PDRS was a department, division, or position within Starfleet's Fleet Operations Center on Earth.
In January of 2155, Starfleet officers T. Scott, G. Agalsoff, and D. Baker worked in (or as) PDRS. (ENT: "Demons" set artwork)
PDRS was seen on directory listings seen on the set of "Demons".
, like many of the other divisions, departments, or positions on the listing, is a reference to NASA
terminology, in this case, the "Payload Deployment and Retrieval System".