Longyun (rocket engine)

Longyun
Country of originChina
ManufacturerJiuzhou Yunjian
StatusActive
Liquid-fuel engine
PropellantLOX / CH4
Performance
Thrust, vacuum770.2 kilonewtons (173,100 lbf)
Thrust, sea-level686.5 kilonewtons (154,300 lbf)
Throttle range30%~100%
Specific impulse, vacuum350s
Specific impulse, sea-level290s
Dimensions
Dry mass880 kg (1,940 lb)
Used in
Long March 12A
References
Notes

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

On 29 May 2025, engine LY70005 powered a flight and sea-recovery test, including shutdown, restart, a hover above the sea and splashdown. On 4 August 2025, Jiuzhou Yunjian reported that the recovered engine had completed four hot-fire tests with its gimbal control system.

Seven Longyun engines powered the first stage on the maiden flight of Long March 12A on 23 December 2025. The second stage reached its intended orbit, but the first-stage recovery attempt failed.

References

  1. ↑ "Longyun Engine JiuZhou Cloud Arrow (Beijing) Space Technology Co., Ltd". en.jzyjspace.com.
  2. ↑ Jones, Andrew (12 August 2019). "Chinese Linkspace reaches 300 meters with launch and landing test". SpaceNews. Retrieved 15 March 2024.
  3. ↑ "JiuZhou YunJian "LongYun" engine has completed multiple start-up hot test runs_JiuZhou Cloud Arrow (Beijing) Space Technology Co., Ltd". en.jzyjspace.com. Retrieved 15 March 2024.
  4. ↑ Jones, Andrew (31 October 2021). "New Chinese launch firm signs deal for reusable rocket engines". SpaceNews. Retrieved 15 March 2024.
  5. ↑ Alaieva, Liliia (20 January 2023). "The Chinese are preparing to launch a "miniature Starship"". The Universe Magazine. Retrieved 15 March 2024.
  6. ↑ "九州云箭 70 吨级"龙云"火箭发动机高压泵后热摇摆试验圆满成功". www.ithome.com. ithome.
  7. ↑ "上天入海：龙云发动机圆满完成海态飞行回收试验！". Jiuzhou Yunjian (in Chinese). 17 June 2025. Retrieved 18 October 2026.
  8. ↑ "九州云箭：海上溅落回收发动机顺利完成热摇摆试车". Jiuzhou Yunjian (in Chinese). 4 August 2025. Retrieved 18 October 2026.
  9. ↑ "长征十二号甲火箭首飞入轨，一级未实现回收". 南方+ (in Chinese). 23 December 2025. Retrieved 18 October 2026.
  10. ↑ "重复使用运载火箭长征十二号甲发射入轨". China Aerospace Science and Technology Corporation (in Chinese). 23 December 2025. Retrieved 18 October 2026.