RD-191

RD-191

Country of origin	Russia
Date	2001
Designer	NPO Energomash
Manufacturer	NPO Energomash / Proton-PM (in transition)
Application	Main engine
Predecessor	RD-170
Status	In use
Liquid-fuel engine
Propellant	LOX / RP-1
Mixture ratio	2.6
Cycle	Oxidizer-rich staged combustion
Configuration
Nozzle ratio	37:1
Performance
Thrust, vacuum	2.09 MN (470,000 lbf) at 100% throttle
Thrust, sea-level	1.92 MN (432,000 lbf) at 100% throttle
Throttle range	27–105%
Thrust-to-weight ratio	89
Chamber pressure	25.8 MPa (3,740 psi)
Specific impulse, vacuum	337 s (3.30 km/s)
Specific impulse, sea-level	310.7 s (3.047 km/s)
Burn time	325 s (Angara A5 core stage)
Gimbal range	8°
Dimensions
Length	4 m (160 in)
Diameter	1.45 m (57 in)
Dry weight	2,290 kg (5,050 lb)
References
References	[1][2]

The RD-191 (Russian: РД-191, Ракетный Двигатель-191, lit. 'Rocket Engine 191') is a high-performance single-combustion chamber rocket engine, developed in Russia and sold by Roscosmos.^[3] It is derived from the RD-180 dual-combustion chamber engine, which itself was derived in turn from the four-chamber RD-170 originally used in the Energia launcher.

The RD-191 is fueled by a kerosene / LOX mixture and uses an oxygen-rich staged combustion cycle. In the future the engine is expected to become a workhorse in the Russian space sector, as older launch vehicles are phased out of production and service.