China tests underwater missile engine in 200-meter deep-sea simulation

Chinese researchers from the Zhengzhou-based Mechano-Electrical Engineering Institute have successfully tested a solid rocket engine under simulated pressures equivalent to 200 meters (656 feet) underwater. This experiment, conducted using a specialized deep-water environment simulation system with compressed air and stable-pressure tanks, demonstrated reliable ignition and stable thrust at depths far greater than the typical shallow-water launches (around 30 meters) currently used for submarine-launched ballistic missiles (SLBMs) like the Trident and China’s Julang series. The ability to launch from such depths enhances stealth by making it harder for enemy surveillance to detect or track the submarine’s launch position, thereby strengthening nuclear deterrence capabilities. The test revealed that ignition at 200 meters triggers a brief, intense interaction between hot gas and cold water, causing temporary thrust fluctuations until a stable gas jet channel forms. Despite stable operation, the extreme external pressure reduces thrust by about 32.7% compared to surface conditions, with projections suggesting thrust could drop by nearly half