The Mobile User Objective System (MUOS) is a

United States Space Force The United States Space Force (USSF) is the space service branch of the U.S. Armed Forces, one of the eight U.S. uniformed services, and the world's only independent space force. Along with its sister branch, the U.S. Air Force, the Spa ...

narrowband Narrowband signals are signals that occupy a narrow range of frequencies or that have a small fractional bandwidth. In the audio spectrum, narrowband sounds are sounds that occupy a narrow range of frequencies. In telephony, narrowband is usu ...

military A military, also known collectively as armed forces, is a heavily armed, highly organized force primarily intended for warfare. It is typically authorized and maintained by a sovereign state, with its members identifiable by their distin ...

communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. ...

system that supports a worldwide, multi-service population of users in the

ultra high frequency Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ( ...

(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 rate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction w ...

s and improved operational availability. The MUOS was declared fully operational for use in 2019.

Overview

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 The United States Department of Defense (DoD, USDOD or DOD) is an executive branch department of the federal government charged with coordinating and supervising all agencies and functions of the government directly related to national secur ...

(DoD) and international allies' use has been declined in the past. 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 In telecommunications, data-transfer rate is the average number of bits (bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mult ...

. The

U.S. Navy The United States Navy (USN) is the maritime service branch of the United States Armed Forces and one of the eight uniformed services of the United States. It is the largest and most powerful navy in the world, with the estimated tonnage of ...

's Communications Satellite Program Office (PMW 146) of the Program Executive Office (PEO) for Space Systems in

San Diego San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United State ...

, is lead developer for the MUOS program.

Lockheed Martin Space Lockheed Martin Space is one of the four major business divisions of Lockheed Martin. It has its headquarters in Littleton, Colorado, with additional sites in Valley Forge, Pennsylvania; Sunnyvale, California; Santa Cruz, California; Huntsvi ...

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. DoD Contract Awards for September 24, 2004
/ref> Key subcontractors include

General Dynamics Mission Systems General Dynamics Mission Systems is a business unit of American defense and aerospace company General Dynamics. General Dynamics Mission Systems integrates secure communication and information systems and technology. General Dynamics Mission Syste ...

(Ground Transport architecture),

Boeing The Boeing Company () is an American multinational corporation that designs, manufactures, and sells airplanes, rotorcraft, rockets, satellites, telecommunications equipment, and missiles worldwide. The company also provides leasing and pr ...

(

Legacy In law, a legacy is something held and transferred to someone as their inheritance, as by will and testament. Personal effects, family property, marriage property or collective property gained by will of real property. Legacy or legacies may refer ...

UFO and portions of the WCDMA

payload Payload is the object or the entity which is being carried by an aircraft or launch vehicle. Sometimes payload also refers to the carrying capacity of an aircraft or launch vehicle, usually measured in terms of weight. Depending on the nature of ...

) and

Harris Harris may refer to: Places Canada * Harris, Ontario * Northland Pyrite Mine (also known as Harris Mine) * Harris, Saskatchewan * Rural Municipality of Harris No. 316, Saskatchewan Scotland * Harris, Outer Hebrides (sometimes called the Isl ...

(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.

WCDMA system

MUOS WCDMA radios can transmit simultaneous voice, video and mission data on an

Internet Protocol The Internet Protocol (IP) is the network layer communications protocol in the Internet protocol suite for relaying datagrams across network boundaries. Its routing function enables internetworking, and essentially establishes the Internet. I ...

-based system connected to military networks. MUOS radios operate from anywhere around the world at speeds comparable to 3G smartphones. MUOS radios can also work under dense cover, such as jungle canopies and urban settings. The MUOS operates as a global cellular service provider to support the warfighter with modern

cell phone A mobile phone, cellular phone, cell phone, cellphone, handphone, hand phone or pocket phone, sometimes shortened to simply mobile, cell, or just phone, is a portable telephone that can make and receive calls over a radio frequency link whil ...

-like capabilities, such as

multimedia Multimedia is a form of communication that uses a combination of different content forms such as text, audio, images, animations, or video into a single interactive presentation, in contrast to traditi ...

. It converts a commercial third generation (3G) Wideband Code Division Multiple Access (WCDMA) cellular phone system to a military UHF SATCOM radio system using

geosynchronous satellites A geosynchronous satellite is a satellite in geosynchronous orbit, with an orbital period the same as the Earth's rotation period. Such a satellite returns to the same position in the sky after each sidereal day, and over the course of a day tra ...

in place of

cell towers A cell site, cell tower, or cellular base station is a cellular-enabled mobile device site where antennas and electronic communications equipment are placed (typically on a radio mast, tower, or other raised structure) to create a cell, or adja ...

. By operating in the

Ultra high frequency Ultra high frequency (UHF) is the ITU designation for radio frequencies in the range between 300 megahertz (MHz) and 3 gigahertz (GHz), also known as the decimetre band as the wavelengths range from one meter to one tenth of a meter ( ...

(UHF) frequency band, a lower frequency band than that used by conventional terrestrial

cellular network A cellular network or mobile network is a communication network where the link to and from end nodes is wireless. The network is distributed over land areas called "cells", each served by at least one fixed-location transceiver (typically thr ...

s, the MUOS provides warfighters with the tactical ability to communicate in "disadvantaged" environments, such as heavily forested regions where higher frequency signals would be unacceptably attenuated by the forest canopy. Connections may be set up on demand by users in the field, within seconds, and then released just as easily, freeing resources for other users. In alignment with more traditional military communications methods, pre-planned networks can also be established either permanently or per specific schedule using the MUOS' ground-based Network Management Center.

Legacy payload

In addition to the cellular MUOS WCDMA payload, a fully capable and separate UFO legacy payload is incorporated into each satellite. The "legacy" payload extends the useful life of legacy UHF SATCOM terminals and enables a smoother transition to MUOS.

Launches

MUOS-1, after several weather delays, was launched into space successfully on 24 February 2012, at 22:15:00 UTC, carried by an

Atlas V Atlas V is an expendable launch system and the fifth major version in the Atlas launch vehicle family. It was originally designed by Lockheed Martin, now being operated by United Launch Alliance (ULA), a joint venture between Lockheed Martin ...

launch vehicle A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pads, supported by a launch control center and system ...

flying in its 551 configuration. MUOS-2 was launched on schedule on 19 July 2013, at 13:00:00 UTC aboard an Atlas V 551 (AV-040). MUOS-3 was launched on board a United Launch Alliance (ULA) Atlas V launch vehicle on 20 January 2015, from

Cape Canaveral Air Force Station Cape Canaveral Space Force Station (CCSFS) is an installation of the United States Space Force's Space Launch Delta 45, located on Cape Canaveral in Brevard County, Florida. Headquartered at the nearby Patrick Space Force Base, the stat ...

(CCAFS),

Florida Florida is a U.S. state, state located in the Southeastern United States, Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia (U.S. state), Geo ...

. MUOS-4 arrived at Cape Canaveral on 31 July 2015. Weather conditions pushed back the launch, which was originally scheduled for on 31 August 2015, at 10:07 UTC. The launch took place on 2 September 2015, at 10:18:00 UTC. MUOS-5 arrived at Cape Canaveral on 9 March 2016. Launch was originally scheduled for on 5 May 2016, but due to an internal investigation into an Atlas V fuel system problem during the Cygnus OA-6 launch on 22 March 2016, the scheduled date was pushed back. The launch took place on 24 June 2016, at 14:30:00 UTC. An "anomaly" aboard the satellite occurred a few days later, however, when it was still in a

Geostationary Transfer Orbit A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step f ...

(GTO), leaving it "Reconfigured into Safe Intermediate Orbit", or stranded in GTO. Amateur observers tracked it in an orbit of approximately since 3 July 2016. On 3 November 2016, the Navy announced that the satellite has finally reached operational orbit.

MUOS operational positions

The four currently operational MUOS satellites are stationed at longitude 100° West (MUOS-1); 177° West (MUOS-2); 15° West (MUOS-3); and 75° East (MUOS-4). MUOS-5 is at 103.8° West spare. They have a 5° orbital inclination. In the first few months after launch, the satellites were temporarily parked in a check-out position at longitude 172° West.

MUOS ground stations

The MUOS includes four ground station facilities. Site selections were completed in 2007 with the signing of a Memorandum of Agreement (MOA) between the U.S. Navy and the

Australian Department of Defence Australian(s) may refer to: Australia * Australia, a country * Australians, citizens of the Commonwealth of Australia ** European Australians ** Anglo-Celtic Australians, Australians descended principally from British colonists ** Aboriginal Au ...

. The four ground stations, each of which serves one of the four active satellites of the MUOS constellation will be located at: the

Australian Defence Satellite Communications Station The Australian Defence Satellite Communications Station (ADSCS), an Earth station in Australia is located at Kojarena east of Geraldton, Western Australia. The ADSCS is part of the US signals intelligence and analysis network ECHELON. The sta ...

at Kojarena, Western Australia about 30 km east of

Geraldton, Western Australia Geraldton (Wajarri: ''Jambinu'', Wilunyu: ''Jambinbirri'') is a coastal city in the Mid West region of the Australian state of Western Australia, north of the state capital, Perth. At June 2018, Geraldton had an urban population of 37,648. ...

;

Naval Radio Transmitter Facility (NRTF) Niscemi Naval Radio Transmitter Facility Niscemi (NRTF Niscemi) is a transmission facility of the United States Navy at Niscemi, Sicily, maintained by the N92 Division of Naval Computer and Telecommunications Station Sicily. The facility houses low frequen ...

about 60 km from

Naval Air Station Sigonella Naval Air Station (NAS) Sigonella is an Italian Air Force base ('' it, Aeroporto "Cosimo Di Palma" di Sigonella''), and a U.S. Navy installation at Italian Air Force Base Sigonella in Sicily, Italy. The whole NAS is a tenant of the Italian Air ...

Sicily Sicily ( it, Sicilia , ) is the list of islands in the Mediterranean, largest island in the Mediterranean Sea and one of the 20 regions of Italy, regions of Italy. The Strait of Messina divides it from the region of Calabria in Southern Italy. I ...

, Italy; Naval SATCOM Facility, Northwest Chesapeake, Southeast Virginia at ; and the

Naval Computer and Telecommunications Area Master Station Pacific Naval Computer and Telecommunications Area Master Station Pacific (NCTAMS PAC) provides operational direction and management to all Pacific Naval Telecommunication System users. In addition to this function, NCTAMSPAC manages, operates, and main ...

Hawaii Hawaii ( ; haw, Hawaii or ) is a state in the Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is an archipelago, and the only ...

Controversy

Construction of the ground station in Italy was halted for nearly half of 2012 by protesters concerned with health risks and environmental damage by radio waves. One scientific study "point to serious risks to people and the environment, such as to prevent its realization in densely populated areas, like the one adjacent to the town of

Niscemi Niscemi is a little town and ''comune'' in the province of Caltanissetta, Sicily, Italy. It has a population of 27,558. It is located not far from Gela and Caltagirone and 90 km from Catania. Etymology The name Niscemi is derived from th ...

". In spite of the controversy, the site at Niscemi was completed in anticipation of the launch of MUOS-4.

Radio terminals

The MUOS waveform with complete red/black operational capability was released in 2012. Until the Joint Tactical Radio System (JTRS) program cancellation in 2011, the JTRS program would provide the DoD terminals that can communicate with the MUOS WCDMA

waveform In electronics, acoustics, and related fields, the waveform of a signal is the shape of its graph as a function of time, independent of its time and magnitude scales and of any displacement in time.David Crecraft, David Gorham, ''Electroni ...

with a series of form-factor models. The JTRS Handheld, Manpack and Small Form Fit (HMS) AN/PRC-155 manpack built by

survived the wider JTRS program cancellation and has shipped several low rate of initial production (LRIP) units.

Rockwell Collins Rockwell Collins was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio Comp ...

AN/ARC-210 airborne terminal and

Harris Corporation Harris Corporation was an American technology company, defense contractor, and information technology services provider that produced wireless equipment, tactical radios, electronic systems, night vision equipment and both terrestrial and space ...

AN/PRC-117G. Manpack have also been certified for operation on the MUOS system.

Arctic and Antarctic capabilities

Lockheed Martin and an industry team of radio vendors demonstrated extensive Arctic communications reach near the

North Pole The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is the point in the Northern Hemisphere where the Earth's axis of rotation meets its surface. It is called the True North Pole to distinguish from the Magn ...

, believed to be the most northerly successful call to a geosynchronous satellite. WCDMA calls to the far north will be increasingly important where there has been an increase in shipping, resource exploration and tourism without much improvement in secure satellite communications access. Based on these and continued tests, full coverage of the

Northwest Passage The Northwest Passage (NWP) is the sea route between the Atlantic and Pacific oceans through the Arctic Ocean, along the northern coast of North America via waterways through the Canadian Arctic Archipelago. The eastern route along the Arc ...

and

Northeast Passage The Northeast Passage (abbreviated as NEP) is the shipping route between the Atlantic and Pacific Oceans, along the Arctic coasts of Norway and Russia. The western route through the islands of Canada is accordingly called the Northwest Passage ( ...

shipping lanes is expected. Several follow-on tests with high quality voice and data including streaming video have occurred in both the

Arctic The Arctic ( or ) is a polar region located at the northernmost part of Earth. The Arctic consists of the Arctic Ocean, adjacent seas, and parts of Canada ( Yukon, Northwest Territories, Nunavut), Danish Realm ( Greenland), Finland, Icel ...

and

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...

, including a 2015 demonstration from

McMurdo Station McMurdo Station is a United States Antarctic research station on the south tip of Ross Island, which is in the New Zealand-claimed Ross Dependency on the shore of McMurdo Sound in Antarctica. It is operated by the United States through the Unit ...

.Researchers take high-bandwidth communications to the South Pole
/ref>

References

External links

MUOS 1, 2, 3, 4, 5 *
MUOS-1 Mission page & launch images, 02/24/2012

{{Lockheed Martin Equipment of the United States Space Force G Military space program of the United States Lockheed Martin General Dynamics Mission Systems

MUOS The Mobile User Objective System (MUOS) is a United States Space Force narrowband military communications satellite system that supports a worldwide, multi-service population of users in the ultra high frequency (UHF) band. The system provides ...