Always hated it that a fleet of small units toasted your command base while you fought in a deep space war? Ever got rushed by nasty Klingons before you even got your yards ready? Then here is a solution for you!
You will be able to improve the offense and defense of your starbase in v3 with two upgrades. All races share the same upgrades to make it fair.

Improve the weapon systems of your starbase to deal increased ammounts of damage with every shot
Level 1: +20 Offensive Value
Level 2: +40 Offensive Value

Power up the defense of your starbase to make it less vulnerable to enemy fire
Level 1: +40 Defensive Value
Level 2: +80 Defensive Value

A Romulan Starbase with the upgrade option highlighted
Happy upgrading!