Longyun (rocket engine)

"Longyun" redirects here. For the Chinese politician, see Long Yun.

Not to be confused with Lingyun (rocket engine).

The Longyun (Chinese: 龙云; pinyin: Lóngyún, lit. Dragon Clouds) is a gas-generator cycle rocket engine burning liquid methane and liquid oxygen under development by Jiuzhou Yunjian.

Lingyun

Country of origin	China
Manufacturer	Jiuzhou Yunjian
Status	Under development
Liquid-fuel engine
Propellant	LOX / CH4
Performance
Thrust, vacuum	770.2 kilonewtons (173,100 lbf)
Thrust, sea-level	686.5 kilonewtons (154,300 lbf)
Throttle range	30%~100%
Specific impulse, vacuum	350s
Specific impulse, sea-level	290s
Dimensions
Dry mass	880 kg (1,940 lb)
References
Notes	[1]

History

In 2018, the gas generator test for the Longyun engine was completed.^[2] The engine completed multiple start-up hot test runs in May 2021.^[3] In October 2021, launch startup Rocket Pi signed a deal to use the Longyun engine to power its Darwin-1 reusable launch vehicle.^[4]

Space Epoch conducted a ground test of a 4.2-meter stainless steel stage powered by the Longyun engine in January 2023.^[5]

In April 2024, Longyun passed a long duration hot firing test with the servo mechanism rotating to the maximum angle of ±8°. The engine has also reportedly passed the customer acceptance test.^[6]