Extraterrestrial Artificial Photosynthetic (EAP) technology aims to simulate the natural photosynthesis of green plants in the extraterrestrial space environment, and convert carbon dioxide into oxygen and carbon-containing fuels through physicochemical processes, making it a promising technology for efficient carbon dioxide conversion and oxygen regeneration. This technology can not only convert the carbon dioxide produced by human respiration into oxygen to realize the regeneration of waste in confined spaces and greatly reduce the material supply requirements of manned space station or manned deep space spacecraft, but also utilize the abundant carbon dioxide and water in-situ resources of the extraterrestrial environment such as Mars to produce oxygen and fuel to achieve the extraterrestrial survival of human beings on other planets. This paper comprehensively overviews the recent progresses of extraterrestrial carbon dioxide conversion technologies. It also clarifies the concept and connotation of EAP technology and analyzes its characteristics and application prospects. On this basis, this study first proposes the space experiment objectives of EAP technology, and then presents the design of the experimental payload, relevant ground tests results, and on-orbit experiment progress. Finally, this paper summarizes and prospects the research progress of EAP technology.
Microbiological control technology in space station is a key technology ensuring the safety of astronauts and the long-term stable operation of spacecraft during extended manned missions. Firstly, the paper systematically reviewed the microbial contamination incidents in history space stations, summarizing the main characteristics of these incidents to provide warnings and lessons for the microbial protection and control of China Space Station. Then, it summarized the research progress in on-orbit microbial detection technology and on-orbit microbial control technology for space stations, with a focus on introducing the research conducted in these areas in China Space Station. Finally, the paper proposed a space station microbiological control technology system constructed by the author's research team from the perspective of systems engineering risk management, with the aim of accelerating the development of China Space Station microbiological control technology and fulfilling the microbial control requirements of China's manned space engineering.
The charged debris generated inside the conductive slip ring of the spacecraft will not only aggravate the wear of the slip ring, but also cause electric field distortion, induce vacuum flashover along the surface, and affect the working reliability of the solar cell array. In the paper, we simulate the distribution of the electric field, potential and magnetic field inside the conductive slip ring, and then study the motion of the live friction. Simulation analysis shows that the maximum internal electric field of the conductive slip ring under the electrostatic field is 2.65×104 V/m, and the charged dust moves to the side of the insulated baffle, and the maximum speed can reach 3.92×10−3 m/s. In the space electron irradiation environment, the maximum value of the internal electric field is 3.7×108 V/m, which appears at the “triple combination” point, and the maximum speed can reach 4.05×10−3 m/s, and the migration movement is more obvious. The on-orbit test confirmed that the debris moved and gathered to the side of the insulated baffle. This paper reveals the migration rules of the charged debris in the conductive slip ring, which provides theoretical support and test basis for the insulation optimization design of the conductive slip ring.
The research on microalgae cultivation and microwave processing technology in a controlled space environment is of great significance for the new generation of environmental control and life support systems. In response to the scientific needs of conducting microalgae cultivation and microwave processing experiments on the China Space Station, firstly, seven candidate microalgae species were screened, and Spirulina and Nannochloropsis were determined as experimental species through factors such as availability, growth cycle, nutrients, and culture environment (light, water, pH); secondly, according to the experimental plan and candidate microalgae species, a microalgae cultivation and microwave processing device was developed, and two microalgae cultivation modes, solid-state and liquid-state, were proposed. The solid cultivation mode was used to evaluate oxygen production rate under a controlled environment, and the liquid cultivation mode was used to verify physiological characteristics of microalgae and microwave processing technologies; finally, key technologies such as controlled space design and miniaturized microwave processing were overcome, and a microalgae cultivation and microwave processing device was developed, and experiments such as ground simulation cultivation and microwave heating of microalgae were carried out. The results of ground experiments show that microalgae in liquid culture mode can be cultured for 30 days in a small volume controlled environment within the device, and the oxygen production rate of microalgae in solid culture mode is about 15 g·m−2·d−1 in the first two days of culture. The targeted microwave heating can cook liquid microalgae in the range of 65~70℃. The microwave-processed microalgae has nutritional retention characteristics and food application potential.
Before the application of the controlled ecological life support system on Lunar or Mars bases, technical verification must be conducted on China Space Station to address the scientific and engineering challenges that arise during the application process. This article studied the task requirements and constraints for conducting the controlled ecological life support system, clarified the technical verification objectives, and developed in orbit specific technical verification approaches and scenarios. For the technical verification of efficient plant cultivation in the first state, technical process, verification contents, ground test scenario, facility development, and in orbit verification scenarios have been studied and clarified. The preliminary tests were carried out, with the selection of the plants varieties. Aeroponics cultivation and microbial control were also verified.
This paper analyzes the structural characteristics of the ventilation ducts of aerospace equipment, the structural constraints and functional requirements they impose on pipeline robots, and concludes that pipeline robots should at least have the ability to control the contact force with the pipe wall, the ability to provide stable support and steering through non-continuous ducts such as T-shaped pipes and gaps, and the ability to adapt to changes in pipe diameter. An integrated typical Series Elastic Actuator (SEA) robot leg scissor mechanism was designed to meet the demand for variable diameter adaptation. This mechanism has the ability to control flexible force. To address steering needs, swing and roll joints were designed. To overcome obstacles such as gaps, two sets of series leg mechanism modules were designed to achieve gap crossing through alternating support movements. This paper experimentally verified that the robot could navigate through complex pipelines of various sizes and types, achieving a variable diameter ratio of 2.
Energy storage battery technology has been developed by leaps and bounds in recent years. As an electric guarantee for space vehicles, the maturity of energy storage batteries must be very high. However, rapid upgrading makes it unable to be fully verified on vehicles. The successful establishment and stable operation of the space station have provided a powerful platform for the in-orbit application verification research of new energy storage battery technologies. This article proposes a new in-orbit application verification for energy storage battery, including lithium-ion battery pack 1, lithium-ion battery pack 2, charge and discharge controller and discharge load. Using the mode of charging and discharging each other by two battery packs, two kinds of energy storage battery technologies can be verified at the same time, and the optimal use of energy can be achieved, only a small amount of energy loss needs to be supplemented by space station. The platform will provide a strong support for the replacement of the new energy storage battery technologies in the space vehicles.
The variable gravity pool boiling experiment is one of the scientific experiments within the varying gravity rack of the Wentian experiment module of the China Space Station (CSS). It investigates the heat transfer performance and bubble dynamics during pool boiling are studied under varying gravity conditions. As a key component developed independently, the multi-functional integrated micro-heater (MIM) was fabricated using micro-electro-mechanical system technology. It features a 10 mm×10 mm×1 mm quartz glass substrate, on which several platinum thin films with specific structural parameters were fabricated to integrate multiple functions, including bubble triggering, temperature measurement, and power input. The chip-on-board packaging technology was used to form it as a separate component. The characteristic resistance-temperature curves of the local temperature sensors and the main heater of the MIM were calibrated using the on-orbit experimental data obtained aboard the CSS. The synchronized measurement data of the bulk liquid temperature within the boiling chamber served as the reference temperature data. The temperature uncertainty of the MIM was also analyzed. The single-phase natural convection heat transfer performance in different gravity conditions, obtained aboard the CSS, was calculated. These results were consistent with the predictions of the common-used empirical correlations and similar experimental data, indicating that the present space experimental results are reliable.
Food is crucial for space missions, tourism, deep space exploration, and mining, serving as the basis and energy sources for survival, health, and activities in space. However, the unique extreme environmental conditions in space, especially microgravity and high radiation, pose serious challenges to space food preservation and safety. Given of its importance in space missions, the research and development of space food has become an indispensable part of space technology development. Here, we introduced the new Space Life Investigation Database（SpaceLID）, a resource for space food research as well as for space biological research and public enquiry. SpaceLID contains a wide range of research on space food, including food variety, menu, quality, preservation methods and nutritional combinations. This article provides detailed overview of the information contents and navigation methods of SpaceLID, and the examples of the use of SpaceLID information for space food research. By in-depth analysis of the information in SpaceLID, one can better understand the needs and challenges of space food and design a safer, more nutritious diet that better meets the needs of human space missions.
Compared with unmanned spacecraft, manned spacecraft information systems must not only perform essential functions including system state monitoring, data routing, and command execution, but also address the human-in-the-loop coordination requirements inherent in crewed operations. With the increasing orbital longevity and mission complexity of contemporary spacecraft, three operational imperatives have emerged as critical challenges for manned spacecraft information systems: optimization of crew habitability during extended missions, enhancement of in-orbit operational efficiency, and improvement of multi-task management capabilities. To address these challenges, researchers have implemented advanced civilian technologies such as cloud computing and smart home in spacecraft environments, thereby generating different technical requirements spanning network bandwidth, latency tolerance, terminal density, and human-machine interface modalities. This study proposes a unified intelligent system design framework that holistically addresses four critical dimensions: system architecture, network protocols, seamless mobility, and system expandability. The proposed methodology demonstrates effective accommodation of diverse technical demands under resource-constrained multi-mission scenarios while maintaining system robustness.
In response to the requirements for precise positioning of on-orbit faults, fine maintenance, and intelligent process of typical power supply and distribution products in the space station, a technical solution for intelligent diagnosis and fine maintenance of on-orbit in-situ faults of typical power supply and distribution products is proposed. Discussions are conducted on the necessity, advancement, safety, and feasibility of the key technical links therein, as well as the application prospects. The overall concept of further reducing the maintenance level and on-orbit repair and reuse of Orbital Replacement Units (ORU) for board-level and component-level faults of products such as power control units and command bus units is expounded. The feasibility, complete technical routes, and implementation plans of essential key technologies for on-orbit maintenance, such as rapid intelligent fault diagnosis and precise positioning, and on-orbit fine-level welding maintenance, are explored. Regarding on-orbit maintenance supported by real-time and multi-mode interaction throughout the process based on augmented reality (AR), the disparities of existing AR technology in meeting the demands of board-level fine maintenance are examined. The significance of developing a domestically controllable and intelligent engine is proposed, along with the necessity and feasibility of key technologies such as dynamic registration technology, high-precision anchoring algorithm, flexible target recognition, and human-machine efficiency evaluation. A development plan for lightweight and highly comfortable wearable equipment is presented. A detailed analysis is carried out on the key technologies affected by differences between space and Earth, such as microgravity, in this set of solutions. The necessity, experimental methods, and implementation plans for on-orbit verification are proposed, including on-orbit welding technology, rapid and precise fault positioning technology, and AR-guided astronaut operations. This set of solutions not only possesses advantages such as low cost, multi-level, and refinement, which can effectively lower the maintenance level, optimize spare parts and supplies, and enhance system safety, but also has strong universality and can be extended to other experimental systems or more industrial fields, presenting broad application prospects.
During human space exploration, small-micro power generation technology for space heat sources can be used without relying on solar energy and is a useful option for deep space exploration missions, including manned Moon landings and Mars landings. The Tesla turbine, as a simple micro-expander, has great potential to play an important role in the field of small micro-generation, thanks to its unique structure and principle. In this study, the performance of the Tesla turbine is experimentally tested under different medium and low temperature heat source temperatures, flow rates, and loads. The experimental results indicate that the Tesla turbine and its accompanying power generation equipment, can achieve more than 60% isentropic efficiency and more than 95% shaft efficiency under different operating conditions at pressures below 1.4 MPa, respectively. It provides experimental basis for the future research and application of Tesla turbine.
In response to the technical requirements for powder level measurement for in-situ space resource utilization, this study proposes a level measurement method based on interdigital capacitors. The measurement characteristics were experimentally investigated with lunar regolith simulant in a vacuum environment. The results indicate that the capacitance of the interdigital capacitor varies linearly with the powder level, exhibiting a sensitivity parameter ranging from 10−1 to 100 pF/mm. This sensitivity is influenced by electrode structure parameters and powder layer thickness, with the electrode spacing and insulating layer thickness having the most significant impact. To achieve a higher sensitivity, smaller electrode spacing and insulating layer thickness should be used. Additionally, for a given electrode spacing, there exists an optimal electrode width that maximizes the sensitivity parameter. This study demonstrates that interdigital capacitors are suitable for measuring the powder of level of lunar regolith simulant in a vacuum environment. Furthermore, their underlying working principle suggests potential applications in powder arching detection and powder layer thickness measurement in future space missions.
This paper investigates the dynamics and control challenges associated with the deployment of a three-body tethered satellite system. For dynamic analysis and control purposes, two types of models are established. Initially, the relative attitude motion between the main satellite and the tether is considered, leading to the establishment of a simplified system model for controller design based on the dumbbell model assumption. Moreover, considering the flexibility of the tether and the satellite attitude, an accurate system model for dynamic analysis was established based on the spring-mass model assumption. In order to achieve the stable deployment process of the three-body tethered satellite formation system, a synthetic control strategy is proposed. First, taking into account the complex state of the system and the control input constraints during the deployment process, a nonlinear model predictive control method is proposed based on a simplified model. The control trajectory for the tether's elastic force and propulsion force is solved by the nonlinear programming method. To address the the control error resulting from trajectory tracking, a proportional-differential feedback controller is proposed to stabilize the system attitude and configuration. Finally, numerical simulations are presented to analyze the nonlinear dynamic behavior of the system during the deployment process and to verify the effectiveness of the control strategy.
On-orbit maintenance is essential for ensuring the long-term health and operation of spacecraft such as space stations and manned spacecraft. In the future, space robots will play a significant role in the on-orbit maintenance of spacecraft. Accurate pose estimation of spacecraft components is a prerequisite for space robots to perform on-orbit maintenance tasks, and it faces challenges such as unknown models, high real-time requirements, and the impact of complex lighting conditions in space. To address these issues, this paper first systematically reviews computer vision and deep learning-based pose estimation methods, analyzing the applicability of different methods in space missions. Building upon this foundation, a pose estimation method for spacecraft components based on viewpoint similarity is proposed. This method utilizes a vision transformer model to construct a reference viewpoint selector, combined with epipolar geometry constraints to achieve rapid estimation of the rough pose of target components. Then, precise estimation of the target component's pose is accomplished through viewpoint similarity weight allocation. The proposed method does not rely on target models, enhances algorithm robustness through similar viewpoint selection, and has been validated on a constructed dataset of spacecraft components. This method can provide methodological support for future intelligent and autonomous on-orbit maintenance by space robots.
This paper first provides an overview of the conceptual connotation, customer portrait, market size, and policy support from national and local governments regarding space tourism and exploration. Then the development of foreign space tourism is introduced in this paper from three dimensions respectively: suborbital tourism system, near-Earth orbit tourism system, and commercial space walk. Both Virgin Galactic and Blue Origin successfully carried out manned suborbital flights many times in 2021. SpaceX successfully achieved the first manned low Earth orbit flight in 2021 and the first commercial space walk in 2024. Then the current development of domestic space tourism is introduced in this paper, with a focus on the space tourism plans of three companies, namely Shenlan Space, CAS Space, and Beijing Interstellor Human Spaceflight Technology. Finally, this paper elaborates on the significant meaning of developing space tourism industry in multiple fields such as science, economy, technology and culture, and provides corresponding suggestions for the challenges faced by space tourism industry in the fields of technology, safety, business models, laws and regulations.
