The Longyun (, lit. ''Dragon Clouds'') is a

gas-generator cycle The gas-generator cycle, also referred to as the GG cycle or colloquially as an open cycle, is one of the most commonly used power cycles in bipropellant liquid rocket engines. Propellant is burned in a gas generator (analogous to, but distinct ...

rocket engine A rocket engine is a reaction engine, producing thrust in accordance with Newton's third law by ejecting reaction mass rearward, usually a high-speed Jet (fluid), jet of high-temperature gas produced by the combustion of rocket propellants stor ...

burning liquid methane and liquid oxygen under development by Jiuzhou Yunjian.

History

In 2018, the gas generator test for the Longyun engine was completed. The engine completed multiple start-up hot test runs in May 2021. In October 2021, launch startup Rocket Pi signed a deal to use the Longyun engine to power its Darwin-1 reusable launch vehicle. Space Epoch conducted a ground test of a 4.2-meter stainless steel stage powered by the Longyun engine in January 2023. 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.

References

Rocket engines of China Rocket engines using methane propellant Rocket engines using the gas-generator cycle {{Rocket-stub