Country of originChina
First flight1995-06-01
DesignerAcademy of Aerospace Liquid Propulsion Technology
Associated LVLong March 1D, Long March 4
StatusIn Production
Liquid-fuel engine
PropellantN2O4 / UDMH
Mixture ratio2.14
CycleGas Generator
Nozzle ratio55
Thrust (vacuum)103 kN (23,000 lbf)
Chamber pressure4.6 MPa (670 psi)
Specific impulse (vacuum)303 seconds (2.97 km/s)
Burn time412s
Gimbal range±4.5°
Length120 centimetres (47 in)
Diameter63 centimetres (25 in)
Dry weight83 kg (183 lb)
Used in
Long March 1D second stage and Long March 4 third stage.

The YF-40 is a Chinese liquid rocket engine burning N2O4 and UDMH in a 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. Archived from the original on 2015-08-24. 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. AIAA. p. 873. ISBN 978-1563476495. Retrieved 2015-07-15.
  5. ^ Mowthorpe, Matthew (2004). "Chinas Military Space Program". The Militarization and Weaponization of Space. Lexington Books. p. 90. ISBN 978-0739107133. Retrieved 2015-07-15.
  6. ^ a b "Chang Zheng-1 (Long March-1)". SinoDefence. Archived from the original on 2015-07-16. 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. ISBN 978-1852335663. Retrieved 2015-07-15.