RD-214
# RD-214

The RD-214 (GRAU Index 8D59) was a liquid rocket engine, burning AK-27I (a mixture of 73% nitric acid and 27% $N_2O_4$ + iodine passivant and TM-185 (a kerosene and gasoline mix) in the gas generator cycle. As was the case with many V-2 influenced engines, the single turbine was driven by steam generated by catalytic decomposition of $H_2O_2.$ It also had four combustion chambers and vector control was achieved by refractory vanes protruding into the nozzle's exhaust.

## Development

For the requirements to have storable propellants and higher thrust, Glushko's OKB-456 developed the RD-211, which had four combustion chambers, each having twice the thrust of the RD-100, a Russian adaptation of the V-2 A-4 engine. The four chambers were fed from a single turbopump powered by steam generated from catalytic decomposition of $H_2O_2.$ When then came the requirement for the Buran cruise missile project, a version for that application was developed in the RD-212. Both RD-211 and RD-212 proved too weak for the application and the project were abandoned for the RD-213 for Buran. When Yangel's OKB-586 was tasked with developing the first storable propellant ballistic missile in the Soviet arsenal, the RD-211 proved too weak. Thus, the project was definitely abandoned and the more powerful RD-214 was developed. While Korolev's refusal to use toxic propellants basically left him out of the ballistic missile development race, the basic design of the RD-211 also served as basis for the RD-107/RD-108 engine, which went to be the most flown rocket engines in history.

The initial R-12 was a pad launched missile. It had significant operative issues on readiness and vulnerability. Thus, the silo launched R-12U was developed. For this development the RD-214U was developed. When Yangel used the R-12U as the basis for the Kosmos-2 63S1, the RD-214F was developed and fire tested, but in the end the stock R-12U was used as first stage. So it was for all subsequent 63S1M and 11K63.

## Versions

This engine many versions:

* RD-211: GRAU Index 8D57. Original design for the R-12. Based on the RD-100, itself an adaptation of the V-2 A4 engine. This engine already had four separate combustion chambers, an $H_2O_2$ steam driven turbine and required vanes in the exhaust to control the rocket.
* RD-212: GRAU Index 8D41. Originally developed from the RD-211 for the Buran cruise missile project. Project drop in favor of RD-213 due to insufficient thrust.
* RD-213: GRAU Index 8D13. Similar to the RD-214. Developed for the Buran cruise missile project. Cancelled with the project.
* RD-214: GRAU Index 8D59. Original version of the engine designed for the R-12 (8K63).
* RD-214U: GRAU Index 8D59. Improved version of the engine. Flew on the R-12U (8K63S) and Kosmos-2 (11K63) launch vehicle.
* RD-214F: GRAU Index 11D45. Project for the initial version of Kosmos-2 (63S1).

RD-214 Family of Engines :

| Engine | RD-211 | RD-212 | RD-213 | RD-214 | RD-214U | RD-214F |
| - | - | - | - | - | - | - |
| AKA | 8D57 | 8D41 | 8D13 | 8D59 | 8D59U | 11D45 |
| Development | 1953-1955 | 1954-1956 | 1956-1957 | 1955-1959 | 1959-1960 | 1960-1962 |
| Engine type | Gas generator | Gas generator | Gas generator | Gas generator | Gas generator | Gas generator |
| Propellant | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) | AK-27I (73% nitric acid, 27% $N_2O_4,$ and iodine passivant) / TM-185 (a kerosene and gasoline mix) |
| Combustion chamber pressure | 3.923 megapascals (569.0 psi) | 3.923 megapascals (569.0 psi) | 4.66 megapascals (676 psi) | 4.36 megapascals (632 psi) | 4.36 megapascals (632 psi) | 4.38 megapascals (635 psi) |
| Thrust, vacuum | 642.3 kilonewtons (144,400 lbf) | 622.7 kilonewtons (140,000 lbf) | 749.2 kilonewtons (168,400 lbf) | 730.2 kilonewtons (164,200 lbf) | 730.6 kilonewtons (164,200 lbf) | 729.6 kilonewtons (164,000 lbf) |
| Thrust, sea level | 549.2 kilonewtons (123,500 lbf) | 559 kilonewtons (126,000 lbf) | 686.5 kilonewtons (154,300 lbf) | 635.2 kilonewtons (142,800 lbf) | 635.5 kilonewtons (142,900 lbf) | 635.5 kilonewtons (142,900 lbf) |
| $I_{sp},$ vacuum | 253 s (2.48 km/s) | 254 s (2.49 km/s) | 264 s (2.59 km/s) | 264 s (2.59 km/s) | 264 s (2.59 km/s) | 264 s (2.59 km/s) |
| $I_{sp},$ sea level | 224 s (2.20 km/s) | 227 s (2.23 km/s) | 231 s (2.27 km/s) | 230 s (2.3 km/s) | 230 s (2.3 km/s) | 230 s (2.3 km/s) |
| Burn time | 122s | 100s | 110s | | 140s | |
| Length | 2,700 millimetres (110 in) | 2,500 millimetres (98 in) | 2,500 millimetres (98 in) | 2,380 millimetres (94 in) | 2,380 millimetres (94 in) | 2,380 millimetres (94 in) |
| Diameter | 1,650 millimetres (65 in) | 1,480 millimetres (58 in) | 1,480 millimetres (58 in) | 1,500 millimetres (59 in) | 1,480 millimetres (58 in) | 1,480 millimetres (58 in) |
| Dry weight | 635 kilograms (1,400 lb) | 642 kilograms (1,415 lb) | 625 kilograms (1,378 lb) | 655 kilograms (1,444 lb) | 655 kilograms (1,444 lb) | 655 kilograms (1,444 lb) |
| Use | R-12 (8K63) Project | Buran Project | Buran Project | R-12 (8K63) | R-12U (8K63S) Kosmos-2 (11K63) | Project for Kosmos-2 (63S1) |
