RD-170

---

title: "RD-170" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["rocket-engines-of-the-soviet-union", "rocket-engines-of-russia", "rocket-engines-using-kerosene-propellant", "soviet-inventions", "rocket-engines-using-the-staged-combustion-cycle", "energomash-rocket-engines"] description: "Soviet (now Russian) rocket engine, the most powerful in the world" topic_path: "geography/russia" source: "https://en.wikipedia.org/wiki/RD-170" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0

::summary Soviet (now Russian) rocket engine, the most powerful in the world ::

::data[format=table title="Infobox rocket engine"]

Field	Value
name	RD-170
image	RD-170.jpg
caption	Model of an RD-170 rocket engine, shown upside down
country_of_origin	Soviet Union
first_date
last_date
designer	NPO Energomash
manufacturer	NPO Energomash
purpose	Main engine
associated	Energia
successor	RD-180RD-191
status	Retired
type	liquid
oxidiser	LOX
fuel	RP-1
mixture_ratio	2.63
cycle	Oxidizer-rich staged combustion
combustion_chamber	4
nozzle_ratio	36.87
thrust(SL)	7250 kN
thrust(Vac)	7900 kN
throttle_range	40–100%
thrust_to_weight	82:1
chamber_pressure	24.52 MPa
specific_impulse_vacuum	337 isp
specific_impulse_sea_level	309 isp
burn_time	150 seconds
restarts
gimbal
length	4 m
diameter	3.8 m
dry_weight	9750 kg
references
::

| name = RD-170 | image = RD-170.jpg | caption = Model of an RD-170 rocket engine, shown upside down | country_of_origin = Soviet Union | first_date = | last_date = | designer = NPO Energomash | manufacturer = NPO Energomash | purpose = Main engine | associated = Energia | successor = RD-180RD-191 | status = Retired | type = liquid | oxidiser = LOX | fuel = RP-1 | mixture_ratio = 2.63 | cycle = Oxidizer-rich staged combustion | combustion_chamber = 4 | nozzle_ratio = 36.87 | thrust(SL) = 7250 kN | thrust(Vac) = 7900 kN | throttle_range = 40–100% | thrust_to_weight = 82:1 | chamber_pressure = 24.52 MPa | specific_impulse_vacuum = 337 isp | specific_impulse_sea_level = 309 isp | burn_time = 150 seconds | restarts = | gimbal = | length = 4 m | diameter = 3.8 m | dry_weight = 9750 kg | references =

The RD-170 () is the world's most powerful and heaviest 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 kerosene fuel and LOX oxidizer in four combustion chambers, all supplied by one single-shaft, single-turbine turbopump rated at 170 MW in a staged combustion cycle.

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.

Variants

RD-170

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 boosters, each powered by one RD-170.

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

RD-171

::figure[src="https://upload.wikimedia.org/wikipedia/commons/9/96/RD171_ILA2006.jpg" caption="RD-171 model"] ::

Building on the technology from the Energia's liquid fuel booster the Zenit was developed, which uses a RD-170 variant, the RD-171. While the RD-170 had nozzles which swiveled on two axes, the RD-171's nozzles only swivel on one axis. 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.

RD-171MV

A modification of RD-171M being developed for the Irtysh rocket. Unlike RD-171M it only uses Russian components and features a new control system.{{cite web|url=http://engine.space/press/pressnews/2378/ |title=В НПО ЭНЕРГОМАШ СОЗДАН ЭТАЛОННЫЙ МАКЕТ ДВИГАТЕЛЯ РД-171 МВ |language=ru |trans-title=Energomash has made a reference model of RD-171MV |work=NPO Energomash |date=16 October 2018 |url-status=dead |archive-url=https://web.archive.org/web/20220102063606/https://engine.space/press/pressnews/2378/ |archive-date=2 January 2022}} First test sample was manufactured in early 2019. Tests were reported to have been successfully completed in September 2021.

Dual-chamber derivative

Main article: RD-180

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.{{cite web|url=http://www.flightglobal.com/articles/2009/08/11/330691/the-bears-stars-shine-brighter.html|title=The Bear's stars shine brighter |last=Coppinger|first=Rob|date=2009-08-11|publisher=Flight International|url-status=dead |archive-url=https://web.archive.org/web/20090814192111/http://www.flightglobal.com/articles/2009/08/11/330691/the-bears-stars-shine-brighter.html |archive-date=14 August 2009}}

Single-chamber derivative

Main article: RD-191

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

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. According to the information, new and proposed variants will be marked as:

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

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.

Specifications

• 4 combustion chambers, 4 nozzles
• 1 set of turbines and pumps; turbine produces approximately 257,000 hp (192MW); equivalent to the power output of 3 nuclear-powered icebreakers
• Ignition: pyrophoric start-up fuel capsule (triethylaluminium)
• Vacuum thrust: 7887 kN
• Vacuum Isp: 338 isp
• Sea-level Isp: 309 isp
• Weight: 9,750 kg
• Thrust-to-weight ratio: 82

References

References

1. [https://web.archive.org/web/20160808152705/http://www.astronautix.com/r/rd-170.html RD-170] Astronautix. Mark Wade
2. (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.".
3. (9 October 2021). "Rocket Report: Next Falcon Heavy launch date set, Soyuz 5 engines clear tests".
4. (2007-12-12). "Successful Tests of Angara Stage 1 Engine". Khrunichev.
5. (August 1, 2011). "Проведено заседание НТС".
6. "Energomash 2011 catalog (Russian)". Roscosmos.
7. "Russia charts new path to super rocket". russianspaceweb.com.
8. "РД-170 (11Д521) и РД-171 (11Д520)".
9. Wade, Mark. "RD-170". Encyclopedia Astronautica.
10. Krebs, Gunter Dick. (2015-09-15). "Zenit family". Gunter's Space Page.
11. Ponomarenko, Alexander. "ЖРД РД-170 (11Д521) и РД-171 (11Д520)".
12. (25 August 2009). "First launch of KSLV-1 is conducted".
13. "RD-193". russianspaceweb.com.
14. (2009-08-25). "South Korea to launch first space rocket on Aug. 19". Yonhap News Agency.

::callout[type=info title="Wikipedia Source"] This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page. ::