The Ultra High Frequency Follow-On (UFO) system is a United States Department of Defense (DOD) program sponsored and operated by the U.S. Navy to provide communications for airborne, ship, submarine and ground forces. The UFO constellation replaced the U.S. DOD Fleet Satellite Communications System (FLTSATCOM) constellation and will consist of eleven satellites. The ground terminal segment consists of equipment and resident personnel at existing satellite communication stations. The spacecraft are controlled by the Naval Satellite Operations Center (NAVSOC) located at the Naval Air Station Point Mugu, CA.