Most ReadFor Falcon 9 rocket launch missions in 2024 and before, a reuse indicator system has been initially established. Statistical analysis is conducted in the time dimension and status dimension, and the development rules of Falcon 9 rocket one-stage reuse technology are initially obtained. By the analysis of the rules, the development and evolution process of Falcon 9 rocket recovery and reuse technology is divided into three stages. Finally, a preliminary prediction is made on the development of China's reusable rockets.
For higher reliability, higher efficiency and easier maintenance, three TVC actuators for a hydrolox launch vehicle block are studied comparatively, in aspects of designs, models and testing performances, namely, a Servo-Valve Controlled Electro-Hydraulic Actuator (SHA), an Electro-Mechanical Actuator (EMA) and an Electro-Hydrostatic Actuator (EHA), each outputting a peak power of 3 kW. A fully packaged duplex EHA design is proposed, lightweight and compact by means of innovating indepth integrations in the actuator, Electro-Hydrostatic Module (EHM), Servo Motor Pumps (SMPs) and Electronic Control Units (ECUs). The weight of a TVC system with four EHAs is 85 kg, reduced by 37%, compared to the SHA counterpart of 135 kg. The dynamic capability of three TVC actuators is almost on a par, with the first-order frequency bandwidth of greater than 30 rad/s. As to the overall efficiency of energy conversion, it is one order of magnitude higher for an EMA or an EHA than a SHA. In an operation profile on ground with a duration of 1 200 s, the efficiency is lowest for an SHA, less than 1%, and heated quickly, with the temperature reaching over 100 ℃ at the hydraulic pump. In contrast, as to the EMA and EHA,the efficiency is remarkably upgraded to over 20%, with the temperature only slightly increasing by 5 ℃ at the pump or the electric motor. It demonstrates that an EHA embodies both the heavy loading, high reliability of a SHA, and the high efficiency, good maintenance of an EMA, at the same time overcoming the weak points in dynamics, power density, oil sealing, etc., providing an intriguing option for highly reliable and secure launch vehicles. The EHA has finished its maiden flight as the first one for launch vehicles.
To address the issues of penetration and precision attacking for air-to-air missiles, an analytical solution for the miss distance of a non-zero-order guidance system is derived. The solution is then extended to advanced guidance laws beyond proportional navigation guidance. Based on these results, the effectiveness of evasion under different maneuvering strategies is analyzed which theoretically explaining the typical characteristics of miss distances in step and serpentine maneuvers and factors influencing the optimal maneuvering strategy are studied. Through reasonable adjustment of maneuver timing and direction, the effectiveness of evasion is improved. Furthermore, considering the integration of penetration and attacking through intelligent guidance laws, an adaptive-stepsize sparsified sampling prior model theory infusion remedial training agent learning (ASTRAL) is introduced. Simulation results show that the missile agent trained with the ASTRAL can effectively evade defender while maintaining its attacking capability during penetration. In addition, the generated guidance law demonstrates good engineering feasibility.
As a critical component of the space transportation system, solid launch vehicle has advantages such as full-vehicle storage, versatility for sea-based and land-based launch, rapid response, and low requirements for launch support. The development process and overall technical scheme of Smart Dragon-3 solid rocket are introduced. In addition, the practical experience in the development of solid launch vehicles is drawn as a brief summery. Furthermore, the series development of solid launch vehicles is claimed, based on the analysis of the future positioning of solid rocket development. The carrying capacity of medium-sized solid launch vehicle needs to be improved, through research innovation, scale development and optimization of comprehensive cost. In this case, the demands of various launch orbits can be satisfied by the style of offhand sea launch.
With the increasing frequency of human space activities, there are surviving debris of re-entry spacecraft and debris that impact the Earth's surface, causing typical damage cases and affecting the future technological development of spacecraft. Firstly typical re-entry damage cases and disposal methods of foreign spacecraft that have attracted significant social attention are analyzeds. Secondly the main international norms and standards for re-entry casualty risk are introduced. Then those assessment methods of re-entry casualty risk are studied together with re-entry risk analysis tools of NASA and ESA. Finally it's looked forward to the furture development and existing problems of major space powers in the technical directions of active deorbit, assisted deorbit, large-scale reentry, and reusable spacecraft. Research shows that although the re-entry casualty risk of spacecraft and debris is still difficult to predicte very accurately, it is expected to be moderately controlled by the design of risk-reduction measures along with technological development.
The theoretical development of weapon equipment system of systems engineering is reviewed from three aspects of the formation process of combat System of Systems, such as mutual reference relationship and connotation, research status of main links, intelligence, toughness and emergence, and the theoretical development of weapon equipment System of Systems engineering under the guidance of system engineering theory is summarized and analyzed. In the space field, the System of Systems project is the main carrier to carry out application exploration in two aspects of technology and management, based on which the future development direction is prospected.
International Space Station has been in orbit for more than 20 years, forming a relatively mature cargo transport system and exploring the development path of low-cost and highly reliable commercial cargo transport system. As China's Space Station enters the stage of application and development, the demand for materials up and down will significantly increase. It will be particularly important to form a rich and stable cargo transport system and significantly reduce cargo costs under normal operating modes. The development and current situation of cargo transport system of the International Space Station are analyzed, the composition of the International Space Staion, commercial orbital transportation service plans, and recent cargo transportation situations are focused on, providing reference and suggestions for China's Space Station's cargo transport system.
With the wide application of cognitive technology in the military field, cognitive Electronic Warfare (EW) has become the inevitable trend of future military war. Given the development of EW combat object in the cognitive direction leading to a decline in the operational effectiveness of traditional EW, an in-depth exploration and analysis of key technologies in cognitive electronic warfare are conducted, including cognitive reconnaissance, cognitive jamming, jamming evaluation, and dynamic knowledge base. Moreover, the basic concepts of cognitive EW are sorted out, by analyzing the numerous challenges to traditional EW. Then, the system architecture and composition of cognitive EW are studied. On this foundation, the key technologies of cognitive EW are summarized. Finally, based on the characteristics of cognitive EW, the development direction of cognitive EW has been prospected.
Trans-media aircraft refers to a new concept special aircraft with both air flight capabilities and underwater submarine capabilities, which includes submersible aircraft and submarine-launched drones. Aircraft that can span multiple domains is focused on. Through literature research, this study elaborates on trans-media aircraft and their characteristics and applications, introduces in detail the development status of trans-media aircraft at home and abroad, analyzes the technical difficulties of achieving trans-media flight, and summarizes the key technologies required for trans-media aircraft. Finally, based on the investigation and the current development at home and abroad, the prospects of the trans-media aircraft are prospected and development suggestions are put forward.
Aerodynamic configuration design is an important technology for hypersonic vehicles. Combined with other relative specialties, it is the key to obtain good flight performance and ensure essential flight quality. As a fundamental research area of modern hypersonic vehicles, air-breathing vehicle has become an indispensable way to realize the sustainable hypersonic flight. The typical hypersonic air-breathing vehicles are focused on and the design concept of configurations is investigated. Proposed from the perspective of combined-cycle propulsion systems, the relationship between propulsion systems and aerodynamic configuration is studied which provides a reference for the aerodynamic configuration design work.