R-4D
RCS quad containing four R-4D thrusters, as used on the Apollo Service Module | |
| Country of origin | United States |
|---|---|
| Manufacturer | Kaiser Marquardt Aerojet Rocketdyne |
| Application | Reaction control system |
| Liquid-fuel engine | |
| Propellant | NTO / MMH |
| Cycle | Pressure-fed |
| Performance | |
| Thrust, vacuum | 110 pounds-force (490 N) |
| Thrust-to-weight ratio | 13.74 |
| Chamber pressure | 100.5 pounds per square inch (6.93 bar) |
| Specific impulse, vacuum | 312 s |
| Dimensions | |
| Length | 12.00 inches (30.5 cm) |
| Diameter | 6.00 inches (15.2 cm) |
| Dry mass | 8.00 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.