Scifi is so rarely done well in anime (trending towards rom-com and dramedies).
Still, some good generic scifi: Armitage, Birdy, Pychopass, Redline, Parasite Dolls, Bubblegum Crisis, Kiddy Grade, Soul Link, Code Geass, Jyu Oh Sei
Spacier fare (dunno about "opera"): Tenchi GXP, Banner of the Stars, Captain Tylor, Glass Fleet, Heroic Age, Nadesico, Vandread, Gundam (I like Wing, 0083, 8th MS Team, X, and Seed), and Macross (some of the newer fare, although Plus is also good).
You mileage may vary, I liked most of these.
EDIT: http://www.anime-planet.com/tags/outer-space/anime