Kyushu Cloud Arrow and Lingke Aerospace Complete Contract for T6 Rocket Engine

   On August 10, 2019, Lingke Aerospace successfully conducted its third launch and recovery test of the next-generation reusable experimental rocket (RLV-T5), independently developed by the company. The test was carried out at the Cold Lake Rocket Test Base in Qinghai Province and concluded with a perfect success—when the T5 rocket landed steadily on the ground, everyone present at the Cold Lake launch site couldn't help but feel deeply proud of these young and talented engineers.

T5 Rocket Launch Shoot

What is T5?
The T5 rocket (RLV-T5) is a reusable experimental rocket independently developed by the talented team at Lingke Aerospace. Powered by a pressure-fed engine that utilizes liquid oxygen and alcohol as propellants, the T5 generates a thrust of 3,000 N and employs a five-engine parallel configuration. One of the key advantages of this type of engine is its ability to easily and directly modulate thrust through valve throttling. However, it also has limitations, primarily due to its relatively low thrust output. To enhance thrust, the engine relies on increasing tank pressure, yet the maximum achievable tank pressure remains quite limited, thereby restricting both the engine's overall thrust capability and the flight altitude. Despite these constraints, the innovative team at Lingke Aerospace has successfully leveraged this engine design to build the T5 experimental rocket. Over several years of dedicated exploration and iterative development, they have mastered advanced control technologies essential for both rocket launch and recovery operations. As a result, they have already conducted three successful launch-and-recovery tests using the T5 rocket—two in Shandong Province and one in Qinghai Province. According to colleagues on-site, the latest test achieved an impressive altitude of 302 meters. Currently, based on the T5 rocket platform, Lingke Aerospace has repeatedly validated its cutting-edge launch and recovery technologies. However, if the goal is to achieve even greater altitudes for future recovery experiments, the next step will require the adoption of a pump-fed liquid rocket engine capable of supporting reusable missions.
Kyushu Yunjian × Lingke Aerospace = T6
At the very site of this Qinghai Lenghu launch and recovery test, Lingke Aerospace and Jiuzhou Yunjian unveiled an exciting plan: the next-generation RLV-T6 reusable rocket project from Lingke Aerospace will be jointly developed through in-depth collaboration with Jiuzhou Yunjian. The T6 rocket is positioned as a vertical recovery verification vehicle capable of reaching altitudes exceeding 100 km. It will undergo rigorous testing under the extreme conditions of atmospheric re-entry, requiring multiple engine ignitions as well as advanced thrust-vector control capabilities. At such high altitudes, the existing compression-cycle engines used on the T5 rocket would no longer meet the mission requirements. Fortunately, Jiuzhou Yunjian’s “Lingyun” liquid oxygen-methane engine stands out as the only domestically developed pump-fed liquid rocket engine currently capable of supporting rocket recovery—making it the ideal partner for the T6 project.

Kyushu Yunjian has completed the project signing with Lingke Aerospace in Cold Lake.

On December 22, 2015, the U.S.-based Space-X successfully launched 11 small communication satellites for Orbcomm using its Falcon-9 rocket. Simultaneously, the Falcon rocket achieved the world's first successful vertical recovery of its first-stage propulsion system, demonstrating the feasibility of recovering orbital launch vehicles and laying a critical technological foundation that would later propel SpaceX to rapid growth. To achieve rocket recovery, two key technologies are essential: 1. Precision control of the vehicle's attitude and landing point. During the return phase, the rocket experiences high re-entry speeds and significant aerodynamic disturbances. After re-entry, the vehicle must be oriented vertically—a process that places stringent demands on control technology. 2. Advanced engine thrust modulation and multi-start capabilities. Without engine retropropulsion, even if the rocket's attitude is precisely controlled, uncontrolled velocity will inevitably lead to accelerated descent and impact with the ground. Moreover, as fuel consumption rapidly reduces the rocket's mass during recovery, the engine must dynamically adjust its thrust vector output in real-time based on the rocket's altitude, velocity, and changing mass characteristics. Only then can the rocket achieve a stable and controlled landing. In essence, the combination of advanced control systems and engines capable of precise thrust modulation accounts for approximately 90% of the factors determining the success or failure of rocket recovery operations.
As early as the first half of this year, the team from Lingke Aerospace reached out to Jiuzhou Yunjian—a professional liquid rocket engine development team. We learned that Jiuzhou Yunjian’s “Lingyun” engine was specifically designed from the outset with an eye toward supporting rocket recovery and reuse applications. Over the past year and more, Jiuzhou Yunjian has been diligently tackling three critical technological challenges plaguing domestic pump-fed engines: multiple ignition capabilities, reusability, rapid maintenance, and deep thrust-vector control. As a result, both parties have now reached a strong intention for in-depth collaboration. The exciting news is that, just one month before Lingke Aerospace’s T5 test rocket took off from Cold Lake this July, Jiuzhou Yunjian successfully completed a series of full-engine hot-fire tests featuring deep thrust-vector control and multi-cycle operation for its reusable liquid oxygen-methane “Lingyun” engine. These tests included a 30% thrust modulation test, a 20% deep thrust modulation test, and a continuous 20-second variable-thrust test—all of which were executed flawlessly. This milestone marks the “Lingyun” engine as China’s first—and currently only—pump-fed liquid rocket engine genuinely capable of supporting the recovery and reuse of launch vehicles.
On the day of the "Lingyun" engine test conducted by Kyushu Cloud Arrow, Mr. Hu Zhenhuo, founder of Lingke Aerospace, joined the Kyushu Cloud Arrow engine team in the engine test and control room to witness this new breakthrough in China's liquid rocket engine technology, further boosting confidence in Lingke Aerospace's future development of the T6 rocket.

Compared to the United States, China's commercial space industry started later and still lags behind in terms of technological accumulation and industrial foundation. For domestic commercial space enterprises aiming for rapid breakthroughs, it is crucial to leverage the unique strengths of each company, foster synergy, and create mutually beneficial outcomes. Notably, since 2017, the domestic commercial space sector has gradually shown signs of industry segmentation, with key nodes across the entire value chain—ranging from satellite manufacturers to launch sites, rocket integrators, rocket engines, and supporting manufacturers—gradually taking shape. Looking back over the past two to three years, China's aerospace industry has already achieved several significant breakthroughs in critical technologies and cutting-edge products. We can confidently anticipate that, in the near future, the collaborative development model involving strong partnerships will further accelerate China's aerospace progress. In the coming era of large-scale human exploration of space, we will see an even greater presence of Chinese private-sector enterprises.