YF-73

YF-73
Country of originChina
First flight1984-01-29
Last flight2000-05-26
DesignerBeijing Aerospace Propulsion Institute
ManufacturerChina Academy of Launch Vehicle Technology (CALT)
Associated LVLong March 3
SuccessorYF-75
StatusRetired
Liquid-fuel engine
PropellantLiquid oxygen / Liquid hydrogen
Mixture ratio5.00
CycleGas-generator
Configuration
Chamber4
Nozzle ratio40
Performance
Thrust, vacuum44.15 kilonewtons (9,930 lbf)
Chamber pressure2,590 kPa (25.9 bar)
Specific impulse, vacuum420 seconds (4.1 km/s)
Burn time800 seconds (13 min)
Dimensions
Length1.44 metres (4 ft 9 in)
Diameter2.2 metres (7 ft 3 in)
Dry mass236 kilograms (520 lb)
Used in
Long March 3 H8 third stage
References
References[1][2][3][4]

The YF-73 was China's first successful cryogenic liquid hydrogen fuel and liquid oxygen oxidizer gimballed engine. It was used on the Long March 3 H8 third stage, running on the simple gas generator cycle and with a thrust of 44.15 kilonewtons (9,930 lbf). It had four hinge mounted nozzles that gimbaled each on one axis to supply thrust vector control and was restart capable. It used cavitating flow venturis to regulate propellant flows. The gas generator also incorporated dual heat exchangers that heated hydrogen gas, and supplied helium from separate systems to pressurize the hydrogen and oxygen tanks. The engine was relatively underpowered for its task and the start up and restart procedures were unreliable. Thus, it was quickly replaced by the YF-75.[3]

  1. ^ Cite error: The named reference braeunig-lgmarch was invoked but never defined (see the help page).
  2. ^ Cite error: The named reference ea-yf73 was invoked but never defined (see the help page).
  3. ^ a b Cite error: The named reference nan-2013 was invoked but never defined (see the help page).
  4. ^ Cite error: The named reference sutton-hlpre was invoked but never defined (see the help page).