May 2022, Volume 3 Issue 2
    

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  • Review
    Key Problems of Space Environmental Engineering for Manned Deep Space Exploration Mission
    SHEN Zicai, DAI Wei, BAI Yu, LIU Rongqiang, DING Yigang, LIU Yenan
    2016, 3(2): 99-107. https://doi.org/10.15982/j.issn.2095-7777.2016.02.001
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    Space environments such as solar cosmic ray, galactic cosmic ray, microgravity, dust and dust storm, deep space microbe and so on, which will be encountered during the course of manned deep space exploration, are firstly introduced. Then, the threat of different deep space environments to the astronauts is discussed, and some countermeasures such as physical protection, monitoring and early warning of radiation risks, radiation protection drugs, astronaut selection, etc, is given. Finally, the further work should be done for manned deep space mission, which includes damage mechanism of space radiation on the astronaut, development of drug against space radiation and microgravity, protection of structure and material from space radiation environments, self cleaning materials and technology for space suit, research and development of materials against microbial erosion, etc, are discussed.
  • Topic：Mars Exploration
    The Development Process and Prospects for Mars Exploration
    YU Dengyun, SUN Zezhou, MENG Linzhi, SHI Dong
    2016, 3(2): 108-113. https://doi.org/10.15982/j.issn.2095-7777.2016.02.002
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    As one of the nearest earth-like planets from earth, Mars exploration is the second hottest point after the lunar exploration of deep space exploration. Based on the review of Mars exploration history, the exploration planning for the future and the key technologies to face are discussed, but also the corresponding enlightenment and prospects are given, the possible research on Mars exploration which can be carried out and advices for China's Mars exploration missions are proposed in this paper.
  • Topic：Mars Exploration
    Analysis of Key Technologies for Unmanned Mars Sample Return Mission
    MENG Linzhi, DONG Jie, XU Yingqiao, WANG Shuo
    2016, 3(2): 114-120,128. https://doi.org/10.15982/j.issn.2095-7777.2016.02.003
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    Unmanned Mars sample return mission is of great significance to obtain scientific results and improve engineering ability. The mission period is longer and technical risk is higher compared with several foreign Mars landing and roving missions. The top-level system design is determined by the mission flight mode. The rendezvous capture and sample transfer process should be completed near the Mars orbit. Therefore, two probes with different functions are required:one is used to perform Mars capture, sample storage and Mars-Earth transfer, the other to complete EDL process, Mars surface ascent and sample delivery. Such key issues as EDL mode, Mars ascent vehicle, Mars orbit rendezvous and capture, sample transfer, earth entry vehicle, system scales, rocket selection, etc. are analyzed in this paper. The main technical difficulty and solution approaches are discussed.
  • Topic：Mars Exploration
    Analysis and Design for the Mars Entry， Descent and Landing Mission
    RAO Wei, SUN Zezhou, MENG LinZhi, WANG Chuang, JI Long
    2016, 3(2): 121-128. https://doi.org/10.15982/j.issn.2095-7777.2016.02.004
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    Entry, Descent and Landing (EDL) is the most pivotal phase for Mars landing exploration. Compared to the Earth reentry, EDL process of Mars has some similitudes. However, the composition and physical characteristics of Mars atmosphere have much discrepancy with earth atmosphere, and it has quite great uncertainty. As a result, this makes the Mars EDL process quite short and changeable, which requires high deceleration ability and makes a tough scheduling. With consideration of project realization, the problems and challenges of Mars EDL process are identified, also the technical solutions of the pivotal phase are proposed.
  • Topic：Mars Exploration
    Analysis on Physical and Mechanical Properties of Martian Soil
    DANG Zhaolong, CHEN Baichao
    2016, 3(2): 129-133,144. https://doi.org/10.15982/j.issn.2095-7777.2016.02.005
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    Martian soil is one of the major factors in the Mars surface exploration which have to be considered during the development of Martian probes. The physical and mechanical properties of Martian soil influence directly the design of landing-pad of Martian lander and the wheels of Martian rover. During the field tests of Martian probes, the proving ground for Martian surface environments must be simulated. The exploration results about the Martian soil and its simulant are analyzed in this paper. The ranges of parameters for physical and mechanical properties of Martian soil are summarized. The results can be used for the development of China's Martian probes.
  • Topic：Mars Exploration
    Selection of the Martian Landing Site Based on the Engineering Constraints
    DONG Jie, WANG Chuang, ZHAO Yang
    2016, 3(2): 134-139. https://doi.org/10.15982/j.issn.2095-7777.2016.02.006
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    The selection of landing site is one of the vital steps for the Martian landing and roving mission. Both the scientific objectives and the engineering constraints should be considered. The engineering constraints are more important for the Martian landing mission due to the high risks in the process, which are mainly related to the surface characteristics of the landing sites, mission trajectory, atmosphere, etc. The surface characteristics include local elevation, slopes and relief, rocks distribution, dust thickness, sunlight and thermal constraints that can affect the EDL safety and the rover mobility. At first the engineering constraints are listed out and sorted in this paper. Then the analysis model based on fuzzy algorithm is set up, and the index for evaluating the suitability of different landing sites based on fuzzy inference is proposed. Finally, the method is validated based on the landing sitts of ExoMars 2020 mission.
  • Topic：Mars Exploration
    Selection of Absolute Positioning Methods for Mars Rover
    PENG Song, JIA Yang, CHEN Baichao
    2016, 3(2): 140-144. https://doi.org/10.15982/j.issn.2095-7777.2016.02.007
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    According to Mars moving detection mission, three absolute positioning methods for Mars rover are proposed:wireless TT&C, image matching, position circling. For the wireless TT&C positioning, the orbit determination is first done, then the rover position relative to the orbit is determined by wireless communicating between two detectors, at last the absolute position of the rover is calculated. For the image matching positioning, the absolute position of the rover is calculated by matching the images during the landing process to the map of the landing zone with geographic information. For the position circling, the orientation of the sun and Mars gravity is measured by sensors at discrete moments, then with these measured results and ephemeris the absolute position of the rover is calculated. The three methods are analyzed and compared, and using advice is given according to factors such as precision, constraints, etc. To get the rover absolute position rapidly and accurately, position circling acts as the primary method to get the position, wireless TT&C method verifies the position, and image matching method revises the position.
  • Topic：Mars Exploration
    Lateral Predictive Guidance for Mars Atmospheric Entry
    LONG Jiateng, GAO Ai, CUI Pingyuan
    2016, 3(2): 145-149,180. https://doi.org/10.15982/j.issn.2095-7777.2016.02.008
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    The state-of-the-art Mars atmospheric entry predictive guidance method focuses on dealing with the longitudinal motion, while the lateral motion is always regulated by the error threshold with bank angle reversal. Such lateral logic strictly limits the lateral motion. In view of this problem, a lateral predictive guidance method for Mars atmospheric entry is put forward, in which the guidance command is generated on board according to the constraints of lateral motion without planning the error threshold. Such a method can avoid the problem of reversing frequently in the method of planning relevant threshold. Numerical simulation illustrates that the lateral predictive guidance method can satisfy the position accuracy of parachute deployment. At the same time, it can also achieve the design flexibility of entry trajectory lateral motion.
  • Topic：Mars Exploration
    Autonomous Navigation for Mars Pin-Point Landing Based on Landmark Image
    XU Chao, WANG Dayi, HUANG Xiangyu
    2016, 3(2): 150-155. https://doi.org/10.15982/j.issn.2095-7777.2016.02.009
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    Aiming at the autonomous and the precise navigation of Mars pin-point landing, an autonomous navigation method based on only landmark image is presented in this paper. In order to deal with image-processing time delay, the position and the attitude of detector at the imaging time are used as system state. The current system state can be updated by these landmark measurements through iterated extended Kalman filter. Using the method, the effects of landmark position error on navigation precision are analyzed. Finally, the validity of the proposed navigation method is confirmed by numerical simulations.
  • Topic：Mars Exploration
    Development of a Piezoelectric-Driven Rock Drilling Device on Mars
    LI He, QUAN Qiquan, WANG Xinjian, JIANG Shengyuan, DENG Zongquan
    2016, 3(2): 156-161. https://doi.org/10.15982/j.issn.2095-7777.2016.02.010
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    Drilling is an effective way to obtain rock sample in future Mars exploration. Since the actuating elements of ultrasonic drilling devices are piezoelectric ceramics, they can adapt to complex environment on Mars. Based on high-frequency percussive drilling method, ultrasonic drills can easily penetrate into hard rocks on Mars. As a kind of light and compact drill with low power consumption, ultrasonic drills are suitable for Mars in-situ rock-sampling missions. By means of simulation and experimental methods, the rock-drilling ability and efficiency of the ultrasonic drill are verified. The development of ultrasonic drills can provide technical reference for future Mars rock-sampling missions.
  • Article
    Research on the Thermal Features of the Drilling Process Under the Simulated Lunar Surface Environment
    LAI Xiaoming, BAI Shuxin, ZHAO Zeng, PANG Yong, YIN Shen
    2016, 3(2): 162-167. https://doi.org/10.15982/j.issn.2095-7777.2016.02.011
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    According to the requirements of the lunar surface sampling task, The lunar regolith sampler need to drill under vacuum conditions, and realize the continuous drilling without aided-cooling medium. It is very easy to cause a rapid temperature rise on bit, which resulted in making effect on the reliability of the sampling task. Thus, in order to study on the thermal characteristics of the bit in drilling process, the cutting and friction mechanism between blade on bit and the lunar soil is analyzed in this paper. A temperature rise model of bit is established, and the main factors that influence the temperature rise of the drill bit are obtained. According to the lunar vacuum environment, the 2 m drilling depth lunar soil simulant is prepared, and its vacuum degree below 10 Pa, simultaneously, the thermal feature drilling tests are performed. The experimental results show that there is a strong positive correlation between the temperature rise and the weight on bit at the front of the drill bit, and the correlation on bit torque is weak. The correlation coefficient of the model of the temperature rise prediction is modified based on the test results. The fitting curve of the temperature rise is obtained, and the comparison of the results between fitting and test has been carried out. The qualitative analysis of the thermal characteristics of the bit in drilling process is acquired.
  • Article
    Conceptual Design of Flexible Thermal Protect Structure for Deployable Lunar Habitats
    XU Yan, ZHENG Yao, KUANG Songsong, ZHOU Sheng
    2016, 3(2): 168-174. https://doi.org/10.15982/j.issn.2095-7777.2016.02.012
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    Constructing lunar habitats is the first and the most important step to explore, exploit and colonize the outer space. A novel deployable lunar habitat concept is designed in the paper. The habitat structures consists of the spatial deployable truss and the flexible thermal protection laminated membrane. The structural design schemes were analyzed and compared. Nine topological schemes of the spatial deployable truss and seven designing schemes of the laminated membrane are presented. The optimal scheme was determined after strength analysis, stiffness analysis and steady thermal analysis were performed. Structural performances of the optimal design scheme for deployable lunar habitats were analyzed including static analysis, modal analysis and steady thermal analysis of three load cases. The analysis results indicates that structural performances and thermal protect performances of deployable lunar habitats are perfect. Then the technology support for scheme selection, structural design and TPS design was provided.
  • Article
    Application Research of DTFLOCK Thread in Anti-Loosing Connection of Drilling Tool
    MA Chao, LIN Chen, ZHAO Zeng, QIAN Cheng, YIN Shen, PAN Qiuyue, JIANG Shengyuan
    2016, 3(2): 175-180. https://doi.org/10.15982/j.issn.2095-7777.2016.02.013
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    In the sample drilling task of China's lunar exploration project, the reliability of drilling machines influences its function directly, and can even lead toa success or failure of the sampling task. By analyzing the mechanical properties and high and low temperature environment of drilling tools in the whole life cycle, this paper identifies the failure mode of the drill string, summarizes the anti-loosing method of conventional thread and proposes an anti-loosing scheme of DTFLOCK thread structure, which was compared with standard thread by experiment. The new anti-loosing method provides reference for the design of connection structure of the drilling tool for the engineering departments.
  • Article
    Research for Flow Separating of Solid Launch Vehicle Orbit Maneuver Motor Nozzle
    ZHOU Wenqing, CUI Jianwei, HAN Xiaobo, ZHU Li
    2016, 3(2): 181-186. https://doi.org/10.15982/j.issn.2095-7777.2016.02.014
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    A researching method for flow separating of solid launch vehicle orbit maneuver motor nozzle is proposed in this paper. The theoretical calculation is carried out for studying the influence of flow separating on the nozzle performance. The numerical simulation analysis is done to obtain the flow separating location, thrust coefficient, wall-surface static pressure, coefficient of convective heat transfer and distribution of temperature field. Results indicate that the ground thrust coefficient is 73.3% of the vacuum thrust coefficient for the engine energy conversion efficiency reduced. Parameter jumping caused by flow separation is harmful to nozzle working. Flow separating research based on using the ground test indicating altitude performance of nozzle gives some suggestion of nozzle thermal protection design for reference.
  • Article
    Identification and Geological Evolution of Hydrated Minerals at Holden and Jezero Impact Craters Mars Using MRO CRISM Hyperspectral Data
    YANG Yi, JIN Shuanggen, XUE Yansong
    2016, 3(2): 187-194. https://doi.org/10.15982/j.issn.2095-7777.2016.02.015
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    Identification of mineral components in different regions on the Mars is crucial to understand the Martian geology and environmental changes. By recognizing the Martian surface mineral, the Martian's environment condition and geological evolution can be understood. Meanwhile, it can be used for further exploration of the habitability of the Mars. The compact reconnaissance imaging spectrometer for Mars (CRISM) on the Mars reconnaissance orbiter (MRO) is the most recent hyperspectral imager that has reached the Mars in order to detecting the minerals. The spectrometer covers the wavelength from visible to near infrared along with enhanced spectral resolution, which provides the ability to map the mineralogy on Mars. In this paper, based on the spectrum matching and calculating CRISM summary product, mineral composition and geological evolution of the Jezero and Holden craters on the Mars are analyzed. These two craters were proposed as the candidates of the landing sites for the Mars 2020 mission due to their complex geological characteristics. Therefore, identification of mineral components of these two sites can not only further analyze the typical geological characteristics and evolutions of the climate of Mars, but also provide practical significance for the analysis of future landing sites on the Mars. We have detected several kinds of hydrated minerals including carbonate, hydrated silicate and hydrated sulfate in the study areas. These minerals suggested the possibility that the Holden and Jezero craters have experienced long time water-rock interactions. Also, the diversity of the minerals found in these regions indicates the aqueous activities in multiple distinct environments and the different environment changes in the study areas. For example unlike the dominating environment evolution from neutral to acidic on the Mars, the evolution around the Jezero may be from neutral to alkaline.