Exciting news has once again emerged from China's aerospace technology sector: the maiden launch mission of the Long March 8A carrier rocket (referred to as the "Long March 8A rocket") was a complete success. At the same time, the new-type expander cycle hydrogen-oxygen engine YF-75DA, meticulously developed by the Sixth Academy of China Aerospace Science and Technology Corporation (CASC), also successfully completed its maiden flight, adding robust new strength to China's liquid propulsion technology.
The Long March 8A rocket adopts a two-and-a-half-stage configuration design, consisting of a first core stage, a second core stage, and two boosters. To ensure the rocket's powerful performance, the Sixth Academy equipped it with four YF-100 liquid oxygen-kerosene engines, two YF-75DA hydrogen-oxygen engines, and a precise auxiliary power system. Compared to its predecessor, the Long March 8 carrier rocket, the Long March 8A rocket achieved significant improvements in both payload capacity and efficiency, showcasing superior performance.
A major highlight of this "upgrade" is undoubtedly the application of the new-type expander cycle hydrogen-oxygen engine YF-75DA. To meet the new structural and payload capacity requirements of the Long March 8A rocket, the Sixth Academy carefully iterated and upgraded the YF-75DA engine. Specifically, the thrust of the YF-75DA engine achieved a remarkable increase of over 10% compared to the YF-75D engine. This enhancement not only boosted the rocket's thrust but also laid a solid foundation for improving its payload capacity.
Additionally, the development team implemented system-level optimization designs to effectively control the weight of the YF-75DA engine, achieving significant weight reduction. This measure not only further improved the engine's thrust-to-weight ratio but also significantly enhanced the payload capacity of the Long March 8A rocket. Preliminary estimates suggest that this improvement has successfully elevated China's hydrogen-oxygen rocket technology to the forefront of the world, standing shoulder to shoulder with international advanced levels.
The successful maiden flight of the YF-75DA engine not only marks a significant breakthrough for China in the field of new-type expander cycle hydrogen-oxygen engines but also injects new vitality and momentum into the future development of China's aerospace endeavors. With the continuous maturation and application of this technology, it is believed that China's aerospace industry will achieve even greater accomplishments in the future.
