Since the 2nd Great War, The Terrans started to turn Command Centers into Orbital Commands to use several support powers to keep the economy growing. The Zerg Swarm though that if it infested the Orbital Commands, It will grant great benefits for Zerg Bases, Then the Swarm infested the Orbital Commands and lift them up to its bases immediately. However, The Infested Orbital Commands don't spawn Larvae like the original Hatchery, so the Swarm always deploys them nearby Hatcheries to activate its support powers.