"RD-175" redirects here. For the Minolta RD-175, see Minolta RD-175.
RD-170 rocket engine model on exhibition in Saint Petersburg's Museum of Space and Missile Technology.
Country of origin Soviet Union/Russian Federation
Manufacturer NPO Energomash
Application Main engine
Liquid-fuel engine
Propellant LOX / RP-1 (Soviet/Russian equivalent)
Cycle Staged combustion
Nozzle ratio 36.87[1]
Thrust (vac.) 7.887MN (1,773,000lbf)
Thrust (SL) 7.550MN (1,697,300lbf) [1]
Thrust-to-weight ratio 82
Chamber pressure 245 bar[1]
Isp (vac.) 338 s (3,315 N·s/kg)
Isp (SL) 309 s (3,030 N·s/kg)
Burn time 150 s[1]

The RD-170 (РД-170, Ракетный Двигатель-170, Rocket Engine-170) is the world's most powerful liquid-fuel rocket engine, 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 turbo pump rated at 170 MW,[2] in a staged combustion cycle.[2]

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 is now out of production, but it forms the basis for a family of modern rocket engines.


One RD-170 variant, the RD-171, is currently used in the Zenit rocket. While the RD-170 had nozzles which swiveled on only one axis, the RD-171 swivels on two axes. Models called the RD-172 and RD-173 were proposed upgrades providing additional thrust, but they were never built.


Main article: RD-180

This variant uses only 2 combustion chambers instead of the 4 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.[3]


Main article: RD-191

Yet another variant, the single-chambered RD-191, will be used in the Russian Angara rocket, which is currently under development.[4]


The RD-151 is the RD-191 with thrust reduced from 196 to 170 tonnes. This engine was test-fired on July 30, 2009. The first flight test of this engine was conducted on August 25, 2009 as part of the first launch of South Korean Naro-1 rocket. The first stage of the Naro-1 rocket is made of the Universal Rocket Module (URM) from the Angara rocket.[5][6]

RD-180V, RD-175 and RD-193

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.[7] According to the information new and proposed variants will be marked as:

  • RD-180M for manned Atlas V rocket.
  • RD-180V for Rus-M rocket.
  • RD-193 for prospective Soyuz family rockets.
  • RD-175 with 9800 kN thrust for proposed Energia-K rocket.[8]


  • 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: Hypergolic
  • Vacuum thrust of 1,773,000 lbf (7,887 kN)
  • Vacuum Isp of 338 s (3,315 N·s/kg)
  • Sea Level Isp of 309 s (3,030 N·s/kg)
  • Weight: 9,750 kg (21,500 lb)
  • Thrust to weight ratio: 82

See also

  • Comparison of orbital rocket engines


External links

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