RD-0120

RD-0120

Model of RD-0120
Country of origin	Soviet Union
Date	1976-1987
First flight	1987-05-15
Last flight	1988-11-15
Designer	OKB-154
Manufacturer	Voronezh Mechanical Plant
Application	Sustainer engine
Associated LV	Energia
Successor	RD-0122
Status	Retired
Liquid-fuel engine
Propellant	LOX / LH2
Mixture ratio	6.0
Cycle	Staged сombustion
Configuration
Chamber	1
Nozzle ratio	85.70
Performance
Thrust, vacuum	1,961.3 kN (440,900 lbf), 106%
Thrust, sea-level	1,526 kN (343,000 lbf), 106%
Thrust-to-weight ratio	57.93, vac., 106% thrust
Chamber pressure	21.9 MPa (3,180 psi)
Specific impulse, vacuum	455 s (4.46 km/s)
Specific impulse, sea-level	353.2 s (3.464 km/s)
Burn time	500 s
Gimbal range	±7°
Dimensions
Length	4,550 mm (179 in)
Diameter	2,420 mm (95 in)
Dry weight	3,450 kg (7,610 lb)
Used in
Energia core stage
References
References	[1][2][3][4]

The Soviet RD-0120 (also designated 11D122) was the Energia core rocket engine, fueled by LH₂/LOX, roughly equivalent to the Space Shuttle Main Engine (SSME). These were attached to the Energia core rather than the orbiter, so were not recoverable after a flight, but created a more modular design (the Energia core could be used for a variety of missions besides launching the shuttle). The RD-0120 and the SSME have both similarities and differences. The RD-0120 achieved a slightly higher specific impulse and combustion chamber pressure with reduced complexity and cost (but it was single-use), as compared to the SSME. It uses a fuel-rich staged combustion cycle and a single shaft to drive both the fuel and oxidizer turbopumps. Some of the Russian design features, such as the simpler and cheaper channel wall nozzles, were evaluated by Rocketdyne for possible upgrades to the SSME. It achieved combustion stability without the acoustic resonance chambers that the SSME required.