RD-250

Last updated
RD-250 (РД-250)
Rd-250.svg
Country of origin USSR
First flightDecember 16th, 1965
Designer OKB-456
Manufacturer PA Yuzhmash
Associated LV R-36, Tsyklon-2 and Tsyklon-3
StatusOut of Production
Liquid-fuel engine
Propellant N2O4 / UDMH
Mixture ratio2.6
Cycle Gas-generator
Configuration
Chamber2
Performance
Thrust, vacuum882 kN (198,000 lbf)
Thrust, sea-level788 kN (177,000 lbf)
Chamber pressure 8.33 MPa (1,208 psi)
Specific impulse, vacuum301 s (2.95 km/s)
Specific impulse, sea-level270 s (2.6 km/s)
Dimensions
Dry weight788 kg (1,737 lb)
Used in
R-36, Tsyklon-2 and Tsyklon-3 first stage
References
References [1] [2] [3] [4] [5] [6]
RD-250 rocket engine.jpg

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 gas-generator open cycle. [7] The RD-250 was developed by OKB-456 for Yangel's PA Yuzhmash ICBM, the R-36 (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.

Contents

Versions

The engine has seen different versions made:

Modules

Some of these engines were bundled into modules of multiple engines. The relevant modules and auxiliary engines are:

Comparison

RD-250 Family of Engines [1]
EngineRD-250RD-250PRD-250MRD-250PMRD-252RD-262
GRAU 8D5188D518P8D518M8D518PM8D72411D26
ModuleRD-251RD-251PRD-251MRD-261N/AN/A
Module GRAU8D7238D723P8D723M11D69N/AN/A
Development1962-19661967-19681966-19681968-19701962-19661968-1970
Propellant N2O4/UDMH
Combustion chamber pressure8.336 MPa (1,209.0 psi)8.924 MPa (1,294.3 psi)
Thrust, vacuum881.6 kN (198,200 lbf)881.6 kN (198,200 lbf)881.6 kN (198,200 lbf)881.7 kN (198,200 lbf)940.8 kN (211,500 lbf)941.4 kN (211,600 lbf)
Thrust, sea level788.5 kN (177,300 lbf)788.5 kN (177,300 lbf)788.5 kN (177,300 lbf)788.7 kN (177,300 lbf)N/AN/A
Isp, vacuum301 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 level270 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/AN/A
Length2,600 mm (100 in)2,600 mm (100 in)2,600 mm (100 in)N/A2,190 mm (86 in)2,190 mm (86 in)
Diameter1,000 mm (39 in)1,000 mm (39 in)1,000 mm (39 in)N/A2,590 mm (102 in)2,590 mm (102 in)
Dry weight728 kg (1,605 lb)728 kg (1,605 lb)728 kg (1,605 lb)N/A715 kg (1,576 lb)715 kg (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 stageR-36, R36P, R-36-O,
Tsyklon-2 2nd stage
Tsyklon-3 2nd stage

Possible technological transfer to North Korea

Several experts think that technology from the RD-250 engine could have been transferred to North Korea from Ukraine. This transfer would explain the rapid progress of North Korea in the development of two new missiles: the intermediate-range Hwasong-12 and the intercontinental ballistic missile (ICBM), Hwasong-14. Due to complexity of the technology involved in this type of engine, modifications or reverse engineering seem difficult to achieve. Thus it is believable that complete hardware could have been bought on black market and directly shipped to North Korea, by Russia or Ukraine. [10] Conversely, there is analysis [11] (made by two Ukrainian authors) suggesting an alternative mechanism for North Korea to receive R-36 missile engines, or an entire missile, from USSR or Russia.

See also

Related Research Articles

The Tsyklon, GRAU index 11K67, was a Soviet-designed expendable launch system, primarily used to put Cosmos satellites into low Earth orbit in the late-1960s. It is based on the R-36 intercontinental ballistic missile designed by Mikhail Yangel and made eight launches, with seven successes and one failure. All of its launches were conducted from LC-90 at the Baikonur Cosmodrome. It is sometimes designated Tsyklon-2A, not to be confused with the later Tsyklon-2 rocket. It was introduced in 1967 and was derived from the R-36 ICBM. It was retired in 1969.

<span class="mw-page-title-main">PA Pivdenmash</span> Ukrainian rocket manufacturer

The State Factory "Production Union Pivdennyi Machine-Building Plant named after O.M. Makarov", officially abbreviated as Pivdenmash and previously as Yuzhmash, is a Ukrainian state-owned aerospace manufacturer. Prior to 1991, it was a Soviet state-owned factory.

The UR-200 was an intercontinental ballistic missile (ICBM) developed by Vladimir Chelomey's OKB-52 in the Soviet Union. It was known during the Cold War by the NATO reporting name SS-10 Scrag and internally by the GRAU index 8K81. The design was authorized by the Decisions of the Central Committee of the CPSU of March 16 and August 1, 1961, and the draft project was finished in July 1962. It first flew on November 4, 1963, from the Baikonur Cosmodrome. The ninth and final flight was conducted on October 20, 1964.

<span class="mw-page-title-main">RD-253</span> Soviet engine design used on the first stage of Proton rockets

The RD-253 ( Russian: Раке́тный дви́гатель 253, Rocket Engine 253) and its later variants, the RD-275and RD-275M, are liquid-propellant rocket engines developed in the Soviet Union by Energomash. The engines are used on the first stage of the Proton launch vehicle and use an oxidizer-rich staged combustion cycle to power the turbopumps. The engine burns UDMH/N2O4, which are highly toxic but hypergolic and storable at room temperature, simplifying the engine's design.

The RD-120 is a liquid upper stage rocket engine burning RG-1 and LOX in an oxidizer rich staged combustion cycle with an O/F ratio of 2.6. It is used in the second stage of the Zenit family of launch vehicles. It has a single, fixed combustion chamber and thus on the Zenit it is paired with the RD-8 vernier engine. The engine was developed from 1976 to 1985 by NPO Energomash with V.P. Radovsky leading the development. It is manufactured by, among others, Yuzhmash in Ukraine.

The RD-0214 (GRAU Index: 8D811) is a rocket vernier engine burning N2O4 and UDMH in a gas generator cycle. It has four nozzles that can each gimbal 45 in plane to provide TVC to the RD-0212 propulsion module of Proton third stage. It is a revised version of the RD-0207.

<span class="mw-page-title-main">RD-0210</span>

The RD-0210 (GRAU Index: 8D411K) is also known as the RD-465. It and its twin, the RD-0211, are rocket engines burning N2O4 and UDMH in an oxidizer rich staged combustion cycle. They have single nozzle, possess TVC and are the latest evolution in the RD-0203/4 lineage. They are the engines used on the Proton second stage. The RD-0213 is a fixed nozzle variation that is used on the RD-0212 module of the Proton third stage.

The RD-0216 and RD-0217 are liquid rocket engines, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. The only difference between the RD-0216 and the RD-0217 is that the latter has not a heat exchanger to heat the pressuring gasses for the tanks. Three RD-0216 and one RD-0217 were used on the first stage of the UR-100 ICBM. The engines were manufactured until 1974 and stayed in operational use until 1991. More than 1100 engines were produced.

The RD-0233 (GRAU Index 15D95) and RD-0234 (GRAU Index 15D96) are liquid rocket engines, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. The only difference between the RD-0233 and the RD-0234 is that the latter has a heat exchanger to heat the pressuring gasses for the tanks. Three RD-0233 and one RD-0234 are used on the first stage of the UR-100UTTKh ICBM. While the engine is out of production, the ICBM as well as Rokot and Strela remain operational as of 2015.

The RD-0236 (GRAU Index 15D114) is a liquid rocket vernier engine, burning N2O4 and UDMH in the gas generator cycle. It is used along the RD-0235 main engine on the UTTKh second stage, which was featured in the UR-100N ICBM as well as the Strela and Rokot launch vehicles derived from it. Its function is to supply thrust vector control by gimbaling each of its four nozzles in a plane. While the engine is out of production, the ICBM as well as Strela remain operational as of 2015. The Rokot launch vehicle conducted its final launch before retirement in December 2019.

The RD-0237 (GRAU Index 15D114) is a pressure-fed liquid rocket vernier engine, burning N2O4 and UDMH. It is used on the UR-100UTTKh MIRV vehicle to supply thrust vector control by gimbaling of its nozzle. While the engine is out of production, the ICBM and Strela remain operational as of 2015.

The RD-263 (GRAU Index 15D117) is a liquid rocket engine, burning N2O4 and UDMH in the oxidizer rich staged combustion cycle. Four RD-263 engines form a propulsion module RD-264 (GRAU Index 15D119). For the R-36M KB Yuzhnoye only ordered the first stage propulsion to Energomash, instead of both stages, arguing that they were overworked with the RD-270 development. By April 1970 Yuzhnoye was getting the engine documentation. By the end of 1972 Energomash started to test fire the engines in its own test stand. And by September 1973 the engine was certified for flight. While the engine is out of production, the ICBM as well as the Dnepr remain operational as of 2015.

<span class="mw-page-title-main">RD-119</span>

The RD-119 was a liquid rocket engine, burning liquid oxygen and UDMH in the gas-generator cycle. It has a huge expansion ratio on the nozzle and uses a unique propellant combination to achieve an extremely high isp of 352 s for a semi-cryogenic gas-generator engine. It also has a unique steering mechanism. The engine main nozzle is fixed, and the output of the gas generator is fed into four nozzles on the side of the engine. Instead of using gimbaled verniers to supply vector control, the combustion gases are distributed by an electrically driven system that can control the thrust among the nozzles.

<span class="mw-page-title-main">RD-215</span> Rocket engine

The RD-215 (GRAU Index 8D513) was a dual nozzle liquid rocket engine, burning AK-27 (a mixture of 73% nitric acid and 27% N2O4 + iodine passivant) and UDMH. It was used in a module of two engines (four nozzles) known as the RD-216 (GRAU Index 8D514). The RD-215 was developed by OKB-456 for Yangel's Yuzhmash R-14 (8K65) ballistic missile. Its variations were also used on the Kosmos-1, Kosmos-3 and Kosmos-3M launch vehicles.

The RD-861 is a Soviet liquid propellant rocket engine burning UDMH and nitrogen tetroxide in a gas generator combustion cycle. It has a main combustion chamber, with four vernier nozzles fed by the gas generator output. It can be reignited a single time.

The RD-855 (GRAU Index 8D68M]), also known as the RD-68M, is a liquid-fueled rocket engine with four nozzles. As a vernier engine, it provides fine steering adjustments for rockets. It is powered by a combination of N2O4, an oxidizer, and UDMH, a propellant. This combination is hypergolic, meaning the two substances ignite on contact, eliminating the need for an external ignition source.

The RD-856 (GRAU Index 8D69M), also known as the RD-69M, is a four-nozzle liquid-fuel rocket vernier engine, burning N2O4 and UDMH in a gas generator cycle. It was used on the R-36, Tsyklon-2 and Tsyklon-3 second stage as thrust vector control by gimbaling of its nozzle. The engine is distributed through a cylindrical structure that is integrated around the main engine RD-252 module. The structure includes aerodynamic protection for the nozzles. The engine was started by a pyrotechnic ignitor.

The RD-0255 is a propulsion module composed of an RD-0256 main engine and a RD-0257 vernier engine. Both are liquid rocket engine, burning UDMH in N2O4. The RD-0256 main engine operates in the oxidizer rich staged combustion cycle, while the vernier RD-0257 uses the simpler gas generator cycle. It was used on the R-36MUTTKh (GRAU:15A18) and R-36M2 (GRAU:15A18M). Subsequently, it has been in the Dnepr second stage and as of 2016 it is still in active service.

The RD-864 is a Soviet liquid propellant rocket engine burning UDMH and nitrogen tetroxide in a gas generator combustion cycle. It has a four combustion chambers that provide thrust vector control by gimbaling each nozzle in a single axis ±55°. It is used on the third stage of the R-36M UTTKh and Dnepr. For the R-36M2, an improved version, the RD-869 was developed.

The Hwasong-14, also known under alternative US designation codename KN-20, is a mobile intercontinental ballistic missile developed by North Korea. It had its maiden flight on 4 July 2017, which coincided with the United States' Independence Day. North Korea is the only known operator of this missile.

References

  1. 1 2 "NPO Energomash list of engines". NPO Energomash. Archived from the original on 7 November 2014.
  2. "RD-250". Encyclopedia Astronautica. Archived from the original on August 26, 2002. Retrieved 2015-06-20.
  3. 1 2 "RD-251". Encyclopedia Astronautica. Archived from the original on June 26, 2002. Retrieved 2015-06-20.
  4. 1 2 "RD-252". Encyclopedia Astronautica. Archived from the original on May 31, 2002. Retrieved 2015-06-20.
  5. Pillet, Nicolas. "Tsiklone - Le premier étage" [Tsyklon - The first stage] (in French). Kosmonavtika.com. Retrieved 2016-07-04.
  6. Pillet, Nicolas. "Tsiklone - Le deuxième étage" [Tsyklon - The second stage] (in French). Kosmonavtika.com. Retrieved 2016-07-04.
  7. "The RD-250 engine at the center of an international storm". www.russianspaceweb.com. Retrieved 2023-01-03.
  8. "RD-262". Encyclopedia Astronautica. Archived from the original on October 28, 2002. Retrieved 2015-06-20.
  9. "RD-261". Encyclopedia Astronautica. Archived from the original on June 27, 2002. Retrieved 2015-06-20.
  10. "The secret to North Korea's ICBM success". www.iiss.org. Retrieved 2017-08-15.
  11. North Korean Missile Engines: Not from Ukraine, Mariana Budjeryn & Andrew Zhalko-Tytarenko, Atlantic Council, 2017-09-12