1:1 scale model of an RD-170 rocket engine, shown upside down
|Country of origin||Soviet Union/Russian Federation|
|Propellant||LOX / RP-1|
|Cycle||Oxidizer-rich staged combustion|
|Thrust (vac.)||7.90 MN (1,780,000 lbf)|
|Thrust (SL)||7.25 MN (1,630,000 lbf)|
|Chamber pressure||24.52 MPa (3,556 psi)|
|Isp (vac.)||337 s (3.30 km/s)|
|Isp (SL)||309 s (3.03 km/s)|
|Burn time||150 seconds|
|Length||4.0 m (160 in)|
|Diameter||3.8 m (150 in)|
|Dry weight||9,750 kg (21,500 lb)|
The RD-170 (РД-170, Ракетный Двигатель-170, Rocket Engine-170) is the world's most powerful liquid-fuel rocket engine and - regardless of the fuel type - second after Space Shuttle's SRB. 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. By comparison, the Rocketdyne F-1 engine (five of which were used on each Saturn V) is the world's most powerful single-combustion chamber rocket engine.
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.
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. 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.
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. First test sample was manufactured in early 2019
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.
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.
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: