Ultrahigh Frequency Follow-On
Communications Satellite System


The Ultra High Frequency Follow-On (commonly referred to as UFO) satellite system will be a nine satellite constellation for communications between U.S. Navy ships, submarines, aircraft, ground units, and global ground stations. UFO will replace the existing Fleet Satellite (FLTSAT) Communications System.

Each UFO satellite will possess 39 UHF communications channels (a 70 percent increase over Fleet Satellites).

The first UHF F/O was launched March 25, 1993. The Atlas II rocket booster malfunctioned, placing the spacecraft in a dangerously low orbit. After efforts by the 3rd Space Operations Squadron, Schriever AFB, Colo., the satellite was prevented from crashing back to Earth and was finally placed in a safe, though unusable, orbit.

The second UHF F/O satellite was launched September 3, 1993, and was successfully placed in its proper orbit, becoming the first fully operational spacecraft in a planned nine-satellite constellation. Seven additional satellites have been launched and placed in their proper orbits. The launch of the final satellite in the constellation is planned for summer 1999.

The 3rd Space Operations Squadron currently performs launch and early orbit and on-orbit operations. This includes mission planning, maneuvers, and contact support. Shortly after Flight 10 is operational, control of the constellation and all operations will be handed over to the Naval Space Operations Center at Pt. Mugu, Calif.


The satellites will be arranged in pairs in four different locations above the Earth for global coverage. The satellites will be launched at a rate of up to three per year. The Air Force Satellite Control Network (AFSCN) and the Navy Satellite Control Stations (NSCS) will provide telemetry, tracking, and commanding (TT&C) coverage.

Each satellite provides 39 channels for Ultra High Frequency (UHF) two-way communications, a Super High Frequency (SHF) anti-jam, command and tracking link and communication uplink for fleet broadcast over UHF, and uses S-band communications for the Space Ground Link Subsystem (SGLS). AFSCN TT&C. Flights 4-10 (Block II) also carry an Extremely High Frequency (EHF) package for secure, anti-jam communications, telemetry and commanding. Flights 8-10 (Block III) add a Global Broadcast Service (GBS) package for one-way, high data-rate communications in place of the SHF package.

The UFO satellite is built by Hughes Aircraft Company and is based on their modular bolt-together HS 601 design. Each satellite will have a projected orbital operational life of 14 years with an on-orbit storage life of four years. The satellite is designed to operate for 30 days without ground contact if necessary.

UHF F/O Specifications

Weight: 2,600 pounds
Orbital Altitude: Geosynchronous orbit - 22,250 miles
Power Plant: Two deployed three-panel solar array wings supplying approximately 2400 watts . In addition, a single 24-cell nickel-hydrogen (NiH2) battery provides power during eclipse operations (Block III satellites have two four-panel solar wings supplying approx. 3800 W and a 32-cell battery).
Dimensions: 9.5 feet high and 60.5 feet long
launch Vehicle: Atlas-Centaur space booster
Launch Site: Cape Canaveral Air Station, Fla.
Primary Contractor: Hughes Aircraft Company

(Current as of March 1999)

Ref: #39 - update: 23.10.01