At 11:23 on April 29, the Chinese Space Station Tianhe Core Module was successfully launched; At 9:22 on June 17, the Long March 2 F Yao 12 carrier rocket carrying the Shenzhou 12 manned spacecraft was successfully launched at Jiuquan Satellite Launch Center; At 18:48 on June 17, three astronauts, Nie Haisheng, Liu Boming and Tang Hongbo, entered the Tianhe Core Module one after another, marking the official start of manned flight of the Tianhe Core Module. The HIT space debris impact on-orbit sensing technology developed by the team of Prof. Pang Baojun (from School of Astronautics in HIT) has been successfully applied to the Tianhe Core Module. This technology can provide a basis for astronauts and ground controllers to take timely countermeasures and protect astronauts’ safety when the module is impacted by space debris.
The Tianhe Core Module of the Chinese Space Station is the largest spacecraft developed in China at present. It is planned to run in orbit for up to 15 years, and it is vulnerable to the impact of space debris (the speed is as high as several kilometers per second), which threatens the operational safety. Astronauts will stay in the module for a long time, so their safety needs to be guaranteed. In addition to taking active evasion and passive protection measures for the Tianhe core module, the General Design Department of the Fifth Academy of China Aerospace Science and Technology Corporation (CASC), as the overall unit, together with HIT and NO. 513 institute of the Fifth Academy of CASC also tailored the space debris impact monitoring module in the structural health monitoring subsystem for the Tianhe Core Module. This module is based on the data-driven sensor network, which can sense, distinguish and locate impact events in real time. The algorithm developed by the team of Prof. Pang Baojun has been applied in the module.
In order to complete the research and development of the structural health monitoring subsystem of the Tianhe Core Module, HIT cooperated with the General Design Department of the Fifth Academy of CASC and the NO. 513 institute to tackle key problems. The research team of HIT has conducted more than 100 hypervelocity impact tests on small-sized specimens and nearly 200 hypervelocity impact tests on large-sized bulkhead structures for 7 years, developed and optimized perception recognition algorithms, and determined key parameters of perception recognition. The team members have made dozens of trips to the space institute and various test bases, carried out the development and verification experiments of the impact positioning algorithm of the module structure at each stage, obtained tens of thousands of sets of data, completed the establishment of the sample database and the optimization of the positioning algorithm, and mastered many key technologies, such as the rapid location of the impact of large complex geometry structures, the identification of the collision in the fuzzy region of the multi-module combination, and the parameter identification of the impact acoustic emission signal in the complex bulkhead structures. Finally, the engineering application of the space debris impact on-orbit sensing technology is successfully realized. The technology will also be used in the Wentian and Mengtian experimental modules in Chinese Space Station.
It is understood that the Space Debris High Speed Impact Research Center led by Prof. Pang Baojun, always adheres to the initial intention of doing scientific research for China's space flight, accurately predicts the demand of large-scale, long-life and highly reliable manned spacecrafts for real-time sensing of space debris impact in the development of China's manned space flight, and plans ahead. As early as 2004, it took the lead in proposing and carrying out the research in China on the space debris impact on-orbit sensing technology based on acoustic emission. Over the years, with the strong support of the State Administration of Science, Technology and Industry for National Defense and HIT, Prof. Pang Baojun’s team has continuously innovated and tackled tough problems. Focusing on the discrimination, positioning and structural damage identification of hypervelocity impacts, they have established a hypervelocity impact and other force source models, solved the basic scientific problems such as the generation mechanism, propagation characteristics, modal conversion and scattering at irregular structures of acoustic emission signals from hypervelocity impact, broken through the key technologies such as feature extraction and recognition of hypervelocity impact signals in spatial noise environment, accurate positioning of debris cloud multi-point source impact, and visual diagnosis of debris cloud impact pitting damage, and developed methods such as double automatic threshold arrival time acquisition, virtual wavefront positioning and fast area positioning, and artificial intelligence recognition of damage patterns, which are universal for complex structures and composite material impacts. Through technical integration, the team developed a prototype of the space debris impact on-orbit sensing system, which was recognized by the engineering department, laying the technical foundation for the engineering application in the Tianhe Core Module.