Another breakthrough in recycling technology! JiuZhou YunJian's "LingYun" engine has successfully completed multiple ignition tests combined with deep thrust-vectoring capability.

　　Recently, Jiuzhou Yunjian's "Lingyun" 10-ton-class liquid oxygen-methane rocket engine successfully completed multiple ignition tests combined with deep thrust-vector control capability at its independently developed 100-ton-class dual-test-bed facility. The test was conducted at the advanced test base built by Jiuzhou Yunjian and achieved complete success.

　　This experiment has the following characteristics:

① Marks China's first breakthrough in mastering the technology for multiple, three-or-more starts of liquid oxygen-methane rocket engines, making our country the world's first to achieve three successful launches using such an engine.

② Before shutting down the engine, throttle it down once to 40% of its operating condition. The "Lingyun" engine has fully verified its variable thrust performance after multiple starts, meeting the engine's variable thrust requirements during the rocket's recovery and landing phase.

③ This test covers the flight test mission profile requirements for the target rocket.

"Lingyun" Engine Multiple Start-Up and Deep-Thrust-to-Idle Integrated Test Run

　　What is multiple ignition of a liquid rocket engine?

　　Multiple ignitions refer to the ability of a liquid rocket engine to achieve three or more ignition starts during a single flight mission. Due to limitations in conventional ignition methods, traditional liquid rocket engines typically support 1–2 ignition cycles. However, the next-generation commercial launch vehicles demand significantly higher engine startup capabilities—requiring more than three ignition attempts—thus posing substantial challenges to engine timing control. By innovating the ignition approach, the engine's startup capability can be effectively enhanced, ensuring it meets the stringent requirements for reusable systems.

　　Why do I need to start it multiple times?

　　Liquid rockets achieve reusability through vertical recovery, significantly reducing the cost per launch while also offering promising potential for a wide range of derivative applications. Currently, however, the key bottleneck hindering the development of China's vertical recovery rockets lies precisely in the liquid rocket engine technology. A vertical recovery rocket must undergo at least three ignition and startup processes—ground ignition and liftoff, retro-propulsion deceleration during the high-wind zone, and retro-propulsion deceleration during the landing phase—in order to ensure the rocket follows its predetermined trajectory and successfully returns to land. Therefore, an engine capable of multiple ignitions—specifically, three or more starts—is an essential requirement for vertically recoverable launch vehicles.

Ignition of the "Lingyun" Liquid Oxygen-Methane Rocket Engine

　　Ji Fenglai, CEO of Kyushu Yunjian, stated:

　　The "Lingyun" engine is the first domestically developed liquid oxygen-methane engine that truly achieves reusable, multiple ignition, and deep thrust-vectoring capabilities. In 2019, it successfully completed a deep thrust-vectoring hot-fire test evaluation. During its development, the "Lingyun" engine underwent a series of bold and challenging explorations and trials, focusing on key areas such as low-cost rapid use and maintenance, multiple ignition capability, wide-range thrust modulation technology, advanced control systems, and the adaptability of critical component assemblies. The successful completion of this recent hot-fire test marks significant progress in refining both the product design and core technologies. With reliable performance now firmly established, the "Lingyun" engine is poised to enter the industrialization phase.

　　Huang Shiqi, the technical head of Kyushu Yunjian Engine, stated:

　　This multi-start and deep thrust-vectoring integrated test of the "Lingyun" engine has successfully verified the precise timing settings for multiple starts, the reliable operation of the dual-path torch-type electric ignition system (primary and secondary), the stable performance of the thrust regulation system with excellent response characteristics, and the robust adaptability of the engine's core components to repeated starts and wide-ranging thrust variations. These results lay a solid foundation for the engine's participation in the customer's maiden flight.

　　Kyushu Yunjian 100-Ton-Class Dual-Station Thermal Test Vehicle Base

　　Currently, the "Lingyun" engine has successfully completed over a thousand seconds of cumulative test runs. Key technologies such as multiple ignition attempts, deep thrust modulation, and cost-effective operation and maintenance have all been validated. Moving forward, the "Lingyun" engine will continue its rigorous efforts in reliability accumulation, conducting extensive continuous variable-thrust tests and off-design condition tests to further solidify both its technological innovation and operational reliability. Additionally, the innovative achievements from the "Lingyun" engine can be seamlessly integrated into the high-thrust "Longyun" engine, paving the way for subsequent test evaluations and validation processes.

　　"Lingyun" and "Longyun" Liquid Oxygen-Methane Engines