Characters will have personal stories. I will be allowing players to customize them quite a bit, but I will also be offering exclusive roles for each and every one of them. Don't worry, I'm not looking to show favoritism; I simply want to make each character have motives, goals and different inclinations that can make the plot much more interesting. And everyone will have the opportunity to have a very different experience for their character compared to the others.
In relation to the previous idea, I want to incorporate an element of mystery and tension. This is especially where I may need some help, because I want to make each character have their own Google Doc page where myself, the GMs and that character's player can collaborate outside of the main thread. I don't aim to make this too cluttered, but I think that this can offer another layer to the RP that will incorporate a true feeling of mystery for the players.
Story progression. Remember how the Mass Effect trilogy allowed previous choices, side missions, etc. to play a role in the main storyline? That's pretty much what I meant when I mentioned it earlier. While I want to allow players to contribute and have their own ideas, I want the GMs to have a map of sorts that allows us to have goals in mind. This also ties in with the previous ideas as the characters' personal experiences can be changed as well. Think of it this way: rather than have a "nature versus nurture" debate on the style of roleplaying, I prefer to instead incorporate both nature and nurture. The whole RP will have it in place but it can expand as we go along. And characters always have the final say in which way to proceed - do they say yes or no?
While I understand we are not making a book, this is the advanced section. I want to have detail the vast amount of space that will be explored. There will definitely be more than one planet, perhaps there will be different races or aliens or perhaps it will only be humans. I have a number of ideas when it comes to that, but we'll worry about that later. The amount of information you will see in the OOC will gradually expand as your characters become increasingly involved in the exploration of the universe. This is another big reason I need help because my organization skills on forums are not as tidy as my Google Docs work. Formatting and editing will be a great help.