Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115770
Jiawei Qiu, Sivaperuman Muniyasamy, Sebastian Blanco-Miranda, Abdelrahman Abdelkhalek, J. Thangavelautham
Abtract- In this paper, we explore the possibility of a distributed communication network that permeates the base infrastructure. These structures consist of modular components that can collect, process, store, and communicate information in a distributed fashion. These networks can make localized decisions independently and offload routine maintenance responsibilities from astronauts, improving the efficiency of base operations and overall safety. We examine the technologies and algorithms available to establish a distributed network within modular base building block components. We analyze units embedded with electronics as a potential candidates, as well as a rudimentary plan for an early lunar base. Some projected functions are detailed. We also compare this concept of a “smart” and conventional lunar bases by simulating plausible catastrophes and examining either base's response.
{"title":"Robust Lunar Base Architectures Using Distributed Processing Network in Smart Building Blocks","authors":"Jiawei Qiu, Sivaperuman Muniyasamy, Sebastian Blanco-Miranda, Abdelrahman Abdelkhalek, J. Thangavelautham","doi":"10.1109/AERO55745.2023.10115770","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115770","url":null,"abstract":"Abtract- In this paper, we explore the possibility of a distributed communication network that permeates the base infrastructure. These structures consist of modular components that can collect, process, store, and communicate information in a distributed fashion. These networks can make localized decisions independently and offload routine maintenance responsibilities from astronauts, improving the efficiency of base operations and overall safety. We examine the technologies and algorithms available to establish a distributed network within modular base building block components. We analyze units embedded with electronics as a potential candidates, as well as a rudimentary plan for an early lunar base. Some projected functions are detailed. We also compare this concept of a “smart” and conventional lunar bases by simulating plausible catastrophes and examining either base's response.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130191358","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115868
Teresa Reiber, N. Newby, R. Scheuring, M. Walton, J. Norcross, Grant Harman, J. Somers
A new Exploration Extravehicular Activity Suit (xEVAS) is being designed to replace the current Extravehicular Mobility Unit (EMU) for the National Aeronautics and Space Administration's (NASA's) Artemis program to return astronauts to the lunar surface. This new suit will allow for increased range of motion compared to the current EMU and Apollo era suits and will have additional features enhancing the health and safety of exploration. With the design of lunar missions and the xEVAS progressing, it is important to consider possible injuries and injury mechanisms that could occur in the suit. To address these concerns, the suited Injury Modes and Effects Analysis (IMEA) was developed to outline suited injury scenarios and rank them based on risk score. The IMEA documents possible scenarios and underlying mechanisms of injury while wearing an extravehicular activity (EVA) suit. Tasks during lunar surface EVA as well as training events to prepare for lunar missions were considered as history has shown that more suit injuries occur during training than in flight. Each scenario is ranked with a consequence and likelihood scoring based on our current understanding of the suit and Artemis design reference missions to identify high-risk cases that will drive further work in suited injury. Injuries, mechanisms of injury, and mitigation strategies are evaluated within each scenario. The Suited Injury Summit was held on January 5, 2022, to vet the IMEA with external experts. This was an all-day virtual meeting with the suited injury team; ergonomists; suit engineers; safety engineers; the flight operations directorate; flight doctors; astronauts; astronaut strength, conditioning, and rehabilitation specialists (ASCRS); and external subject matter experts (SMEs). External SMEs consisted of surgeons with varying specialties. The intent of this meeting was to walk through the top injury risks identified in the analysis, identify any gaps that were not captured, and discuss mitigations. With participation from all groups, countless lessons-learned came from the Summit meeting. Using the lessons-learned and discussion from the Summit, the top 10 risks have been identified: neutral buoyancy laboratory training, hand/glove injuries, poor suit fit, field training, specific EVA tasks/design of task, boots/ankle injuries, falls from heights, background radiation, repetitive contact, and ambulation/long-distance ambulation. Mitigation steps have also been determined for each of the top risks. The IMEA and documentation of top risks is a living document. Yearly meetings are planned to update the analysis and reevaluate top risks and mitigations. The IMEA is being used to drive work in suited injury, and this work will continue to evolve with IMEA and lunar mission updates.
{"title":"Development of the Suited Injury Modes and Effects Analysis for Identification of Top Injury Risks in Lunar Missions and Training","authors":"Teresa Reiber, N. Newby, R. Scheuring, M. Walton, J. Norcross, Grant Harman, J. Somers","doi":"10.1109/AERO55745.2023.10115868","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115868","url":null,"abstract":"A new Exploration Extravehicular Activity Suit (xEVAS) is being designed to replace the current Extravehicular Mobility Unit (EMU) for the National Aeronautics and Space Administration's (NASA's) Artemis program to return astronauts to the lunar surface. This new suit will allow for increased range of motion compared to the current EMU and Apollo era suits and will have additional features enhancing the health and safety of exploration. With the design of lunar missions and the xEVAS progressing, it is important to consider possible injuries and injury mechanisms that could occur in the suit. To address these concerns, the suited Injury Modes and Effects Analysis (IMEA) was developed to outline suited injury scenarios and rank them based on risk score. The IMEA documents possible scenarios and underlying mechanisms of injury while wearing an extravehicular activity (EVA) suit. Tasks during lunar surface EVA as well as training events to prepare for lunar missions were considered as history has shown that more suit injuries occur during training than in flight. Each scenario is ranked with a consequence and likelihood scoring based on our current understanding of the suit and Artemis design reference missions to identify high-risk cases that will drive further work in suited injury. Injuries, mechanisms of injury, and mitigation strategies are evaluated within each scenario. The Suited Injury Summit was held on January 5, 2022, to vet the IMEA with external experts. This was an all-day virtual meeting with the suited injury team; ergonomists; suit engineers; safety engineers; the flight operations directorate; flight doctors; astronauts; astronaut strength, conditioning, and rehabilitation specialists (ASCRS); and external subject matter experts (SMEs). External SMEs consisted of surgeons with varying specialties. The intent of this meeting was to walk through the top injury risks identified in the analysis, identify any gaps that were not captured, and discuss mitigations. With participation from all groups, countless lessons-learned came from the Summit meeting. Using the lessons-learned and discussion from the Summit, the top 10 risks have been identified: neutral buoyancy laboratory training, hand/glove injuries, poor suit fit, field training, specific EVA tasks/design of task, boots/ankle injuries, falls from heights, background radiation, repetitive contact, and ambulation/long-distance ambulation. Mitigation steps have also been determined for each of the top risks. The IMEA and documentation of top risks is a living document. Yearly meetings are planned to update the analysis and reevaluate top risks and mitigations. The IMEA is being used to drive work in suited injury, and this work will continue to evolve with IMEA and lunar mission updates.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131760690","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115624
Arthur Bouton, William Reid, T. Brown, Adriana Daca, Mielad Sabzehi, H. Nayar
This paper reports on an experimental study to quantify the influence of the different adaptation capabilities that can be leveraged to improve the performance of low-cost four-wheeled rovers on sandy terrain. Conjointly with the ability to displace the center of mass and incline the rover's body, three configurations of passive suspensions and eight different locomotion modes are examined. The experiments are performed on sub-scale prototypes, with size, mass, and wheel geometry determined by a scaling analysis that ensures the consistency and transferability of the performance metrics to a 500 kg lunar rover equipped with 80 cm diameter wheels. The different configurations and locomotion modes are tested on GRC-1 lunar simulant on either a flat ground, a 20° slope or a 30° slope, while climbing uphill or downhill, with a 90° or 45° angle of attack. The performance metrics observed are the travel reduction, the lateral deviation and the energy consumption.
{"title":"Experimental Study of Alternative Rover Configurations and Mobility Modes for Planetary Exploration","authors":"Arthur Bouton, William Reid, T. Brown, Adriana Daca, Mielad Sabzehi, H. Nayar","doi":"10.1109/AERO55745.2023.10115624","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115624","url":null,"abstract":"This paper reports on an experimental study to quantify the influence of the different adaptation capabilities that can be leveraged to improve the performance of low-cost four-wheeled rovers on sandy terrain. Conjointly with the ability to displace the center of mass and incline the rover's body, three configurations of passive suspensions and eight different locomotion modes are examined. The experiments are performed on sub-scale prototypes, with size, mass, and wheel geometry determined by a scaling analysis that ensures the consistency and transferability of the performance metrics to a 500 kg lunar rover equipped with 80 cm diameter wheels. The different configurations and locomotion modes are tested on GRC-1 lunar simulant on either a flat ground, a 20° slope or a 30° slope, while climbing uphill or downhill, with a 90° or 45° angle of attack. The performance metrics observed are the travel reduction, the lateral deviation and the energy consumption.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"1071 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132785775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115689
Michael J. Cannizzaro, Alan D. George
Radiation-hardened (rad-hard) components are frequently used in reliable spacecraft-computing systems. While these components improve mission dependability, they also suffer from high development and integration costs, support relatively low operating frequencies, and leverage outdated architectures. These characteristics motivate the consideration of more cost-effective and performant commercial alternatives. The open-source and highly configurable RISC-V architecture has recently become a popular choice for both space and commercial applications. While the reliability of RISC-V on FPGAs has been evaluated extensively, commercial RISC-V silicon has only begun to be investigated in a similar manner. This study evaluates the single-event upset (SEU) susceptibility of two commercial RISC-V processors, the Microchip PolarFire SoC and the SiFive HiFive Unmatched, in the presence of neutron radiation. These devices are compared to the flight-proven Xilinx Zynq-7020 system-on-chip, which contains an ARM Cortex-A9 processor. The industry-standard EEMBC CoreMark and SHREC-developed SpaceBench benchmarks are used to evaluate the presence of data and execution errors on each device under test (DUT). Neutron radiation beam testing was performed at the Los Alamos Neutron Science Center (LANSCE) Weapons Neutron Research (WNR) facility. Data- and execution-error results were recorded and analyzed to measure the proportion of errors present out of all calculations performed during the experiment. Effective dosimetry was also used to calculate cross sections of the processors that are susceptible to SEUs. The Po-larFire and Unmatched DUTs experienced no errors in 99.70% and 99.59% of operations, respectively. The Zynq achieved only 65.23% error-free operations. Execution errors were observed in 0.28%, 0.38%, and 18.67% of operations performed by the PolarFire, Unmatched, and Zynq, respectively. Similar trends were seen for data errors, with the PolarFire, Unmatched, and Zynq experiencing data errors in 0.02%, 0.03%, and 16.10% of operations, respectively. These results alongside dosimetry data produced cross sections of 8.033 × 10–12cm2 for the PolarFire and 8.342 × 10–12 cm2 for the Unmatched, indicating the area vulnerable to SEUs. The calculated cross section for the Cortex-A9 in the Zynq-7020 was 3.759 × 10–9 cm2a much larger value compared to either RISC-V platform. Both the error and cross-section analyses suggest that the evaluated commercial RISC-V devices have significantly lower SEU sus-ceptibility compared to the flight-proven Cortex-A9 platform, showing great promise for the reliable use of RISC-V silicon in embedded space applications.
{"title":"Evaluation of RISC-V Silicon Under Neutron Radiation","authors":"Michael J. Cannizzaro, Alan D. George","doi":"10.1109/AERO55745.2023.10115689","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115689","url":null,"abstract":"Radiation-hardened (rad-hard) components are frequently used in reliable spacecraft-computing systems. While these components improve mission dependability, they also suffer from high development and integration costs, support relatively low operating frequencies, and leverage outdated architectures. These characteristics motivate the consideration of more cost-effective and performant commercial alternatives. The open-source and highly configurable RISC-V architecture has recently become a popular choice for both space and commercial applications. While the reliability of RISC-V on FPGAs has been evaluated extensively, commercial RISC-V silicon has only begun to be investigated in a similar manner. This study evaluates the single-event upset (SEU) susceptibility of two commercial RISC-V processors, the Microchip PolarFire SoC and the SiFive HiFive Unmatched, in the presence of neutron radiation. These devices are compared to the flight-proven Xilinx Zynq-7020 system-on-chip, which contains an ARM Cortex-A9 processor. The industry-standard EEMBC CoreMark and SHREC-developed SpaceBench benchmarks are used to evaluate the presence of data and execution errors on each device under test (DUT). Neutron radiation beam testing was performed at the Los Alamos Neutron Science Center (LANSCE) Weapons Neutron Research (WNR) facility. Data- and execution-error results were recorded and analyzed to measure the proportion of errors present out of all calculations performed during the experiment. Effective dosimetry was also used to calculate cross sections of the processors that are susceptible to SEUs. The Po-larFire and Unmatched DUTs experienced no errors in 99.70% and 99.59% of operations, respectively. The Zynq achieved only 65.23% error-free operations. Execution errors were observed in 0.28%, 0.38%, and 18.67% of operations performed by the PolarFire, Unmatched, and Zynq, respectively. Similar trends were seen for data errors, with the PolarFire, Unmatched, and Zynq experiencing data errors in 0.02%, 0.03%, and 16.10% of operations, respectively. These results alongside dosimetry data produced cross sections of 8.033 × 10–12cm2 for the PolarFire and 8.342 × 10–12 cm2 for the Unmatched, indicating the area vulnerable to SEUs. The calculated cross section for the Cortex-A9 in the Zynq-7020 was 3.759 × 10–9 cm2a much larger value compared to either RISC-V platform. Both the error and cross-section analyses suggest that the evaluated commercial RISC-V devices have significantly lower SEU sus-ceptibility compared to the flight-proven Cortex-A9 platform, showing great promise for the reliable use of RISC-V silicon in embedded space applications.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"32 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132807238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115595
Christopher Manderino, Jere Porter, A. Horchler
Distributed consensus is proposed to provide software-based modular redundancy for spaceflight applications, in order to overcome the risk of environmental effects - especially radiation - on digital avionics designs for spacecraft. Consensus for Asynchronous Space Applications (CASA) is an application developed by Astrobotic as a reusable, portable, extensible, and scalable solution for space systems requiring low overhead and low latency operations. Mission use cases for space systems that require performance and safety-critical constraints were chosen to develop CASA as a software application. CASA was developed for managing distributed consensus algorithms as a service to be used by other space applications and is implemented as an application in NASA's open-source flight software framework, Core Flight System (cFS). This mission-ready implementation leverages the hardware abstraction that cFS offers and enables a certain degree of hardware and platform agnosticism. Software-based distributed consensus, as implemented in CASA, is evaluated, here, as an alternative to commonly used hardware-based voter logic for modular redundancy in spaceflight. Radiation-tolerant designs for spaceflight applications often employ N-modular redundant processes to overcome radiation-induced faults and errors. These processes may be threads of code, combinational logic, entire applications, or board-level outputs. Redundant processes are joined as a voter domain behind common voter logic between their outputs. In spaceflight, voters are typically a radiation-hardened, hardware-based voter circuit. Voter logic takes input from N redundant process outputs, compares them, and outputs a single answer when a majority of the inputs are identical. While more complicated designs exist, single voters are a single point of failure in a system. In contrast, distributed consensus algorithms are robust against single-points-of-failure. These consensus algorithms provide a logical procedure for coordinating data and ensuring consistency between redundant processes, e.g., in a distributed computing cluster. Hardware redundancy carries a certain amount of overhead and constrains reusability. To overcome the constraints and complexity of hardware, CASA's distributed consensus approach focuses on a flexible software-based architecture for modular redundancy. This work investigates distributed consensus as an alternative to voters for fault-tolerant infrastructure in software for space systems with respect to dependability, latency, and resiliency. This paper presents the background for distributed consensus, its application for space systems, use cases for CASA in real space missions, the testing methodology, discussion of this work's preliminary test results within a context of overhead and reconfiguration costs, and direction for future work.
{"title":"Distributed Consensus for Asynchronous Space Applications (CASA)","authors":"Christopher Manderino, Jere Porter, A. Horchler","doi":"10.1109/AERO55745.2023.10115595","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115595","url":null,"abstract":"Distributed consensus is proposed to provide software-based modular redundancy for spaceflight applications, in order to overcome the risk of environmental effects - especially radiation - on digital avionics designs for spacecraft. Consensus for Asynchronous Space Applications (CASA) is an application developed by Astrobotic as a reusable, portable, extensible, and scalable solution for space systems requiring low overhead and low latency operations. Mission use cases for space systems that require performance and safety-critical constraints were chosen to develop CASA as a software application. CASA was developed for managing distributed consensus algorithms as a service to be used by other space applications and is implemented as an application in NASA's open-source flight software framework, Core Flight System (cFS). This mission-ready implementation leverages the hardware abstraction that cFS offers and enables a certain degree of hardware and platform agnosticism. Software-based distributed consensus, as implemented in CASA, is evaluated, here, as an alternative to commonly used hardware-based voter logic for modular redundancy in spaceflight. Radiation-tolerant designs for spaceflight applications often employ N-modular redundant processes to overcome radiation-induced faults and errors. These processes may be threads of code, combinational logic, entire applications, or board-level outputs. Redundant processes are joined as a voter domain behind common voter logic between their outputs. In spaceflight, voters are typically a radiation-hardened, hardware-based voter circuit. Voter logic takes input from N redundant process outputs, compares them, and outputs a single answer when a majority of the inputs are identical. While more complicated designs exist, single voters are a single point of failure in a system. In contrast, distributed consensus algorithms are robust against single-points-of-failure. These consensus algorithms provide a logical procedure for coordinating data and ensuring consistency between redundant processes, e.g., in a distributed computing cluster. Hardware redundancy carries a certain amount of overhead and constrains reusability. To overcome the constraints and complexity of hardware, CASA's distributed consensus approach focuses on a flexible software-based architecture for modular redundancy. This work investigates distributed consensus as an alternative to voters for fault-tolerant infrastructure in software for space systems with respect to dependability, latency, and resiliency. This paper presents the background for distributed consensus, its application for space systems, use cases for CASA in real space missions, the testing methodology, discussion of this work's preliminary test results within a context of overhead and reconfiguration costs, and direction for future work.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131013978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115545
Thomas V. Cook, B. Grainger
A key consideration in spacecraft applications is the conducted and radiated electromagnetic interference (EMI) generated by electronic components. One of the biggest sources of EMI is from the power system, caused by converters rapidly switching large amounts of current and voltage that generates unwanted noise. Without significant engineering considerations of mechanical and electrical layout, EMI can have serious impacts on other spacecraft systems such as communication equipment. Isolated supplies typically use a forward or flyback converter topology with a coil wound toroidal transformer. The transformer can experience a high voltage impulse called an inductive kickback during switching due to its leakage inductance, which contributes to overall power system radiated and conducted emissions. The transformer is a major source of EMI in currently available switching forward topologies, requiring a significant amount of input filtering, snubbing, and shielding. A high efficiency, isolated, cascaded prototype utilizing resonant switching techniques was developed in the form of a Buck-LLC utilizing a traditional wire wound transformer. With the successful testing of a 200W, 1MHz, Buck-LLC converter utilizing gallium nitride (GaN) devices, a planar transformer design was desired for an improvement in overall converter efficiency and EMI performance. In this work, a new transformer winding design is presented for a planar transformer using paired Litz winding interleaving. Ansys finite element analysis (FEA) software is used to verify design parameters. The winding configuration is designed to be compatible with a standard PCB stack-up so that the transformer windings can be directly integrated into the converter PCB even further reducing leakage inductance and increasing power density.
{"title":"Low EMI Planar Transformer for an Isolated, Cascaded Buck-LLC Converter","authors":"Thomas V. Cook, B. Grainger","doi":"10.1109/AERO55745.2023.10115545","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115545","url":null,"abstract":"A key consideration in spacecraft applications is the conducted and radiated electromagnetic interference (EMI) generated by electronic components. One of the biggest sources of EMI is from the power system, caused by converters rapidly switching large amounts of current and voltage that generates unwanted noise. Without significant engineering considerations of mechanical and electrical layout, EMI can have serious impacts on other spacecraft systems such as communication equipment. Isolated supplies typically use a forward or flyback converter topology with a coil wound toroidal transformer. The transformer can experience a high voltage impulse called an inductive kickback during switching due to its leakage inductance, which contributes to overall power system radiated and conducted emissions. The transformer is a major source of EMI in currently available switching forward topologies, requiring a significant amount of input filtering, snubbing, and shielding. A high efficiency, isolated, cascaded prototype utilizing resonant switching techniques was developed in the form of a Buck-LLC utilizing a traditional wire wound transformer. With the successful testing of a 200W, 1MHz, Buck-LLC converter utilizing gallium nitride (GaN) devices, a planar transformer design was desired for an improvement in overall converter efficiency and EMI performance. In this work, a new transformer winding design is presented for a planar transformer using paired Litz winding interleaving. Ansys finite element analysis (FEA) software is used to verify design parameters. The winding configuration is designed to be compatible with a standard PCB stack-up so that the transformer windings can be directly integrated into the converter PCB even further reducing leakage inductance and increasing power density.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130692463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115620
H. Witzgall
This paper describes how eXtending Rapid Class Augmentation (XRCA) optimization can be integrated into a modern single-shot detector (SSD) architecture to enable fast and efficient progressive learning of new objects. The key distinguishing property of XRCA optimization is the incorporation of memory from previously learned classes into its weight update equations. This allows XRCA models to optimally learn new types of objects using just the new object training data. The new XRCA-SSD object detection framework replaces the traditional SSD's prediction heads with the XRCA prediction heads that use different XRCA optimization modes to update the weights. The mean average precision (mAP) performance metric for a SSD model trained using XRCA versus stochastic gradient descent is compared and the XRCA-SSD trained model is shown to greatly outperform the SGD-SSD model by largely mitigating the impact of catastrophic forgetting during new object augmentation. We expect the new XRCA-SSD framework to be especially relevant for real-time progressive learning applications where rapid training times are critical, and compute and memory are often limited.
{"title":"Extending Rapid Class Augmentation to a Single-Shot-Detector Object Detection Framework","authors":"H. Witzgall","doi":"10.1109/AERO55745.2023.10115620","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115620","url":null,"abstract":"This paper describes how eXtending Rapid Class Augmentation (XRCA) optimization can be integrated into a modern single-shot detector (SSD) architecture to enable fast and efficient progressive learning of new objects. The key distinguishing property of XRCA optimization is the incorporation of memory from previously learned classes into its weight update equations. This allows XRCA models to optimally learn new types of objects using just the new object training data. The new XRCA-SSD object detection framework replaces the traditional SSD's prediction heads with the XRCA prediction heads that use different XRCA optimization modes to update the weights. The mean average precision (mAP) performance metric for a SSD model trained using XRCA versus stochastic gradient descent is compared and the XRCA-SSD trained model is shown to greatly outperform the SGD-SSD model by largely mitigating the impact of catastrophic forgetting during new object augmentation. We expect the new XRCA-SSD framework to be especially relevant for real-time progressive learning applications where rapid training times are critical, and compute and memory are often limited.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130917520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115934
C. Spittler, D. Malaspina, R. Ergun, Jason J. Link, B. Unruh, M. Danowski, R. Rohrschneider, J. Goldstein, Lauren DeMoudt, J. Parker
Magnetospheric physics has a massive problem: we have not yet determined the fundamental processes that govern plasma mass and energy flow through the terrestrial magnetosphere, nor the degree to which these flows regulate key magnetospheric subsystems. The Plasma Imaging LOcal and Tomographic experiment (PILOT) mission concept leverages a small satellite constellation to provide the transformational multi-scale observations needed to resolve critical heliophysics problems related to mass and energy flow through a planetary magnetosphere, enabling previously infeasible magnetospheric science. The PILOT mission concept, developed as a NASA-funded Heliophysics Mission Concept Study, is a potential Flagship-class NASA Heliophysics mission to be considered by the 2024–2033 Solar and Space Physics Decadal Survey. PILOT uses a constellation of 30 microsat spacecraft and 4 smallsat spacecraft in two highly-elliptical, equatorial Earth orbits to make high-resolution radio tomographic density maps of total plasma density in the equatorial plane, augmented by EUV imaging of ion plasma density and flows in the meridional plane, and in-situ measurements of electric and magnetic fields, plasma density, energetic particles, and ion composition. The comprehensive suite of measurements made by the PILOT constellation fully captures plasma mass dynamics and its impact on magnetospheric systems over an unprecedented range of spatial and temporal scales. Here we discuss the PILOT mission architecture, including instrument heritage, manufacturing strategy, concept of operations, and required technology development.
{"title":"PILOT: Using a Small Satellite Constellation to Understand Cold Plasma in the Inner Magnetosphere","authors":"C. Spittler, D. Malaspina, R. Ergun, Jason J. Link, B. Unruh, M. Danowski, R. Rohrschneider, J. Goldstein, Lauren DeMoudt, J. Parker","doi":"10.1109/AERO55745.2023.10115934","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115934","url":null,"abstract":"Magnetospheric physics has a massive problem: we have not yet determined the fundamental processes that govern plasma mass and energy flow through the terrestrial magnetosphere, nor the degree to which these flows regulate key magnetospheric subsystems. The Plasma Imaging LOcal and Tomographic experiment (PILOT) mission concept leverages a small satellite constellation to provide the transformational multi-scale observations needed to resolve critical heliophysics problems related to mass and energy flow through a planetary magnetosphere, enabling previously infeasible magnetospheric science. The PILOT mission concept, developed as a NASA-funded Heliophysics Mission Concept Study, is a potential Flagship-class NASA Heliophysics mission to be considered by the 2024–2033 Solar and Space Physics Decadal Survey. PILOT uses a constellation of 30 microsat spacecraft and 4 smallsat spacecraft in two highly-elliptical, equatorial Earth orbits to make high-resolution radio tomographic density maps of total plasma density in the equatorial plane, augmented by EUV imaging of ion plasma density and flows in the meridional plane, and in-situ measurements of electric and magnetic fields, plasma density, energetic particles, and ion composition. The comprehensive suite of measurements made by the PILOT constellation fully captures plasma mass dynamics and its impact on magnetospheric systems over an unprecedented range of spatial and temporal scales. Here we discuss the PILOT mission architecture, including instrument heritage, manufacturing strategy, concept of operations, and required technology development.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132700327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115657
C. Maldonado, A. J. Rogers, J. Steinberg, R. Skoug, S. Morley, Yue Chen, B. Larsen, G. Wilson, Keri A. Goorley, Sean L. Haley, J. Barney, M. Kroupa, P. Fernandes, R. Balthazor, John D. Williams, P. Neal, M. McHarg
The Falcon Solid-state Energetic Electron Detector (SEED) is a single element particle telescope designed to measure 14 to 145 keV electrons in geostationary Earth orbit. The instrument is designed to be a low-resource space weather sensor and utilizes commercial-off-the-shelf components to further reduce cost. The instrument is calibrated on-orbit against the Los Alamos National Laboratory Space Atmospheric Burst Report System plasma spectrometer co-located on the same STPSat-6 satellite, as well as electron measurements from NOAA GOES satellites.
{"title":"Initial Results for On-Orbit Calibration of the FalconSEED on-board STPSat-6","authors":"C. Maldonado, A. J. Rogers, J. Steinberg, R. Skoug, S. Morley, Yue Chen, B. Larsen, G. Wilson, Keri A. Goorley, Sean L. Haley, J. Barney, M. Kroupa, P. Fernandes, R. Balthazor, John D. Williams, P. Neal, M. McHarg","doi":"10.1109/AERO55745.2023.10115657","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115657","url":null,"abstract":"The Falcon Solid-state Energetic Electron Detector (SEED) is a single element particle telescope designed to measure 14 to 145 keV electrons in geostationary Earth orbit. The instrument is designed to be a low-resource space weather sensor and utilizes commercial-off-the-shelf components to further reduce cost. The instrument is calibrated on-orbit against the Los Alamos National Laboratory Space Atmospheric Burst Report System plasma spectrometer co-located on the same STPSat-6 satellite, as well as electron measurements from NOAA GOES satellites.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127654747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115836
E. Crues, Paul Bielski, Eddie Paddock, Cory D. Foreman, Brad Bell, Chris Raymond, Tanner Hunt, Denys Bulikhov
NASA's Artemis campaign is making heavy use of simulation to help return humans to the lunar surface by the end of the decade. There are several aspects of the lunar surface and its environment which must be accurately modeled before these simulations can be relied upon to influence decisions being made under these programs. Digital Lunar Exploration Sites, a paper submitted to the 2022 IEEE Aerospace Conference, outlined the process used to generate the lunar surface in a digital environment. This paper will expand upon this topic and delve into the steps being taken by the NASA Exploration Systems Simulations (NExSyS) team at NASA's Johnson Space Center (JSC) to properly verify and validate these simulations, with a focus on the visual aspects of the environment. Natural lighting validation relies in part on the wealth of data generated during the Apollo program. Many images taken by Apollo astronauts on the lunar surface have been replicated in the simulated environments to gain confidence in the accuracy of terrain and lighting models. However, because the environment the Artemis astronauts will experience at the Lunar South Pole (LSP) is dissimilar from the near-equatorial Apollo sites, other validation techniques must be applied. At the LSP, the sun crests only about 1.5 degrees above the horizon and when combined with the lack of a lunar atmosphere, lighting in this region is often very different than what a human would experience on Earth. Solar illumination, earthshine, human eye response, solar blooming, lunar regolith optical properties, and shadows cast by rocks and crater walls will play a significant role in an astronaut's ability to safely conduct an Extra-Vehicular Activity (EVA) or perform a traverse with a lunar rover. Approaches for validation of these aspects of the rendered LSP environment are considered in this paper. In addition to natural lighting, approaches for the validation of artificial lighting models at the LSP are discussed. The JSC Lighting Lab has been studying the illumination profile of the Exploration Informatics Subsystem (xINFO) lighting on the Exploration EVA Mobility Unit (xEMU). How these lights interact with the solar illumination and the shadows being cast on the lunar surface is of particular interest, so the validity of models representing these lights in a human-in-the-loop virtual reality environment becomes very important. This paper also touches on some of the simulation performance considerations when a Human in the Loop (HITL) is present, which drives the need for realtime rendering of the environment. Natural and artificial lighting will play a crucial role to decisions being made when planning and executing missions at the Lunar South Pole (LSP) and it is vitally important to understand the LSP environment before we return.
{"title":"Approaches for Validation of Lighting Environments in Realtime Lunar South Pole Simulations","authors":"E. Crues, Paul Bielski, Eddie Paddock, Cory D. Foreman, Brad Bell, Chris Raymond, Tanner Hunt, Denys Bulikhov","doi":"10.1109/AERO55745.2023.10115836","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115836","url":null,"abstract":"NASA's Artemis campaign is making heavy use of simulation to help return humans to the lunar surface by the end of the decade. There are several aspects of the lunar surface and its environment which must be accurately modeled before these simulations can be relied upon to influence decisions being made under these programs. Digital Lunar Exploration Sites, a paper submitted to the 2022 IEEE Aerospace Conference, outlined the process used to generate the lunar surface in a digital environment. This paper will expand upon this topic and delve into the steps being taken by the NASA Exploration Systems Simulations (NExSyS) team at NASA's Johnson Space Center (JSC) to properly verify and validate these simulations, with a focus on the visual aspects of the environment. Natural lighting validation relies in part on the wealth of data generated during the Apollo program. Many images taken by Apollo astronauts on the lunar surface have been replicated in the simulated environments to gain confidence in the accuracy of terrain and lighting models. However, because the environment the Artemis astronauts will experience at the Lunar South Pole (LSP) is dissimilar from the near-equatorial Apollo sites, other validation techniques must be applied. At the LSP, the sun crests only about 1.5 degrees above the horizon and when combined with the lack of a lunar atmosphere, lighting in this region is often very different than what a human would experience on Earth. Solar illumination, earthshine, human eye response, solar blooming, lunar regolith optical properties, and shadows cast by rocks and crater walls will play a significant role in an astronaut's ability to safely conduct an Extra-Vehicular Activity (EVA) or perform a traverse with a lunar rover. Approaches for validation of these aspects of the rendered LSP environment are considered in this paper. In addition to natural lighting, approaches for the validation of artificial lighting models at the LSP are discussed. The JSC Lighting Lab has been studying the illumination profile of the Exploration Informatics Subsystem (xINFO) lighting on the Exploration EVA Mobility Unit (xEMU). How these lights interact with the solar illumination and the shadows being cast on the lunar surface is of particular interest, so the validity of models representing these lights in a human-in-the-loop virtual reality environment becomes very important. This paper also touches on some of the simulation performance considerations when a Human in the Loop (HITL) is present, which drives the need for realtime rendering of the environment. Natural and artificial lighting will play a crucial role to decisions being made when planning and executing missions at the Lunar South Pole (LSP) and it is vitally important to understand the LSP environment before we return.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127855622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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