R-4D
The R-4D is L3Harris's family of approximately 100-lbf-class monomethylhydrazine/nitrogen-tetroxide bipropellant spacecraft thrusters. Originally developed for Apollo and central to the Apollo 13 rescue, the family evolved into a current apogee-insertion, maneuvering, and reaction-control product. The commonly documented R-4D-11 configuration is a distinct 110-lbf (490 N), 315 s variant; that rating is not universal across the family.
Identity
- Aliases
- R4D
- Domains
- spaceflight
- Identity Level
- family
- Kind
- chemical-thruster
- Name
- R-4D
- Status
- active
Details
- Description
- The R-4D is L3Harris's family of approximately 100-lbf-class monomethylhydrazine/nitrogen-tetroxide bipropellant spacecraft thrusters. Originally developed for Apollo and central to the Apollo 13 rescue, the family evolved into a current apogee-insertion, maneuvering, and reaction-control product. The commonly documented R-4D-11 configuration is a distinct 110-lbf (490 N), 315 s variant; that rating is not universal across the family.
- Manufacturers
- Propellants
- monomethylhydrazine (MMH)nitrogen tetroxide (NTO)
- Rocket Specs
- Vacuum Thrust Kn
- 0.4448
Assets & Meta
- Creation Time
- August 15, 2026 at 05:08:08 UTC
- Updated Time
- August 15, 2026 at 05:08:08 UTC
Other
- Sources
- Accessed Date
- 2026-08-14
- Note
- Current product page identifies the R-4D as a 100-pound-thrust bipropellant family and says it remains an available apogee-insertion engine.
- Publisher
- L3Harris Technologies
- Title
- Chemical In-Space Propulsion
- Accessed Date
- 2026-08-14
- Note
- Manufacturer family sheet documents Apollo origin, 100-pound-thrust class, and more than 300 successful apogee-insertion missions.
- Published Date
- 2025-05
- Publisher
- L3Harris Technologies
- Title
- Bipropellant Rocket Engines
- Accessed Date
- 2026-08-14
- Note
- NASA technical paper identifies the R-4D as an iconic spacecraft reaction-control thruster and gives the R-4D-11 490 N/315 s configuration.
- Published Date
- 2020-07-01
- Publisher
- NASA
- Title
- Development of Concept Illustration Variants of the JUMP Lander