UHF Follow-On (satellite)
UHF Follow-On (UFO) satellites are a system for U.S. military tactical users, replacing the United States Navy's Fleet Satellite Communications (FLTSATCOM) and the Hughes-built Leasat spacecraft. These, in turn, are to be replaced by the UFO-compatible Mobile User Objective System (satellite). They are in geosynchronous orbit.
These satellites, operating in the UHF frequency band, provide service characterized as narrowband (i.e., low data rate), although UFO gives more bandwidth than FLTSATCOM, and MUOS will give more bandwidth than UFO. The advantage of UHF satellites is that they lend themselves to direct broadcast to end users, rather than requiring complex earth stations from which information must flow over terrestrial networks. Later models carry a one-way transponder for the Global Broadcast Service (GBS), another broadcast application.
UFO satellites are derived from the Boeing (formerly Hughes) model 601 commercial communications satellite.