MUOS-4 Completes On-Orbit Testing Ahead of Operational Acceptance Next Spring

File photo of the U.S. Navy's MUOS-4 satellite, which this week completed on-orbit testing and was officially accepted by the Navy to go operational next spring. Photo Credit: Lockheed Martin
File photo of the U.S. Navy’s MUOS-4 satellite, which this week completed on-orbit testing and was officially accepted by the Navy to go operational next spring. Photo Credit: Lockheed Martin

The fourth in a Lockheed Martin-built five-ship fleet for a next-generation, narrowband tactical military satellite communications system was officially accepted by the U.S. Navy this week, following successful completion of the satellite’s on-orbit testing. Launched on Sep. 2, the 7.5-ton Mobile User Objective System-4 (MUOS-4) satellite extends a new, $7 billion secure military communications network (MUOS) for U.S. military forces on the move, expanding the network’s coverage now around nearly the entire planet.

With on-orbit testing now complete the satellite is ready to relocate to its 22,000-mile-high on-orbit operational slot in preparation for operational acceptance next spring.

The Atlas V 551 rockets into the darkened Florida sky at 8:04 p.m. EST Tuesday, 20 January, to deliver MUOS-3 into orbit. Photo Credit: Mike Killian / AmericaSpace
The Atlas V 551 rockets into the darkened Florida sky at 8:04 p.m. EST Tuesday, 20 January, to deliver MUOS-3 into orbit. Photo Credit: Mike Killian / AmericaSpace

“MUOS-4 completes the initial constellation, providing the MUOS network with nearly global coverage. Mobile forces, equipped with MUOS terminals, will soon be able to communicate with each other – including voice, data and exchanging imagery – real-time, virtually anywhere on the Earth,” said Iris Bombelyn, Lockheed Martin’s vice president for Narrowband Communications. “This is a tremendous upgrade in communications capabilities over what currently exists for our nation and our allies.”

MUOS operates like a “smart phone cell tower in the sky,” supporting a worldwide, multi-service population of users in the UHF band, providing increased communications capabilities to smaller terminals while still supporting interoperability with legacy terminals. The new military SATCOM system will, for the first time, give MUOS Wideband Code Division Multiple Access technology users beyond-line-of-sight capability to transmit and receive voice and data using an Internet Protocol-based system, giving users greater mobility, higher data rates, and improved operational availability.

However, as noted by AmericaSpace’s Military Space reporter Craig Covault earlier this year:

The Government Accountability Office (GAO) said earlier this year that the unique MUOS ultra-high frequency multi-service capability can not be fulfilled until the program fully solves waveform communications software issues that have significantly delayed operational use of the spacecraft’s most advanced capabilities.

More than 90 percent of the MUOS capabilities remain underutilized, according to Christina T. Chaplain, GAO’s Director of Acquisition and Sourcing, speaking before a Senate Armed Services subcommittee in April.

MUOS program manager, Navy Capt. Joe Kan (pronounced Con), told AmericaSpace he did not agree with that statement, stating that U.S. military services are conducting highly successful tests around the world, including in the Arctic and Antarctic with MUOS radios through the first three MUOS satellites parked over the equator covering the Atlantic, Pacific, and CONUS. MUOS-4 is parked over the Indian Ocean.

“The MUOS program faces challenges that prevent full use of its satellite capabilities,” Chaplain testified. “The Issue is related to the development of the MUOS waveform [UHF radio software] meant to provide increased communications capabilities beyond those offered by the [earlier Boeing] UHF legacy system.” The Boeing satellites were launched between 1993 and 2003.

The waveform issues have “caused delays in the use of radios being developed by the Army as the first operational terminals to incorporate the MUOS waveform. Use of over 90 percent of MUOS’ planned capability is dependent on resolving problems with integrating the waveform, terminals, and ground systems.” Chaplain testified. The 10 percent that is operational involves the MUOS legacy system that is providing continuous service to users operating lower data rate UHF systems with the aging Boeing satellites.

“The MUOS program extended testing to fix software and reliability issues with the waveform integration and now plans to complete operational testing by November 2015—a 17-month delay from the initial schedule estimate. As a result, the Army’s plans to field its MUOS-compatible radios have now slipped from 2014 to 2016, roughly four years since the first MUOS satellite launch,” Chaplain told the subcommittee.

Lockheed engineers prepare MUOS-3 for acoustic testing, one of several simulated environmental tests to validate the satellite’s performance throughout its launch and on-orbit mission life. Photo Credit: Lockheed Martin
Lockheed engineers prepare MUOS-3 for acoustic testing, one of several simulated environmental tests to validate the satellite’s performance throughout its launch and on-orbit mission life. Photo Credit: Lockheed Martin

Lockheed Martin has since confirmed in a phone call to AmericaSpace that operational testing was in fact completed last month, and noted that the DOD’s Multi-Service Operational Test and Evaluation (MOT&E) results should be released sometime early next year.

By operating in the UHF frequency band, which is lower than that used by conventional cellular networks, MUOS will provide U.S. and allied warfighters with the tactical ability to communicate in “disadvantaged” environments, including heavily forested areas where higher-frequency signals would be otherwise impaired. Even troops in buildings with no satellite access are expected to see an increase in communications capability.

The size of the MUOS satellites are a result of the nature of the size of the UHF waveform, and, at 15,000 pounds each, their weight is due to the fact that—besides requiring bigger hardware for UHF—they are designed to operate from GEO for an expected 15 years, and so they need a lot of fuel.

MUOS is an IP-based communications protocol based on 3G, which gives military users on the move more communications capability over existing systems, including simultaneous voice, video, and data—similar to the capabilities experienced today with smart phones, providing users with 10 times more communications capacity.

With MUOS-4 ready to go operational next spring Lockheed is busy preparing the next satellite of the constellation for launch In May or June of 2016, MUOS-5, which will actually serve as an on-orbit spare and is currently in final assembly and testing at Lockheed’s satellite manufacturing facility in Sunnyvale, Calif. Once ready the satellite will fly to Florida on a C-5 Galaxy (courtesy of the 60th Air Mobility Wing of Travis Air Force Base) for final preparations and launch, which will take place from Cape Canaveral Air Force Station Space Launch Complex-41 (SLC-41) atop a ULA Atlas-V 551 rocket—the most powerful configuration of the Atlas-V.

“This is another major step toward achieving a fully operational MUOS end-to-end capability by 2016,” said Navy Capt. Joseph Kan, the MUOS program manager. “The Navy, in close collaboration with the Army, Air Force and our industry partners, is bringing the future of worldwide mobile satellite communications into reality for the United States and potentially allied nations.”

The MUOS satellites represent some of the heaviest payloads ever to be launched by ULA’s Atlas-V, second only to Orbital ATK’s new and improved Cygnus spacecraft, which is currently waiting for bad weather to clear central Florida in order to launch to the International Space Station with over 7,000 pounds of supplies, equipment, and experiments. The spacecraft itself, along with its full payload, weighs over 1,500 pounds more than the Navy’s MUOS satellites.

 – Written by Mike Killian and Craig Covault


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Missions » MUOS » Missions » MUOS » MUOS-4 »


  1. It will mainly be used for controlling the new generation of drones.

    Unfortunately, tens of billions per year will continue to be poured into manned platforms because of the “pilot lobby.” Reminds me of the Space Shuttle. NASA chose to keep Human Space Flight going on a post-Apollo budget by combining crew and cargo vehicles into a do-everything-pay-for-itself-cargo-bay-of-dreams. The sad reality was that LEO was not even really space flight anymore after Apollo 8 left it far behind in 1968.

    Combat aircraft supposedly capable of penetrating enemy air defenses with human crews are no longer plausible and are a drain on resources. Moore’s law has finally made this a true statement though howls of dismay and denial will continue for years.

    A very different scenario exists concerning the nuclear deterrent. Though the nuclear bomber force was taken off 24 hour in-flight readiness long ago a 100 billion dollar contract for a new bomber was just signed. The aging ICBM and Submarine force are now in danger of becoming vulnerable to a “first strike” and the risk of an accidental nuclear exchange is once again ratcheting up. Replacing the the missile and submarine fleet over the next ten years is going to cost well over a trillion dollars and looks unavoidable. Unfortunately, advances in technology mean the new weapons will probably not restore deterrence as ICBMs can now be very precisely targeted and sea gliders (undersea drones) will infest the oceans and constantly target any submarine force.

    The solution is to move the nuclear deterrent into deep space on human-crewed spaceships.

    Lunar ice and the Moon being just outside the magnetosphere means nuclear propulsion systems and weapons can be tested without risk of contaminating the Earth. Lunar ice would provide cosmic ray shielding for the spaceship’s human crews. Moving the NATO, Russian, and Chinese nuclear arsenal into deep space assures deterrence and effectively eliminates the present hair-trigger-minutes-to-launch situation.

    Space deterrence also directs the trillions of dollars earmarked for global ICBM, submarine, and obsolete bomber fleets into space. The spaceships on patrol will also automatically provide a comet/asteroid intercept capability and protect the Earth from impacts. Such “space battleships” loaded with nuclear weapons are platforms that must have humans on board and thus take us back into space.

    • Drones, seriously? And then a paragraphs-long rant completely off-topic in an attempt to troll.
      Gary Church just go away…

    • To add to this scenario from another thread:

      December 8, 2015 at 7:29 am · Reply

      “Would a dual SLS launch really be less expensive than a SLS / Delta Heavy launch?”

      Not with the manufacturing infrastructure having been restricted to allow no more than two SLS launches a year.

      It does not have to be that way, but that is the way it is set up.

      Conway Costigan
      December 10, 2015 at 6:06 am · Reply

      In my view Joe there are about a half a dozen key technologies required for Human Space Flight Beyond Earth Orbit and a second space age to become reality.

      The first basic building block is the reusable pressure-fed booster of several million pounds of thrust. In hindsight going cheap with the SRB’s was perhaps THE singular mistake that doomed the Shuttle program. While the shuttle was actually a Saturn V class system it wasted most of the lift on the 737 size orbiter. The Saturn V was actually only just powerful enough to accomplish Moon landings and only because of LOR. Even the evolved 130 ton payload SLS is too small. So we still need to build these boosters and nothing is being done in this area. Until it is a key technology is missing and any HSF-BEO program will be hobbled and lacking. It is discouraging to watch so much time and effort being wasted on landing back rocket stages which is a dead end due to the rocket equation. The problem is scale more than anything else.
      Conway Costigan
      December 10, 2015 at 6:43 am · Reply

      I would add these pressure-fed boosters alongside the Ehricke/von Braun wet workshop seem to be the only path that will establish a long duration human presence BEO (by way of lunar-water-as-radiation-shielding).

      It is like a puzzle and all the pieces are on the table but nobody is interested in putting it together.

      The first piece was the Soviet/U.S space race. The communists had the totalitarian mechanism to throw the resources of the state behind their program but were lacking the capitalistic motivation that created our technical excellence. Though it is hard for many to admit, we largely mimicked their state-run enterprise and applied our private enterprise expertise to make up for the Soviet system disadvantage. We have to revisit that. Unfortunately, the libertarian underpinnings of the NewSpace movement are toxic to any such organizing principle.
      Conway Costigan
      December 10, 2015 at 6:58 am · Reply

      The second piece of the puzzle was put on the table by Gerard K. O’Neill. He presented a model taking into account all the salient features of our situation. He correctly correlated three elements:

      No natural bodies in the solar system are suitable for colonization and we would have to build spinning hollow moons (Bernal Spheres).

      Space Solar Energy is the base industry from which all progress will originate. He was particularly prescient considering the present climate change situation.

      The shallow gravity well of the Moon makes that body the resource enabling the first two elements. The ice on the Moon has validated this view.

      These first two pieces make it clear that a state-sponsored public works project, like the Panama Canal or Hoover dam, and the Moon are how to begin putting the puzzle together. NewSpace completely rejects this.
      Conway Costigan
      December 10, 2015 at 7:18 am · Reply

      And to finish this little dissertation, I will ask and answer a question: what should be the first goalpost, the first milestone to measure success for the U.S. Space Program and the public?

      Place wet workshops in lunar orbit with an iteration of the SLS.

      Ferry water up from the surface with robot harvesters till the first two of these empty stages have full radiation shields.

      Connect the twin workshops with a tether system and spin the construct to produce Earth gravity.

      The resulting “true” space station would provide a near-sea-level radiation environment at one G and the over one thousand tons of water would provide a medium for a closed-cycle-life-support system providing air and water for several years without resupply.

      The crew would look out through the double view port through the water shield at a slowly rotating star field. Continuous production of these stations would send a chain of them back across the cislunar sea to GEO to replace the satellite junkyard and capture hundreds of billions in telecom revenues.

      This would be the first step and a nuclear propulsion system to mate with such stations, thus creating an exploration fleet of “true” spaceships, would be the second.

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