China's latest breakthrough lays foundation for heavy-lift launch vehicle development

March 20, 2021 CV TECH INC

A Chinese state-owned conglomerate has successfully developed the country’s first 2.5-meter diameter class of heavy-duty hydrogen-oxygen engine nozzles, laying the foundation for the development of heavy-lift launch vehicles.


The China Aerospace Science and Technology Corporation (CASC), the nation’s leading space contractor, on March 19 announced the breakthrough, achieved by its Plant 211, saying it marks the first time its diffusion brazing technology capability for large stainless steel components has reached the world’s advanced level.


The largest and most visible part of a rocket engine is the huge nozzle, whose main function is to convert the heat energy of the high-temperature, high-pressure gas produced by the rocket’s propellant fuel into kinetic energy, thus giving the rocket a huge thrust.


China's latest breakthrough lays foundation for heavy-lift launch vehicle development-CnTechPost


China's latest breakthrough lays foundation for heavy-lift launch vehicle development-CnTechPost


(Preparing the 2.5-meter diameter regenerative cooling nozzle before entering the furnace.)


The CASC’s engine nozzle is divided into two sections, the upper section with a maximum diameter of 1.8 meters and the lower section with a maximum diameter of 2.5 meters.


It has a wall thickness of just 1 mm at its thinnest point and is manufactured using a diffusion brazing process with a milled inner wall and a direct overlay structure on the outer wall, the CASC said.


In this breakthrough, the CASC overcame technical problems including structural design technology of diffusion brazing process for large-size parts, matching of the high and low temperature of tooling, and control of brazing deformation of large-size parts.


Currently, China’s most powerful rocket is the Long March 5, which has a near-Earth orbit capacity of 25 tons.


In order to meet the needs of future deep space exploration and lunar exploration projects, China needs to develop a brand-new launch vehicle.


Previously, Luan Enjie, an academician of the Chinese Academy of Engineering and the first chief director of China’s lunar exploration project, said in a media interview that China will develop a 100-ton heavy launch vehicle in the future to meet the demand for going deeper into space.


At present, the demonstration stage of China’s heavy launch vehicle has been basically completed, entering the follow-up stage of the project, its research work is expected to be launched during the 14th Five-Year Plan.


China’s Long March 5B carrier rocket makes its maiden flight



China's latest breakthrough lays foundation for heavy-lift launch vehicle development-CnTechPost


China's latest breakthrough lays foundation for heavy-lift launch vehicle development-CnTechPost


(The 2.5m diameter regenerative cooling nozzle after welding.)