One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet（MBC, Active Asteroid） 311P/PANSTARRS. This paper outlines the scientific objectives, measurement targets, and measurement requirements for the proposed Gas and Ion Analyzer（GIA）. The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions, such as hydrogen,carbon, and oxygen, in the vicinity of 311P. Ion sampling techniques are essential for the GIA's Time-of-Flight（TOF） mass analysis capabilities. In this paper, we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model. The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling, which is influenced by the satellite's surface positive charging. The ion source model simulates the processes of gas ionization and ion multiplication. Simulation results indicate that the GIA can achieve a lower pressure limit below 10 -13 Pa and possess a dynamic range exceeding 10～9. These performances ensure the generation of ions with stable and consistent current, which is crucial for high-resolution and broad dynamic range mass spectrometer analysis. Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H 2 O and N 2 . In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms, the evolution of the atmospheric and ionized environments of main-belt comets, the interactions with solar wind, and the origin of Earth's water.

The Tianwen-2 mission aims at exploring the near-Earth asteroid 2016HO3 and the main belt comet 311P by means of near-distance measuring and asteroid sampling and return. As one of main payloads of the Tianwen-2 mission, the Charged and Neutral Particle Analyzer (CANPA) will measure in-situ the plasmas and neutral atmosphere around the asteroid and the comet. The CANPA instrument is highly integrated and miniaturized, and composes four independent subsystems: the thermal ion analyzer (TIA), the thermal electron analyzer (TEA), the solar wind ion analyzer (SIA) and the gas and ion analyzer (GIA). The flight model has been calibrated by using the on-ground calibration system. The results show that the TIA can measure thermal ions at the energy range of 2.79 eV-32.03 keV with an energy resolution of 8.79%. The TEA can measure thermal electrons at the energy range of 1.07 eV-20.61 keV with an energy resolution of 14.29%. Both TIA and TEA have the field-of-view of 360 degrees x 90 degrees. The SIA can measure solar wind ions at the energy-per-charge range of 5 eV-5 keV with an energy resolution of 4.23%. The GIA can measure neutral gas and ions of the comet ionosphere at the mass range of 1-350 amu and the mass resolution is about 0.17 amu@1-50 amu, 0.52 amu@51-150 amu, and 1.22 amu@151-350 amu. The CANPA instrument can fulfill the detection requirements for the asteroid and the comet.

The FY-3E satellite plasma analyzer marks China’s first detection of the characteristics, occurrence, and development of the typical plasma environment in the dawn–dusk orbit space. It provides data source support for operational space weather alerts and forecasts, helps ensure the in-orbit safety of the satellite, and accumulates space environment detection data for space environment modeling and space physics research. This paper gives a detailed introduction to the detection technology adopted by the FY-3E satellite plasma analyzer. We calibrated its performance through a calibration experiment and then analyzed and compared it with similar instruments in China. It is indicated that the instrument is capable of measuring an ion energy spectrum of 24 eV~32 keV and an electron energy spectrum of 23.7 eV~31.6 keV, its field of view reaches 180° × 90°, and the inversed measurement range of spacecraft absolute potential is better than −30 kV~+30 kV. All these contribute to a notably improved technology for plasma and satellite potential detection of China’s LEO satellites.

火星离子与中性粒子分析仪共设计10种在轨探测模式,不同探测模式下数据率不同,多种探测模式下数据量远超出最大下行数据率的限制.为降低数据率,利用仪器内部FPGA有限的资源对压缩处理方法进行了详细设计.通过分析仪器数据特点,火星离子与中性粒子分析仪压缩算法采用合并处理、对数压缩和无损压缩三种压缩算法组合.对于每种探测模式,FPGA程序可根据压缩标志选择相应压缩算法,实现三种压缩算法串行使用,或选择其中一种或两种算法.并且压缩标志可通过注入指令改写,实现在轨时根据需求灵活配置.合并处理压缩比为2或4,对数压缩的压缩比为2,无损压缩效率与样本数据间的相关性有关.在此基础上,利用等离子体定标测试系统完成了地面测试.测试结果表明,各探测模式下科学数据经过压缩后数据率满足任务指标要求.

The FY-4B satellite is one of the second generation of China’s geosynchronous meteorological satellites aiming at numerical weather forecasts. The space environment monitoring package (SEMP) onboard the FY-4B is a comprehensive instrument package for plasma, high-energy particle, and energetic neutral particle measurements. The low-energy particle analyzer (LEPA) is one of the instruments of the SEMP and consists of two top hat electrostatic analyzers designed for plasma detection. The electron and ion sensors are back-to-back assembled and are integrated to a shared electronic box. It measures the three-dimensional velocity distribution of low-energy electrons and ions on the geosynchronous orbit. In this paper, we present the ground calibration and in-flight performance of the instrument. With the electrostatic deflectors and the cylindrically symmetric structure, the instrument provides high-cadence measurements of electron and ion velocity distributions with a wide field of view (FOV) of 180° by 100°, an angular resolution of 16.7° × 20°, and a broad energy range for both the electrons and ions from tens of eV to above 30 keV, with a 1 s time resolution. The geometric factors of the electron and ion analyzers are 1.1 × 10−3 cm2·sr·eV/eV and 1.4 × 10−3 cm2·sr·eV/eV, respectively, which fulfills the requirements of the low-energy plasma measurement. The LEPA monitored typical space environment disturbance such as geomagnetic storms and successfully recorded the responses of plasma energy fluxes. Satellite surface charging events were measured, with the highest potentials of −2000 V in the shadow period and −500 V in the nonshadow period.

In order to meet the needs of ionospheric research and monitoring of space station charging, the technology of plasma in-situ imaging detection is studied. The plasma in-situ imaging detector is one of the first outside scientific payloads of the Chinese space station to detect the space environment. It is installed on the extravehicular platform of the Wentian module, and will carry out multi-element comprehensive detection of ionospheric plasma, including in-situ, imaging, and charging potential. The refined detection data of the low latitude ionosphere will provide plasma parameters for improving the orbital ionospheric model of the space station. And the long-term charging potential data are collected to support the studying of the charging effect of plasma on the space station and promoting the establishment of the space station charging evaluation system.The plasma in-situ imaging detector integrates Langmuir probe, retarding potential analyzer, ion drift meter, reference potentiometer, ion imaging technology, etc. Electron density and electron temperature are measured by Langmuir probe. Ion composition,ion density,ion temperature, and ion drift velocity are measured by retarding potential analyzer and ion drift meter. The ion imaging parameters are obtained by ion imager. The reference potential sensor is available to provide the measurements of charging potential of Wentian module. The Langmuir probe sensor inherits the design of the Langmuir probe sensor of CSES (Zhangheng-1 satellite). The retarding potential analyzer and ion drift meter also inherit the design of CSES (Zhangheng-1 satellite), and improve the design of grid voltage and collector voltage which can be adjusted adaptively according to on orbit state. The ion imager consists of an electrostatic deflection module, a Whalen analyzer and an imaging module. The ion imaging technology is for the first time applied to the field of space environment detection in China.The plasma in-situ imaging detector is tested and calibrated to verify the performance at the National Space Science Center of the Chinese Academy of Sciences. when this paper is submitted, the detector mounted on Wentian module has been successfully launched. Next, the detector will be assembled by astronauts inside the capsule using external interfaces . Then, the detector will be grabbed by the robotic arm and installed on the extravehicular experimental platform to start a long-term exploration mission.

The plasma in situ detector is a multi-sensor package designed to in situ measure the bulk parameters of the local ionospheric plasma. The plasma in situ detector is comprised of three sensors: Langmuir probe (LP), retarding potential analyzer (RPA) and ion drift meter (IDM). LP measures electron density and temperature. RPA measures ion density, temperature and ion horizontal velocity. IDM measures the transverse horizontal component of the ram velocity. The plasma in situ detector has been installed outside the wentian module cabin, and the boom has been successfully deployed which extends the spherical sensor of LP beyond the sheath of the cabin. RPA and IDM were installed at the front of the experiment package, with the horizontal axis direction along the forward flight direction of the space station. This paper discusses the general performance characteristics of the in situ detector, the functional performance of each sensor, and initial results of some classical ionospheric features being observed.

The main objective of the Mars Ion and Neutral Particle Analyzer (MINPA) aboard the Chinese Mars Exploration Mission (Tianwen-1) is to study the solar wind–Mars interaction by measuring the ions and energetic neutral atoms (ENAs) near Mars. The MINPA integrates ion and ENA measurements into one sensor head, sharing the same electronics box. The MINPA utilizes a standard toroidal top-hat electrostatic analyzer (ESA) followed by a time of flight (TOF) unit to provide measurement of ions with energies from 2.8 eV to 25.9 keV and ENAs from 50 eV to 3 keV with a base time resolution of 4 seconds. Highly polished silicon single crystal substrates with an Al2O3 film coating are used to ionize the ENAs into positive ions. These ions can then be analyzed by the ESA and TOF, to determine the energy and masses of the ENAs. The MINPA provides a 360°×90° field of view (FOV) with 22.5°×5.4° angular resolution for ion measurement, and a 360°×9.7° FOV with 22.5°×9.7° angular resolution for ENA measurement. The TOF unit combines a –15 kV acceleration high voltage with ultra-thin carbon foils to resolve H+, He2+, He+, O+, O2+ and CO2+ for ion measurement and to resolve H and O (≥ 16 amu group) for ENA measurement. Here we present the design principle and describe our ground calibration of the MINPA.

The miniature and integrated design is a main trend in science payload development for deep space. An integrated ion and neutral particle analyzer is built for Chinese Mars exploration project. The measurements of ion and energetic neutral atom share the sensor and electronics and are integrated in a single instrument with lower mass and power. Electrostatic analyzing method is used to measure the ions'energy and direction. Time of flight method is used to measure the ions species. The energetic neutral atoms are ionized firstly and the same measurement method with ions. The qualification model is calibrated and the results fulfill the requirements for the Mars project.

The China Seismo-Electromagnetic satellite (CSES) was designed to study the ionospheric disturbances associated with earthquakes. Satellite payload includes nine instruments. Among them, we recall instruments for plasma analysis, electric, magnetic fields and high energy particle detectors. Langmuir probe (LP) and plasma analyzer package (PAP) are the in-situ payloads to measure space plasma. Its scientific objective is to research space plasma physics phenomena and the ionosphere changes caused by seismic. It is the first application of in-situ measurement technology in the field of space exploration in China. The Langmuir probe and Plasma Analyzer Package have been tested and calibrated to verify the performance in INAF-IAPS. Currently, on-orbit testing is being performed with satellites.

A lot of electromagnetic anomalies observed by satellites before earthquakes indicate that there is interrelation between earthquake and ionosphere.China seismo-electromagnetic satellite (CSES) is the first Chinese space-based platform of three-dimensional earthquake monitoring system.The scientific payload of plasma analyzing package (PAP) aboard CSES is designed to study the possible influence of the seismic activity on the ionospheric plasma and thereby to monitor the earthquakes from space.The PAP is made up of three sensors,retarding potential analyzer (RPA),ion drift meter (IDM),and ion capture meter (ICM).The main objective of IDM is to detect the ion bulk velocity from-3 to 3 km/s with a precision better than 20 m/s,perpendicular to the sensor-look direction. The IDM sensor consists of six-layer grids and a collector.The grid is made of beryllium copper,plated with gold.Polyimide is used to achieve electrical insulation between grids.The grid transmission rate of signal layer is designed to be 82.64%,and total transmission rate of six layers is 31.85%.To ensure the performance of IDM,the side length of the square aperture and the depth of the sensor are designed to be 40 and 20 mm,respectively.The radius of segmented planar collector is 50 mm.The arrival angle of the ions is determined by measuring the ratio between the currents from the different electrically isolated collector segments.Accordingly,velocity perpendicular to the sensor-look direction is calculated,based on arrival angle and ion velocity parallel to the sensor-look direction which is measured by the RPA. In addition,a wide-range and high-precision current measurement circuit is designed to measure the current of IDM.The preamplifier circuit has three measurement ranges,providing different amplification factors.The right measurement range is chosen automatically by the field programmable gate array (FPGA).The test results show that the circuit provides a total measuring dynamic range from 20 pA to 6A with an accuracy better than 0.4%. Finally,the method of testing in the plasma environment and the measurement results are discussed.The plasma environment test of the IDM flight model is carried out in the Institute for Space Astrophysics and Planetology,National Institute of Astrophysics (INAF-IAPS).Since the plasma source is fixed to a large volume vacuum tank,the arrival angle of the plasma with respect to the sensor-look direction is changed by horizontally or vertically mounted IDM on the rotating platform in the vacuum tank.As the platform rotates,the performance of IDM is proved by testing different ion arrival angles in vacuum tank.The ion velocities along the Y and Z axes of the spacecraft are validated by testing the horizontal arrival angle and the vertical arrival angle respectively.The IDM test data are consistent with those obtained under the setting angle of the rotating platform.The experimental results show that the detector has good performance and will fulfill the mission goal of monitoring the bulk velocity of ion,perpendicular to the sensor-look direction.

China seismoelectromagnetic satellite (CSES) is the first space-based platform of three-dimensional earthquake monitoring system in china. Plasma analyzing package (PAP) is one of scientific payloads aboard on CSES, which is the first application to the field of Chinese satellite. The main scientific objective of PAP is to measure ion density, ion temperature, ion composition and ion drift velocities (parallel and perpendicular to the direction of the satellite flight on orbit), and ion density fluctuation in the ionosphere. The PAP payload is composed of four parts, including retarding potential analyzer (RPA), ion drift meter, ion capture meter, and metal plate. The RPA is used to test ion density, ion temperature, ion composition and ion drift velocity (parallel to the direction of the satellite flight on orbit). The detailed design process of the sensor of RPA is described in this paper. The grid of RPA sensor is made of Beryllium copper, plated with gold to ensure uniform surface work function, and to prevent space atomic oxygen from eroding. The design value of the transmission rate of grid is 82.64% +/- 1.4%, with taking into account the Debye length on the orbit of satellite. And the total transmission rate of multilayer grid for RPA is verified by SIMON simulation experiment. To ensure the accuracy of RPA, the radii of sensor window and sensor collector are designed to be 20 mm and 50 mm respectively, and the height of sensor is 20 mm. The sweeping voltage ranges from 2 V to 20 V. And the step of sweeping voltage is adjustable between 0.056 and. 179 V. In this paper electronic design of RPA is also discussed. The electronic box is composed of preamplifier circuit, digital logical circuit, satellite interface circuit, etc. The sweeping voltage and the signal acquisition are controlled by field-programmable gate array. The design of three measurement ranges in digital logical circuit improves RPA measurement accuracy, which is better than 1.3% in the full range. In addition, the method of testing the plasma environment and the testing results are introduced. The plasma environment test of the RPA payload is carried out in INAF-IAPS. The performance of ion density measurement is validated by testing different ion densities in a vacuum tank, through changing three different distances between RPA and the plasma source. And the ion drift velocity measurement is verified by testing three different ion energies of the plasma source. Furthermore, the RPA test data are consistent with the test data from the INAF-IAPS reference RPA. The experimental results show that the detector has good performances and will contribute much to monitoring the space plasma parameters.

The scientific objective of Ion Drift Meter (IDM) is to measure ion drift velocity,which is perpendicular to the direction of the satellite flight on orbit.IDM calibration includes electronics calibration and plasma environment test.The measurement precision of velocity is validated through testing electronics noise.The velocity measurement range is calibrated by testing the current measurement range.The method and results of gain and temperature drift of electronics circuit testing are introduced.The plasma environment test of IDM has been carried out in INAF-IAPS plasma environment test instrument.The experimental results show that the detector has good performances and will contribute much to the space plasmas parameters monitoring.

Thermal ion mass discrimination is one of the key techniques for the space plasma detection.In order to measure the energy spectra and composition of space plasma,the Thermal Ion Mass Spectrometer (TIMS) utilizes a hemisphere electrostatic analyzer accompanied with a time of flight unit based on ultra-thin carbon foil.It has been used broadly in space plasma measurement.Three key techniques,such as 5 mV high resolution sweeping high voltage,10～20nm ultra-thin carbon foil treatment,and 30kV acceleration high voltage,have been resolved in the process of TIMS development.The prototype of TIMS has been calibrated by the calibration system in the University of Bern.The calibration results show that the performances of TIMS are as follows.The energy measurement range is from 0.499eV to 29.94keV,and the energy resolution is 10.5％.The field of view is 360° ×8.4°,and the angular resolution is 22.5°× 8.4°.The main ion species including H+,He+,O+ can be resolved.On the basis of the research work in this study,more advanced plasma instruments with higher mass resolution,larger field of view and more miniature design can be developed.

China seismo-electromagnetic satellite (CSES) is launched to detect the electromagnetic environment in space for the study of seismic early warning. Langmuir probe is one of the payloads of the CSES satellite, and it is the first time that the Langmuir probe technique has been used in the Chinese satellite. The use of the Langmuir probe is to measure the space plasma parameters, such as electron density (Ne), electron temperature (Te), and to identify the instantaneous change of the space plasma. The Langmuir probe payload is composed of three parts, i.e., two sensors, two rods, and one electronics box. The sensor is installed at the top of the rod to extend out of the satellite surface, and is parallel to the direction of the satellite orbit. The electronics box is installed inside the satellite which includes the sweep voltage circuit, sensor signal circuit, DPU control and processing circuit, the satellite interface circuit, power supply circuit, etc. The sensor is spherical. Its upper hemisphere is a collecting electrode, and its lower hemisphere is a protective electrode. The same sweep voltage is applied to the upper hemisphere and the lower one which can eliminate the terminal effect of the connecting point between the traditional spherical structure and the rod. The diameters of the two sensors are respectively 50 and 10 mm, and the surface areas of the two sensors are respectively 1/2000 and 1/13000 times the satellite surface area. The stability of the satellite ground potential is not affected by the sweep voltages on the sensors. In addition, TiN material is coated on the sensor surface to ensure a uniform surface work function, and to prevent the space atomic oxygen erosion. The decontamination function is designed for the Langmuir probe to eliminate the possible pollution on the orbit. A positive 100 V voltage is applied to the sensor to accelerate electrons to bombard the sensor surface, thereby removing the contamination from the sensor surface. The advantage of the electron bombardment effect is that the TiN film is not damaged, meanwhile the positive 100 V voltage has high reliability and safety on orbit. The decontamination function has been proved to be effective by the test in Italy National Institute for Astrophysics-Institute for Space Astrophysics and Planetology (INAF-IAPS). The plasma environment calibration test of the Langmuir probe is carried out in INAF-IAPS. We measure the electron density and temperature at three different distances from the plasma source, and compare the results with the measured results of the INAF-IAPS reference Langmuir probe. Results show that the test data of our Langmuir probe are consistent with the INAF-IAPS reference data. Our Langmuir probe design is proved to be feasible to achieve the missions of the satellite.

The miniature design technology is an important trend in space exploration.Mass spectrometer is used extensively in the space environment detection.The miniature ion mass spectrometer utilizes a 127° cylindrical electrostatic analyzer accompanied with a Time of Flight（TOF）unit based on ultrathin carbon foil to measure the energy spectra and composition of space plasma.The Time of Flight technique has been used broadly in space plasma measurement.A new type of miniature method for the ion mass spectrometer is introduced.The total mass of the instrument is1.8 kg and the total power consumption is 2.0 W.The calibration results show that the energy measurement range is 8.71~43550eV,the energy resolution is 1.86%and the ion mass from 1 amu(1 amu= 1.67 × 10 -27 kg) to 58 amu can be resolved by the miniature mass spectrometer.The miniature ion mass spectrometer also has a potential to be increased in the field of view by an electrostatic deflecting system to extend its application in space plasma detection.The miniature ion mass spectrometer has been selected for pre-study of Chinese Strategic Priority Research Program on Space Science.

A technique of using a semiconductor diode voltage-current characteristic to test Langmuir probe performance is presented. The Langmuir probe is an important technique for in-suit detecting the space plasma, its performance test is a key to ensure that its technical indicators meet the mission requirements. The technique of using a semiconductor diode volt-ampere characteristic demands less of external factors, so it can be carried out in a laboratory environment. And its test results can be used as preliminary performance verification before calibration test of ground Plasma environment. The article proved the effectiveness and feasibility of the method by a lab environment test.

Space radiation will lead to single event effects of the microcontrollers in electronic devices. This paper develops a new type of on-orbit single event effect monitoring system for microcontrollers. This system can monitor the single event latch up and detect the single event upset in the RAM and FLASH memories by a program embedded in the microcontrollers. This system could test different kinds of microcontrollers at the same time with fewer resources. The technology and methods are shown to be practical in spaceflight.

中国遥感卫星上的单粒子探测器对某种400万门FPGA和60万门FPGA进行在轨单粒子翻转探测.文中给出了单粒子翻转探测器的基本组成及单粒子翻转的监测方法,并给出了采用模拟量描述器件翻转次数的设计思路.在轨测试期间,单粒子探测器成功的对被测器件进行了在轨单粒子翻转监测,文中给出了两个被测器件的翻转次数统计和翻转类型统计,依据轨道根数获得了翻转事件的空间分布,并对两个被测芯片的翻转事件的差异进行了分析.