Aerojet, a GenCorp company, is marking the delivery of its 100th R-4D-15 High Performance Apogee Thruster to Boeing Space & Intelligence Systems in a ceremony today at Aerojet’s Redmond, Calif., production facility.
The event is commemorating the milestone delivery and the R-4D record of 100 percent mission success throughout five decades of service.
As the premier apogee engine of choice for raising large satellites and spacecraft into geosynchronous orbit, the HiPAT performs orbit-raising maneuvers for many of the world’s communication satellite platforms, including Astrium’s Eurostar 3000, Boeing Space Systems’ 702HP, MELCO’s DS-2000 and Loral’s LS-1300. It also has played critical roles in NASA missions such as Cassini’s orbit insertion of Saturn.
“The HiPAT is the highest-performing rocket engine in its class,” said Aerojet Vice of President of Space and Launch Systems, Julie Van Kleeck. “By offering a higher specific impulse than comparable engines, the HiPAT reduces the total amount of fuel required for the mission, allowing for either more equipment or longer operation of the spacecraft.”
The R-4D product line includes a series of liquid bipropellant engines using the propellant combination of nitrogen tetroxide oxidizer and either monomethylhydrazine or hydrazine 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 for the reaction control systems for the Apollo Service Module and Lunar Excursion Module. The HiPAT is the fifth generation of the R-4D 100 lbf thrust class of liquid bipropellant engines.
“This engine has incredible lineage,” said Aerojet Bipropellant Propulsion Program Manager, Steve Harper. “R-4Ds have supported every Apollo flight. During the Apollo program, 469 engines were flown in space and logged more than 875,000 pulses with the equivalent time of 16 years in space.”
Over the years, the R-4D has evolved into new design configurations as more modern rocket engine materials and technologies were developed. The R-4D-11, an intermediate iteration, is still in active production and has played critical roles in orbital maneuvering and braking for International Space Station missions on the European ATV and Japanese HTV resupply vehicles. It also is planned for use on the Orion service module. Developments in material systems in the 1990s resulted in the high performance HiPAT design flying today. More than 850 R-4Ds have been produced to date, including the 100th HiPAT, and all have performed successfully during the missions.
Looking to the future, Aerojet now has a next-generation design iteration which offers increased performance and reliability. The “dual-mode” HiPAT and Advanced Material Bipropellant Rocket thrusters provide a 1-3 percent improvement over the HiPAT and a nearly 20 percent performance increase over the original Apollo design. The HiPAT DM was qualified in 2002 and the AMBR thruster is ready for qualification testing.