Liquid launch vehicles, as the primary means for human space access currently and in the foreseeable future, have their testing and launch modes closely tied to the technical status of the launch vehicle, the construction of launch site conditions, and the achievement of high-efficiency launch capability. Through a comprehensive analysis of the main characteristics and underlying reasons at each developmental stage of global liquid launch vehicle test-and-launch modes, the evolution of these modes is divided into three phases: reliability-and-safety-driven, test-efficiency-driven, and flexibility-and-cost-driven. In each phase, the test-and-launch mode of liquid rockets is refined and improved based on the previous stage, with current developments emphasizing safety, reliability, efficiency, and low cost simultaneously. The key factors influencing the selection of test-and-launch modes for liquid launch vehicles are analyzed, including technical feasibility and heritage, launch-site adaptability, test-and-launch efficiency and flexibility, and economic considerations. Major trends in the future development of test-and-launch modes are proposed, providing useful references for the construction of future space launch sites.

In response to the strategic needs of becoming a leading space power, and against the backdrop of hot topics such as "Airline-Flight-Based transportation of reusable rocket" and the successful in-situ recovery at launch tower during the fifth test flight of SpaceX's Super Heavy-Starship, this study benchmarks against world-class space launch sites, and combines the actual development of Chinese space launch site construction. It refines the basic characteristics that an "Airline-Flight-Mode" launch site should possess, including multi-station parallel operation, fast turnaround launch, high safety and reliability, and low-cost launch. The current gaps in China's space launch site in adapting to "Airline-Flight-Mode" launch are analyzed, and a demand system for building the "Airline-Flight-Mode" launch capability of China's launch site is proposed. At the organizational management level, China's launch site should develop from a single-mode construction and operation to a diversified mode involving national, civilian and commercial entities, while adhering to the concept of a large industrial ecosystem, integrated deployment and collaborative design of satellites, rockets and launch sites should be promoted to achieve "launch upon delivery and reuse upon recovery". At the key technology level, emphasis should be placed on the development of pre-launch rapid refueling, post-launch rapid recovery, special robots, in-situ recovery at launch towers, modular construction, etc., to achieve efficient turnaround, high-frequency launches, and multi-station implementation. The research can support the high-quality development of space launch site planning and construction.

A novel smart bolt combined with fiber EFPI/FBG micro-structures is presented to monitor the state of tightening force of a bolted aerospace structure under high temperature circumstance. In this smart fiber bolt, the fiber EFPI micro-structure is applied to obtain the length variation in the direct of bolt axis under the effect of tightening force. And the fiber Bragg grating micro-structure is applied to obtain the bolt temperature. With the parameters obtained by the fiber EFPI/FBG micro-structures, the tightening force can be obtained through the approach presented. Test samples which are 50mm long M8 bolts combined with fiber EFPI/FBG micro-structures are made and tested by a universal testing machine with a heating chamber. The test results show that the smart fiber bolt presented can be used to obtain maximum 10kN tightening force under the temperature of 500 degree centigrade with maximum relative error 3.1%. This smart fiber bolt can be used to monitor the state of structure connection under high temperature circumstance.

Nuclear thermal rockets, as a revolutionary potential space luanch vehicle, have the capability to significantly reduce the scale of space transportation missions or enhance transportation capacity. The historical research of nuclear thermal propulsion (NTP) technology in the United States and Russia (The Soviet Union) is reviewed, the development challenges of nuclear thermal rocket are analysed. By proposing feasible lunar return missions and manned Mars exploration transportation tasks for nuclear thermal rocket, the study examines key technological challenges form an engineering application perspective, including optimization of overall parameters, high-power thermal propulsion, nuclear safety design and protection. At the end of the research, it is suggested to strengthen the research and development of key nuclear thermal rocket technologies and promote the construction of non nuclear and nuclear testing capabilities.

For the aerodynamic and overall optimization of hypersonic glide vehicles, this study proposes a performance evaluation method grounded in exergy theory. A multidisciplinary exergy dissipation model is developed, integrating aerodynamics, thermal protection, control, structures, and trajectory. This framework consolidates diverse metrics—such as aerodynamic efficiency, stability, and maneuverability—into a single, physically meaningful exergy loss parameter, enabling quantitative trade-off analysis. Using an HTV-2-like lifting-body configuration, aerodynamic optimization is performed with the objective of minimizing exergy loss, and its differences from lift-to-drag ratio optimization are examined. Based on the exergy balance equation, the potential applications of exergy loss analysis in conceptual design are discussed. The results indicate that this approach can rapidly identify performance bottlenecks, support multidisciplinary design optimization, and offer a new theoretical tool and evaluation paradigm for hypersonic vehicle design.

Aiming at the high temperature environment of the attitude control solenoid valve, the affected performance of the valve is simulated and analyzed. At the same time, the high temperature experiment of the valve is carried out. The results of simulation analysis and high temperature experiment indicate that the moving distance of the armature reduced due to the Non-metallic expansion of the core at high temperature, which causes the valve unable to open normally. And with the swelling effect of the oxidant to the core, the reliable operation temperature of oxidant valve is lower than fuel valve. By taking measures of enlarging the moving distance and replacing the core material to PFA, the high temperature environmental adaptability of the solenoid valve is improved.

In order to optimize the rational design of the thermal structure of solid rocket motor and accurately measure the erosion morphology of the insulation layer, a three-dimensional scanning technology is employed for this purpose. This study proposes a three-dimensional laser scanning strategy and a method for processing solid rocket motor three-dimensional data to analyze the wrapping characteristics of the insulation layer and cylindrical cylinder section of the shell. The proposed approach enables realization of three-dimensional data on erosion morphology in solid rocket motor insulation layers, facilitating determination of corresponding erosion amounts. Compared to traditional methods, this intelligent, comprehensive, and efficient method offers great application prospects for measuring erosion thickness in solid rocket motor insulation layers.

To achieve the design goals of high performance and reliability of propulsion systems for attitude control in the future, study on the dynamic characteristics has important scientific and engineering value. The dynamic simulation method for the MMH/NTO dual component propulsion system for attitude control is studied based on AMESim software. Firstly, the dynamic models of each components are determined and their simulation modules are established based on the system scheme. Secondly, the simulation model of each component is built by the AMESim software and the simulation model of the whole system is established. Finally, the processes of tank pressurization and multi thrust chamber pulse and interactive working are simulated. The changes in key parameters like pressure and flow rate of the thrust chamber are analyzed and the modeling method is verified. Meanwhile, the stability of the check valve is analyzed. The influences of working parameters and structural parameters on the stability of the valves are discussed. The results indicate that the dynamic simulation model established in this study can be used to accurately simulate the processes of multi thrust chamber pulse interaction. The inlet pressure and the throttle area of the check valve have an obvious impact on the stability of the system. The dynamic simulation method can be used for dynamic characteristics and stability analysis, which can provide useful references for the system scheme design and dynamic characteristics study.

To study the dynamic characteristics of the cantilever turbopump rotor in rocket engines, finite element models of the rotor dynamic characteristics are established using 3D solid elements and 2D beam elements to conduct dynamic characteristic analysis. The sensitivity of the impeller and turbine to unbalance on the rotor is obtained. High speed dynamic balance tests of the rotor are conducted on a high-speed rotating tester, and the results show that the finite element model well reflects the true dynamic characteristics of the rotor, with a calculation error of no more than 5%. Compared with 2D beam element model, the calculation accuracy of the 3D solid elements model is higher. The rotor is most sensitive to the imbalance on the turbine, providing a theoretical reference for high-speed dynamic balancing test. After high-speed dynamic balancing, the amplitude reduction of the rotor at critical speed is not less than 70.27%, and the reduction of elastic support stress is not less than 84.38%, indicating good dynamic balancing effect. The research provides a reference for the analysis of the dynamic characteristics of the rotor of a large cantilever turbopump and high-speed dynamic balancing tests.

As an important component of aviation control and power systems, the suction characteristics of DC electromagnetic coils used in aviation valves are a key factor in the design of electromagnetic coils. Taking the magnetic-proof ring magnet in the DC magnets for aviation valves as the research object, the magnetic-proof ring magnetis modeled in ANSYS Maxwell and the magnetic field distribution is given. The effects of different air gap, different parameters and armature length of the magnetic-proof ringon the suction characteristics of the electromagnet are analyzed. On this basis, two optimization methods are applied to the multi-objective design of the suction force at different positions of the electromagnet. One is to use the orthogonal test method to carry out the primary and secondary analysis of the factors that affect the suction force characteristics of the electromagnet more obviously. The other is to use the optimization software optislang to carry out the sensitivity analysis of the factors and the optimization design based on the evolutionary algorithm. Finally, a comparative analysis of the improvement effect of the two pairs of methods on the suction characteristics is carried out. The results show that optislang optimization is more in line with the requirements of electromagnet suction.