- 标题
- 摘要
- 关键词
- 实验方案
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InSight Auxiliary Payload Sensor Suite (APSS)
摘要： NASA’s InSight mission to Mars will measure seismic signals to determine the planet’s interior structure. These highly sensitive seismometers are susceptible to corruption of their measurements by environmental changes. Magnetic fields, atmosphere pressure changes, and local winds can all induce apparent changes in the seismic records that are not due to propagating ground motions. Thus, InSight carries a set of sensors called the Auxiliary Payload Sensor Suite (APSS) which includes a magnetometer, an atmospheric pressure sensor, and a pair of wind and air temperature sensors. In the case of the magnetometer, knowledge of the amplitude of the fluctuating magnetic field at the InSight lander will allow the separation of seismic signals from potentially interfering magnetic signals of either natural or spacecraft origin. To acquire such data, a triaxial fluxgate magnetometer was installed on the deck of the lander to obtain magnetic records at the same cadence as the seismometer. Similarly, a highly sensitive pressure sensor is carried by InSight to enable the removal of local ground-surface tilts due to advecting pressure perturbations. Finally, the local winds (speed and direction) and air temperature are estimated using a hot-film wind sensor with heritage from REMS on the Curiosity rover. When winds are too high, seismic signals can be ignored or discounted. Herein we describe the APSS sensor suite, the test programs for its components, and the possible additional science investigations it enables.
关键词： Wind,Magnetometer,Spacecraft,Pressure,Temperature,Instruments
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Shenzhen, China (2018.7.13-2018.7.15)] 2018 IEEE 3rd International Conference on Signal and Image Processing (ICSIP) - Spacecraft Detection Based on Deep Convolutional Neural Network
摘要： Spacecraft detection is one of essential issues on aerospace information processing and control, and can provide reliable dynamic state of target, so as to support decisions made on target recognition, classification, catalogue, et al. Although numerous spacecraft detection methods exist, most of them cannot achieve real-time detection, and are still lack of better accuracy and fault-tolerance for different scenes. Recently, deep learning algorithms have achieved fantastic detection performance in computer vision community, especially the regression-based convolutional neural network YOLOv2, which has good accuracy and speed, and outperforming other state-of-the-art detection methods. This paper for the first time applies CNN to the detection of spacecraft and sets up a dataset for target detection in space. Our method starts with image annotation and data augmentation, and then uses our improved regression-based convolutional neural network YOLOv2 to detect spacecraft in an image. The experimental results have shown that our algorithm achieves 97.8% detection rate in the test set, and the average detection time of each image is about 0.018s, which has lower time overhead and better robustness to rotation and illumination changes of spacecraft.
关键词： Spacecraft,CNN,Target detection,YOLOv2
更新于2025-09-23 15:23:52
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A review of Quartz Crystal Microbalances for Space Applications
摘要： The aim of this work is a technical review about Quartz Crystal Microbalance (QCM) sensors used in space missions, i.e. Space Shuttle flights, i.e. NASA Space Transportation System (NASA STS) and satellite missions, that aimed at monitoring the contamination generated by outgassing processes of materials onboard satellites and sensitive payloads. The contamination processes are critical for scientific instrumentation (e.g. optics, telescopes, detectors) because scientific measurements and performances can be jeopardized or worsened by uncontrolled contamination. This issue has been addressed by the space agencies, e.g. NASA, ESA and JAXA that have implemented many different studies to monitor the material outgassing and degradation in space environment. During the past years, the QCM sensors have become the baseline solution for measuring material outgassing and characterizing the on-orbit contamination environment. This work summarizes the main QCM applications in Space and their findings, providing an overview of the sensors’ performances in terms of stability, power, data rate, measurement accuracy and resolution. Different QCM technologies will be compared highlighting the advantages of their use for the next space missions and instrumentations that require an accurate monitoring of contamination environment. In particular, due to more severe contamination requirements for next payloads and instrumentations, QCM sensors would be useful to estimate the cleanliness degree by evaluating the induced contamination and degradation on sensitive instrumentations.
关键词： quartz crystal microbalance,contamination monitoring,spacecraft contamination,molecular and particulate contamination,outgassing,satellite contamination
更新于2025-09-23 15:23:52
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[IEEE IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Valencia (2018.7.22-2018.7.27)] IGARSS 2018 - 2018 IEEE International Geoscience and Remote Sensing Symposium - Spacecraft Formation Design for Bistatic SAR with GEO Illuminator and LEO Receiver
摘要： The bistatic synthetic aperture radar (BiSAR) system consists of a geosynchronous Earth orbit (GEO) illuminator and a low Earth orbit (LEO) receiver. Compared with GEO SAR, it offers great advantages of higher signal-to-noise ratio (SNR) and finer spatial resolution with lower system complexity. The concept also raises significant technical challenges. The spacecraft formation has great effect on radar performance, such as spatial resolution, the angle of two-dimensional (2-D) resolution direction and noise-equivalent sigma zero (NESZ). This paper establishes the relationship between the imaging performance and the formation parameters. Then, a novel design method of spacecraft formation is presented, identifying the principal formation design choices and constraints. Finally, simulation results are provided for typical observational tasks, to verify the effectiveness of the proposed method.
关键词： imaging performance,spacecraft formation,bistatic SAR,geosynchronous
更新于2025-09-23 15:23:52
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Structural Stability of Hafnia-Based Materials at Ultra-High Temperature
摘要： This study assesses the structural stability at ultra-high temperature of the following selected compositions: 6.5 and 14 mol. % of RE2O3 (RE = Dy, Y, Er, Yb, and Lu) doped HfO2. Under thermal cycling and thermal shock, the structural stability was evaluated at 2400°C with water vapor flux using a specific test bench with a 3 kW CO2 laser. The cubic phase stability, which is theoretically important in the broad temperature range from 25 to 2800°C, was determined by a quantitative analysis of the X-ray diffractograms. Fully and partially stabilized HfO2, obtained respectively with 14 mol. % and 6.5 mol. % of dopants, showed different behaviors to thermal damage. Thermal expansion was measured up to 1650°C to anticipate dimensional changes of these stabilized samples and to be able to design an optimized material solution fitting with future combustion chamber requirements. All of these results were then considered in order to exhibit a trend on the thermal stability at 2400°C of the ionic radius of the dopants and their optimal doping rates.
关键词： Phase stability,UHTC,Thermal expansion,Spacecraft propulsion,HfO2
更新于2025-09-23 15:22:29
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LCL-T Resonant Converter Based on Dual Active Bridge Topology in Solar Energy Applications
摘要： Resonant LCL-T converter can operate as stable voltage source, being fed from current, for instance, the photovoltaic battery. It is shown that LCL-T resonant tank has intrinsic ability to convert stable AC current into stable AC voltage thus parametrically regulating output voltage at a fixed value. This mode of operation is made possible by the use of active (synchronous) rectifier to recoup energy from the output back to the LCL-T resonant tank. Basic characteristics of resonant LCL-T converter regulated by phase shift between inverter and rectifier regardless of a solar battery current drift have been defined. It is shown that phase control guarantees 0 voltage and 0 current on switching; however, turn-off current could be substantial. Calculations and assumptions made in this study have been confirmed by simulation and hardware prototype.
关键词： Bidirectional dual active bridge,ZCS,LCL resonant converter,Resonant converter,Spacecraft power supply system,ZVS
更新于2025-09-23 15:21:21
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Fast Attitude Maneuver of a Flexible Spacecraft with Passive Vibration Control Using Shunted Piezoelectric Transducers
摘要： This paper is concerned with designing a bang-bang control input to perform a quick rotational maneuver of a rigid spacecraft hub connected with flexible appendages. The control design is based on only the rigid body mode making it very simple to design and at the same time achieve the quickest maneuver possible. The induced vibrations are suppressed using piezoelectric transducers bonded to the appendages and connected to an electric circuit with the objective of converting the vibrational energy to electrical energy and then dissipating it using passive electric elements, such as a resistance and an inductor. The proposed control design method is applied to a spacecraft containing a rigid hub and flexible appendages. The attitude control torque is produced using either the reaction wheels contained inside the rigid hub or jet thrusters mounted outside it. The control design process starts with deriving the nonlinear partial differential equations of motion for the spacecraft using Hamilton’s principle which accounts for the electromechanical coupling and the presence of resistive or resistive-inductive circuits. To simplify the analysis, the nonlinear ordinary differential equations of motion are then obtained using the assumed mode method. The effectiveness of the control design method is numerically tested on a spacecraft that is required to perform a quick attitude maneuver and, simultaneously, suppress the induced vibrations. The simulations show a quick and accurate maneuver has been achieved combined with very low levels of vibrations resulting from the reduced coupling between flexible and rigid motions as well as the damping added as a result of the passive shunt circuit. Furthermore, the resistance-inductance shunt circuit is shown to be more effective in damping the vibrations than the resistance shunt circuit.
关键词： vibration control,piezoelectric transducers,attitude maneuver,bang-bang control,flexible spacecraft,shunt circuits
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Portland, OR, USA (2019.10.14-2019.10.16)] 2019 IEEE International Conference on Space Optical Systems and Applications (ICSOS) - Demonstration of Reliable High-Rate Optical Communication over an Atmospheric Link using ARQ
摘要： A quaternion-based attitude unscented Kalman ?lter is formulated with quaternion errors parameterized by small angle approximations and is applied to a ?lter with a state vector consisting of the attitude quaternion and the gyro bias vector. The ?lter is evaluated using extensive Monte Carlo data in a simulated lost-in-space scenario of a low-Earth orbiting spacecraft processing only three-axis magnetometer and gyro measurements. The ?lter is found to be robust, accurate, and rapidly convergent in this scenario for small true gyro biases and small initial uncertainties in their values, often converging in only one half of an orbit period to an attitude accuracy of 0.1 degrees. The ?lter convergence is found to depend signi?cantly on the value of the true gyro biases as well as the initial gyro bias covariances. Monte Carlo results also indicate that this unscented Kalman ?lter is signi?cantly less robust than an extended Kalman ?lter with the same attitude approach, but performs slightly better than another unscented Kalman ?lter with a generalized Rodrigues parameter approach to quaternion errors.
关键词： Attitude control,Kalman ?lters,gyroscopes,calibration,unscented,spacecraft,geomagnetism
更新于2025-09-19 17:13:59
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Design of two and four-terminals InGaP/GaAs//Si tandem solar cells
摘要： Proper spacecraft design and testing depend on a knowledge of the worst case environment and the number of arcs to be endured during the spacecraft lifetime. In this paper, we define the criteria to be used to specify the worst case geosynchronous earth orbit (GEO) charging environment (plasma density and temperature), including the physical constraints on particle and magnetic field energy densities and the relative importance of frame charging and differential charging. A previous estimate of the frequency of arcing (found in the literature and incorporated into an International Standards Organization standard) and the consequent total number of arcs to be encountered in a GEO satellite lifetime are found to be incorrect because they were based on environmental measurements using a faulty algorithm to determine spacecraft charging and plasma density. Using more accurate estimates of the frequency of GEO plasma densities and temperatures, we arrive at a much lower estimate of the total number of arcs during a GEO satellite lifetime. Finally, the worst case GEO charging environment seen to date is determined from Nascap-2k simulations. Our estimates of worst case charging environments and arc frequencies may be more confidently used by GEO spacecraft designers and test engineers.
关键词： GEO,plasmas,worst cases,spacecraft charging
更新于2025-09-19 17:13:59
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[IEEE 2018 3rd International Conference on Robotics and Automation Engineering (ICRAE) - Guangzhou (2018.11.17-2018.11.19)] 2018 3rd International Conference on Robotics and Automation Engineering (ICRAE) - Research and Application of Laser Projection Technology Used in Spacecraft Assembly
摘要： During the spacecraft assembly, the assembling information of the equipment is mainly determined by viewing the 3D model and manually measuring the lines. The assembly method is with high workload and low efficiency. To solve the problem that the 3D model cannot effectively guide the assembly, the approach to use the combination of laser projection technology and 3D model can make the assembly information on the 3D model projected to the assembly surface quickly and accurately, thus to obtain assembly information intuitively. This way can improve the efficiency and level of spacecraft assembly.
关键词： spacecraft assembly,laser projection technology,3D model
更新于2025-09-11 14:15:04