YF-23 (rocket engine)

This article is about the Chinese rocket engine. For the American fighter jet, see Northrop YF-23.

The YF-23 is a liquid rocket vernier engine, burning N₂O₄ and UDMH.^[5] It is used in along the YF-22 to form the YF-24 and YF-25 propulsion modules.^[3][6][7][8]

YF-23E

Country of origin	China
First flight	1974-11-05
Designer	Academy of Aerospace Liquid Propulsion Technology
Application	Vernier engine
Associated LV	Feng Bao 1, Long March 2, Long March 3 and Long March 4
Status	In Production
Liquid-fuel engine
Propellant	N2O4 / UDMH
Mixture ratio	1.57
Configuration
Chamber	4
Performance
Thrust, vacuum	47.1 kN (10,600 lbf)
Specific impulse, vacuum	297 seconds (2.91 km/s)
Burn time	300s
Used in
Long March 2F, Long March 3A, Long March 3B, Long March 3C, Long March 4B and Long March 4C second stage.
References
References	[1][2][3][4]

Versions

The basic engine has been used since the Feng Bao 1 rocket and has been the vernier propulsion of the Long March 2, Long March 3 and Long March 4 families second stage.^[1][9][10]

• YF-23: Original version.
• YF-23B (AKA DaFY21-1): Improved version.^[9][11][12]
• YF-23F: Improved version.^[9]

Modules

This engine is bundled into modules along the YF-22 upper stage engine.^{[13][14][15][16]}

The relevant modules for second stage application are:

• YF-24: A module comprising an YF-22 and a single YF-23 verniers.
• YF-24B: A module comprising an YF-22B and a single YF-23B verniers.
• YF-24E: A module comprising an YF-22E and a single YF-23F verniers.^[17]