The Caldea IV orbital supply station was a supply station in Caldea IV's orbit used for passing Starfleet and Federation starships to beam supplies to without stopping at the colony, as it was so remote. It also served as a base for setting up the colony in its early days.
Twice, once between the colony's creation and 2372, and once in 2372, its isolation bay was used as an emergency shelter for Starfleet officers infected with Caldean Acute Cardiopulmonary Syndrome. (Star Trek: The Cantabrian Expeditions: "Isolation")