The encapsulation of lunar samples is a core research area in the third phase of the Chinese Lunar Exploration Program.The seal assembly,opening and closing mechanism(OCM),and locking mechanism are the core components...The encapsulation of lunar samples is a core research area in the third phase of the Chinese Lunar Exploration Program.The seal assembly,opening and closing mechanism(OCM),and locking mechanism are the core components of the encapsulation device of the lunar samples,and the requirements of a tight seal,lightweight,and low power make the design of these core components difficult.In this study,a combined sealing assembly,OCM,and locking mechanism were investigated for the device.The sealing architecture consists of rubber and an Ag-In alloy,and a theory was built to analyze the seal.Experiments of the electroplate Au coating on the knife-edge revealed that the hermetic seal can be significantly improved.The driving principle for coaxial double-helical pairs was investigated and used to design the OCM.Moreover,a locking mechanism was created using an electric initiating explosive device with orifice damping.By optimizing the design,the output parameters were adjusted to meet the requirements of the lunar explorer.The experimental results showed that the helium leak rate of the test pieces were not more than 5×10^(-11) Pa·m^(3)·s^(-1),the minimum power of the OCM was 0.3 W,and the total weight of the principle prototype was 2.9 kg.The explosive driven locking mechanism has low impact.This investigation solved the difficulties in achieving tight seal,light weight,and low power for the lunar explorer,and the results can also be used to explore other extraterrestrial objects in the future.展开更多
New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the firs...New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the first scientific questions to be answered.However,the precious samples,most in the micrometer size range,challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples.Here,we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis(μXRF).The selected particles were verified via scanning electron microscopy(SEM),3D X-ray microscopy(XRM),and focused ion beam scanning electron microscopy(FIB-SEM)techniques,which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry(SIMS).Such protocol could be also appli-cable in non-destructively screening other types of particles for different scientific purposes.We there-fore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales.Linking various microscopic and spectromicroscopic instru-ments together,this workflow consists of six steps:(1)single-particle selection with non-destructive μXRF technique,(2)2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods,(3)SEM analysis of the surface morphology and chemistry of the selected particle,(4)a series of microscopic and microbeam analyses(e.g.,SEM,electron probe microanalysis,and SIMS)on the cross-section of the selected particle to obtain structural,mineralogical,chemical,and isotopic features from the micron to nanometer scale,(5)advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of inter-est in the selected particle with FIB-SEM technique,and(6)comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray micro-scopy,analytic transmission electron microscopy,and atom probe tomography.Following this technical roadmap,one can integrate multiple modalities into a uniform frame of multimodal and multiscale cor-related datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples.展开更多
The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides...The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.展开更多
The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(...The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(CFD)simulation and flight dynamics coupling method,the parachute container cover ejection separation is simulated.The rationality of the ejection separation speed and dynamic characteristics of the separation process is analyzed.Meanwhile,the influences of angle of attack,Mach number and ejection separation speed on the parachute container cover ejection are also investigated.Results show that the ejection separation speed design is reasonable.It has a certain design margin for parachute container cover to escape from the wake region,and to pull out the drag parachute completely.The results may provide a theoretical basis for recovery system engineering design of the lunar exploration project.展开更多
The sampling auger used in lunar sampling and return mission is to transmit power and convey soil, and its performance is the key factor of the whole mission. However, there is currently a lack of the optimization res...The sampling auger used in lunar sampling and return mission is to transmit power and convey soil, and its performance is the key factor of the whole mission. However, there is currently a lack of the optimization research on soil conveying volume and power consumption models in auger structure design. To provide the drilled object, the simulation lunar soil, whose physical and mechanical property is the same as the real soil, is made by reducing soil void ratio. The models are formulated to analyze the influence of auger structure parameters on power consumption and soil conveying volume. To obtain the optimized structure parameters of auger, the multi-objective optimization functions of the maximum soil conveying volume and minimum power consumption are developed. To verify the correctness of the models, the performances of different augers drilling simulation soil are tested. The test results demonstrate that the power consumption of optimized auger is the lowest both in theory and test, and the experimental results of soil conveying volume are in agreement with theoretical analysis. Consequently, a new method for designing a lunar sampling auger is proposed which includes the models of soil conveying volume and transportation power consumption, the optimization of structure parameters and the comparison tests. This method provides a reference for sampling auger designing of the Chinese Lunar Sample Mission.展开更多
Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acqui...Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acquire drilling cores without damaging stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and coring for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, coring experiments indicate that the sampling method has a high coring rate greater than 80%. For hard rock, drilling experiments indicate that the percussive frequency greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and coring. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and coring a test-bed for validation on earth and the execution of drilling experiments in complex media.展开更多
Lunar materials are overall more reducing compared with their terrestrial counterparts,but the mechanism remains to be elucidated.In this study,we present a possible explanation for the changes in redox state of the l...Lunar materials are overall more reducing compared with their terrestrial counterparts,but the mechanism remains to be elucidated.In this study,we present a possible explanation for the changes in redox state of the lunar regolith caused by impact events,based on our investigations of the impact glass beads from Chang’e-5 mission.These glass beads contain iron metal grains and show concentration gradients of FeO and K_(2)O(with or without Na_(2)O)from their rims to centers.The compositional profiles exhibit errorfunction-like shapes,which indicates a diffusion-limited mechanism.Our numerical modeling results suggest that the iron metal grains on the surface of the glass beads were generated through the reduction of FeO by elemental K and(or)Na produced during the impact events.Meanwhile,the iron metal grains inside the bead may have formed due to oxygen diffusion driven by redox potential gradients.Furthermore,our study suggests that impact processes intensify the local reducing conditions,as evidenced by the presence of calcium sulfide particles within troilite grains that coexist with iron metal grains on the surface of the glass beads.This study provides insights into the oxygen diffusion kinetics during the formation of iron metal spherules and sheds light on the changes in redox conditions of lunar materials caused by impact events.展开更多
In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain,...In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior(composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample(CE5 C0000 YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy(HR-XTM), energy dispersive X-ray spectroscopy(EDS)-based scanning electron microscope(SEM), and electron probe microanalysis(EPMA) to reveal its 3 D petrology and minerology.Our results show that this sample has a fine-to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance(17.8 vol%) and contains a significant amount(0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5 C0000 YJYX065 is a high-Ti mare basalt with a rare earth element(REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.展开更多
基金Supported by Research Foundation of CLEP of China (Grant No.TY3Q20110003)。
文摘The encapsulation of lunar samples is a core research area in the third phase of the Chinese Lunar Exploration Program.The seal assembly,opening and closing mechanism(OCM),and locking mechanism are the core components of the encapsulation device of the lunar samples,and the requirements of a tight seal,lightweight,and low power make the design of these core components difficult.In this study,a combined sealing assembly,OCM,and locking mechanism were investigated for the device.The sealing architecture consists of rubber and an Ag-In alloy,and a theory was built to analyze the seal.Experiments of the electroplate Au coating on the knife-edge revealed that the hermetic seal can be significantly improved.The driving principle for coaxial double-helical pairs was investigated and used to design the OCM.Moreover,a locking mechanism was created using an electric initiating explosive device with orifice damping.By optimizing the design,the output parameters were adjusted to meet the requirements of the lunar explorer.The experimental results showed that the helium leak rate of the test pieces were not more than 5×10^(-11) Pa·m^(3)·s^(-1),the minimum power of the OCM was 0.3 W,and the total weight of the principle prototype was 2.9 kg.The explosive driven locking mechanism has low impact.This investigation solved the difficulties in achieving tight seal,light weight,and low power for the lunar explorer,and the results can also be used to explore other extraterrestrial objects in the future.
基金the National Key R&D Program of China(2018YFA0702600)the Key Research program of Chinese Academy of Sciences(ZDBS-SSW-JSC007-13)+1 种基金the institute of Geology and Geophysics,Chinese Academy of Sciences(IGGCAS-202101)the National Natural Science Foundation of China(grants no.41890843,41920104009)。
文摘New samples returned by China Chang’e-5(CE-5)mission offer an opportunity for studying the lunar geologic longevity,space weathering,and regolith evolution.The age determination of the CE-5 samples was among the first scientific questions to be answered.However,the precious samples,most in the micrometer size range,challenge many traditional analyses on large single crystals of zircon developed for massive bulk samples.Here,we developed a non-destructive rapid screening of individual zirconium-containing particle for isotope geochronology based on a Micro X-ray fluorescence analysis(μXRF).The selected particles were verified via scanning electron microscopy(SEM),3D X-ray microscopy(XRM),and focused ion beam scanning electron microscopy(FIB-SEM)techniques,which showed that zirconium-bearing minerals with several microns were precisely positioned and readily suitable for site-specific isotopic dating by second ion mass spectrometry(SIMS).Such protocol could be also appli-cable in non-destructively screening other types of particles for different scientific purposes.We there-fore proposed a correlative workflow for comprehensively studying the CE-5 lunar samples from single particles on nanometer to atomic scales.Linking various microscopic and spectromicroscopic instru-ments together,this workflow consists of six steps:(1)single-particle selection with non-destructive μXRF technique,(2)2D/3D morphological and structural characterization with a correlative submicron 3D XRM and nanoscale resolution FIB-SEM imaging methods,(3)SEM analysis of the surface morphology and chemistry of the selected particle,(4)a series of microscopic and microbeam analyses(e.g.,SEM,electron probe microanalysis,and SIMS)on the cross-section of the selected particle to obtain structural,mineralogical,chemical,and isotopic features from the micron to nanometer scale,(5)advanced 2D/3D characterization and site-specific sample preparation of thin foil/tip specimens on a microregion of inter-est in the selected particle with FIB-SEM technique,and(6)comprehensive analyses on the FIB-milled specimens at nanometer to atomic scale with synchrotron-based scanning transmission X-ray micro-scopy,analytic transmission electron microscopy,and atom probe tomography.Following this technical roadmap,one can integrate multiple modalities into a uniform frame of multimodal and multiscale cor-related datasets to acquire high-throughput information on the limited or precious terrestrial and extraterrestrial samples.
基金supported by the National Natural Science Foundation of China(Nos.12125509,12222514,11961141003,and 12005304)National Key Research and Development Project(No.2022YFA1602301)+1 种基金CAST Young Talent Support Planthe CNNC Science Fund for Talented Young Scholars Continuous support for basic scientific research projects。
文摘The Moon provides a unique environment for investigating nearby astrophysical events such as supernovae.Lunar samples retain valuable information from these events,via detectable long-lived“fingerprint”radionuclides such as^(60)Fe.In this work,we stepped up the development of an accelerator mass spectrometry(AMS)method for detecting^(60)Fe using the HI-13tandem accelerator at the China Institute of Atomic Energy(CIAE).Since interferences could not be sufficiently removed solely with the existing magnetic systems of the tandem accelerator and the following Q3D magnetic spectrograph,a Wien filter with a maximum voltage of±60 kV and a maximum magnetic field of 0.3 T was installed after the accelerator magnetic systems to lower the detection background for the low abundance nuclide^(60)Fe.A 1μm thick Si_(3)N_(4) foil was installed in front of the Q3D as an energy degrader.For particle detection,a multi-anode gas ionization chamber was mounted at the center of the focal plane of the spectrograph.Finally,an^(60)Fe sample with an abundance of 1.125×10^(-10)was used to test the new AMS system.These results indicate that^(60)Fe can be clearly distinguished from the isobar^(60)Ni.The sensitivity was assessed to be better than 4.3×10^(-14)based on blank sample measurements lasting 5.8 h,and the sensitivity could,in principle,be expected to be approximately 2.5×10^(-15)when the data were accumulated for 100 h,which is feasible for future lunar sample measurements because the main contaminants were sufficiently separated.
基金Supported by the Aeronautical Science Foundation of China(2012ZC52035)
文摘The parachute container cover ejection separation is the first and foremost motion for the return capsule recovery system,which is related to the success of a recovery system.Adopting the computational fluid dynamics(CFD)simulation and flight dynamics coupling method,the parachute container cover ejection separation is simulated.The rationality of the ejection separation speed and dynamic characteristics of the separation process is analyzed.Meanwhile,the influences of angle of attack,Mach number and ejection separation speed on the parachute container cover ejection are also investigated.Results show that the ejection separation speed design is reasonable.It has a certain design margin for parachute container cover to escape from the wake region,and to pull out the drag parachute completely.The results may provide a theoretical basis for recovery system engineering design of the lunar exploration project.
基金Supported by National Defense Science and Technology Major Project(Grant Nos.TY3Q20110001,TY3Q20110005)College Discipline Innovation Wisdom Plan of China(111 Project,Grant No.B07018)National Natural Science Foundation of China(Grant No.51105092)
文摘The sampling auger used in lunar sampling and return mission is to transmit power and convey soil, and its performance is the key factor of the whole mission. However, there is currently a lack of the optimization research on soil conveying volume and power consumption models in auger structure design. To provide the drilled object, the simulation lunar soil, whose physical and mechanical property is the same as the real soil, is made by reducing soil void ratio. The models are formulated to analyze the influence of auger structure parameters on power consumption and soil conveying volume. To obtain the optimized structure parameters of auger, the multi-objective optimization functions of the maximum soil conveying volume and minimum power consumption are developed. To verify the correctness of the models, the performances of different augers drilling simulation soil are tested. The test results demonstrate that the power consumption of optimized auger is the lowest both in theory and test, and the experimental results of soil conveying volume are in agreement with theoretical analysis. Consequently, a new method for designing a lunar sampling auger is proposed which includes the models of soil conveying volume and transportation power consumption, the optimization of structure parameters and the comparison tests. This method provides a reference for sampling auger designing of the Chinese Lunar Sample Mission.
基金Supported by National Natural Science Foundation of China(Grant No.51105092)Introducing Talents of Discipline to Universities(111 Program,Grant No.B07018)+1 种基金Heilongjiang Postdoctoral Grant(Grant No.LBHZ11168)China Postdoctoral Science Foundation(Grant No.2012M520722)
文摘Drill sampling has been widely employed as an effective way to acquire deep samples in extraterrestrial exploration. A novel sampling method, namely, flexible-tube coring, was adopted for the Chang＇e mission to acquire drilling cores without damaging stratification information. Since the extraterrestrial environment is uncertain and different from the terrestrial environment, automated drill sampling missions are at risk of failure. The principles of drilling and coring for the lunar subsurface should be fully tested and verified on earth before launch. This paper proposes a test-bed for conducting the aforementioned experiments on earth. The test-bed comprises a rotary-percussive drilling mechanism, penetrating mechanism, drilling medium container, and signal acquisition and control system. For granular soil, coring experiments indicate that the sampling method has a high coring rate greater than 80%. For hard rock, drilling experiments indicate that the percussive frequency greatly affects the drilling efficiency. A multi-layered simulant composed of granular soil and hard rock is built to test the adaptability of drilling and coring. To tackle complex drilling media, an intelligent drilling strategy based on online recognition is proposed to improve the adaptability of the sampling drill. The primary features of this research are the proposal of a scheme for drilling and coring a test-bed for validation on earth and the execution of drilling experiments in complex media.
基金the China National Space Administration(CNSA)for providing the CE-5 lunar sample(CE5C0800YJFM00101GP)supported by the National Natural Science Foundation of China(41773052,41973058,42003054,and 42073062)+3 种基金the China Postdoctoral Science Foundation funded project(2020M680155)the Strategic Priority Research Program of Chinese Academy of Sciences(XDB 41000000)the key research program of frontier sciences of Chinese Academy of Sciences(ZDBS-SSW-JSC007-10)the pre-research Project on Civil Aerospace Technologies(D020201)funded by CNSA.
文摘Lunar materials are overall more reducing compared with their terrestrial counterparts,but the mechanism remains to be elucidated.In this study,we present a possible explanation for the changes in redox state of the lunar regolith caused by impact events,based on our investigations of the impact glass beads from Chang’e-5 mission.These glass beads contain iron metal grains and show concentration gradients of FeO and K_(2)O(with or without Na_(2)O)from their rims to centers.The compositional profiles exhibit errorfunction-like shapes,which indicates a diffusion-limited mechanism.Our numerical modeling results suggest that the iron metal grains on the surface of the glass beads were generated through the reduction of FeO by elemental K and(or)Na produced during the impact events.Meanwhile,the iron metal grains inside the bead may have formed due to oxygen diffusion driven by redox potential gradients.Furthermore,our study suggests that impact processes intensify the local reducing conditions,as evidenced by the presence of calcium sulfide particles within troilite grains that coexist with iron metal grains on the surface of the glass beads.This study provides insights into the oxygen diffusion kinetics during the formation of iron metal spherules and sheds light on the changes in redox conditions of lunar materials caused by impact events.
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (XDB 41000000)the Civil Aerospace Pre-research Projects (D020202 and D020302)+2 种基金the National Natural Science Foundation of China (41773059, 41873076, 41803051, 41973060, 42073060, and 42173044)the National Key Research and Development Program of China (2021YFA0716100)the Minor Planet Foundation of China
文摘In December 2020, Chang’E-5(CE-5), China’s first lunar sample return mission, successfully collected samples totaling 1731 g from the northern Oceanus Procellarum. The landing site was located in a young mare plain, a great distance from those of Apollo and Luna missions. These young mare basalts bear critical scientific significance as they could shed light on the nature of the lunar interior(composition and structure) as well as the recent volcanism on the Moon. In this article, we investigated a CE-5 basalt sample(CE5 C0000 YJYX065) using a combination of state-of-art techniques, including high resolution X-ray tomographic microscopy(HR-XTM), energy dispersive X-ray spectroscopy(EDS)-based scanning electron microscope(SEM), and electron probe microanalysis(EPMA) to reveal its 3 D petrology and minerology.Our results show that this sample has a fine-to medium-grained subophitic texture, with sparse olivine phenocrysts setting in the groundmass of pyroxene, plagioclase, ilmenite and trace amounts of other phases. It has an extremely high ilmenite modal abundance(17.8 vol%) and contains a significant amount(0.5 vol%) of Ca-phosphate grains. The mineral chemistry is in excellent agreement with that of Apollo and Luna high-Ti basalts. The major phase pyroxenes also display strong chemical zoning with compositions following the trends observed in Apollo high-Ti basalts. Based on current data, we came to the conclusion that CE5 C0000 YJYX065 is a high-Ti mare basalt with a rare earth element(REE) enriched signature. This provides a rigid ground-truth for the geological context at the CE-5 landing site and clarifies the ambiguity inferred from remote sensing surveys.
基金This work was supported by the National Natural Science Foundation of China(42241109 and 42202297)Tsinghua University Initiative Scientific Research Program(20211080097).
