Starships & Spacemen (via RPGNow.com) that is. This was one of the earliest SF roleplaying games, and I remember enjoying the heck out of it with my brothers and sister. It was basically an unlicensed Star Trek game, with the PCs serving as crew on a “Confederation” starship. Classes represented various branches of the service, and there were various races that were analogs of the races of Star Trek: the logical emotionless Taurans, the telepathic Andromedans, the space-mercenary Rigelians, or the boring old Humans.
I was tempted to pick up Space Opera while I was at it, but my recollection of that was that it was so complex that by the time we had finished rolling up characters we had pretty much exhausted our interest in the game. I think we made it through a couple of sessions before giving up and going back to Traveller.