Outpost Outposts are designed as depots for deep-space exploratory starships. As such, they help increase the range of starships. While outposts can aid in a solar system's defense, they are not intended to counter attacks on their own. One troop transport is expended to build an outpost.
Starbase Starbases are large space stations that repair starships, have long range scanners, enhance a starships range, and add significant defensive capacity to a solar system against attacks. A starbase also enhances the rate of repair to damaged starships docked there. One troop transport and outpost is expended to build a starbase.