1:1 scale model of an RD-170 rocket engine, shown upside down
Country of originSoviet Union/Russian Federation
First flight1985-04-13
ManufacturerNPO Energomash
ApplicationMain engine
Associated LVEnergia
Liquid-fuel engine
PropellantLOX / RP-1
Mixture ratio2.63
CycleOxidizer-rich staged combustion
Nozzle ratio36.87
Thrust (vacuum)7.90 MN (1,780,000 lbf)
Thrust (sea-level)7.25 MN (1,630,000 lbf)
Throttle range100–40%
Thrust-to-weight ratio75:1
Chamber pressure24.52 MPa (3,556 psi)
Specific impulse (vacuum)337 s (3.30 km/s)
Specific impulse (sea-level)309 s (3.03 km/s)
Burn time150 seconds
Length4.0 m (160 in)
Diameter3.8 m (150 in)
Dry weight9,750 kg (21,500 lb)
Used in

The RD-170 (РД-170, Ракетный Двигатель-170, Rocket Engine-170) is the world's most powerful and heavy liquid-fuel rocket engine. It was designed and produced in the Soviet Union by NPO Energomash for use with the Energia launch vehicle. The engine burns the Russian equivalent of RP-1 fuel and LOX oxidizer in four combustion chambers, all supplied by one single-shaft, single-turbine turbopump rated at 170 MW (230,000 hp) in a staged combustion cycle.[3][5]

Shared turbopump

Several Soviet and Russian rocket engines use the approach of clustering small combustion chambers around a single turbine and pump. During the early 1950s, many Soviet engine designers, including Valentin P. Glushko, faced problems of combustion instability while designing bigger thrust chambers. At that time, they solved the problem by using a cluster of smaller thrust chambers.



The RD-170 engine featured four combustion chambers and was developed for use on the Energia launch vehicle – both the engine and the launch vehicle were in production only for a short time. Energia was launched twice. Each Energia vehicle had 4 Zenit boosters, each booster had one RD-170. So eight RD-170 engines flew (on Energia).

The engine was designed for 10 reuses but tests showed they could stand up to 20 burns.[6]


RD-171 model

Building on the technology from the Energia's liquid fuel booster the Zenit (rocket family) was developed, which uses a RD-170 variant, the RD-171. While the RD-170 had nozzles which swiveled on one axis only, the RD-171 swivels on two axes.[2] RD-171 was intended to be used on Zenit rocket. Models called the RD-172 and RD-173 were proposed, upgrades that would provide additional thrust, and the RD-173 proposal was finalized as the RD-171M upgrade in 2006.[2]


A modification of RD-171M being developed for the Irtysh rocket. Unlike RD-171M it's completely made from Russian components and features a new control system.[7] First test sample was manufactured in early 2019[8]

Dual-chamber derivative

The RD-180 uses only two combustion chambers instead of the four of the RD-170. The RD-180 used on the Atlas V replaced the three engines used on early Atlas rockets with a single engine and achieved significant payload and performance gains. This engine had also been chosen to be the main propulsion system for the first stage of the now cancelled Russian Rus-M rocket.[9]

Single-chamber derivative

The RD-191 is a single-chamber version used in the Russian Angara rocket.[10] Variants of RD-191 include RD-151 in South Korean Naro-1 rocket,[11] RD-181 in American Orbital ATK Antares rocket, and the proposed RD-193 for the Soyuz-2-1v project.[12]

Proposed variants

On 28 July 2011, NPO Energomash summarised the results of the work on Rus-M rocket engine and considered the possibility of construction several new variants of RD-170 family engines.[13] According to the information, new and proposed variants will be marked as:

  • RD-180M for manned Atlas V rocket (Not required, current RD-180 meets manned Atlas V requirements.)[14]
  • RD-180V for Rus-M rocket.
  • RD-175 with 9800 kN thrust for proposed Energia-K rocket.[15]

In 2017, Director General of RKK Energia Vladimir Solntsev referred to a "simplified" and "cheaper" version of the RD-171 engine in connection with the Soyuz-5 (Sunkar) project.[16]


  • 4 combustion chambers, 4 nozzles
  • 1 set of turbines and pumps; turbine produces approximately 257,000 hp (192 MW); equivalent to the power output of 3 nuclear-powered icebreakers
  • Ignition: pyrophoric start-up fuel capsule (triethylaluminium)[17]
  • Vacuum thrust: 7,887 kN (1,773,000 lbf)
  • Vacuum Isp: 338 s (3.31 km/s)
  • Sea-level Isp: 309 s (3.03 km/s)
  • Weight: 9,750 kilograms (21,500 lb)
  • Thrust-to-weight ratio: 82

See also


  1. ^ "RD-171M". NPO Energomash. Retrieved 2018-02-22.
  2. ^ a b c Ponomarenko, Alexander. "ЖРД РД-170 (11Д521) и РД-171 (11Д520)" [RD-170 (11D521) and RD-171 (11D520)] (in Russian). Retrieved 2015-10-08.
  3. ^ a b Wade, Mark. "RD-170". Encyclopedia Astronautica. Retrieved 2015-10-08.
  4. ^ Krebs, Gunter Dick (2015-09-15). "Zenit family". Gunter's Space Page. Retrieved 2015-10-08.
  5. ^ "South Korea to launch first space rocket on Aug. 19". Yonhap News Agency. 2009-08-25. Retrieved 2015-10-08.
  6. ^ RD-170Astronautix. Mark Wade
  7. ^ "В НПО ЭНЕРГОМАШ СОЗДАН ЭТАЛОННЫЙ МАКЕТ ДВИГАТЕЛЯ РД-171 МВ" [Energomash has made a reference model of RD-171MV]. NPO Energomash (in Russian). 16 October 2018. Retrieved 17 March 2019.
  8. ^ @Rogozin (8 February 2019). "Первый двигатель РД-171МВ для новейшей ракеты среднего класса Союз-5 "Иртыш" собран на подмосковном "НПО Энергомаш" и готовится к огневым испытаниям" [First sample RD-171MV for Soyuz-5 Irtish manufactured in Energomash is ready for testing.] (Tweet) (in Russian) – via Twitter.
  9. ^ Coppinger, Rob (2009-08-11). "The Bear's stars shine brighter". Flight International. Retrieved 2009-08-22.
  10. ^ "Successful Tests of Angara Stage 1 Engine". Khrunichev. 2007-12-12. Archived from the original on 2007-12-30.
  11. ^ "First launch of KSLV-1 is conducted". 2009-08-25.
  12. ^ Zak, Anatoly. "RD-193". russianspaceweb.com. Retrieved 2015-06-04.
  13. ^ "Проведено заседание НТС" (in Russian). August 1, 2011. Archived from the original on September 30, 2011. Retrieved August 26, 2011.
  14. ^ "Energomash 2011 catalog (Russian)". Roscosmos. Retrieved February 15, 2018.
  15. ^ "Russia's Energomash: new rocket engines in development". VoiceofRussia.com. The Voice of Russia. 2012-02-22. Retrieved 2014-11-12.
  16. ^ "Russia charts new path to super rocket". russianspaceweb.com. Retrieved February 15, 2018.
  17. ^ "РД-170 (11Д521) и РД-171 (11Д520)".

External links

  • Manufacturer's Page
  • RD-170/171 specifications and design (in Russian)
  • External image
  • Astronautix.com entry on RD-170