Quote:how much disk space
For reference.
I have a solo game going right now. It has multiple avatars in multiple home solar systems, not all in the same sector because startup works just like online. One avatar has built a civilization that can manufacture spacecraft, enough to play through the entire Relic story, which ends at a ringworld.
The game save file is 165MB. It doesn't take long to load the saved game. Interstellar travel is fairly quick with no server hand offs, just the time needed to generate new systems as they are explored.
For the most part, it feels like I am playing the mmo but nobody is here except me and there is no network latency.
Systems in the solo game do not decay (I think).