AKA: YF-120;YF-120t. Status: Operational 2016. Thrust: 1,339.48 kN (301,127 lbf). Specific impulse: 335 s. Specific impulse sea level: 300 s.
Said to have been developed with Russian assistance and has turbomachinery design features in common with the Glushko RD-170/-180/-190 series. However the Russians have no thrust chamber in this thrust category and therefore the engine represents an entirely new design using all-indigenous components. Turbopump-fed, built in one- and two-axis gimbaled versions. Oxygen bled from engine is used to pressurize oxygen tank; helium to pressurize kerosene tank. The engine can be throttled to 65% of rated thrust. Firing tests began in 2003 and were to be completed by early 2006. Instead there were delays and the first 300-second full-duration firing test did not occur until 8 November 2005. The engine was certified by the government in 2012. First launch, originally expected in 2008, did not occur until 2016.
Throttled thrust(vac): 871.000 kN (195,808 lbf). Thrust (sl): 1,199.190 kN (269,500 lbf). Oxidizer to Fuel Ratio: 2.7.
Development of the engine began in the 2000s, along with its sibling, the smaller YF-115, which would power the LM-6 and LM-7 upper stages. Testing was directed by the China National Space Administration (CNSA) commencing in 2005. Development works are mainly carried out by the Xi'an Aerospace Propulsion Institute. The engine had its first 300 seconds test fire on November 2007.
A high efficiency/high thrust environmentally-friendly rocket engine was always an objective within Programme 863. But Chinese industry was not mature enough to produce such a rocket until they obtained examples (and probably documentation) of the Russian RD-120 in the early 1990s.It was the first Chinese rocket engine to adopt the staged-combustion cycle and the most powerful to date. During July 2012 the engine fired for 200 seconds generating 120 t (260,000 lb) of thrust. On May 28, 2012, the National Defense Science and Industry Bureau certified the engine.
The engine was planned to be used on the first stage of the Chinese government's next generation of launch vehicles, the Long March 5, the Long March 6 and the Long March 7.
The YF-100 was a pump-fed oxidizer rich staged combustion rocket engine. It had adjustable thrust and variable mixture ratio. Its preburner burned all the LOX mass flow with a bit of kerosene to generate hot gas that powered the single turbine. The turbopump was a single-shaft design, with a single-stage oxygen pump and a dual-stage kerosene pump driven by the same turbine. It also had two low pressure pumps that prevented cavitation. This arrangement was very similar to the RD-170 design. The engine had a heat exchanger to heat oxygen gas for LOX tank pressurization, and also supplied high pressure kerosene as hydraulic fluid for the thrust vector control actuators. The development required ten years of research, requiring the mastering of 70 key technologies, the development of 50 new materials and the construction of 61 sets of engines with a combined total of more than 40,000 seconds of ignition time by 2013.