RD-170

"RD-175" redirects here. For the Minolta RD-175, see Minolta RD-175.

RD-170

RD-170 rocket engine model on exhibition in Saint Petersburg's Museum of Space and Missile Technology.
Country of origin	Soviet Union/Russian Federation
First flight	1985-04-13
Manufacturer	NPO Energomash
Application	Main Engine
Associated L/V	Energia
Successor	RD-171M
Status	Retired
Liquid-fuel engine
Propellant	LOX / RG-1
Mixture ratio	2.63
Cycle	Oxidizer Rich Staged Combustion
Configuration
Chamber	4
Nozzle ratio	36.87
Performance
Thrust (vac.)	7,904 kN (1,777,000 lbf)
Thrust (SL)	7,257 kN (1,631,000 lbf)
Throttle range	100% to 40%
Thrust-to-weight ratio	75
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
Dimensions
Length	4.0 m (160 in)
Diameter	3.8 m (150 in)
Dry weight	10,750 kg (23,700 lb)
Used in
Energia
References
References

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 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-151

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.

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.

RD-171

RD-171 model

Building on the technology from the Energia launch vehicle the Zenit rocket was developed, which uses a RD-170 variant, the RD-171. 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 that would provide additional thrust, but they were never built.

RD-180

Main article: RD-180

This variant 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.

RD-181

The RD-181 is based on the RD-191 and is adapted for integration on the Antares rocket. While the RD-193 was designed as a close replacement for the NK-33, on December 17, 2014, Orbital Sciences confirmed that it had contracted directly with NPO Energomash for up to 60 RD-181 engines (each launch requires two engines. While Russian press had stated that the contract was valued at 1 Billion USD with options, on January 26, 2015, Orbital stated that even when exercising all the options the contract was less than that amount, and that the initial contractual commitment was significantly less than that. Orbital ATK on February 19, 2015, said that its revamped Antares rocket featuring a new main engine would make its first launch in March 2016. On May 29, 2015, Orbital stated that the new engines had successfully conducted seven certification firings and all went as expected. It also stated that the first two flight models were doing its final tests and would be delivered to Orbital in early July.

RD-191

Main article: RD-191

Yet another variant, the single-chambered RD-191, is used in the Russian Angara rocket.

RD-193

RD-193 was proposed as a replacement for the NK-33, which is being used in the Soyuz-2-1v vehicle.

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

Specifications

• 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 7,887 kN (1,773,000 lb_f)
• Vacuum I_sp of 338 s (3.31 km/s)
• Sea Level I_sp of 309 s (3.03 km/s)
• Weight: 9,750 kg (21,500 lb)
• Thrust to weight ratio: 82

See also

• Comparison of orbital rocket engines

External links

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