Starbase Builder
Rare6.6%ObjectiveOptionalAnywhere
Have at least 10 starbases in a single game.
Each gravity well can only have one starbase, so you'll need to colonise at least 10 places to be able to build 10 starbases. They are very heavily upgradable with offensive, defensive and civilian capabilities - to the point they almost act as a whole 2nd colony in the well.
Any medium or larger game should be pretty easy to build 10 starbases.