Online First

Online First have been peer-reviewed and accepted, which are not yet assigned to volumes/issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Closeby Habitable Exoplanet Survey (CHES): An Astrometry Mission for Probing Nearby Habitable Planets
JI Jianghui, LI Haitao, ZHANG Junbo, LI Dong, FANG Liang, WANG Su, DENG Lei, CHEN Guo, LI Fei, DONG Yao, LI Baoquan, GAO Xiaodong, XIAN Hao
, Available online  , doi: 10.11728/cjss2024.02.yg03
Abstract(29) FullText HTML (12) PDF 5173KB(9)
Abstract:
The Closeby Habitable Exoplanet Survey (CHES) employs state-of-the-art, high-precision astrometry and positioning technology at the microarcsecond level in space. Its primary objective is to conduct a thorough survey of approximately 100 FGK-type stars within the Sun’s proximity (within 10 parsecs), with the goal of detecting potentially habitable Earth-like planets or super-Earths. This pioneering mission involves a detailed census of habitable planets, providing intricate information on their numbers, true masses, and three-dimensional orbits. Notably, CHES marks a historic milestone as the inaugural international space exploration mission exclusively dedicated to the study of terrestrial planets within the nearby habitable zone. CHES’s payload features a cutting-edge optical telescope with a 1.2 m aperture, a field of view measuring 0.44°×0.44°, and a focal length of 36 meters. The telescope utilizes a coaxial three-mirror TMA optical imaging system. Impressively, CHES is designed with a positioning measurement accuracy of 1 microarcsecond, solidifying its status as the most precise space exploration project globally in terms of positioning accuracy. To achieve the detection objectives of CHES, it is essential to refine and further substantiate the scientific goals through comprehensive argumentation. Overcoming three key technological challenges is crucial: advancing optical systems for large field of view, developing high-quality space telescopes with minimal distortion; breaking through measurement technology for stellar separations at the 10–5 pixel level; and achieving high stability in satellite system attitude control and thermal control precision. CHES stands on the threshold of groundbreaking discoveries, with the exciting prospect of revealing 50 Earth-like planets. This announces a significant leap forward in China’s space science exploration technology.
Simulation and Experimental Validation of Charge-driven Extreme Ultraviolet Photoelectric Effect
WANG Zidong, ZHOU Bin
, Available online  , doi: 10.11728/cjss2024.02.2023-0038
Abstract(95) FullText HTML (20) PDF 2971KB(35)
Abstract:
The test masses of the inertial sensor is the core of the precision gravity measurement system. The surface of test masses accumulates charges due to continuous injection of high-energy particles from space, which generates stray noise under the action of the internal electromagnetic field of the sensor and affects the precision gravity measurement results. According to the principle of photoelectric effect, use UV LED to generate extreme ultraviolet light to irradiate the electrodes of an inertial sensor and the surface of the test masses, and applying an appropriate electric field between the electrodes, it is possible to change the charge amount of the test masses without external forces and under non-contact conditions. Based on the simplified electrode model of the parallel plate capacitor, this paper carried out theoretical modeling and simulation of the extreme ultraviolet charge driving process. Based on this, a set of charge driving verification test system was designed and constructed, and experiments were carried out on the effects of light power and bias voltage on the charging and discharging rates and AC charge driving. The experiment proved that the charge-discharge rate is proportional to the extreme ultraviolet light power, and its quantum yield changes with the electric field strength between the plates. Ultimately, a stable control of the test masses discharge rate between 0.31 pC⋅s–1 and 0.76 pC⋅s–1 and charge rate between –0.05 pC⋅s–1 and –0.17 pC⋅s–1 can be achieved. The theoretical model of charge-discharge rate proposed in this article for the test masses is consistent with the results of ground experiments, which can strongly support the development of charge management and control systems.
Research Progress of Lunar In-situ Water Production Techniques
ZHANG Peng, LIU Guanghui, LIU Xin, ZHANG Guang, ZHENG Haibo, DAI Wei, WANG Zhi, NIU Ran, BO Zheng, GAO Ming
, Available online  , doi: 10.11728/cjss2024.02.2023-0006
Abstract(260) FullText HTML (33) PDF 3567KB(86)
Abstract:
With the continuous advancement of deep space exploration, lunar exploration will be the first step for mankind to carry out interplanetary exploration and expand living territory. The lunar in-situ resource utilization will be a key technical approach to support manned exploration and long-term survival on the Moon surface. Almost all space powers are carrying out continuous research on lunar in-situ water production technology, and China has also listed lunar surface in-situ water production as one of the key technologies for lunar exploration missions. Lunar in-situ water production can be mainly divided into two methods: polar water ice exploration/extraction and hydrogen reduction of lunar regolith. The water ice resources that had been detected are mainly located in the lunar polar region, with uneven distribution and great difficulty in extraction method. Many different types of polar water ice exploration and extraction schemes have been put forward, but the actual effect needs to be verified by sufficient verification experiments and the lunar in-situ test. Hydrogen reduction of lunar regolith can be used for in-situ water production, and its working conditions are not limited by the region, and its application scope is wide. However, there are some remaining technical limitations such as extreme reaction condition requirements and high energy consumption, which implies urgent demand to make breakthroughs in energy conservation and effective ingredient enrichment. Thus, according to the development strategy deployment of lunar exploration missions and the requirements of in-situ water resource acquisition technology in the future, some suggestions are put forward on developing the key development path of in-situ water resource acquisition technology in the future. Target areas for future exploration missions, in-situ energy acquisition scheme, security and reliability of different technologies will be used as the main basis for different technology selection. It is hoped that this work will provide guidance for in-situ resource utilization in future lunar exploration missions.
Analysis of the Nighttime Variation Characteristics of Mesospheric Ozone and Correlation with Solar Activity
LIU Dan, WU Zhijing, YANG Junfeng, CHENG Xuan, WANG Jianmei, ZHANG Yiming, HU Xiong
, Available online  , doi: 10.11728/cjss2024.02.2023-0061
Abstract(38) FullText HTML (7) PDF 1622KB(6)
Abstract:
The satellite ozone data of ENVISAT-1/GOMOS (Global Ozone Monitoring by Occultation of Stars) and TIMED/SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) are analyzed to provide a statistical analysis of the distribution of ozone in the tropical mesosphere (60～110 km) at night (20:00 LT－24:00 LT) and explore its correlation with the 27-day solar cycle with HAMMONIA (Hamburg model of the neutral and ionized atmosphere). Both observations and model indicate that the nighttime ozone in the mesosphere peaks at 95 km and there is a semiannual oscillation in the upper mesosphere; Comparison with Lyman-α solar radiative forcing data over the same period shows that upper mesospheric (above 80 km) ozone may be inversely correlated with solar forcing, and lower mesospheric ozone may be positively correlated with solar forcing.. In order to better explore the correlation with solar activity, the ozone data were processed by filtering, and it was found that the inverse correlation between ozone at 95 km and Lyman-α was more significant. This correlation is more pronounced when long-term and short-term fluctuations are removed, especially in the months before and after the period of maximum amplitude of the 27-day solar radiative forcing cycle (around January and July 2004). Although the observations and the model results share some common features in the temporal and spatial distribution of ozone variations with months, large differences are found in the values of the peaks where the amplitude of ozone sensitivity is greatly underestimated by the model.
Dynamic Characteristics of Airship Envelope Material with Concentrated Mass
CHENG Jingsong, WANG Sheng, NIE Ying, SONG Lin
, Available online  , doi: 10.11728/cjss2024.02.2023-0008
Abstract(43) FullText HTML (7) PDF 1770KB(3)
Abstract:
Aiming at the design and analysis of stratospheric airship rigid and flexible integrated large complex structure system, this paper carried out the simulation analysis of dynamic characteristics of airship envelope material with concentrated mass. The structural parts with high stiffness and relatively concentrated mass are simplified as concentrated mass. The airship envelope is simplified as a biaxially stretched cross envelope material sample. Firstly, the influences of the number of open arm slits on the stress transfer uniformity in the central region of the cross envelop material sample are analyzed. Then the influences of pretension, mass and concentrated mass of the size on the natural frequency of cross film material sample are analyzed. The influence of the mass and concentrated mass of the size on the natural frequency of the airship capsule is also reflected. The results show that the uniformity of stress transfer in the central region of the cross envelop material sample is better with the increase of the number of arm slits. When the number of arm slits is 3, the proportional coefficient of stress transfer uniformity is 0.943. In addition, the natural frequency of the sample increases with the pretension increase, decreases with the mass of the concentrated mass increase, and increases with the side length of the connection between the concentrated mass and the sample increase. The fundamental frequency of the sample is independent of the height of the concentrated mass, but the second and third order frequencies decrease with the height of the concentrated mass increase. The second and third order frequencies are significantly more affected by various physical quantities than the first order. Under the condition of the same pretension and mass, the influence of the height of the concentrated mass on the second and third order frequencies of the cross envelop sample is higher than that of the side length. The research results provide a theoretical basis for the overall design and analysis of airship structure and the further dynamic experiments of airship envelope materials with concentrated mass.
Space-based Distributed Optical Synthetic Aperture Techniques
WANG Xiaoyong, ZHANG Jiafu, LI Ling, GUO Chongling
, Available online  , doi: 10.11728/cjss2024.02.yg06
Abstract(5) FullText HTML (8) PDF 4017KB(0)
Abstract:
The exploration and study of habitable zone planets is one of the hot research fields of exoplanets in recent years. The exploration of habitable planets near the solar system is of great significance to the study of the origin of life and has become the main theme of exoplanet exploration. As an important means of detecting exohabitable planets, space-based distributed synthetic aperture technology has become a hot spot in the research of advanced optical technology. In this paper, the technical principle of space-based distributed optical synthetic aperture system based on Michelson interferometric imaging is discussed in detail, and the development of typical distributed synthetic aperture systems at home and abroad is introduced. The technical challenges involved are demonstrated.
International Space Station External Multi-payload Operational Mission Planning
SHAN Yadong, ZHANG Hanxun, DU Changshuai, ZHONG Hongen
, Available online  , doi: 10.11728/cjss2024.02.2023-0047
Abstract(156) FullText HTML (26) PDF 726KB(34)
Abstract:
The external payload platform of the space station supports the deployment of many different types of payloads, which provides opportunities for massive space scientific research. However, with the continuous increasing number of external payloads and corresponding number of missions, and limited by resource constraints, it is necessary to develop scientific and reasonable mission planning to improve the operational efficiency of external payloads and the output of the science benefit. In this paper, the status of mission planning for external payloads on the International Space Station (ISS) is comprehensively analyzed, focusing on the external payload platform, payload types and characteristics, and methods for multi-payload operation mission planning. The current mission planning strategies, methods, and future development directions are analyzed. Based on the characteristics of the external payload platform of the China’s Space Station (CSS), this paper provides reference and suggestions for the subsequent mission planning of multi-payload system operation on the China’s space station from the aspects of overall payload design and mission planning methods.
Analysis of Sea Surface Backscatter Coefficient Errors and Its Effects for the CFOSAT Scatterometer
DONG Ying, LIN Wenming
, Available online  , doi: 10.11728/cjss2024.02.2023-0144
Abstract(63) FullText HTML (11) PDF 1689KB(15)
Abstract:
Noise is a key factor that affects the accuracy of spaceborne scatterometer backscatter coefficient (σ0), as well as the retrieved sea surface wind quality. In general, the scatterometer σ0 measurement error is attributed to both instrumental noise and geophysical noise, which are expressed in terms of normalized standard deviation (Kp). In this paper, the instrumental noise (Kpc) and the geophysical noise (Kpg) are analyzed as a function of sea surface wind speed, incidence angle, spatial resolution and offshore distance for the China-France Oceanography Satellite Scatterometer. The result shows that the variability of sea surface wind field is large under low wind conditions, so the geophysical noise dominates the measurement error of radar backscatters. Notably, the larger the grid size of Wind Vector Cell (WVC), the more inhomogeneous the sea surface wind, such that the Kpg value increases as the WVC size, but at the same time, the larger the wind cell grid and the larger the number of independent observation samples, the smaller the Kpc. While under high wind conditions, the variability of sea surface wind is small, and the contribution of instrument noise and geophysical noise is similar. Regarding the sensitivity of measurement error to the incidence Angle, Kpc and Kpg show a minimum value at the incidence angle of 40°, which is consistent with the antenna gain pattern. Finally, the relationship between the backscatter measurement error and the offshore distance is studied in order to clarify the feasibility of near shore wind field inversion for the CSCAT. The results show that the observation error generally increases as the offshore distance decreases, indicating that the near-shore geophysical noise is non-negligible for the scatterometer measurements approaching to the coastal line. In summary, the results presented in this paper reveal the influence factors of scatterometer σ0 measurements, which are relevant for better understanding the wind inversion and quality control of CSCAT, notably near the coastal areas.
Near-Earth Asteroid Impact Event Disposal Rules and Processes
HONG Yu, CHEN Yongqiang, CAI Tinbin, CHANG Xiao, XU Liang, JING Hongbao
, Available online  , doi: 10.11728/cjss2024.02.2023-0064
Abstract(66) FullText HTML (18) PDF 1079KB(10)
Abstract:
In response to the shortcomings in the areas of disposal rules, coordination mechanisms, and operational procedures in China’s research on the defense of near-Earth asteroids, a simulation strategy for asteroid defense is proposed to meet the increasing demand for asteroid defense and disaster relief. Based on the current development status of asteroid defense at home and abroad, the gaps in China’s asteroid defense are analyzed. From the perspectives of mechanism establishment and coordinated emergency response, the simulation and deduction of asteroid defense at home and abroad are analyzed. Based on the current research status at home and abroad, a set of asteroid defense simulation and deduction plans are designed, and an organizational structure for China’s asteroid defense exercises is proposed, including three levels: guidance layer, event disposal layer, and business support layer, providing basic organizational support for asteroid defense exercises. The emergency response mechanism and general disposal rules for asteroid impact events are proposed, providing a rule basis for the disposal of events and the operation of each level in the organizational structure. The simulation scenarios are initially designed to verify the mechanisms and rules, providing a reference for the organization and implementation of near-Earth asteroid defense work.
Study of Sample Imbalance in Deep Learning Modeling of Solar Flare Forecasting
ZHOU Jun, TONG Jizhou, LI Yunlong, FANG Shaofeng
, Available online  , doi: 10.11728/cjss2024.02.2023-0028
Abstract(213) FullText HTML (29) PDF 788KB(33)
Abstract:
Solar flares, as violent eruptions occurring in the lower atmosphere of the Sun, exert significant impacts on human activities. Researchers globally have developed multiple prediction models for solar flares, employing empirical, physical, statistical, and other methodologies. There is an order of magnitude difference in the occurrence of different classes of flares. This makes it difficult for traditional convolutional neural network-based flare prediction models to capture M, X class flare features, which leads to the problem of low precision of high level flare prediction. With the breakthrough of deep learning technology in recent years, it has shown strong potential in modelling and prediction of complex problems and a number of works have begun to try to use deep learning methods to construct flare prediction models. In this paper, different deep long-tail learning methods are discussed by us to improve the precision of flare forecasting by controlling the variables for the long-tail distribution phenomenon in flare forecasting. The forecast performance of the model for M and X flares is tried to be improved from the perspectives of training set optimization, loss function optimization and network weight optimization. The experiments on SDO/HMI solar magnetogram data show that the precision of M, X class flare prediction is significantly improved by 53.10% and 38.50%, respectively, and the recall is increased by 64% and 52% compared with the baseline model trained by conventional methods. It shows that the treatment of the long-tailed distribution of data is crucial in the flare forecasting problem, and verifies the effectiveness of the deep long-tailed learning method. This method of improving the precision of tail class forecasts can be applied not only to the field of flare forecasting, but also can be transferred to the analysis of forecasting other typical events of space weather with long-tailed distribution phenomenon.
Laboratory Thermal Emission Spectral Measurement and Calibration Methods for Planetary Science Research
YANG Yazhou, MILLIKEN Ralph E, BRAMBLE Michael S, PATTERSON William R, ZOU Yongliao, LIU Yang
, Available online  , doi: 10.11728/cjss2024.01.2023-0116
Abstract(120) FullText HTML (27) PDF 1823KB(40)
Abstract:
Accurate information regarding the surface composition is crucial for understanding the formation and evolution history of planetary bodies. Visible and near-infrared remote sensing spectroscopic techniques have long been used for the detection of surface composition. However, in the thermal infrared spectral range, various types of planetary surface materials exhibit richer spectral features. With the development of thermal emission spectroscopic techniques, it has been increasingly used in planetary exploration. Particularly, in the ongoing and planned asteroid exploration missions, thermal emission spectrometers are employed as key payloads. In order to better interpret the thermal emission spectral data to be obtained in the future, it is essential to establish scientifically reasonable data processing and calibration schemes. This paper provides a comprehensive overview on the design of thermal emission spectral measurement devices for planetary science research, the measurement process, and data reduction methods. To obtain accurate emissivity spectra data, the challenge of distinguishing sample radiation signals from instrument radiation during thermal emission measurements must be properly addressed first. Especially, for measurements conducted under low-temperature and vacuum conditions that are similar to the surface conditions of the Moon and asteroids. This paper proposes and demonstrates a data reduction method based on interferograms, which are the original signals measured by FTIR spectrometer. This method can effectively separate the actual radiation signal from the samples, thus yielding more accurate emissivity spectra data. The insights derived from this study can serve as valuable references for the development and construction of thermal emission measurement devices and can facilitate the processing and scientific interpretation of data from future missions such as Tianwen-2.

Journal Introduction

ISSN 0254-6124       CN 11-1783/V

Copyright © Editorial Office of Chinese Journal of Space Science.  京ICP备08100722号

Supported by: Beijing Renhe Information Technology Co., Ltd.