空间科学学报

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Dataset of Solar Prominences from 2011 to 2022

WANG Yitao, ZHANG Quanhao, LIU Jiajia

, Available online , doi: 10.11728/cjss2025.06.2025-0089

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Abstract:
Solar prominences are magnetic structures suspended in the corona, characterized by relatively low temperatures (typically below 10000K) and higher electron densities(10⁹～10¹¹ cm^–3). Research indicates a clear correlation between prominences and solar eruptive activities, such as solar flares and coronal mass ejections that may trigger hazardous space weather. Studying the spatiotemporal distribution of solar prominences can aid in forecasting space weather efforts and help mitigate potential catastrophic impacts. This dataset is based on the 30.4 nm wavelength images captured by the Atmospheric Imaging Assembly (AIA) instrument aboard the Solar Dynamics Observatory (SDO) satellite, with a temporal resolution of 10 minutes. By employing background reconstruction to enhance the contrast of off-limb images, the automated algorithms, such as the skeleton extraction and the region-growing techniques, were used to identify prominence regions in the reconstructed images and extract relevant parameters. For those evolving in the same region during continuous frames, Misidentification caused by duplicate naming is avoided by K-Nearest Neighbor (KNN) classification . Before tracking a procedure called non-prominence feature removal is used to discriminate real prominences from non-prominence features: Through Linear Discriminant Analysis (LDA), the eigenvalue of any target region can be calculated, and compare it with the derived distribution which is fitted with Gaussian distribution functions, to determine the likeliness of a real prominence, by which SLIPCAT can exclude active regions without involving other observation methods. Persisting prominences were tracked and stored in data files. At last, the processed images and prominence data files are organized in a year-month-day three-level directory structure. The dataset encompasses a total of 101741 prominence files, covering the period from 00:00 UT on 1 January 2011 to 23:50 UT on 31 December 2022. Rigorous validation was conducted in accordance with relevant protocols and classification standards to ensure high reliability. This dataset provides scientific support for research on the spatiotemporal distribution of solar prominences over their activity cycles and for the prediction of hazardous space weather events.

Optimization of Fixed Honeycomb Panel Radiator Based on NSGA-II Algorithm

WANG Jianpeng, GUO Tong, CHEN Liang

, Available online , doi: 10.11728/cjss2025.06.2024-0177

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Abstract:
Space radiator is an important part of aerospace thermal control system. In order to meet the heat dissipation and weight reduction requirements of a low-orbit satellite, an optimization strategy of fixed honeycomb plate space radiator has been proposed with the help of inverse design concept, and the root cause of space radiator performance improvement has been expounded from the perspective of macro and micro heat transfer. Taking the layout parameters of heat pipes and fluid loop as the design variables, Kriging was used to construct the surrogate model, and schemes α and β were obtained by iterative optimization based on NSGA-II algorithm. The simulation results show that the optimization schemes improve the surface temperature uniformity by 3.09 K and 4.98 K respectively, and improve the heat dissipation capacity by 18.7% and 28.8% on the basis of reducing the mass ratio by about 1/4. The on-orbit temperature levels of satellite were compared and analyzed. The verification results show that the optimal design of the radiator makes the spacecraft thermal control system have greater temperature control margin and significant weight reduction advantages, which is more conducive to the development and expansion of spacecraft on-orbit tasks.

Payload Application and Resource Management for GEO Satellite-based Electromagnetic Spectrum Monitoring

SUN Zhengbo, ZHOU Xiaoguang, YI Yujiang

, Available online , doi: 10.11728/cjss2025.06.2024-0096

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Abstract:
The electromagnetic spectrum is a vital strategic resource. Electromagnetic spectrum monitoring is a crucial aspect of the allocation, utilization, and management of this resource, serving as a key responsibility of government radio regulatory authorities. Although multiple methods are employed for electromagnetic spectrum monitoring, the predominant reliance on ground-based systems introduces significant limitations.The satellite-based Electromagnetic Spectrum Monitoring (ESM) systems is an effective approach and a research hotspot for wide area surveillance. The space-based electromagnetic spectrum monitoring industry has gradually scaled up with the development of aerospace, electronic, and information technologies. Compared to Low Earth Orbiting (LEO) ESM, Geostationary Earth Orbiting (GEO) ESM has the advantages of fast task response speed, high timeliness of data reception and processing, and ability for long-time continuous surveillance. There is scarce pubilic reporting on GEO satellite-based ESM. Starting from the features of GEO satellite-based ESM, this paper, operation modes of payload resources, payload resource management and control technology, and application systems are studied. Besides, some key technologies deserving deep research are briefly described. It is hoped that this paper will provide some guidance for the design and application of such satellites.

Optimization Strategy for Single-satellite to Multi-station Data Transmission

LU Zhaoyan, FAN Senquan, FU Bihong, BAO Liping, WANG Hao

, Available online , doi: 10.11728/cjss2025.06.2024-0083

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Abstract:
In order to solve the problems of link handover time selection and complex relay scenarios in the multi-station data relay problem, a multi-station data relay method based on link handover time optimization was proposed, which simplified the multi-station relay scene and selected the optimal relay time, so as to improve the transmission time of data relay transmission. In this method, the mathematical description of multi-station relay is established based on the satellite-ground model and the motion constraints of the mechanical antenna, and the expression method of the link switching time between the satellite and the ground station is constructed. Based on the characteristics of mainstream low-orbit remote sensing satellites and ground stations, the relay scenarios of satellite-to-ground data transmission are established, the characteristics of their visible time arcs are summarized, and a two-station optimization strategy for complex multi-station relay scenarios is constructed. Finally, the typical satellite-to-ground data transmission model simulation is used to verify the data transmission relay method with optimization strategy constructed in this paper. The simulation results show that there are 32.0% relayable data transmission arcs in the data transmission links between satellite and the three typical ground station located in China, of which the three-station relay scenario accounts for 17.9%, and the three-station relay scenario can be simplified into a two-station relay scenario through the optimization strategy. In the link handover interval of multiple stations with visible arcs, there is a relay time with the shortest relay time, and the shortest link switching time can be shortened by up to 25% compared with the worst relay time after using the relay time optimization strategy. Using the optimized data relay method for relay data transmission, the average time available for each time was increased from 7.61 minutes to 11.12 minutes.

Calibration of Thermospheric Atmospheric Density Empirical Model Based on SegRNN

CAO Qingpeng, HUANG Liupeng, WEI Chunbo, GU Defeng

, Available online , doi: 10.11728/cjss2025.06.2024-0179

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Abstract:
Atmospheric drag is the largest non-gravitational perturbation experienced by low-orbit satellites, and the main source of error in calculating atmospheric drag stems from inaccuracies in the empirical models of thermospheric density. Currently, these empirical models generally exhibit errors exceeding 30%. To enhance the prediction accuracy of these models, a calibration method for thermospheric density empirical models based on Segment Recurrent Neural Network (SegRNN) is proposed. This method employs the segmentation and parallelism strategies of SegRNN for model training and inference, mitigating the issues of error accumulation and gradient instability that arise from excessive iterations in traditional RNNs. By analyzing the relationship between atmospheric density and external environmental parameters such as Ap, F_10.7, and F_10.7a, an improved neural network architecture named SegRNN with Residual Block is proposed. This architecture introduces external environmental parameters as dynamic covariates and employs a residual block to encode these covariates, thereby extracting density-related information for the prediction period and further enhancing the prediction accuracy of SegRNN. Finally, the density data derived from the onboard accelerometer of the GRACE (Gravity Recovery and Climate Experiment) satellite is used to calibrate the NRLMSIS 2.0 model. The results indicate that the original error of the NRLMSIS 2.0 model is 31.3%. After calibration with SegRNN, the error was reduced to 8.0%. By introducing dynamic covariates, the model error was further reduced to 7.2%. Ultimately, the error of the final calibrated model decreased by 24.1%, demonstrating significant calibration effects.

Design Scheme and Verification of the Thermal Control System for Balloon-borne Coronagraph in Near Space

WANG Jingxing, LIN Jun, KANG Kaifeng, LI Yan, SONG Tengfei, XU Fangyu, LIU Dayang

, Available online , doi: 10.11728/cjss2025.06.2025-0047

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Abstract:
The optical system of the balloon-borne coronagraph typically adopts a small focal ratio design, leading to a slender tube structure that is highly sensitive to fluctuations in ambient temperature. To ensure stable operation under the low-temperature and low-pressure conditions of near-space, this study developed a high-precision thermal control system. The system comprises 12 sets of independently regulated temperature control units, utilizing thermistors as sensors, along with thin-film heaters and a PID control algorithm, to accurately maintain the mirror tube temperature within –5±3℃. By exploiting the differential thermal contraction properties between aluminum alloy and optical materials, the system effectively eliminates structural gaps and mitigates thermal deformation, while an active focusing mechanism compensates for focal shift caused by temperature variations. Through systematic analysis of the structural characteristics of the coronagraph and its operating environment, a heat transfer model specific to near-space conditions was established, identifying the key factors influencing the system temperature, and then a thermal control scheme combining multi-layer insulation and active heating was proposed. On 4 October 2022, a successful flight experiment was conducted in Da Qaidam, Qinghai Province, where the system operated at an altitude of 30 km, acquiring valuable observational data. The recovered data indicates that the temperature control system operates stably, with the temperature fluctuation of the coronagraph tube controlled within the design range. This effectively ensures the normal of the coronagraph in extreme environments, and provides an important technical reference for future similar missions.

Research on the Electromagnetic Locking Device Design for Aerial Towed System Probe Docking

ZHAO Junjie, JIANG Yong, WU Fuzhang

, Available online , doi: 10.11728/cjss2025.06.2024-0196

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Abstract:
The aerial towing system consists of a towing aircraft platform, a cable, and a towed body. It can perform tasks such as material transportation and load recovery, significantly expanding the scope of aerial operation space. During the connection process between the towed body and the towing aircraft platform, the towed body faces difficulties in connection due to the interference from the wake flow field of the towing aircraft platform and the influence of airflow on the flexible cable. Therefore, a detailed study on the docking method is required. The research object is the aerial towed system probe docking. An electromagnetic locking device is designed. The electromagnetic locking principle of rapid locking and emergency release is given. By establishing the finite element model considering the docking process, the response data of the electromagnetic docking mechanism is obtained considering the electromagnetic force as a variable. When the capacitor is used for power supply, the maximum electromagnetic force can reach more than 1000 N under the condition of 2 mm×15 mm wire gauge when the capacitor is above 0.5 F. This docking electromagnetic locking device in this paper provides a new idea for the air docking design.

Research on Heat Dissipation of Split Diamond/Copper Microchannels

FENG Xiaoming, MA Xiang, ZHANG Yonghai, WANG Shuai, LI Bin

, Available online , doi: 10.11728/cjss2025.06.2024-0184

Abstract(431) FullText HTML (50) PDF 1083KB(13)

Abstract:
With the development of aerospace technology, the intelligence level of spacecraft is increasing day by day. The increasing demand for chip computing power leads to a significant increase in its heat flux density, and the life and reliability of related electronic devices are facing severe heat dissipation challenges. The combination of microchannel heat dissipation technology and high thermal conductivity diamond/copper composites provides an effective way to solve the heat dissipation challenges of spacecraft. In view of the poor machinability of diamond/copper composites, a split diamond/copper composite microchannel heat dissipation system is designed in this paper and compared with a pure copper microchannel system. The heat transfer characteristics of the two microchannel systems at different flow rates (0.3, 0.5, 0.7 m·s^–1) and rib heights (1, 1.5, 2 mm) were investigated using HFE-7100 as the heat transfer medium. When the flow rate is 0.7 m·s^–1, the chip surface temperatures of diamond/copper microchannels at the critical power are lower than those of pure copper microchannels by 12℃, 19℃, and 19.6℃, respectively, with the increase of rib height. The heat transfer coefficients were maximally enhanced by 27.8%, 30.1%, and 28.1% at the three rib heights, respectively, showing the heat dissipation advantages of the diamond/copper composite microchannels. The better heat transfer performance of the diamond/copper composite microchannel system is mainly due to its higher thermal conductivity and surface roughness. The pressure drop between the inlet and outlet of the two microchannel systems is basically the same in the single-phase flow section, and the difference gradually becomes apparent when entering nucleate boiling. At critical power, the pressure drop of the diamond/copper microchannel system is slightly higher than that of the pure copper microchannel system, with a maximum increase of 11.8%. The reason for the higher pressure drop in the diamond/copper microchannel system is that the turbulence level of the working fluid is higher in the diamond/copper microchannel system.

Experimental Research Progress on Fuel Cells and Electrolytic Cells under Unconventional Gravity

LI Zihang, YU Ruijiao, YE Fang, DU Wangfang, CHEN Hao, GUO Hang

, Available online , doi: 10.11728/cjss2025.05.2024-0157

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Abstract:
Fuel cells and electrolytic cells can provide energy support for long-term missions and bases in space, but different gravitational levels in space affect their performance, so experimental studies in unconventional gravity environments are necessary for the development and improvement of fuel cells and electrolytic cells for spaceflight. The experimental studies of fuel cells and electrolytic cells in unconventional gravity conditions are reviewed. The analyses and discussions show that the change of gravity level leads to the change of gas-liquid two-phase flow characteristics inside the fuel cell and electrolytic cell, which affects the performance differently. There is still a lack of experimental data on fuel cells in hypergravity and long-term microgravity, as well as unconventional gravity experiments on regenerative fuel cells. Fuel cell and electrolysis cell experiments under unconventional gravity conditions will not only help to promote the intersection of fluid physics and thermophysics with electrochemistry, but will also provide a data basis for the development of regenerative fuel cell systems in space.

Design of Finite Frequency Domain Disturbance Rejection Controller for the Drag-free Spacecraft in Space-borne Gravitational Wave Detection

XU Qianjiao, CUI Bing, WANG Pengcheng, XIA Yuanqing, ZHANG Yonghe

, Available online , doi: 10.11728/cjss2024.05.2024-0022

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Abstract:
In space-borne gravitational wave detection, there are technical challenges in designing the controller for the drag-free spacecraft with dual test masses. These difficulties arise from constraints within the limited measurement frequency domain and the necessity for a high-precision control index. In this paper, a design method of disturbance rejection controller in the finite frequency domain based on the generalized Kalman-Yakubovich-Popov (GKYP) lemma is proposed. Firstly, to address the performance constraints within the designated frequency band of the detection mission, a finite frequency domain control performance index in the form of a frequency response function is constructed. This index is meticulously developed by amalgamating the sensitivity and complementary sensitivity control indexes. Then, a control structure with fixed-order characteristics for output feedback is proposed, and a method for selecting controller parameters based on the GKYP lemma is established. By this, a finite frequency domain disturbance-resistant controller design method is constructed. In contrast to current drag-free controller design methods, the proposed approach significantly diminishes the conservatism in the control index. This realizes the precise design of the controller in the specified frequency band, ultimately resulting in a reduction in the order of the controller. Finally, numerical simulations demonstrate that the proposed method successfully meets the control performance index for each loop of the drag-free system even in the presence of complex disturbances and noises.