Satellite Internet serves as the core of next-generation communication networks, and exhibits several distinctive features, such as blurred internal and external boundaries, globally open networks, and overlapping hostile and friendly spaces. These features inevitably make security issues a focal point in the design and construction of such networks. Firstly, the primary security threats faced by Satellite Internet were analyzed, particularly in terms of network transmission involving nodes, links, and routing, with a special emphasis on novel satellite spoofing attacks. Subsequently, the current states of security technology development were reviewed in the areas of node access authentication, link secure transmission, and network security routing. Finally, the development trends of Satellite Internet security technology were predicted, highlighting the importance of endogenous, systematic, and intelligent Satellite Internet techniques. Furthermore, several key future research directions in Satellite Internet security were suggested, including integrated security protection systems for Satellite Internet, satellite radio frequency fingerprint authentication, cross-layer secure transmission between satellite and ground, location protection for satellite-ground wireless communication, and deterministic mission security execution based on intrinsic security.

orbit prediction is crucial for assessing the likelihood of collisions between space objects and for better managing the near-earth space environment. Traditional orbit prediction methods rely on physical dynamic models, which necessitate the modeling of complex space environments and space objects. In reality, the limited understanding of many non-gravitational perturbations restricts the accuracy of orbit predictions. Considering the limitations of traditional orbit prediction methods, we proposed a technique to predict orbits based on the long short-term memory (LSTM) network. This approach leveraged a series of convolutions to extract features from the satellite orbit data over time, uncovering the underlying operational patterns. Experimental results indicated that this method improved the accuracy of satellite orbit predictions and provided a theoretical foundation for improving space situational awareness capabilities.

In the context of the continuous development of modern communication technologies, the satellite communication plays a crucial role in global information transmission. However, the communication security and the timeliness of information are always key issues that urgently need to be addressed. The information freshness of covert communication in a satellite-terrestrial system consisting of a satellite transmitter Alice, a terrestrial full-duplex receiver Bob, and a terrestrial warden Willie, was taken as the object of the study. Particularly, Alice tried to transmit the covert information to Bob under the detection of Willie, while Bob emitted jamming signals to confuse Willie simultaneously. Therefore, a theoretical model was provided for the average age of information (AoI) of Bob and the covert constraint of Willie. This model considered the impact of various interferences and noises during the communication process, providing a solid theoretical basis for analyzing system performance. Based on the theoretical model, a optimal transmit power of Alice was drived to minimize the average AoI with the constraint of covertness requirement. By optimizing the transmission power, Alice is capable of ensuring the maximum the freshness of information while minimizing the delay in information transmission under the precondition of covert communication. Subsequently, numerical simulations were carried out to verify the accuracy of the theoretical model, and the impacts of transmission power and interference power on the concealment and average AoI were analyzed. Finally, the numerical results showed that the balance between concealment and AoI could be effectively achieved by reasonably adjusting the transmission and jamming power.

As the development of onboard computing power and inter-satellite communication technology, the space-ground integrated computing network is expected to solve the issues of response delay caused by optimizing sensing, communication, and computing separately in a multitude of time-sensitive tasks by using the distributed data, onboard computing and communication resources collaboratively. The forthcoming space-ground integrated computing network serving as an integrated network system for providing wide-area information services, involves a significant amount of data interaction. However, its characteristics such as open channels and highly dynamic network topology expose a broad range of vulnerabilities in data sensing, storage, transmission, intelligent processing and service, making the high-value data like remote sensing susceptible to attacks, and thereby threatening the data security and user privacy. To this end, the future technical architecture, key technologies and applications of the space-ground integrated computing network were summarized. Then, the key features and the security issues of data were deeply analyzed. Next, a series of possible countermeasures were further discussed, and the future research directions of data security were prospected.

With the development of Satellite Internet technology, content delivery network (CDN) with the integrated satellite- terrestrial environment plays a significant role in enhancing the experience of information access and alleviating the stress on the Internet's backbone. However, CDN in Satellite Internet also faces a series of security vulnerabilities. The vulnerabilities of CDN in Satellite Internet were analyzed and the corresponding countermeasures were discussed, delving into the security issues of content distribution in Satellite Internet. Based on this, a series of difficulties to enhance the security mechanism of CDN in Satellite Internet were proposed and the security threats of CDN in Satellite Internet were summarized, providing an outlook for future research directions.

With the rapid development of Satellite Internet, how to ensure the security of satellite-to-ground communication has become an inevitable problem. Compared with the traditional key encryption method used for communication security, the new and practical physical layer security technology is a new choice, which makes up many shortcomings of the key encryption method. By making full use of the wireless channel characteristics during the information transmission, it provides a new solution to the existing problem during the security transmission. Focusing on the secure communication model, the actual satellite communication scenario was divided into two situations according to the location relationship, and the physical layer security technologies adopted under different conditions were reviewed from the basic theory. Finally, the future research directions and challenges of the secure communication technology were pointed out.

The evolution of low earth orbit (LEO) satellite networks has introduced an innovative paradigm for achieving the continuous, seamless and global coverage. In the dynamically complex environment of LEO satellite networks, intelligent and efficient resource management strategies are crucial given the limited resources. Focusing on the resource management issues of LEO satellite networks, the integration of intent-driven networking with the resource management of LEO satellite networks was considered. Firstly, a heterogeneous resource management model for LEO satellite networks was established. Subsequently, an intent-driven resource management framework was designed to enhance the utilization of limited resources and to meet the diverse needs of various tasks. Then, heterogeneous resource management strategies were employed to address the resource management issues. Finally, the application of this architecture was illustrated in a specific scenario. The simulation results showed that compared to the traditional resource management architecture, the intent-driven resource management architecture could effectively improve the task benefits and efficiency.

Satellite-assisted Unmanned Device Networks (SUNets) integrate satellite communication, unmanned devices, ground support facilities, and cloud computing to achieve wide-area connectivity in agricultural production. However, the security issues introduced by the wide-area coverage and complex multi-layered communication structure of SUNets have not been thoroughly researched in the agricultural field. The future "cloud-network-end" agricultural architecture based on SUNets is systematically reviewed, and the specific application cases of future agriculture under the wide-area coverage of SUNets are explored, focusing on cross-regional agricultural machinery scheduling and field management. Additionally, the collaborative security and the security issues caused the data transparency, transmission path complexity, and the dynamic nature of the network environment within the SUNets architecture are summarized. The paper aims at investigating the architectures, applications, and security challenges of future agricultural SUNets, providing a reference for future research to fill the gaps in SUNets about agriculture.