The USA 397 satellite, also known by its object ID 2024-134B and NORAD catalog ID 60323, was launched on July 30, 2024, from the Space Launch Complex 41 at Cape Canaveral Air Force Station using an Atlas V 551 launch vehicle. The satellite has a length of 7 meters, a diameter of 2.5 meters, and a span of 35 meters. It had a launch mass of 3200 kg and a dry mass of 2800 kg. The satellite is owned by the Space Force Space Systems Command (SFSSC) and was manufactured in an unknown facility in the United States under the code name UNKUS. Its payload is identified as USSF-51 PL2, but its specific mission, purpose, equipment, motor type, and power source remain undisclosed.