RD-0120
The Soviet RD-0120 was the Energia core rocket engine, fueled by LH2/LOX, roughly equivalent to the Space Shuttle Main Engine. 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 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, 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.Specifications
RD-0120
