Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115599
Kyle Logue
A complex-valued autoencoder neural network ca-pable of compressing & denoising radio frequency signals with arbitrary model scaling is proposed. Complex-valued time sam-ples received with various impairments are encoded into an embedding vector, then decoded back into complex-valued time samples. The embedding and the related latent space allow search, comparison, and clustering of signals. Traditional signal processing tasks like specific emitter identification, geolocation, or ambiguity estimation can utilize multiple compressed embed-dings simultaneously. This paper demonstrates an autoencoder implementation capable of compression by a factor of 64 that is still resilient against RF channel impairments. The autoencoder allows individual scaling by network depth, width, and resolution or in a compound sense to target both embedded and data center deployments. The common building block is inspired by the fused inverted residual block (Fused-MBConv), popularized by EfficientNetV2 & MobileNetV3, but with kernel sizes more appropriate for time-series signal processing. A complex-valued PyTorch implementation is available along with a pre-trained model, at https://github.com/the-aerospace-corporation/glaucus.
{"title":"Glaucus: A Complex-Valued Radio Signal Autoencoder","authors":"Kyle Logue","doi":"10.1109/AERO55745.2023.10115599","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115599","url":null,"abstract":"A complex-valued autoencoder neural network ca-pable of compressing & denoising radio frequency signals with arbitrary model scaling is proposed. Complex-valued time sam-ples received with various impairments are encoded into an embedding vector, then decoded back into complex-valued time samples. The embedding and the related latent space allow search, comparison, and clustering of signals. Traditional signal processing tasks like specific emitter identification, geolocation, or ambiguity estimation can utilize multiple compressed embed-dings simultaneously. This paper demonstrates an autoencoder implementation capable of compression by a factor of 64 that is still resilient against RF channel impairments. The autoencoder allows individual scaling by network depth, width, and resolution or in a compound sense to target both embedded and data center deployments. The common building block is inspired by the fused inverted residual block (Fused-MBConv), popularized by EfficientNetV2 & MobileNetV3, but with kernel sizes more appropriate for time-series signal processing. A complex-valued PyTorch implementation is available along with a pre-trained model, at https://github.com/the-aerospace-corporation/glaucus.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"218 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":"134000500","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/AERO55745.2023.10115807
Viktor Langofer, Ralph Bayer, A. Kolb, Kaname Sasaki
The advent of exploring low-gravity environments gives the opportunity to land rovers on celestial bodies without any landing platform and perform manipulative tasks under mostly unknown conditions. In addition to common loads, for example vibration, operation and thermal loads, the rover will face also impact loads during touchdown. This circumstance re-quires additional mechanisms to protect exposed parts, like the legs and wheels of a rover. Previous research attaches the wheels to the rover body or the landing platform through cup-cone interfaces at the wheel hub, which leads to unfavorable force distribution at the wheel rim in certain load cases, especially if the wheel represents the first point of contact during touchdown. This paper gives a detailed description in the mechanical design and testing of the locomotion subsystem (LSS) of the Martian Moons eXploration (MMX) rover. As the rover will fall to the moon Phobos unprotected and without any landing platform, the exposed locomotion subsystem has a high probability of being the initial contact point at touchdown. Besides the driv-etrains and thermal hardware, a novel hold down and release mechanism (HDRM) will be introduced as an integral part of the locomotion subsystem. The HDRM is realized using three support structures at the wheel rim and one fixation in the wheel axis. In this way, the exposed locomotion subsystem will be stabilized in described load cases, since each support structure forms a closed kinematic loop with the wheel and the central fixation in stowed configuration. This approach leads to vibration and impact resistant behavior.
{"title":"MMX Locomotion Subsystem: mechanics for extraterrestrial low gravity drive","authors":"Viktor Langofer, Ralph Bayer, A. Kolb, Kaname Sasaki","doi":"10.1109/AERO55745.2023.10115807","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115807","url":null,"abstract":"The advent of exploring low-gravity environments gives the opportunity to land rovers on celestial bodies without any landing platform and perform manipulative tasks under mostly unknown conditions. In addition to common loads, for example vibration, operation and thermal loads, the rover will face also impact loads during touchdown. This circumstance re-quires additional mechanisms to protect exposed parts, like the legs and wheels of a rover. Previous research attaches the wheels to the rover body or the landing platform through cup-cone interfaces at the wheel hub, which leads to unfavorable force distribution at the wheel rim in certain load cases, especially if the wheel represents the first point of contact during touchdown. This paper gives a detailed description in the mechanical design and testing of the locomotion subsystem (LSS) of the Martian Moons eXploration (MMX) rover. As the rover will fall to the moon Phobos unprotected and without any landing platform, the exposed locomotion subsystem has a high probability of being the initial contact point at touchdown. Besides the driv-etrains and thermal hardware, a novel hold down and release mechanism (HDRM) will be introduced as an integral part of the locomotion subsystem. The HDRM is realized using three support structures at the wheel rim and one fixation in the wheel axis. In this way, the exposed locomotion subsystem will be stabilized in described load cases, since each support structure forms a closed kinematic loop with the wheel and the central fixation in stowed configuration. This approach leads to vibration and impact resistant behavior.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"130 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":"132210165","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/AERO55745.2023.10115733
Daniel Muradás, F. Nieto, S. Hernández
The last years have witnessed a number of initiatives aimed to generate feasible designs of aircraft able to fly above the speed of sound. Some correspond to projects in the USA, and others are being developed in Europe, with prototypes designed for missions reaching up to Mach 8 speed. Hypersonic Test Bed (HTB) vehicles are an important part in the definition of new supersonic aircraft as they allow to study geometries, propulsion systems and mission performance, among other considerations, that are of utmost importance in aircraft design. This work addresses the research done adopting a HTB prototype of a vehicle aimed to fly up to Mach 5, with a propulsion system consisting of an experimental air-breathing engine situated on the top of the fuselage, and a rear rocket. The main dimensions of the considered aircraft are the following: a total length of 24.53 m, and a wing span of 8.89 m. The work carried out included high-fidelity CFD simulations using RANS techniques, aimed to identify the aerodynamic characteristics and generate a database that contains the relevant properties along a complete mission. The special configuration of the aircraft required previous studies in order to identify the proper boundary conditions at the inlet and outlet of the air-breathing engine. They included pressure value and mass flow conditions. That issue required a campaign of preliminary simulations using 2D and 3D models that helped in identifying the solution to the problems. Afterwards, the computer simulations were worked out using 3D conformal meshes with more than 15 million polyhedral elements. In the numerical models, compressible fluid was considered, as well as the two-equation $k$ - $w$ SST turbulence model. Special care was taken in the definition of the boundary layer mesh in the most sensitive locations of the geometry. The CFD simulations required relevant computing resources, so the calculations were completed in a HPC cluster, using 64 cores and allocating 180 GB of RAM memory for each run. The study provided the aerodynamic properties of the HTB for a range of aircraft speeds from Mach 0.4 to Mach 2.0.
{"title":"CFD Simulations of an Experimental Hypersonic Test Bed Aircraft in Subsonic and Supersonic Regime","authors":"Daniel Muradás, F. Nieto, S. Hernández","doi":"10.1109/AERO55745.2023.10115733","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115733","url":null,"abstract":"The last years have witnessed a number of initiatives aimed to generate feasible designs of aircraft able to fly above the speed of sound. Some correspond to projects in the USA, and others are being developed in Europe, with prototypes designed for missions reaching up to Mach 8 speed. Hypersonic Test Bed (HTB) vehicles are an important part in the definition of new supersonic aircraft as they allow to study geometries, propulsion systems and mission performance, among other considerations, that are of utmost importance in aircraft design. This work addresses the research done adopting a HTB prototype of a vehicle aimed to fly up to Mach 5, with a propulsion system consisting of an experimental air-breathing engine situated on the top of the fuselage, and a rear rocket. The main dimensions of the considered aircraft are the following: a total length of 24.53 m, and a wing span of 8.89 m. The work carried out included high-fidelity CFD simulations using RANS techniques, aimed to identify the aerodynamic characteristics and generate a database that contains the relevant properties along a complete mission. The special configuration of the aircraft required previous studies in order to identify the proper boundary conditions at the inlet and outlet of the air-breathing engine. They included pressure value and mass flow conditions. That issue required a campaign of preliminary simulations using 2D and 3D models that helped in identifying the solution to the problems. Afterwards, the computer simulations were worked out using 3D conformal meshes with more than 15 million polyhedral elements. In the numerical models, compressible fluid was considered, as well as the two-equation $k$ - $w$ SST turbulence model. Special care was taken in the definition of the boundary layer mesh in the most sensitive locations of the geometry. The CFD simulations required relevant computing resources, so the calculations were completed in a HPC cluster, using 64 cores and allocating 180 GB of RAM memory for each run. The study provided the aerodynamic properties of the HTB for a range of aircraft speeds from Mach 0.4 to Mach 2.0.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"7 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":"134201183","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/AERO55745.2023.10115694
Patrick D. Maley, Alan M. Hubbard, Jude M. Urban, L. Hook
General aviation, the mode of air travel typified by small personal aircraft, accounts for roughly 19 of every 20 fatalities every year in the US. However, recent technological solutions are becoming available which may bring the total number of fatalities in general aviation down considerably. Potentially the most effective of these solutions is the Ground Collision Avoidance System or GCAS. GCAS avoids ground collision in a large number of cases: pilot error, disorientation, and temporary incapacitation. However, GCAS does not yet exist for general aviation, despite it being a field that would widely benefit from it's implementation. In response to this reality, GCAS development for general aviation has begun. This paper describes the design and verification of a GCAS controller on a simulated Cessna 172 aircraft. The GCAS controller provides the ability for the aircraft to automatically avoid ter-rain and is an important step in the initial phases of GCAS design. Considerations for the design of the controller's lateral and longitudinal axes are provided along with discussions on the overall controller structure. Controller modes and limiters have been designed and described to ensure safe operation of the controller, along with considerations for transient switching effects. Analysis of controller response along with verification of mode and limiter operation are provided. Finally, a comparison between the trajectory generated by the GCAS controller and one predicted by the GCAS system are included. With these sections, this paper provides important considerations on the initial stages of GCAS design for general aviation, and the beginning of safety assurance for GA.
{"title":"Recovery Autopilot Analysis for a General Aviation Ground Collision Avoidance System","authors":"Patrick D. Maley, Alan M. Hubbard, Jude M. Urban, L. Hook","doi":"10.1109/AERO55745.2023.10115694","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115694","url":null,"abstract":"General aviation, the mode of air travel typified by small personal aircraft, accounts for roughly 19 of every 20 fatalities every year in the US. However, recent technological solutions are becoming available which may bring the total number of fatalities in general aviation down considerably. Potentially the most effective of these solutions is the Ground Collision Avoidance System or GCAS. GCAS avoids ground collision in a large number of cases: pilot error, disorientation, and temporary incapacitation. However, GCAS does not yet exist for general aviation, despite it being a field that would widely benefit from it's implementation. In response to this reality, GCAS development for general aviation has begun. This paper describes the design and verification of a GCAS controller on a simulated Cessna 172 aircraft. The GCAS controller provides the ability for the aircraft to automatically avoid ter-rain and is an important step in the initial phases of GCAS design. Considerations for the design of the controller's lateral and longitudinal axes are provided along with discussions on the overall controller structure. Controller modes and limiters have been designed and described to ensure safe operation of the controller, along with considerations for transient switching effects. Analysis of controller response along with verification of mode and limiter operation are provided. Finally, a comparison between the trajectory generated by the GCAS controller and one predicted by the GCAS system are included. With these sections, this paper provides important considerations on the initial stages of GCAS design for general aviation, and the beginning of safety assurance for GA.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"195 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":"134312088","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/AERO55745.2023.10115660
J. Velazco
This paper discusses the development of an omnidirectional optical terminal (OOT) that will provide fast connectivity and navigation information to small spacecraft forming a swarm or a constellation in cislunar space. The cislunar OOT operates at 1550nm, employs a dodecahedron body holding 6 optical telescopes and 20 external arrays of detectors for angle-of-arrival determination. The cislunar OOT will provide full sky (4π steradian) coverage and gigabit connectivity among smallsats forming a swarm or constellation (e.g., LunaNet). The OOT will also provide continuous positional information among these spacecraft including bearing, elevation, and range. We also envision the OOT to provide fast low-latency connectivity to assets on the surface of the moon such as landers, rovers, instruments, and astronauts. In this paper we will present results of a thorough study of the cislunar OOT architecture including key factors that affect angular accuracy and available ranging techniques suitable for accurate range calculation. We also present design details that will lead to successful OOT prototype construction and testing. We believe that, once fully developed, the OOT will provide commercial, high data rate connectivity and navigation to future scientific, military, and commercial missions around cislunar space and beyond.
{"title":"Cislunar Omnidirectional Optical Terminal for Fast Connectivity and Accurate Navigation","authors":"J. Velazco","doi":"10.1109/AERO55745.2023.10115660","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115660","url":null,"abstract":"This paper discusses the development of an omnidirectional optical terminal (OOT) that will provide fast connectivity and navigation information to small spacecraft forming a swarm or a constellation in cislunar space. The cislunar OOT operates at 1550nm, employs a dodecahedron body holding 6 optical telescopes and 20 external arrays of detectors for angle-of-arrival determination. The cislunar OOT will provide full sky (4π steradian) coverage and gigabit connectivity among smallsats forming a swarm or constellation (e.g., LunaNet). The OOT will also provide continuous positional information among these spacecraft including bearing, elevation, and range. We also envision the OOT to provide fast low-latency connectivity to assets on the surface of the moon such as landers, rovers, instruments, and astronauts. In this paper we will present results of a thorough study of the cislunar OOT architecture including key factors that affect angular accuracy and available ranging techniques suitable for accurate range calculation. We also present design details that will lead to successful OOT prototype construction and testing. We believe that, once fully developed, the OOT will provide commercial, high data rate connectivity and navigation to future scientific, military, and commercial missions around cislunar space and beyond.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"584 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":"134189913","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/AERO55745.2023.10115586
Hrudayavani S Vellore, R. Galvan-Garza, A. Diaz-Artiles
Future human aerospace systems will consist of a complex integration of multiple technologies, including Artificial Intelligence (AI) driven autonomy. We expect autonomous systems to support and augment human performance, especially when humans are experiencing physiological or cognitive decrements in operational scenarios. To accomplish this, we need the ability to identify these human performance decrements in different individuals and in different mission contexts (e.g., varying g-levels, acceleration profiles). Factors such as sex, weight, and height can alter physiological response to various stressors. Therefore, accounting for these differences is essential to build effective autonomous systems in these operational contexts. Computational models and algorithms that drive our human assessment systems are rooted in theory but also need realistic data for testing and evaluation. While there is a basic understanding of expected changes in physiology under varying stressors, available data are largely lab-based and sparse. However, experimentally determining the response of each individual in a large variety of mission contexts is prohibitively expensive and time-consuming. Thus, future human assessment algorithm development efforts would substantially benefit from simulated, representative datasets created through configurable human models. We will build on prior cardiovascular, metabolic, and other modeling work to create a physiological model tailorable to specific operational mission contexts and personalized input parameters. In particular, we have implemented a 21-compartment lumped-parameter model to simulate physiological responses of a 50th percentile female and a 50th percentile male during a parabolic flight maneuver. The modeled individuals were differentiated by anthropometric and total blood volume data based on U.S. Army personnel. Results of the simulations highlight and quantify the differences in physiological responses between the two individuals when exposed to the same parabolic fight maneuver. Differences between the male and female models were greatest during hypergravity for almost all parameters except for Stroke Volume (SV), which presented the greatest differences between the two individuals during the transition between hypergravity and 1g. Our preliminary modeling effort demonstrates that differences exist in the cardiovascular response between two simulated, anthropometrically different individuals during a parabolic flight maneuver. In addition, those physiological differences are dependent on the magnitude of the gravity level. These results support and further justify the need for individualized modeling.
{"title":"Computational Modeling of Individual Differences in Cardiovascular Response during Parabolic Flight","authors":"Hrudayavani S Vellore, R. Galvan-Garza, A. Diaz-Artiles","doi":"10.1109/AERO55745.2023.10115586","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115586","url":null,"abstract":"Future human aerospace systems will consist of a complex integration of multiple technologies, including Artificial Intelligence (AI) driven autonomy. We expect autonomous systems to support and augment human performance, especially when humans are experiencing physiological or cognitive decrements in operational scenarios. To accomplish this, we need the ability to identify these human performance decrements in different individuals and in different mission contexts (e.g., varying g-levels, acceleration profiles). Factors such as sex, weight, and height can alter physiological response to various stressors. Therefore, accounting for these differences is essential to build effective autonomous systems in these operational contexts. Computational models and algorithms that drive our human assessment systems are rooted in theory but also need realistic data for testing and evaluation. While there is a basic understanding of expected changes in physiology under varying stressors, available data are largely lab-based and sparse. However, experimentally determining the response of each individual in a large variety of mission contexts is prohibitively expensive and time-consuming. Thus, future human assessment algorithm development efforts would substantially benefit from simulated, representative datasets created through configurable human models. We will build on prior cardiovascular, metabolic, and other modeling work to create a physiological model tailorable to specific operational mission contexts and personalized input parameters. In particular, we have implemented a 21-compartment lumped-parameter model to simulate physiological responses of a 50th percentile female and a 50th percentile male during a parabolic flight maneuver. The modeled individuals were differentiated by anthropometric and total blood volume data based on U.S. Army personnel. Results of the simulations highlight and quantify the differences in physiological responses between the two individuals when exposed to the same parabolic fight maneuver. Differences between the male and female models were greatest during hypergravity for almost all parameters except for Stroke Volume (SV), which presented the greatest differences between the two individuals during the transition between hypergravity and 1g. Our preliminary modeling effort demonstrates that differences exist in the cardiovascular response between two simulated, anthropometrically different individuals during a parabolic flight maneuver. In addition, those physiological differences are dependent on the magnitude of the gravity level. These results support and further justify the need for individualized modeling.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"35 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":"133104191","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/AERO55745.2023.10115561
A. Aziz, Shawki A. Saad, M. Mostafa, Ahmed S. Shalaby
In multitarget tracking, measurement correlation uncertainty occurs when remote sensors, such as radars, yield measurements whose origin is uncertain. Using incorrect measurements in multitarget tracking systems leads to tracks loss. In such cases, efficient measurement correlation methods are needed to select measurements from many to be used to update the target tracks of interest in the tracking systems. This paper proposes a measurement correlation approach for multitarget tracking in a noisy environment. In this approach, measurements-to-targets correlation is computed across all targets and measurements based on minimization of weighted total squared errors. For a given track, the measurement that has the maximum correlation is used for updating the target track. The proposed correlation approach is applied to a scenario of multitarget tracking system and performance comparison with other correlation approaches is also presented. The results showed that performance improvement in terms of correct measurements correlation is achieved.
{"title":"A Measurement Correlation Approach for Multitarget Tracking in a Noisy Environment","authors":"A. Aziz, Shawki A. Saad, M. Mostafa, Ahmed S. Shalaby","doi":"10.1109/AERO55745.2023.10115561","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115561","url":null,"abstract":"In multitarget tracking, measurement correlation uncertainty occurs when remote sensors, such as radars, yield measurements whose origin is uncertain. Using incorrect measurements in multitarget tracking systems leads to tracks loss. In such cases, efficient measurement correlation methods are needed to select measurements from many to be used to update the target tracks of interest in the tracking systems. This paper proposes a measurement correlation approach for multitarget tracking in a noisy environment. In this approach, measurements-to-targets correlation is computed across all targets and measurements based on minimization of weighted total squared errors. For a given track, the measurement that has the maximum correlation is used for updating the target track. The proposed correlation approach is applied to a scenario of multitarget tracking system and performance comparison with other correlation approaches is also presented. The results showed that performance improvement in terms of correct measurements correlation is achieved.","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":"134096370","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/AERO55745.2023.10115552
Andrew Choate, D. Harris, T. Nickens, Paul D. Kessler, M. Simon
As NASA prepares for the next human footsteps on the lunar surface, the Agency is already looking ahead to systems that will enable a sustained human presence on the lunar surface and mission to Mars, including a lunar Surface Habitat (SH) and Mars Transit Habitat (TH). This paper describes the latest NASA government reference design for the TH and how it will support NASA's Moon to Mars human exploration architecture. First, it will serve as a test and demonstration platform in lunar orbit, demonstrating capabilities required for long-duration microgravity human spaceflight as part of the lunar-Mars analog missions. Then, the TH will serve as a major Mars exploration element to support crew habitation during their transit from the Earth's orbit to Mars and returning safely before TH's return to a lunar orbit. This paper will cover several considerations contributing to the latest habitat design refinement, including the TH's concept of operations, system functional definition, subsystem assumptions, notional interior layouts, a detailed mass and volume breakdown, and identify future trade studies and analyses required to close identified technology/ development/architecture gaps. In addition to a technical description of the TH, this paper describes how the current TH government reference design will achieve many of the current lunar and Mars mission goals. Additionally, there are many assumed technological advances needed to support the prescribed mission phases leading up to the crewed mission to Mars in the late 2030s. The paper will describe many of the TH systems requiring further technology development and identify architectural solutions to achieve these mass, reliability, autonomy, and crew health targets. As a whole, the data shows the government reference TH design meeting the 26.4 metric ton launch /trans-Mars injection burn control mass limit outlined within NASA's Moon to Mars Campaign. This is achievable near the desired timeframe with moderate strategic investments including maintainable life support systems, innovative structures configuration and materials, and system/ logistics packaging. The resulting design detail and data contained in this paper are intended to help teams across NASA and potential commercial, academic, or international partners understand the current performance targets of the Transit Habitat and vehicle interface considerations imposed by the latest Moon to Mars mission scope.
{"title":"NASA's Moon to Mars (M2M) Transit Habitat Refinement Point of Departure Design","authors":"Andrew Choate, D. Harris, T. Nickens, Paul D. Kessler, M. Simon","doi":"10.1109/AERO55745.2023.10115552","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115552","url":null,"abstract":"As NASA prepares for the next human footsteps on the lunar surface, the Agency is already looking ahead to systems that will enable a sustained human presence on the lunar surface and mission to Mars, including a lunar Surface Habitat (SH) and Mars Transit Habitat (TH). This paper describes the latest NASA government reference design for the TH and how it will support NASA's Moon to Mars human exploration architecture. First, it will serve as a test and demonstration platform in lunar orbit, demonstrating capabilities required for long-duration microgravity human spaceflight as part of the lunar-Mars analog missions. Then, the TH will serve as a major Mars exploration element to support crew habitation during their transit from the Earth's orbit to Mars and returning safely before TH's return to a lunar orbit. This paper will cover several considerations contributing to the latest habitat design refinement, including the TH's concept of operations, system functional definition, subsystem assumptions, notional interior layouts, a detailed mass and volume breakdown, and identify future trade studies and analyses required to close identified technology/ development/architecture gaps. In addition to a technical description of the TH, this paper describes how the current TH government reference design will achieve many of the current lunar and Mars mission goals. Additionally, there are many assumed technological advances needed to support the prescribed mission phases leading up to the crewed mission to Mars in the late 2030s. The paper will describe many of the TH systems requiring further technology development and identify architectural solutions to achieve these mass, reliability, autonomy, and crew health targets. As a whole, the data shows the government reference TH design meeting the 26.4 metric ton launch /trans-Mars injection burn control mass limit outlined within NASA's Moon to Mars Campaign. This is achievable near the desired timeframe with moderate strategic investments including maintainable life support systems, innovative structures configuration and materials, and system/ logistics packaging. The resulting design detail and data contained in this paper are intended to help teams across NASA and potential commercial, academic, or international partners understand the current performance targets of the Transit Habitat and vehicle interface considerations imposed by the latest Moon to Mars mission scope.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"10 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":"115592378","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/AERO55745.2023.10115800
Qian Shi, W. Tsutsui, I. Walter, Jitesh H. Panchal, D. DeLaurentis
The space industry has seen promising advancements in additive manufacturing (AM) technologies, including the production of rocket engines and spacecraft components. Nevertheless, AM adoption decisions are still complex due to the many considerations, uncertainties, and stakeholders involved. This paper proposes and demonstrates a decision support framework – including a utility theory-based decision engine that was developed in-house – to support users in evaluating AM-use options. The key decision attributes (i.e., performance, cost, and time) of a space satellite bracket assembly were identified through a requirements definition process. Utility functions representing different decision-maker risk preferences were defined based on relevant spacecraft operating conditions. Attribute data for machine-material pair options were also quantified using data sheets, AM cost, and build-time models. The utility functions, attribute values, and attribute weights were input to the decision engine software for a machine-material pair recommendation. A sensitivity analysis was conducted by varying the utility functions, attribute weights, build volume, and applying “hard constraints”. The results demonstrated the versatility and applicability of the decision framework and engine in tackling AM machine-material pair selection problems, including for the satellite design and manufacturing use case.
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Pub Date : 2023-03-04DOI: 10.1109/AERO55745.2023.10115752
T. Royster, Jun Sun, A. Narula-Tam, T. Shake
Low-earth-orbit satellite constellations with hundreds to thousands of satellites are emerging as practical alternatives for providing various types of data services such as global networking and large-scale sensing. The network performance of these satellite constellations is strongly dependent on the topology of the inter-satellite links (ISLs) in such systems. This paper studies the effects of six different ISL topologies, coupled with three configurations of ground relay terminals, on path failure rate, path latency, and link transmission efficiency in an example highly-inclined Walker Delta constellation with 360 satellites. These network performance parameters are calculated in the presence of satellite failures in the constellation. Trade-offs between ISL connection density and overall performance are examined and quantified. Topologies with 4 active ISLs per satellite are shown to perform significantly better than topologies requiring fewer, especially as the average number of active ISLs per satellite becomes significantly less than three. Latencies for a topology requiring 3 active ISLs per satellite are shown to be between 15 and 60 % higher than for a 4- ISL reference topology. Path availabilities for the 3- ISL topology are shown to be on the order of 30 % lower for a benchmark case of 10 satellite failures. The performance of near-minimal topologies (e.g., an average of 2.2 active ISLs per satellite) is much worse. Latency reductions of 10-30% and path failure rate improvements on the order of 45 % are shown to be obtainable by the inclusion of 2 to 5 strategically located ground relay stations. 11DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. This material is based upon work supported by the Defense Advanced Research Projects Agency under Air Force Contract No. FA8702-15-D-0001. The views, opinions and/or findings expressed are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.
拥有数百至数千颗卫星的低地球轨道卫星星座正在成为提供各种类型数据服务(如全球联网和大规模传感)的实际替代方案。这些卫星星座的网络性能强烈依赖于这些系统中卫星间链路(isl)的拓扑结构。以360颗高倾斜Walker Delta星座为例，研究了六种不同ISL拓扑结构和三种地面中继终端配置对路径故障率、路径延迟和链路传输效率的影响。这些网络性能参数是在星座中存在卫星故障的情况下计算的。ISL连接密度和整体性能之间的权衡进行了检查和量化。每颗卫星有4个活动isl的拓扑比需要更少活动isl的拓扑表现得好得多，特别是当每颗卫星的活动isl的平均数量明显少于3个时。每颗卫星需要3个活动ISL的拓扑的延迟比4个ISL参考拓扑高15%到60%。对于10颗卫星故障的基准情况，3- ISL拓扑的路径可用性显示为低30%左右。接近最小拓扑(例如，每颗卫星平均有2.2个有效isl)的性能要差得多。通过包含2至5个战略位置的地面中继站，可以将延迟减少10-30%，并将路径故障率提高45%。A.批准公开发行。分发是无限的。这份材料是基于美国空军合同第5号国防高级研究计划局支持的工作。fa8702 - 15 d - 0001。所表达的观点、意见和/或调查结果仅代表作者的观点，不应被解释为代表国防部或美国政府的官方观点或政策。
{"title":"Network Performance of pLEO Topologies in a High-Inclination Walker Delta Satellite Constellation","authors":"T. Royster, Jun Sun, A. Narula-Tam, T. Shake","doi":"10.1109/AERO55745.2023.10115752","DOIUrl":"https://doi.org/10.1109/AERO55745.2023.10115752","url":null,"abstract":"Low-earth-orbit satellite constellations with hundreds to thousands of satellites are emerging as practical alternatives for providing various types of data services such as global networking and large-scale sensing. The network performance of these satellite constellations is strongly dependent on the topology of the inter-satellite links (ISLs) in such systems. This paper studies the effects of six different ISL topologies, coupled with three configurations of ground relay terminals, on path failure rate, path latency, and link transmission efficiency in an example highly-inclined Walker Delta constellation with 360 satellites. These network performance parameters are calculated in the presence of satellite failures in the constellation. Trade-offs between ISL connection density and overall performance are examined and quantified. Topologies with 4 active ISLs per satellite are shown to perform significantly better than topologies requiring fewer, especially as the average number of active ISLs per satellite becomes significantly less than three. Latencies for a topology requiring 3 active ISLs per satellite are shown to be between 15 and 60 % higher than for a 4- ISL reference topology. Path availabilities for the 3- ISL topology are shown to be on the order of 30 % lower for a benchmark case of 10 satellite failures. The performance of near-minimal topologies (e.g., an average of 2.2 active ISLs per satellite) is much worse. Latency reductions of 10-30% and path failure rate improvements on the order of 45 % are shown to be obtainable by the inclusion of 2 to 5 strategically located ground relay stations. 11DISTRIBUTION STATEMENT A. Approved for public release. Distribution is unlimited. This material is based upon work supported by the Defense Advanced Research Projects Agency under Air Force Contract No. FA8702-15-D-0001. The views, opinions and/or findings expressed are those of the authors and should not be interpreted as representing the official views or policies of the Department of Defense or the U.S. Government.","PeriodicalId":344285,"journal":{"name":"2023 IEEE Aerospace Conference","volume":"62 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":"114396900","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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