3,000 second at a time! Compatibility between ZQ-2 control system and second-stage vernier engine verified
For the first time, sub-cooled propellant loading and operating conditions were assessed in the test. The success indicates that TQ-11 is the first lOX+LCH4 engine passing the test on propellant sub-cooling, and LandSpace is the sole Chinese private aerospace enterprise mastering the technique in propellant sub-cooling and possessing the capacity for the sub-cooling test, with many of the engine’s performance parameters attaining the domestic advanced level.
ZQ-2’s electromechanical servo featured high reliability, great testability, good maintainability, lightweight, and low costs. In this test, the engine was controlled through the electromechanical servo for assessing oscillation, including sine wave, square wave, and triangle wave. The assessment covered the maximum sway and the frequency range of 0.1-25 Hz. The static and dynamic characteristics of the servo were identified and its performance met the requirements of the rocket’s control system. The oscillation program and the electromechanical servo of the engine passed the test, demonstrating the compatibility and coordination between the engine and the control system.
This type of engine has been tested for over 10,000 seconds in total. A single-engine has been tested for 4,500 seconds, over 6 times its rated operating time, while one test lasted for 3,000 seconds. All tops the highest records of cryogenic LREs in China. The design, production, assembly quality, and work reliability of the engine have been fully assessed.
LOX and LCH4 propellants were sub-cooled through heat change with liquid nitrogen. Sub-cooling enabled increase in propellant density, decrease in saturated vapor pressure, increase in engine thrust and thrust-to-weight ratio, reduction in rocket size, and it is a key measure in expanding payload capability and reducing launch costs.
Other tests included generator sequence fluctuation test, assessment of continuous regulation of mixture ratio, assessment of the oxygen & methane pressurization system, and verification of the simulated flight procedure. It was found that the technical data of the engine meet the rocket flight requirements. In the future, the engine would be tested under extreme boundary conditions and its maximum life span would be explored. We intend to provide ZQ-2 with a robust engine and lay a solid foundation for reusable rocket technology.