Primex is a maker of rocket engines, for example for Lockheed Martin's Athena 2. It carries four Primex MR107 hydrazine-fueled engines that are used for the orbital adjustment module. They already were used on the Athena I, the same engines for the same purpose.

From Appendix 7: The Primex Aerospace Company (PAC) offers chemical rocket propulsion systems based on hydrazine technology.

-They are considered low cost for all types of small space ship and satellite maneuvering engines.

-They also make accessories such as gas generators, hot gas to pressurize tanks, etc.

"Primex has almost 40 years of experience in motors"

From Appendix 9: Primex Aerospace is a part of Aerojet today. Before it was a subsidiary of Primex Technologies, and before that of the renowned Rocket Research Co.

-Primex got the contract from Lockheed-Martin (LLMS) to build small maneuvering engines to be used in space: PPT, Iridium, EHT, etc.

-We located a Pulse Plasma Thruster. Information is missing.

“PPT motor”

-Thruster for maneuvering space vehicles, satellites, etc.

“Set of Iridium, EHT motors”

“Group of thrusters from the Centaur”