The Joint Polar Satellite System (JPSS) Data Products and Algorithms division is responsible for Calibration and Validation (Cal/Val) efforts for the NPOESS Preparatory Project (NPP). NPP Cal/Val plans continue to mature with the establishment of Cal/Val OPSCONs for the fourteen different discipline teams. These OPSCONs were rehearsed in a series of Cal/Val Rehearsals during the prelaunch Cal/Val campaign. This presentation will describe the execution of these Cal/Val Rehearsals and highlight key contributions to post-launch preparation and lessons learned.