I know I like a whole bunch of stuff and I want to list it down as inspirations I can turn to.
Top of the list has to be Newtons Wake: A space opera
Also must have Karl Shroder's Permanence and Virga series
Andrew S. Swann for his Moreau and Apotheosis series
The Long Run: A Tale of the Continuing Time by Daniel Keys Moran
Rama by Arthur C. Clark.
Allen Steele's Near Space series in particular Labyrinth of Night
Dan Simmons Cantos
Brin, David --- The Uplift series
Pohl, Frederick --- Gateway
A Deepness in the Sky by Vernor Vinge
Ok so what needs to be in the mix? I want a settled and civilized hub and "spokes" out from that hub which are fraught with danger. Passage either way will be prohibitive [this is a setting conceit to make the players stay out where the action is]. So travel to the frontiers is expensive - except if you win the Outbound lottery - and time consuming - I think its safe to say it requires cryo-sleep for a number of reasons.
I don't think we need to go to far off the farm. Just like D&D in its fantasy settings doesn't stray to far.
We have to have Earth - its a dystopia you know how everyone loves the imagery of Blade-runner? Well so do I, so that is more or less the way Earth looks. However there is a tether/beanstalk reaching down from orbit and connecting to:
Midway Station - this is earths major space side space port station. It accepts and launches most of the missions into Near Space which includes the moon.
Moonbase Alpha - This is the moons version of Midway there is also mining on the moon for Caesium oxide and Helium-3 but its also the new center of space transportation
Mars and Venus both have colonies.
Mars has a system of ruins of an ancient civilization the most notable of which is the Fallen Needle and the Queharg Temple complex. Hence tourism, research and archeology are important.
Venus has its Aerostats and cloud cities.
The Asteroid belt is a teaming boom town with the asteroids proving to be far richer then initially supposed
The Jovians have a civilization as well consisting of mining the gas giant and its moons
Next comes initial thoughts about space travel...