Let's be honest here: When most of us think of space operas, we're really thinking of Star Wars. And with good cause! Star Wars took the oft-maligned genre of the space opera - essentially, an adventurous melodrama in set in outer space and/or on distant planets - and found just the right way to take it seriously. George Lucas took the fantastical locales, costumes and weapons from the old Flash Gordon serials and filtered them through World War II "men on a mission" films (complete with space Nazis), epic samurai dramas and Western fantasy tropes to create a world that was both alien and lived in. You can really believe in the world of Star Wars. That's why it endures to this day.
Source : IGN.com