I am starting to work on getting persistent planets and caves. Right now, planets will reload correctly, but things are "reset" each time you visit.
For starters, I want to get any caches and aliens to maintain their attributes between visits. Items stored in a cache will be there the next time you come back. Quests offered by an alien will stay the same on each visit, just like on the mothership.
This will motivate the player to return to previously visited locations, and maybe set the stage for making a type of Home Base on different worlds.