SACRAMENTO, Calif., Sept. 2, 2015 (GLOBE NEWSWIRE) -- Aerojet Rocketdyne (NYSE:AJRD) played a critical role in successfully placing the fourth of five planned Mobile User Objective System (MUOS-4) satellites, designed and built by Lockheed Martin, into orbit for the U.S. Navy. The mission was launched from Cape Canaveral Air Force Station in Florida aboard a United Launch Alliance Atlas V rocket, with five Aerojet Rocketdyne AJ60 solid rocket boosters (SRB), an RL10C-1 upper-stage engine, pressurant tanks and upper stage thrusters.

"Congratulations to the entire team for the successful delivery of the MUOS-4 into orbit," said Steve Bouley, vice president of Space Launch Systems at Aerojet Rocketdyne. "The combined effort of everyone involved makes it possible for troops deployed worldwide to better communicate with one another in their mission to keep us safe from harm."

MUOS-4 is part of a next-generation narrowband tactical satellite communications system designed to provide mobile U.S. forces with reliable and secure global communications, including simultaneous, high-speed voice and data capabilities. Once complete, MUOS will replace the UHF Follow-On (UFO) satellite constellation currently used by the U.S. Navy, providing up to 16 times the capacity of the legacy system. The Navy's Program Executive Office for Space Systems and its Communications Satellite Program Office are responsible for the MUOS program. The MUOS satellites use 12 MR-103G 0.2 lbf and six MR-106L 5.0 lbf Aerojet Rocketdyne monopropellant hydrazine thrusters for attitude control aboard the spacecraft.

At liftoff, the five AJ60 SRBs were ignited, increasing the launch thrust of the Atlas V rocket by more than 1.7 million pounds. All Atlas V launches requiring extra boost performance have flown Aerojet Rocketdyne-produced SRBs. These motors have demonstrated a 100 percent success record in flight since the first Atlas V launch with SRBs on July 17, 2003. After the separation of the first stage, a single RL10C-1 upper-stage engine ignited, delivering 22,890 pounds of thrust to power the Atlas V upper stage. The RL10C-1 burns cryogenic liquid hydrogen and liquid oxygen propellants. In addition to the five SRBs and upper-stage engine, 12 Aerojet Rocketdyne MR-106 monopropellant (hydrazine) thrusters in four modules on the Atlas V Centaur upper stage provided roll, pitch and yaw control as well as settling burns for the upper-stage main engine. ARDÉ, a subsidiary of Aerojet Rocketdyne based in New Jersey, provides the pressure vessels on the first and second stages on the launch vehicle.

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