Lightweight is a substantial theme in the research and development of aerospace and aeronautical equipment due to its decisive impact on the comprehensive performance and operational efficiency of the equipment. Over the past decades， a handful of innovative optimization design approaches， emerging high-performance materials， and revolutionary manufacturing technologies have been uninterruptedly developed， and the level of lightweighting in aerospace and aeronautical equipment has been significantly advanced. However， the increasing demands for comprehensive performance and multifunctionality of the next generation of equipment present serious challenges to existing lightweight design and manufacturing technologies. Therefore， with a particular emphasis on the layout design， electromechanical system design， materials and structures， high-performance manufacturing and assembly， this paper analyzes the posed challenges and future perspectives.

Technological breakthroughs have once again spawned a lot of attention to the commercialization of Urban Air Mobility （UAM） in urban low-altitude airspace. The urban low-altitude airspace environment is complex， the density of urban air traffic flow in commercial scenarios is high， and the specifications of vehicles are not uniform. As a new infrastructure for UAM， low-altitude public routes are an important means for UAM to carry out refined management. However， the planning methods of low-altitude public routes， the required infrastructure， and the urban air traffic operation and control mode are still unclear. In response to the above issues， this article sorts out the basic concepts and development history of UAM and low-altitude public air routes， as well as UAM management based on low-altitude public air routes； In addition， an UAM operation management framework is proposed. Suggestions and countermeasures are provided on the possible responsibilities of relevant administrative departments in the development UAM； Finally， the construction method of low-altitude public routes network， the difficulties in the development process of UAM and implementation suggestions are summarized， in order to shed light on the healthy and orderly development of the UAM.

With the increasing convenience of data acquisition for aerial photography of Unmanned Aerial Vehicle （UAV）， the multi-target detection and tracking technology based on the UAV platform has developed rapidly and has broad prospects for applications in civil and military fields. In recent years， the rapid progress of in-depth learning has also provided a variety of more effective solutions. However， the challenging problems such as sudden changes in the appearance of the target， serious occlusion of the target area， and disappearance and reappearance of the target from the perspective of UAV have not been completely solved. In this paper， we summarize the algorithms for multi-target detection and tracking in UAV aerial video based on deep learning， and summarize the latest progress in this field， including multi-target detection and multi-object tracking. The multi-object detection module is divided into two parts： two-stage and one-stage detection. For the multi-object tracking module， according to the two classical frameworks of tracking-based detection and joint-detection tracking， the principles of the two algorithms are described and their advantages and disadvantages are analyzed. Then， the existing public data sets are statistically analyzed， and the optimal schemes of the benchmark challenge VisDrone Challenge in the field of multi-target detection and tracking based on UAV aerial video in recent years are compared and analyzed. Finally， the paper discusses the urgent problems of multi-object detection and tracking from the perspective of UAV and the possible research directions in the future， providing a reference for the follow-up researchers.

In view of the current situation of the future battlefield, such as high complexity of the environment, strong antagonism of the game, high real-time response, information incomplete, and boundary uncertainty, manned/unmanned cooperative combat system can become the core key to win the future and space battlefield by means of its advantages of superposition release of effectiveness, complementarities of combat weaknesses and high efficiency of action coordination. This paper focuses on the research status of manned/unmanned cooperative combat. It is a new direction of high difficulty, rapid development, broad application prospect and multidisciplinary combat. The research status of manned/unmanned cooperative combat is summarized from three aspects: system concept, key technologies and challenges. It focuses on the definition of system combat, winning mechanism and application process. The key technologies such as detection and situational awareness, mission planning, command and decision making, formation control, and effectiveness evaluation are expounded. Finally, the challenges to be solved in the future battlefield of manned/unmanned cooperative combat are analyzed. It provides new development ideas for future intelligent combat technology.

Morphing aircraft， capable of real-time shape deformation according to task requirements and flight conditions to achieve optimal flight performance， has emerged as a significant direction for the future development of aircraft. This paper reviews the research status of deformation modes and key technologies of aerodynamic layout design for morphing aircraft. Firstly， the development of morphing aircraft can be divided into two stages by the progression of time： the mechanical deformation stage and the flexible and muti-dimensional deformation stage. Then， this article summarizes morphing solutions for different parts of the aircraft， namely， the head deformation， wing deformation， power plant deformation， and combined deformation. It particularly explores the developmental history of various wing morphing schemes， discusses their applications in different aerodynamic configurations including variable sweep wing， variable forward sweep wing， folding wing， telescopic wing， oblique wing， continuous variable curvature wing， and analyzes their aerodynamic and stability characteristics， respectively. Next， the implementation objectives of morphing aircraft are summarized and divided into three types： single domain optimal variable configuration， multi-domain fusion variable configuration， and one vessel multi-energy variable configuration. Subsequently， compared with fixed shape aircraft， the key technical challenges in aerodynamic layout and overall coordination design， time-varying aerodynamic effect evaluation， aerodynamic layout scheme optimization， and multidisciplinary coupling design derived from the implementation of morphing aircraft are analyzed， with particular focus on the research progress and current status of dynamic aerodynamic calculation methods and aerodynamic optimization design technologies for morphing aircraft. Finally， the future research direction and development prospects of morphing technologies are envisioned. Targeting at the needs of wide velocity domain and large airspace flight， exploring new conceptual deformation methods that can improve the performance of multiple flight missions and establishing intelligent morphing design model and multidisciplinary strong coupling integrated design system will become important development trends.

The rapid development of brain and neuroscience in recent decades has initially revealed the neural mechanism of animal navigation. Drawing on the brain neural structures and information processing mechanisms， the study of brain-inspired intelligent navigation systems provides new inspiration for low-power， highly robust autonomous intelligent navigation in complex environments. Based on a detailed review of the neural mechanisms of animal spatial navigation， this paper then outlines and discusses current intelligent algorithms for robotic bionic brain-inspired navigation， which can be categorized into three types according to the three types of neural networks used to process navigation information for intelligent navigation： attractor neural networks， deep reinforcement learning， and spiking neural networks. Then， the ways for implementing brain-inspired navigation， including bionic intelligent sensors and neuromorphic processor platforms， are sorted out. Finally， the development trend of brain-inspired navigation is discussed， including further exploration of the brain neural mechanism of navigation in the biological world and its information processing process with low energy consumption and high robustness mechanism， subcategorization of the conceptual connotation of brain-inspired navigation， and the ways to improve the evaluation index and the unified implementation framework.

Multi-scale structure is one of the important directions of next-generation structural lightweighting and has great potential and strategic value for application in the aerospace field. Topology optimization techniques for multi-scale structures have also been extensively researched， leading to great progress and achievements. However， many challenges and difficulties remain before realizing actual engineering practice. This paper firstly introduces the mainstream methods and characteristics of single-scale structural topology optimization， the basic idea and special position of homogenization methods， as well as the relationship between topology optimization methods for multi-scale structures and topology optimization methods for single-scale structures. Then， using the structural distribution characteristics as the classification criteria， this paper systematically sorted out the topology optimization design methods for three distribution forms of multi-scale structures： periodic， functional gradient and heterogeneous. For the important issues， including structural connectivity， applicability of multi-scale methods， and application of machine learning technology in multi-scale structural topology optimization， relevant research progresses are reviewed and discussed. Finally， pressing challenges and important research directions in the field are summarized and prospected.

Aeroengine amalgamates state-of-the-art technologies across diverse domains， serving as a comprehensive manifestation of a nation’s prowess in science and industry. Frequent malfunctions occur due to its complicated structure and harsh service environment. Therefore， it is essential to employ prognostic and health management technology to provide crucial support for aviation safety and reliable operations. As vibration faults constitute a primary failure mode in aeroengine， this paper， grounded in this premise， systematically reviews and analyzes existing vibration monitoring and fault diagnosis for aviation engines both domestically and internationally. The analysis is categorized into three dimensions， covering the application of overall vibration monitoring and diagnostic systems， typical fault characteristics and diagnostic methods， and the overall vibration fault diagnostic technology， including dynamic analysis， signal processing techniques， and relevant technologies such as deep learning. Then， the problems and challenges faced by the existing vibration fault diagnosis of aeroengine are identified. Furthermore， future development goals are provided.

Low-Altitude Intelligent Network （LAIN）， as a new type of intelligent network， relies on space-air-ground-sea facilities to constitute a digital intelligent network system. It is a key component of the space-air-ground integrated network， and can support the seamless and ubiquitous connections of the sixth generation communication technology and promote the development of intelligent network service from ground to low-altitude space. However， LAIN is still in the developing stage and faces the following key challenges： intractability of aerial control， severe spectrum interference， and multi-dimensional resource limitation. This article focuses on the issues of LAIN architecture and safety control， including the current development status of low-altitude network and its significance for industrial technology transformation. Then， from the perspective of spectrum resources， network resources， and airspace resource management， the recent related works are analyzed. Furthermore， we analyze the key technologies such as low-altitude aircraft air-ground spectrum sharing， sensing， transmission， computing networking coverage， low-altitude airspace intelligent supervision， and point out future development directions. Finally， an application demonstration of LAIN is proposed， aiming to satisfy the significant requirements for efficient operation and safety in low-altitude airspace， and providing the theoretical basis as well as technology for the further development of the next generation space-air-ground integrated network.

With the development and application of artificial intelligent technologies in the military field， future intelligent warfare is to demonstrate the following traits： more complex cognition and decision making， more rapid changes and evolution， and access and denial in the whole warfare. The next-generation flight vehicles will be flight-demand oriented， artificial-intelligence centered， and changing flexible. Smart morphing aircraft， obviously characterized by intelligent technology and deformation technology， can have dual advantages of fast algorithm upgrades and extremely flexible hardware. It introduces new flight modes and combat capabilities， and will therefore become an important trend. However， smart morphing aircraft design requires complicated technologies. The costs of deformation， such as the increased complexity of the machine system， pose challenges to aerodynamic design， flight control， and structural implementation. The challenges include the full-profile optimization， structural application， and performance prediction and validation in the deformation process， where the core problem is to achieve the optimal design in each shape in the context of multidisciplinary engineering.

This paper analyzes the development trend and the key to success of Penetrating Counter Air(PCA) combat in the future, aiming at the two remarkable characteristics of PCA full platform stealth and distributed killing. Firstly, based on the organic integration and complementary advantages of two fire control modes, " target-centered all-aspect attack " and "all-aspect attack of the launch platform", under the full-time airspace framework of before and after shooting, covering multi-aircraft, multi-missiles and multi-targets. The concept and design principle of Penetrating Counter Air all-domain fire field reflecting the dynamic and comprehensive lethality performance of multi-fire nodes of coordinated air combat from a global multi-level perspective was proposed, and the time-varying lethal performance model of air-to-air missiles based on the acquisition probability and its full-probability formula was redefined. Based on this, a sin-gle-machine fire field model and a dual-machine fire field aggregation model are established. Secondly, by introducing the three physical concepts of "gradient, divergence and curl" of field, the characterization model of space distribution, action range and deflection change characteristics of fire field is established respectively, and the corresponding simu-lation and characteristic analysis of fire field are carried out. Finally, two typical air-to-air combat tactical scenarios of applying the all-domain fire field to OODA (observation-positioning-decision-action) closed loop fire control aiming and manipulation, single-aircraft stealth penetrating and two-aircraft coordinated attack are preliminarily explored. It is proved that this new fire control principle possess good technical advantages and application potential. The above research work plays an important role in giving full play to the performance of new weapons and equipment, effective-ly improving the capability of free attack and free escape, and improving the effectiveness of air combat. At the same time, it can provide theoretical support and technical reference for the agile construction of distributed kill net, dynamic combination of killing chain and analysis of new tactical methods.

Image matching is a key technology in aircraft visual navigation. The image matching methods based on deep learning have developed rapidly in recent years. The feature extraction network of the methods has obvious advantages over traditional methods， and has broad prospects for application. The image matching method based on deep learning can be divided into the single-link matching network model method and the end-to-end matching network model matching method according to different network structures. In this paper， the feature detection， descriptor learning， similarity measurement and error elimination network model of the network model of the single-link matching method network model are first investigated and analyzed. Then， the single-network structure method and multi-network structure combination method in the end-to-end matching network model are reviewed， and the classic end-to-end matching network model algorithm is introduced and analyzed. Finally， the problems of current image matching methods based on deep learning are pointed out， and the possible development trend and direction in the future are discussed to provide a certain reference for subsequent research on deep-learning based image matching.

Reusable launch vehicles are an important way for humans to enter and exit space on a large scale and at a low cost. Starting from the technical requirements of vertical takeoff and landing reusable launch vehicles， this paper summarizes the technical challenges faced by vertical takeoff and landing reusable launch vehicles， and analyzes the key technologies of vertical takeoff and landing reusable launch vehicles. The research progress and future development directions of key technologies for vertical takeoff and landing reusable launch vehicles are then discussed in terms of overall optimization design， power， structure and thermal protection， navigation， guidance and control， and health management， which can provide reference for the technical research of reusable launch vehicles.

Since the 1950s， scramjet has been regarded as a goal of the hypersonic propulsion system in the aerospace field， and extensive research work has been conducted in both theory and practical technology. At the beginning of the 21st century， the United States made a series of technological breakthroughs close to practical applications， pushing the research and application of the scramjet technology to a new stage. This paper briefly describes the working principle of the scramjet， discusses the difficulties and latest progress in key technologies such as dual-mode working process， hypersonic compression flow， supersonic combustion， ultra-high temperature structure and thermal protection， ground test and numerical simulation， and expounds the understanding and suggestions on the development direction of key technologies such as wide speed range， repeatability， and higher Mach number of scramjet.

Drag and heat reductions are two core issues in the design of high-speed flight vehicles. Drag reduction can enhance the lift-drag ratio of vehicles and decrease the fuel consumption， while heat reduction can reduce the weight of thermal protection system and promote the effective load of flight vehicles. Drag and heat reductions are the key technologies to improve the fine design and enhance the flight performance. This paper mainly reviews the research status of flow control technology for drag and heat reductions of shock wave and boundary layer， from the perspective of the engineering requirements for drag and heat reductions of high-speed flight vehicles. This paper also points out the existing problems in engineering application and the direction that should be paid close attention to in the future， to realize the engineering application of active flow control of flight vehicles and improve the flight performance.

Fiber reinforced polymer composites are of great significance for improving the thrust-to-weight ratio， fuel economy and environmental protection of aeroengines. This paper introduces the applications of polymer composites in aero-engine. The key challenges and technologies of composites-based fan case and fan blades including the design technology of preforms with complex shapes， high-precision manufacture technology of special-shaped composite structures， multi-scale and high-fidelity modeling method of composites， and the containment design criteria for composites fan cases are summarized. Drawing on the recent research hotspots， new ideas and technologies for composite aero-engine structures are prospected.

The development of electric Vertical Take-off and Landing （eVTOL） aircraft is greatly promoted for the advances in battery and motor technologies and the application of distributed electric propulsion system. In this paper， the advantages and disadvantages of different eVTOL configurations and their application scenarios are summarized， and a comprehensive comparison between eVTOL and conventional fuel aircraft is made in terms of performance， noise and cost. The interaction noise by rotors and rotor-wing is more prominent for eVTOL， but the electric propulsion rotor system with low tip speed and large rotor solidity greatly reduces its noise level （about a reduction of 15 dB）. Lithium-ion batteries are the main energy source for current and future eVTOL. The advanced battery material system， integrated design of battery-structure and excellent battery management system are effective ways to improve the energy density and energy security of the whole aircraft in the future. The redundant manipulation of eVTOL increases the difficulty of flight control system design， but improves the safety of the whole aircraft at the same time. Fault reconstruction and collaborative control are new challenges faced by eVTOL. A wide variety of configurations and novel design features such as high voltage power， electric propulsion， flight-by-wire flight system and electric actuation are proposed for eVTOLs. In the absence of flight test data， the system-based method is the main method for safety design of eVTOL.

Hydrogen fuel has significant importance in mitigating global climate change and protecting the environment by achieving zero carbon emission in aviation engines， aerospace propulsion engines， and ground gas turbines. However， the application of hydrogen combustion technology still faces many challenges. Hydrogen combustion in traditional burners poses a risk of flashback and high nitrogen oxide （NO _x ） emission. Thus， it requires exploration of new combustion technologies and pollution control measures to satisfy the urgent need of hydrogen energy. Micromix combustion technology implements hundreds of microchannels combined with micro-injection of hydrogen to rapidly mix air and hydrogen to form small-scale flames. The residence time of N₂ in the high-temperature zone is shortened to the level of milliseconds， significantly reducing the production of nitrogen oxide. This paper reviews the application history of hydrogen in gas turbine engines and the progress of hydrogen combustion simulation and experimental studies， summarizes the hydrogen characteristics， NO _x generation mechanism， micromix combustion principle， premixed combustion， diffusion combustion and dome structure characteristics， and discusses the influence of critical parameters of micromix combustors on aerothermodynamic process， NO _x generation and control measures， providing theoretical and empirical bases for the engineering design of hydrogen combustion chambers. Finally， the future development of hydrogen combustion technology is prospected.

Disruptive technologies， with their innovative and destructive characteristics， have been leading the transformation of human mode of life and combat operations， and also playing an important role in the rise and fall of major powers and civilization evolution. In the history of aviation， numerous disruptive technologies have emerged to replace the previous technologies， profoundly influencing the process of aviation and shaping the basic pattern of today's air combat and civil aviation transportation. The world is currently at the crossroads of a new round of industrial and military revolution， and whether it is possible to identify， research， and industrialize various disruptive technologies including those in the aviation field is crucial for reshaping the future social form and military landscape. This article briefly illustrates the understanding of disruptive technologies from the aspects of concept， three significant characteristics， and identification and acquisition. The important influence of disruptive technologies on the previous three industrial revolutions is discussed， the significant changes brought by five typical aviation disruptive technologies in history presented， the important trend of the high-energy and intelligent compound development of aviation science and technology in the future analyzed， nine possible disruptive technologies and potential impacts in the four fields of material manufacturing， energy power， information electronics and cross-integration predicted， and suggestions for the development of disruptive technologies in aviation proposed. We expect that more future disruptive technologies in aviation will be initiated and developed by Chinese people.

The lower-cost， maneuverable， faster， and reliable earth/orbit transportation system is an inevitable trend in the development of future aerospace technology， which puts forward a strong demand for propulsion systems with wide speed range， large airspace， high specific impulse， and high thrust to weight ratio. Combined cycle power is an ideal power plant for future advanced aerospace transportation systems by efficiently combining different power modes， fully leveraging the performance advantages of each type of propulsion within its working range， and achieving outstanding comprehensive performance throughout the entire mission profile. For the combined cycle propulsions which have the most promising development prospects， especially the rocket based combined cycle， this article reviews their research progress， analyzes their technological development characteristics and breakthroughs achieved， and proposes the main development directions and suggestions for the future development of rocket ramjet combined cycle engines.