Bipropellant In-Space Propulsion

  • Bipropellant Motor

Enabling in-space operations and exploration

Beginning with the Apollo missions to the moon, Aerojet Rocketdyne has delivered more than 2,500 bipropellant rocket engines for in-space propulsion use. Bipropellant engines produce thrust when two propellant valves open and liquid fuel (typically monomethyl hydrazine, or hydrazine) and liquid oxidizer (nitrogen tetroxide) hypergolically ignite in the chamber. The resulting hot gas exits the nozzle, creating thrust.

Key Features

Bipropellant engines are used on various spacecraft for a wide variety of missions including geosynchronous-orbiting satellites, International Space Station servicing vehicles, and interplanetary exploration to assist with orbit insertion, delta – v, reaction and control.

Our Role

Aerojet Rocketdyne’s R-4D engines – a family of 100 pound thrust bipropellant thrusters – that was originally developed for the Apollo missions and was key to the rescue of the Apollo 13 crew. Since then, the R-4D has evolved into the world’s highest reliability apogee insertion engine available today. R-4D engines have flown over 300 apogee-insertion missions, with a 100 percent success rate.