Space Opera and Military SF

Anybody know of any space opera operas? I know there are a few science fiction operas (Offenbach's "Tales of Hoffman", Janacek's "Vec Makropulos", Machover's "VALIS"), but I don't know of any that could be called space opera.

I know it's a silly question. But I've learned that our world is so crazy that sometimes all you need to do is dream of something awesome and you'll find out it already exists. And I like opera and I like space opera, so... it seems a natural combination.