I was thinking some aliens would be known, and some would be discovered as the story develops- but I was thinking more about privately operated space travel rather than a Star Trek style United Federation of Planets. I also think that the players should have their own ships, but crews aren't out of the question. I just assumed that each player would have multiple characters to be their "crew", if they had one. I'm not sure if this would work or not, but I appreciate all the interest!