Country of origin China
Date 1958-1969
Designer Academy of Aerospace Liquid Propulsion Technology, Ren Xinmin, Mo Tso-hsin, Zhang Guitian
Associated L/V DF-3A, DF-4 and Long March 1
Predecessor С2.1100
Successor YF-20
Status Retired
Liquid-fuel engine
Propellant N2O4 / UDMH
Cycle Gas Generator
Chamber 1
Nozzle ratio 10
Thrust (vac.) 303.6 kN (68,300 lbf)
Thrust (SL) 275.3 kN (61,900 lbf)
Chamber pressure 7.1 MPa (1,030 psi)
Isp (vac.) 267.4 seconds (2.622 km/s)
Isp (SL) 242.5 seconds (2.378 km/s)
Burn time 140s
Diameter 56 centimetres (22 in)
Used in
DF-3A, DF-4 and Long March 1 first stage.



The YF-1 was a Chinese liquid rocket engine burning N2O4 and UDMH in an gas generator cycle. It is a basic engine which when mounted in a four engine module forms the YF-2. It was used as the basis for developing a high altitude version known as the YF-3.[2][9]

Some authors state that it was a direct copy of С.2.1100/С.2.1150 La-350 booster engine developed by Isayev OKB-2 (NII-88).[10] What is known is that the engine development had great trouble with combustion instabilities and it took a long time to have a reliable combustion.


  • Versions 1
  • Modules 2
  • See also 3
  • References 4


The basic engine has been used since the DF-3 rocket and has been the main propulsion of the Long March 1 orbital launch vehicles.[2]

  • YF-1: Core engine. Flown originally on the DF-3. Used UDMH/AK27S as propellant. Allegedly a copy of OKB-2's С.2.1150.[3][10]
  • YF-1A: Core engine. Improved version that would power the DF-3A, DF-4 and Long March 1.[3][2][10][11]
  • YF-1B: Core engine. Improved version used on the Long March 1D. Switched propellants to UDMH/N2O4[2]
  • YF-3: Upper stage version. Used on the DF-4.[2]
  • YF-3A: Improved upper stage version. Used on the Long March 1.[2]


While the basic engine was used multiple times, it was only used as a single engine for booster application. It is usually bundled into modules of multiple engines.

The relevant modules for first stage application are:

  • YF-2: A module comprising four YF-1. Flown originally on the DF-3.[3]
  • YF-2A: A module comprising four YF-1A. Improved version. Used on the DF-3A, DF-4 and Long March 1.[3][2]
  • YF-2B: A module comprising four YF-1B. Improved version. Final version used on the Long March 1D.[2]

See also


  1. ^ Norbert Bgügge. "Asian space-rocket liquid-propellant engines". B14643.DE. Retrieved 2015-07-25. 
  2. ^ a b c d e f g h i Norbert Bgügge. "Propulsion CZ-1". B14643.DE. Retrieved 2015-07-25. 
  3. ^ a b c d e Norbert Bgügge. "The Chinese DF-3 missile". B14643.DE. Retrieved 2015-07-25. 
  4. ^ "Long March". Rocket and Space Technology. Retrieved 2015-07-25. 
  5. ^ "CZ-1". Encyclopedia Astronautica. Retrieved 2015-07-25. 
  6. ^ "YF-2A". Encyclopedia Astronautica. Retrieved 2015-07-25. 
  7. ^ "YF-3". Encyclopedia Astronautica. Retrieved 2015-07-25. 
  8. ^ Harvey, Brian (2004). "Launch Centers Rockets and Engines". China's Space Program — From Conception to Manned Spaceflight. Springer Science & Business Media. p. 230.  
  9. ^ Mowthorpe, Matthew (2004). "Chinas Military Space Program". The Militarization and Weaponization of Space. Lexington Books. p. 90.  
  10. ^ a b c "Dong Feng-3 (CSS-2)". SinoDefence. Retrieved 2015-07-25. 
  11. ^ "Dong Feng-4 (CSS-3)". SinoDefence. Retrieved 2015-07-25.