The Navy on June 24 put in orbit the fifth satellite in its Mobile User Objective System (MUOS) constellation. The satellite went into space on an Atlas V 551 rocket.
MUOS enables worldwide, secure voice and mission data at high data rates, making these capabilities available to ships, aircraft and ground vehicles used by all U.S. military services. Launch of this latest satellite expands network coverage, making this "a major milestone for the MUOS program for the Navy, as well as the rest of the armed forces," Dr. Walt Lauderdale, MUOS-5 Mission Director, Air Force Space and Missile Systems Center, said in a pre-launch conference call to journalists.
The MUOS constellation incorporates a five-satellite array, working in concert with four ground stations across the globe, a Wideband Code Division Multiple Access waveform, radios and complex network management software.
MUOS's legacy UHF payload already provides communications capabilities to combatant commanders worldwide. The fifth satellite will provide redundancy to the existing spacecraft and will expand coverage further toward the poles, up to 89.5 degrees North Latitude, Lauderdale said. This could provide some operational advantage to U.S. forces, as well as to allied nations.
With the latest launch, MUOS also becomes available for further testing of its Wideband Code Division Multiple Access (WCDMA) waveform, an advanced wireless standard with 10 times more capacity than legacy systems.
The Army's Manpack radios successfully completed the first WCDMA voice and data calls with the on-orbit MUOS-1 satellite in early 2013. Multi-service testing and evaluation will continue as the services explore different terminal options. The Army likely will deploy a terminal later this year, with digital modular radios to start rolling out onto Navy and Coast Guard vessels in 2018, said Navy Capt. Joe Kan, MUOS program manager.
Because MUOS operates beyond the line of sight, "the communications for our service men and women will change drastically" with the completion of the satellite constellation, said Mark Woempner, Lockheed Martin MUOS program manager.
"Our war fighters no longer need to be standing under the satellite footprint to communicate with one another," he said. "You won't have to come out from under cover to make a call anymore."
The successful launch also marked a win for partners Lockheed Martin and United Launch Alliance, who had worked together to remediate a problem encountered by another Atlas V in March.
In that event, an engine that was set to burn for four minutes and 15.5 seconds shut down six seconds earlier than planned. Onboard software triggered a subsequent engine firing to last a minute longer than slated, thus making up for the premature shutdown. The payload, a Cygnus CRS OA-6 spacecraft, successfully carried out its mission.
Engineers conducted over 156 hardware reviews and 330 data package reviews to get to the root of that anomalous event, which they eventually classed as a fault with the RD-180 Mixture Ratio Control Valve (MRCV) assembly. The review reflected "an uncompromising dedication to mission success," Lauderdale said.
