| Country of origin | Soviet Union |
|---|---|
| First flight | 31 October 1977 |
| Designer | Yuzhnoye Design Bureau |
| Manufacturer | Yuzhmash |
| Application | Upper stage |
| AssociatedLV | R-36M UTTKh andDnepr |
| Successor | RD-869 |
| Liquid-fuel engine | |
| Propellant | N2O4 /UDMH |
| Mixture ratio | 1.8 |
| Cycle | Gas-generator |
| Configuration | |
| Chamber | 4 |
| Performance | |
| Thrust |
|
| Chamberpressure |
|
| Specific impulse |
|
| Burn time | Up to 600 seconds |
| Restarts | Up to 25 |
| Gimbal range | ±55° |
| Dimensions | |
| Length | 4,020 mm (13 ft 2 in) |
| Diameter | 1,420 mm (4 ft 8 in) |
| Dry mass | 199 kg (439 lb) |
| Used in | |
| R-36M UTTKh andDnepr third stage | |
| References | |
| References | [1][2][3][4][5][6][7][8][9] |
| Country of origin | Soviet Union |
|---|---|
| First flight | March 1986 |
| Designer | Yuzhnoye Design Bureau |
| Manufacturer | Yuzhmash |
| Application | Upper Stage |
| AssociatedLV | R-36M2 |
| Predecessor | RD-864 |
| Liquid-fuel engine | |
| Propellant | N2O4 /UDMH |
| Mixture ratio | 1.8 |
| Cycle | Gas-generator |
| Configuration | |
| Chamber | 4 |
| Performance | |
| Thrust |
|
| Chamberpressure |
|
| Specific impulse |
|
| Burn time | Up to 700 seconds |
| Restarts | Up to 50 |
| Gimbal range | ±55° |
| Dimensions | |
| Length | 4,020 mm (13 ft 2 in) |
| Diameter | 1,420 mm (4 ft 8 in) |
| Dry mass | 196 kg (432 lb) |
| Used in | |
| R-36M2 third stage | |
| References | |
| References | [1][5][6][10] |
TheRD-864 (Russian:Ракетный Двигатель-864,romanized: Raketnyy Dvigatel-864,lit. 'Rocket Engine 864',GRAU index:15D177) is aSovietliquid-fuel rocket engine burning ahypergolic mixture ofunsymmetrical dimethylhydrazine (UDMH) fuel withdinitrogen tetroxide (N2O4) oxidizer in agas generator combustion cycle.[1] It has a four combustion chambers that providethrust vector control bygimbaling each nozzle in a single axis ±55°. It is used on the third stage of theR-36M UTTKh (GRAU index:15A18) andDnepr.[5] For theR-36M2 (GRAU index:15A18M), an improved version, theRD-869 (GRAU index:15D300) was developed.[1][6][10][11]
When theSoviet military developed an improved version of theR-36MICBM,Yangel'sOKB-586 developed a new engine for the third stage, theRD-864. Developed between 1976 and 1978 it flew for the first time on October 31, 1977. With theSTART I andSTART II the some 150 R-36M and R-36M UTTKh were retired and to be destroyed by 2007.[1][4] So, a civilian application was looked for and during the 1990s,Yuzhnoe Design Bureau (the R-36M designer) successfully developed theDneprlaunch vehicle.[3] It flew for the first time on April 21, 1999, and as of June 2016 it is still operational.[12] So, while the production of the RD-864 has long since been finished, the engine is still to this day operational.[12][13]
TheRD-869 was an improved version for the most powerfulSovietICBM ever, theR-36M2 (15A18M). It had improved efficiency, restart capability and burn life over the RD-864.[1][10] As of January 2016 there are still 46 operational R-36M2 (RS-20V, SS-18) and thus the RD-869 is still in service, if out of production.[13]
There are two versions of this engine:
| Liquid fuel |
|  | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solid fuel |
| |||||||||||||||||
| ||||||||||||||||||