The advent of the fifth-generation (5G) technology has revolutionized the way we think about communication networks, enabling a plethora of new use cases and scenarios that were not possible with previous generations of wireless technology. The existing 5G communication networks predominantly rely on terrestrial communication infrastructure, which, however, exhibits several notable limitations such as capacity constraints, latency issues, and energy inefficiencies, necessitating this next-generation leap. The 6G aims to provide a comprehensive solution for a hyperconnected, intelligent, and immersive digital ecosystem, seamlessly integrating terrestrial, airborne, and spaceborne networks which is referred to as the space-air-ground-sea integrated network (SAGSIN). A traditional SAGSIN scenario mainly includes 3 segments: spaceborne network, airborne network, and terrestrial network. The classical SAGSIN architecture has shown remarkable capabilities in providing massive connectivity by integrating spaceborne, airborne, and terrestrial cellular networks, which, however, encounters inherent technical challenges against their respective practical implementation. On the other hand, the philosophy of near-space communications (NS-COM) is gradually emerging. The distinctive location of near space which is 20 ~ 100 km above Earth’s surface positiones at the core of the SAGSIN, thus allowing the NS-COM network to address the shortcomings of traditional spaceborne, terrestrial, and airborne networks. NS-COM present a promising addition to SAGSIN, making them the final piece of the SAGSIN puzzle.

With the advancement of Internet applications, the global demand for broadband satellite communication services is incessantly escalating. Furthermore, there exists an exponential surge in the requisition for the capacity of satellite communication systems. In response to this evolving demand, the domain of satellite communication technology is progressively evolving toward the realm of high-throughput satellite (HTS) communication systems. The typical technical characteristics of HTS are: (a) the satellite adopts multibeam technology for beam overlapping coverage of the service area, which improves the quality of the wireless link while realizing the spatial dimension segmentation; (b) based on this, the system adopts multiple frequency multiplexing to improve the communication capacity of a single satellite; (c) the gateway station is tightly coupled with the user beam clusters are tightly coupled to complete 2-hop communication, which makes multiple gateway stations share the communication resources of the same satellite, forming a spatial isolation of the gateway stations, and once again realizing the frequency multiplexing of the gateway station links. A key requirement for future multibeam broadband satellite communication systems is the ability to flexibly adjust beam capacity according to changes in business distribution, in order to meet time-varying business requirements. Beam hopping technology provides an efficient solution to achieve the efficient use of frequency resources and power resources. At the same time, the use of beam hopping makes the beam hopping of satellite payload need to match the business signals of ground signal stations, bringing about the need for synchronization of beam hopping between satellite and ground.

The gravitational wave is a prediction of the general theory of relativity that can be detected by measuring the relative distance between two test masses (TM) along the geodesics. The TM is fixed by the cage and vent mechanism to avoid collision with the spacecraft cavity during launch. Once the drag-free spacecraft reaches its target orbit, the TM must be released by the grabbing positioning and release mechanism (GPRM) to the cage center of the inertial sensor in a limited amount of time. The capture of the TM by means of the electrostatic suspensions is crucial for the mission. However, the GPRM inevitably generates large release errors and the low electrostatic force makes the TM capture control a difficult task. Moreover, the experimental results of the LISA Pathfinder mission have shown that the TM release velocities were well higher than the ones expected. The previous robust sliding mode controller needs to be optimized.

Free-space optical communications (FSOC), which use lasers for high-speed data links between aircraft, spacecraft, and ground stations, are limited by size and power constraints. To overcome this, researchers from the Karlsruhe Institute of Technology, Germany, proposed and experimentally validated a fiber-bundle-based architecture that could enable compact, multi-directional FSOC.

Space manipulators play an important role in the on-orbit services and planetary surface operation whose reliability is a key issue. In the extreme environment of space, space manipulators are susceptible to a variety of unknown disturbances. Since it is difficult for the manipulator to be repaired immediately, once it fails, it will mean that it cannot complete the mission as expected, which may cause serious losses and dangers. How to have a resilient guarantee, i.e., the manipulator’s ability to resiliently recover and continue to complete tasks, in failure or disturbance is the core capability of its future development. The motion planning unit is used as the computing terminal of the manipulator’s joint motion trajectory. Compared with traditional motion planning, learning-based motion planning has gradually become a hot spot in current research. However, no matter what kind of research ideas, the single robotic manipulator is studied as an independent agent, making it unable to provide sufficient flexibility under conditions such as external force disturbance, observation noise, and mechanical failure.

Photocatalytic seawater splitting is an attractive way for producing green hydrogen. Significant progresses have been made recently in catalytic efficiencies, but the activity of catalysts can only maintain stable for about 10 h. Here, we develop a vacancy-engineered Ag₃PO₄/CdS porous microreactor chip photocatalyst, operating in seawater with a performance stability exceeding 300 h. This is achieved by the establishment of both catalytic selectivity for impurity ions and tailored interactions between vacancies and sulfur species. Efficient transport of carriers with strong redox ability is ensured by forming a heterojunction within a space charge region, where the visualization of potential distribution confirms the key design concept of our chip. Moreover, the separation of oxidation and reduction reactions in space inhibits the reverse recombination, making the chip capable of working at atmospheric pressure. Consequently, in the presence of Pt co-catalysts, a high solar-to-hydrogen efficiency of 0.81% can be achieved in the whole durability test. When using a fully solar-driven 256 cm² hydrogen production prototype, a H₂ evolution rate of 68.01 mmol h⁻¹ m⁻² can be achieved under outdoor insolation. Our findings provide a novel approach to achieve high selectivity, and demonstrate an efficient and scalable prototype suitable for practical solar H₂ production.