R-4D

R-4D
RCS quad containing four R-4D thrusters, as used on the Apollo Service Module
Country of originUnited States
ManufacturerKaiser Marquardt
Aerojet Rocketdyne
ApplicationReaction control system
Liquid-fuel engine
PropellantNTO / MMH
CyclePressure-fed
Performance
Thrust, vacuum110 pounds-force (490 N)
Thrust-to-weight ratio13.74
Chamber pressure100.5 pounds per square inch (6.93 bar)
Specific impulse, vacuum312 s
Dimensions
Length12.00 inches (30.5 cm)
Diameter6.00 inches (15.2 cm)
Dry mass8.00 pounds (3.63 kg)
Used in
Orion (spacecraft)
H-II Transfer Vehicle (1, 2, 4)
Space Shuttle
Apollo (spacecraft)
Cassini (spacecraft)
ESA Automated Transfer Vehicle

The R-4D is a small hypergolic rocket engine, originally designed by Marquardt Corporation for use as a reaction control system thruster on vehicles of the Apollo crewed Moon landing program. Aerojet Rocketdyne manufactures and markets modern versions of the R-4D.[1]

  1. ^ "Bipropellant Rocket Engines". Aerojet Rocketdyne. Archived from the original on 12 May 2014. Retrieved 7 May 2014.