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Aerojet Rocketdyne Celebrates 100th High Performance Apogee Thruster Flight

Written by: developer

SACRAMENTO, Calif., (Dec. 1, 2014) – Aerojet Rocketdyne, a GenCorp (NYSE: GY) company, is pleased to report the completion of its 100th geosynchronous satellite apogee insertion using its iridium/ rhenium High Performance Apogee Thruster (HiPAT™), including first and second generation design configurations. The successful insertion was achieved with a large geosynchronous telecommunications satellite, built by commercial satellite manufacturer, SSL, which was recently launched. The milestone will be commemorated by a ceremony at the company’s Redmond, Washington facility, with SSL officials in attendance.

The R-4D-15 HiPAT™ performs orbit-raising maneuvers for many of the world's communication satellite platforms. Variants of the R-4D have played critical roles in NASA missions such as Cassini’s exploration of Saturn and its moons; as well as the European Space Agency and the Japan Aerospace Exploration Agency International Space Station re-supply vehicles.

“The model R-4D-15 HiPAT™ is the highest-performing rocket engine in its class,” said Warren Yasuhara, vice president of Space Systems at Aerojet Rocketdyne. “By offering a higher specific impulse than comparable engines, the HiPAT™ reduces the total amount of fuel required for the mission and allows spacecraft operators to trade propellant mass for high-value payload.”

The R-4D product line includes a series of liquid bipropellant engines that use the propellant combination of nitrogen tetroxide (MON-3) oxidizer and monomethylhydrazine (MMH) fuel. These propellants are storable at room temperature and do not require a separate ignition source, simplifying many higher-level integration issues while still providing high performance.

The R-4D was originally developed as a thruster for the reaction control systems for the Apollo Service Module and the Lunar Excursion Module. The HiPAT™ is the fifth generation of the R-4D 100 lbf thrust class of liquid bipropellant engines and the second generation of high performance iridium/rhenium engines.

“This engine has incredible lineage,” said Steve Harper, Bipropellant Propulsion Product Line manager at Aerojet Rocketdyne. “Dating back to Apollo, Aerojet-Rocketdyne’s R-4D family of 100 lbf bipropellant engines holds an impressive record of 100 percent mission success throughout five decades of service in space.”

Aerojet Rocketdyne is a world-recognized aerospace and defense leader providing propulsion and energetics to the space, missile defense and strategic systems, tactical systems and armaments areas, in support of domestic and international markets. GenCorp is a diversified company that provides innovative solutions that create value for its customers in the aerospace and defense, and real estate markets. Additional information about Aerojet Rocketdyne and GenCorp can be obtained by visiting the companies’ websites at and


Glenn Mahone, Aerojet Rocketdyne, 202.302.9941
[email protected]
Erin Dick, Aerojet Rocketdyne, 818.586.4977
[email protected]