Lockheed Martin's fifth Mobile User Objective System (MUOS-5) satellite is now providing secure, beyond-line-of-sight communications to the US military legacy ultra-high frequency (UHF) radios, the company announced on 24 April.

Working with the US Strategic Command, the US Navy configured one of MUOS-5's two communications payloads to provide additional support for its legacy UHF satellite communications mission. Narrowband UHF communications is used by every combatant command in aircraft, ships, submarines, ground vehicles, as well as by troops in the field and special operations.

Legacy narrowband UHF communications will eventually transition to next-generation Wideband Code Division Multiple Access(WCDMA) capabilities provided by MUOS. To facilitate that transition, MUOS was intentionally designed with two communications payloads, with each satellite able to simultaneously support both new WCDMA waveform capabilities and legacy UHF satellite communications.

MUOS-5 is the latest addition to a network of satellites and relay ground stations that is upgrading communications for mobile forces. Users with new MUOS terminals will be able to connect beyond line-of-sight and into the global information grid, as well as into the defence switched network. MUOS provides simultaneous, crystal-clear voice, video and mission data over a secure high-speed Internet Protocol-based system.

Over 55,000 currently fielded radio terminals can be upgraded to be MUOS-compatible via a software upgrade.

Once fully operational, MUOS will provide users with over ten times the communications capacity of the legacy system it will replace.