The Mobile User Objective System (MUOS) is an United States narrowband military communications satellite system that supports a worldwide, multi-service population of users in the ultra high frequency (UHF) band. The system provides increased communications capabilities to newer, smaller terminals while still supporting interoperability with legacy terminals. MUOS is designed to support users who require greater mobility, higher bit rates and improved operational availability. The MUOS was declared fully operational for use in 2019.
The Mobile User Objective System (MUOS), through a constellation of five satellites (four operational satellites and one on-orbit spare), provides global narrowband connectivity to terminals, platforms, tactical operators and operations centers. The system replaces the slower and less mobile 1990s-era Ultra High Frequency Follow-On (UFO) satellite communication system. MUOS primarily serves the United States Department of Defense (DoD) and international allies use is under consideration. Primarily for mobile users (e.g. aerial and maritime platforms, ground vehicles, and dismounted soldiers), MUOS extend users’ voice, data, and video communications beyond their lines-of-sight at data rates up to 384 kbit/s.
The U.S. Navy’s Communications Satellite Program Office (PMW 146) of the Program Executive Office (PEO) for Space Systems in San Diego, is lead developer for the MUOS program. Lockheed Martin Space is the prime system contractor and satellite designer for MUOS under U.S. Navy Contract N00039-04-C-2009, which was announced on 24 September 2004. Key subcontractors include General Dynamics Mission Systems (Ground Transport architecture), Boeing (Legacy UFO and portions of the WCDMA payload) and Harris (deployable mesh reflectors). The program delivered five satellites, four ground stations, and a terrestrial transport network at a cost of US$7.34 billion.
Each satellite in the MUOS constellation carries two payloads: a legacy communications payload to maintain Department of Defense narrowband communications during the transition to MUOS, and the advanced MUOS Wideband Code Division Multiple Access (WCDMA) capability, according to NAVWAR.