STARS Clusters were groups of 4-12 Stealth Tactical Aerial Reconnaissance Satellites and Defense satellites. The Remsian Republic used them to observe systems that they didn't have large presences in. One example was Cluster J4DE in the Alf System which contained 12 Stars and 12 Defense Satellites. The clusters were capable of tracking any and all ships within the system and space around it, and had hyperspace sensors as well. They also acted as relays for the TemplarNet.