AeroVia LogoAeroVia
Back to Propulsion Systems

Aerojet LR91-AJ-11 rocket engine

Aerojet's historical LR91-AJ-11 was the single-chamber, gas-generator storable-propellant engine for Titan III and Titan IV second stages. NASA documents nitrogen tetroxide/Aerozine-50 propellants, 467,040 N (about 467.04 kN) maximum thrust, 316 s specific impulse, and a 247 s maximum firing lifetime; this record keeps the historical Titan application without inferring a current lifecycle or vehicle relationship.

Aerojet LR91-AJ-11 rocket engine
Justin Smith (J.smith), Wikimedia Commons · Creative Commons Attribution-ShareAlike 3.0 Unported (CC BY-SA 3.0): https://creativecommons.org/licenses/by-sa/3.0/. Reuse and unmodified redistribution are permitted with appropriate credit, license link, and no implied endorsement. · Source

Identity

Aliases
LR91-AJ-11LR91-AJ-11 engineLR91-AJ-11 Titan engine
Domains
spaceflight
Identity Level
model
Kind
liquid-rocket-engine
Name
Aerojet LR91-AJ-11 rocket engine
Status
historical

Details

Description
Aerojet's historical LR91-AJ-11 was the single-chamber, gas-generator storable-propellant engine for Titan III and Titan IV second stages. NASA documents nitrogen tetroxide/Aerozine-50 propellants, 467,040 N (about 467.04 kN) maximum thrust, 316 s specific impulse, and a 247 s maximum firing lifetime; this record keeps the historical Titan application without inferring a current lifecycle or vehicle relationship.
Propellants
nitrogen tetroxideAerozine-50
Rocket Specs
Chamber Count
1
Cycle
gas generator
Vacuum Specific Impulse
…
Vacuum Thrust
…

Links

Official Url
https://ntrs.nasa.gov/api/citations/19950006191/downloads/19950006191.pdf

Assets & Meta

Creation Time
August 15, 2026 at 05:33:16 UTC
Updated Time
August 22, 2026 at 10:42:35 UTC
Image
Download

Other

Sources
  • Accessed Date
    2026-08-14
    Note
    NASA's Titan III propulsion analysis identifies the exact LR91-AJ-11 second-stage engine, its single-engine architecture, N2O4/Aerozine-50 propellants, 467,040 N maximum thrust, 316 s specific impulse, and 247 s maximum firing lifetime.
    Publisher
    NASA Technical Reports Server
    Title
    Titan III Propulsion Systems
    Url
    https://ntrs.nasa.gov/api/citations/19950006191/downloads/19950006191.pdf
  • Accessed Date
    2026-08-14
    Note
    NASA's Titan launch-vehicle propulsion memorandum distinguishes the LR91-AJ-11 single second-stage engine from the twin LR87-AJ-11 first-stage assembly and documents the Titan application.
    Publisher
    NASA Technical Reports Server
    Title
    Titan III Launch Vehicle Propulsion System
    Url
    https://ntrs.nasa.gov/api/citations/19750013258/downloads/19750013258.pdf