RD-191

Known engine modifications:

• RD-191 - was used in the first stage of the Korean launch vehicle Naro-1 ;
• RD-191 No. DO27 - advanced for the Angara launch vehicle;
• RD-193 is intended for use in the first stage of the Soyuz-2.1v launch vehicle;
  • RD-181 (export version of RD-193 ) is installed on the US Antares launch vehicle of Orbital Sciences Corporation , as a replacement for the NK-33 engines.

• By the beginning of 2010, the RD-191 passed the full cycle of fire tests at the bench and three fire tests as part of the first-stage unit ( URM-1 ) of the Angara launch vehicle. The test programs corresponded to the cyclograms of the work of the URM as part of the Angara-1.2PP, the Angara-A5 side unit and the Angara-A5 central unit. In the latter case, the engine was throttled to 30% of the nominal value, which is a record for engines operating at atmospheric pressure at sea level.

• Also, in 2009, the RD-191 engine passed flight tests as part of the first stage of the Naro-1 LV ( Republic of Korea ). The first stage worked fine, but, due to the non-discharge of the head fairing, the satellite did not enter orbit ^[2] .
  

The second launch, which took place on June 10, 2010, also ended in failure, and this time the failure occurred at the 137th second of the flight, at the stage of the first stage. One of the possible causes of an emergency was called an emergency failure of the main engine of the first stage. To find out the causes of the accident, a joint commission was created, which included Russian and South Korean experts ^[3] . The Commission found that the Russian stage, like the first time, was not to blame, and the cause of the accident was the erroneous work of the second, Korean, stage ^[4] .

• In July 2010, during the planned interdepartmental tests, he could not withstand repeated overloads and burned out RD-191 for the first stage of the Angara launch vehicle.

The engine was supposed to burn out. This is an absolutely normal standard situation, experts had to establish what kind of load he was able to withstand.

- Press center - NPO Energomash ^[5]

• On March 29, 2011, the RD-191 engine successfully passed the next firing tests at the test bench of NPO Energomash. The engine has successfully completed the program for 223 s.

• On May 23, 2011, an interdepartmental commission (MVK), formed by a joint decision of the Space Forces of the Ministry of Defense of the Russian Federation and the Federal Space Agency, signed an act stating that the RD-191 engine successfully completed the ground development stage and is suitable for use as part of a launch vehicle family The Angara ^[6] .

• On January 30, 2013, the successful launch of the Naro-1 launch vehicle took place ^[7] . Thus, RD-191 for the third time successfully worked out as part of the first stage of the Naro-1 launch vehicle.

• On July 9, 2014, the first test launch of the Angara-1.2PP launch vehicle with the first stage RD-191 propulsion engine was successfully carried out from the Plesetsk Cosmodrome .

• On December 23, 2014, the first test launch of the Angara-5 LV with the first stage RD-191 mid-flight engine was successfully carried out from the Plesetsk Cosmodrome.

• On January 23, 2015, it became known that, within the framework of the state defense order, NPO Energomash, during 2015-2016, will produce 10 RD-191 engines for use in the Angara-A5 LV ^[8] .

• On August 25, 2015 NPO Energomash began to create a modernized version of the RD-191 engine - RD-191M - which will be used on the Angara-A5V and Angara-A5P rocket launchers and will be 10-15% more powerful than its predecessor. The first phase of the advance project will be completed in September 2015. Development is planned to be completed by 2018.

• In November 2015, Proton-Perm Motors PJSC announced a tender for the reconstruction of workshops for the production of the RD-191 engine for Angara missiles. ^[9]

• In September 2016, it became known that digital design would be introduced for the RD-191. For this, a project team, a steering committee was formed and a budget was determined. The project is designed for three years ^[1] .

• January 18, 2017 Center them. Khrunicheva told the media about the planned increase in the Angara-1.2 and Angara-A5 ILV payloads thanks to the use of the RD-191M engine, the technical design of which was developed by NPO Energomash. Specialists managed to create and test the RD-191M with access to the thrust mode of 110%. Thus, for Angara-A5M, the carrying capacity will increase from 24 to about 25.5 tons when launched into a low orbit, which is 3.5 tons more than the capabilities of Proton-M ^[10] .

• On August 1, 2017, the Energomash press service reported that in August the company began periodic confirmation tests of the RD-191 for Angara launch vehicles, the total number of which would be six burns ^[11] .

• February 27, 2018 NPO Energomash announced the start of the introduction of additive technologies in the production of liquid rocket engines. According to KBHA experts, the use of additive technologies will reduce the labor input of this engine by 20%. According to R&D, the designers of NPO Energomash plan to carry out work in several areas of application of additive technologies for use in the production of RD-191:
• Development of an engine boost engine RD-191, made by additive technology;
• Testing of additive manufacturing technology for the roll nozzle block housing (KBSK) of the RD-191 engine;
• Redesign of the pneumatic unit of the RD-191 engine;
• Conducting topological optimization and manufacturing of engine brackets RD-191 ^[12]

• On April 11, 2018, NPO Energomash announced that it was working on the translation of all technical documentation for the RD-191 engine into electronic format and into 3D models of parts, assemblies and the engine as a whole. On the basis of electronic documentation, technological processes and control programs for modern multi-axis machine tools with numerical control are compiled. That allows you to optimize the manufacturing process and, as a result, reduce the total cost. ^[13] .

• On August 27, 2019, the head of Roscosmos, Dmitry Rogozin, at the International Aviation and Space Salon MAKS-2019 announced that the production of RD-191 for Angara launch vehicles will increase multiple from 2023 with the start of mass production of carriers. The Proton-PM enterprise will actively participate in the manufacture of RD-191 ^[14] .

• Thrust (at sea level / in vacuum): 196 / 212.6 tf ;
• Specific impulse (at sea level / in vacuum): 311.5 / 337.4 s ;
• Throttle throttle range (from the nominal value): 27-105% ^[15] ;
• Fuel components: liquid oxygen and kerosene RG-1;
• Dry weight: about 2.2 tons

Main characteristics of the RD-191M

• Thrust (at sea level / in vacuum): 217.4 / 234 tf ;
• Specific impulse (at sea level / in vacuum): 314/338 s;
• Pressure
• Liquid rocket two-component
• Afterburning oxidative generator gas
• The option of a retractable nozzle nozzle was considered, but in this case it would have to be put forward with the engine running, which is connected with a lot of difficulties that could not be solved with the current manual (the retractable nozzle nozzles would significantly raise the PN of two-stage missiles without boosting the engine and a noticeable increase in cost)

• RD-180
• RD-170
• NK-33
• Closed cycle rocket engine