RD-250
Country of origin | USSR |
---|---|
First flight | December 16th, 1965 |
Designer | OKB-456 |
Manufacturer | PA Yuzhmash |
Associated LV | R-36, Tsyklon-2 and Tsyklon-3 |
Status | Out of Production |
Liquid-fuel engine | |
Propellant | N2O4 / UDMH |
Mixture ratio | 2.6 |
Cycle | Oxidizer Rich Staged Combustion |
Configuration | |
Chamber | 2 |
Performance | |
Thrust, vacuum | 788 kilonewtons (177,000 lbf) |
Thrust, sea-level | 882 kilonewtons (198,000 lbf) |
Chamber pressure | 8.33 megapascals (1,208 psi) |
Specific impulse, vacuum | 301 s (2.95 km/s) |
Specific impulse, sea-level | 270 s (2.6 km/s) |
Dimensions | |
Dry weight | 788 kg (1,737 lb) |
Used in | |
R-36, Tsyklon-2 and Tsyklon-3 first stage | |
References | |
References | [1][2][3][4][5][6] |
The RD-250 (GRAU Index 8D518) is the base version of a dual nozzle family of liquid rocket engines, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. The RD-250 was developed by OKB-456 for Yangel's PA Yuzhmash ICBM, the R-36 (missile) (8K67). Its variations were also used on the Tsyklon-2 and Tsyklon-3 launch vehicles. It was supposed to be used on the Tsyklon-4, but since the cancellation of the project it should be considered as out of production.
Versions
The engine has seen different versions made:
- RD-250 (GRAU Index 8D518): Base engine of the family. Used on the R-36. A bundle of three RD-250 form the RD-251 cluser.
- RD-250P (GRAU Index 8D518P): Improved version of the RD-250. Used on the R-36P. A bundle of three RD-250P form the RD-251P cluser.
- RD-250M (GRAU Index 8D518M): Improved version of the RD-250P. Used on the R-36-O. A bundle of three RD-250M form the RD-251M cluser.
- RD-250PM (GRAU Index 8D518PM): Improved version of the RD-250M. Used on the Tsyklon-3. A bundle of three RD-250PM form the RD-261 cluser.
- RD-252 (GRAU Index 8D724): Vacuum optimized version of the RD-250. Used on the R-36 and Tsyklon-2 second stages.[4]
- RD-262 (GRAU Index 11D26): Improved version of the RD-252. Used on the Tsyklon-3 second stages.[7]
Modules
Some of these engines were bundled into modules of multiple engines. The relevant modules and auxiliary engines are:
- RD-251 (GRAU Index 8D723): A module comprising three RD-250. Propulsion module of the R-36 (8K67) first stage.[3]
- RD-251P (GRAU Index 8D723P): A module comprising three RD-250P. Propulsion module of the R-36P (8K68) first stage.
- RD-251M (GRAU Index 8D723M): A module comprising three RD-250M. Propulsion module of the R-36-O (8K69) and Tsyklon-2 first stage.
- RD-261 (GRAU Index 11D69): A module comprising three RD-250PM. Propulsion module of the Tsyklon-3 first stage.[8]
Comparison
Engine | RD-250 | RD-250P | RD-250M | RD-250PM | RD-252 | RD-262 |
---|---|---|---|---|---|---|
GRAU | 8D518 | 8D518P | 8D518M | 8D518PM | 8D724 | 11D26 |
Module | RD-251 | RD-251P | RD-251M | RD-262 | N/A | N/A |
Module GRAU | 8D723 | 8D723P | 8D723M | 11D69 | N/A | N/A |
Development | 1962-1966 | 1967-1968 | 1966-1968 | 1968-1970 | 1962-1966 | 1968-1970 |
Propellant | N2O4/UDMH | |||||
Combustion chamber pressure | 8.336 megapascals (1,209.0 psi) | 8.924 megapascals (1,294.3 psi) | ||||
Thrust, vacuum | 881.6 kilonewtons (198,200 lbf) | 881.6 kilonewtons (198,200 lbf) | 881.6 kilonewtons (198,200 lbf) | 881.7 kilonewtons (198,200 lbf) | 940.8 kilonewtons (211,500 lbf) | 941.4 kilonewtons (211,600 lbf) |
Thrust, sea level | 788.5 kilonewtons (177,300 lbf) | 788.5 kilonewtons (177,300 lbf) | 788.5 kilonewtons (177,300 lbf) | 788.7 kilonewtons (177,300 lbf) | N/A | N/A |
Isp, vacuum | 301 s (2.95 km/s) | 301 s (2.95 km/s) | 301 s (2.95 km/s) | 301.4 s (2.956 km/s) | 317.6 s (3.115 km/s) | 318 s (3.12 km/s) |
Isp, sea level | 270 s (2.6 km/s) | 270 s (2.6 km/s) | 270 s (2.6 km/s) | 269.6 s (2.644 km/s) | N/A | N/A |
Length | 2,600 millimetres (100 in) | 2,600 millimetres (100 in) | 2,600 millimetres (100 in) | N/A | 2,190 millimetres (86 in) | 2,190 millimetres (86 in) |
Diameter | 1,000 millimetres (39 in) | 1,000 millimetres (39 in) | 1,000 millimetres (39 in) | N/A | 2,590 millimetres (102 in) | 2,590 millimetres (102 in) |
Dry weight | 728 kilograms (1,605 lb) | 728 kilograms (1,605 lb) | 728 kilograms (1,605 lb) | N/A | 715 kilograms (1,576 lb) | 715 kilograms (1,576 lb) |
Use | R-36 (8K67) 1st stage | R-36P (8K67P) 1st stage | R-36-O (8K67-O) and Tsyklon-2 1st stage | Tsyklon-3 1st stage | R-36, R36P, R-36-O, Tsyklon-2 2nd stage | Tsyklon-3 2nd stage |
See also
- UR-36 - ICBM for which this engine was originally developed for.
- Tsyklon-2 - launch vehicle based on the UR-36.
- Tsyklon-3 - Three stage launch vehicle developed from the Tsyklon-2.
- Rocket engine using liquid fuel
References
- ^ a b "NPO Energomash list of engines". NPO Energomash. Retrieved 2015-06-20.
- ^ "RD-250". Encyclopedia Astronautica. Retrieved 2015-06-20.
- ^ a b "RD-251". Encyclopedia Astronautica. Retrieved 2015-06-20.
- ^ a b "RD-252". Encyclopedia Astronautica. Retrieved 2015-06-20.
- ^ Pillet, Nicolas. "Tsiklone - Le premier étage" [Tsyklon - The first stage] (in French). Kosmonavtika.com. Retrieved 2016-07-04.
- ^ Pillet, Nicolas. "Tsiklone - Le deuxième étage" [Tsyklon - The second stage] (in French). Kosmonavtika.com. Retrieved 2016-07-04.
- ^ "RD-262". Encyclopedia Astronautica. Retrieved 2015-06-20.
- ^ "RD-261". Encyclopedia Astronautica. Retrieved 2015-06-20.