// PROPULSION SYSTEMS AND ENGINE TECHNOLOGY TERM
Autogenous Pressurization
Autogenous pressurization is a method used in rockets where a small amount of the liquid propellant is turned into gas to push the remaining liquid propellant into the engine, instead of using a separate tank of inert gas.
TECHNICAL DEFINITION
Autogenous pressurization is an aerospace propulsion technique where a portion of the primary liquid propellant (fuel or oxidizer) is vaporized or gasified to create the required pressure within its storage tank, thereby expelling the bulk liquid propellant towards the engine turbopumps or combustion chamber without relying on an external inert gas pressurization system. This approach significantly reduces system mass, complexity, and tankage volume for launch vehicles and spacecraft.
BACKGROUND
Autogenous pressurization is the use of self-generated gaseous propellant to pressurize liquid propellant in rockets. Traditional liquid-propellant rockets have been most often pressurized with other gases, such as helium, which necessitates carrying the pressurant tanks along with the plumbing and control system to use it. Autogenous pressurization has been operationally used on the Titan 34D, Space Shuttle, Space Launch System, Starship, Terran 1, and New Glenn. Autogenous pressurization is planned to be used on Rocket Lab's Neutron rocket.
READ MORE ON WIKIPEDIASYNONYMS & ALIASES
- Self-pressurization
- Propellant vapor pressurization
- Internal pressurization
- Tank auto-pressurization
USAGE NOTE
This technique is increasingly favored in reusable launch vehicle designs and advanced in-space propulsion systems due to its significant mass reduction and operational simplicity benefits.
DEVELOPERS
Organizations developing technology related to Autogenous Pressurization.
Pioneered the operational use of autogenous pressurization in their Falcon 9 (for the liquid oxygen tank) and extensively in their Starship development, which uses propellant vapor for tank pressurization, eliminating the need for separate pressurant tanks and improving efficiency.
Developing engines like the BE-4 (for ULA's Vulcan Centaur and their own New Glenn rocket) which leverage autogenous pressurization, using turbopump exhaust gas to pressurize propellant tanks, enhancing performance and reusability.
Through various research centers (e.g., Marshall Space Flight Center, Glenn Research Center), NASA has conducted extensive research and development into autogenous pressurization systems for advanced propulsion, including future lunar and Mars missions and in-space propellant depots.
Developing 3D-printed rockets, including Terran R, which utilizes liquid methane/liquid oxygen engines. Autogenous pressurization is a key technology for their engine cycles to reduce complexity and increase performance for their reusable launch vehicles.
As the developer of the Vulcan Centaur launch vehicle, ULA incorporates Blue Origin's BE-4 engines, which are designed with autogenous pressurization capabilities, directly leveraging this technology for their next-generation rockets.