UFO (UHF Follow-On) satellites are a new generation of United States Navy ultra-high-frequency communications satellites in geostationary orbits designed to replace the FLTSATCOM (Fleet Satellite Communications) and Leasat systems. They are bigger, more powerful, and have more channels than their predecessors but are compatible with the same terminals on the ground. UFO 4 to 9 carry an EHF (extremely high frequency) communications payload that enables the UHF (ultrahigh frequency) network to connect to the Milstar system. UFO 8 to 10 also carry a payload called the Global Broadcast Service which can relay reconnaissance images and other data to a greater number of users at higher rates than any previous defense satellite. With the launch of the tenth satellite in November 1999 the UFO constellation was completed. It is controlled from the Naval Satellite Operations Center (NAVSOC) at Point Mugu, California.