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]
