USA 339, also known by its object ID 2022-144B and NORAD catalog ID 54220, is a US satellite configured as a Propulsive ESPA launched on November 1, 2022, from Launch Complex 39A at Cape Canaveral Air Force Station using the Falcon Heavy launch vehicle. The satellite has dimensions of 0.6 meters in length, 1.6 meters in diameter, and spans 3.6 meters when its deployable solar arrays are extended. It has a dry mass of 500 kilograms and was launched with the same mass. Its mission is to demonstrate technology for shepherd operations. The satellite's shape is described as box-shaped with panels, and it operates on power supplied by a deployable solar array and batteries. The ownership of USA 339 is attributed to SFSSC (Space Force Space Systems Command).