The YF-23 is a

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

rocket A rocket (from , and so named for its shape) is a vehicle that uses jet propulsion to accelerate without using any surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely ...

vernier engine, burning N₂O₄ and

UDMH Unsymmetrical dimethylhydrazine (abbreviated as UDMH; also known as 1,1-dimethylhydrazine, heptyl or Geptil) is a chemical compound with the formula H2NN(CH3)2 that is primarily used as a rocket propellant. At room temperature, UDMH is a colorle ...

. It is used in along the

YF-22 The Lockheed/Boeing/General Dynamics YF-22 is an American single-seat, twinjet, twin-engine, stealth aircraft, stealth fighter aircraft, fighter technology demonstrator prototype designed for the United States Air Force (USAF). The design te ...

to form the YF-24 and YF-25 propulsion modules.

Versions

The basic engine has been used since the

Feng Bao 1 The Feng Bao 1 (), also known as FB-1, was a Chinese carrier rocket launched between 1972 and 1981. It was replaced by the nearly identical Long March 2, which had been developed at the same time for political reasons related to China's Cultural ...

rocket and has been the vernier propulsion of the

Long March 2 Long March 2 rocket family or Chang Zheng 2 rocket family as in Chinese pinyin is an expendable launch system operated by the People's Republic of China. The rockets use the abbreviations LM-2 family for export, and CZ-2 family within Chi ...

Long March 3 The Long March 3 (), also known as the Changzheng 3, CZ-3 and LM-3, was a Chinese orbital carrier rocket design. They were all launched from Launch Area 3 at the Xichang Satellite Launch Center. It was a three-stage rocket, and was mostly used ...

and Long March 4 families second stage. * YF-23: Original version. * YF-23B (AKA DaFY21-1): Improved version. * YF-23F: Improved version.

Modules

This engine is bundled into modules along the

upper stage engine. 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.

References

Rocket engines of China Rocket engines using hypergolic propellant {{rocket-stub