Country of origin China
First flight 1995-06-01
Designer Academy of Aerospace Liquid Propulsion Technology
Associated L/V Long March 1D, Long March 4
Status In Production
Liquid-fuel engine
Propellant N2O4 / UDMH
Mixture ratio 2.14
Cycle Gas Generator
Chamber 2
Nozzle ratio 55
Thrust (vac.) 103 kN (23,000 lbf)
Chamber pressure 4.6 MPa (670 psi)
Isp (vac.) 303 seconds (2.97 km/s)
Burn time 412s
Gimbal range ±4.5°
Length 120 centimetres (47 in)
Diameter 63 centimetres (25 in)
Dry weight 83 kg (183 lb)
Used in
Long March 1D second stage and Long March 4 third stage.
References [1][2][3][4][5][6]

The YF-40 is a Chinese liquid rocket engine burning N2O4 and UDMH in an gas generator cycle. It has dual gimbaling combustion chambers.

Originally it was developed for the Long March 1D second stage.[6] It is used on the third stage of the Long March 4 family of launch vehicles.[1][3][7]


  1. ^ a b "Long March". Rocket and Space Technology. Retrieved 2015-07-08. 
  2. ^ "YF-40". Encyclopedia Astronautica. Retrieved 2015-07-15. 
  3. ^ a b Gunter Dirk Krebs. "CZ-4 (Chang Zheng-4)". Gunter's Space Page. Retrieved 2015-07-15. 
  4. ^ Sutton, George Paul (November 2005). "Liquid Rocket Propellant Engines in the People's Republic of China". History of Liquid Propellant Rocket Engines.  
  5. ^ Mowthorpe, Matthew (2004). "Chinas Military Space Program". The Militarization and Weaponization of Space. Lexington Books. p. 90.  
  6. ^ a b "Chang Zheng-1 (Long March-1)". SinoDefence. Retrieved 2015-07-15. 
  7. ^ Harvey, Brian (2004). "Launch Centers Rockets and Engines". China's Space Program — From Conception to Manned Spaceflight. Springer Science & Business Media. p. 231.