|Country of origin||China|
|Designer||Academy of Aerospace Liquid Propulsion Technology, Ren Xinmin, Mo Tso-hsin, Zhang Guitian|
|Associated LV||DF-3A, DF-4 and Long March 1|
|Propellant||N2O4 / UDMH|
|Thrust, vacuum||303.6 kN (68,300 lbf)|
|Thrust, sea-level||275.3 kN (61,900 lbf)|
|Chamber pressure||7.1 MPa (1,030 psi)|
|Specific impulse, vacuum||267.4 seconds (2.622 km/s)|
|Specific impulse, sea-level||242.5 seconds (2.378 km/s)|
|Diameter||56 centimetres (22 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 a 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.
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). 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.
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.
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: