Today I saw an RPGNet inquiry on how "epic space opera" can work in BRP. A very general inquiry, and while I am interested in the subject I fear I might have been very little help. The only thought I had was adapting some of the rules material in BRP Mecha to fighting space vehicles.

Even that would probably only work on the scale of small ships -- something like the Millennium Falcon would probably be the top end of the scale. The roleplaying paradigm breaks down a bit the bigger the ships and crews get. If you're playing Honor Harrington and commanding a ship or a fleet, the GM has to find stuff for the other players to do. And the Enterprise-D, with a crew of more than a thousand, would have very little for most of them to do in a big fight. (Mind you, there are many, many types of adventures you can have on an exploration/war ship, but if you want to be important in a big starship battle there are only a few things you can be.)

But some things in the genre are still doable as well. A lot of characters in the d100 multiverse are alien -- many of them very alien -- so it shouldn't be too hard to populate a universe with weird and wonderful critters. Or even move some around a bit (Dragonewts in space, anyone?).