The Experts below are selected from a list of 960 Experts worldwide ranked by ideXlab platform
Matthew J. Genge - One of the best experts on this subject based on the ideXlab platform.
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the origins of i type spherules and the atmospheric entry of iron Micrometeoroids
Meteoritics & Planetary Science, 2016Co-Authors: Matthew J. GengeAbstract:The Earth's extraterrestrial dust flux includes a wide variety of dust particles that include FeNi metallic grains. During their atmospheric entry iron Micrometeoroids melt and oxidize to form cosmic spherules termed I-type spherules. These particles are chemically resistant and readily collected by magnetic separation and are thus the most likely micrometeorites to be recovered from modern and ancient sediments. Understanding their behavior during atmospheric entry is crucial in constraining their abundance relative to other particle types and the nature of the zodiacal dust population at 1 AU. This article presents numerical simulations of the atmospheric entry heating of iron meteoroids to investigate the abundance and nature of these materials. The results indicate that iron Micrometeoroids experience peak temperatures 300–800 K higher than silicate particles explaining the rarity of unmelted iron particles which can only be present at sizes of <50 μm. The lower evaporation rates of liquid iron oxide leads to greater survival of iron particles compared with silicates, which enhances their abundance among micrometeorites by a factor of 2. The abundance of I-types is shown to be broadly consistent with the abundance and size of metal in ordinary chondrites and the current day flux of ordinary chondrite-derived MMs arriving at Earth. Furthermore, carbonaceous asteroids and cometary dust are suggested to make negligible contributions to the I-type spherule flux. Events involving such objects, therefore, cannot be recognized from I-type spherule abundances in the geological record.
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The Origins of I-type Spherules and the Atmospheric Entry of Iron Micrometeoroids.
'Wiley', 2016Co-Authors: Matthew J. GengeAbstract:The Earth's extraterrestrial dust flux includes a wide variety of dust particles that include FeNi metallic grains. During their atmospheric entry iron Micrometeoroids melt and oxidize to form cosmic spherules termed I-type spherules. These particles are chemically resistant and readily collected by magnetic separation and are thus the most likely micrometeorites to be recovered from modern and ancient sediments. Understanding their behavior during atmospheric entry is crucial in constraining their abundance relative to other particle types and the nature of the zodiacal dust population at 1 AU. This paper presents numerical simulations of the atmospheric entry heating of iron meteoroids in order to investigate the abundance and nature of these materials. The results indicate that iron Micrometeoroids experience peak temperatures 300-800K higher than silicate particles explaining the rarity of unmelted iron particles which can only be present at sizes of
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Thermal gradients in Micrometeoroids during atmospheric entry
Cospar Colloquia Series, 2007Co-Authors: Matthew J. Genge, Monica M. GradyAbstract:Melted rims found on micrometeorites recovered from Antarctic ice indicate thatMicrometeoroids as small as 50 μm in diameter can maintain temperature differences of at least 600 K between their surfaces and cores. We present the results of finite element simulations of the thermal evolution of Micrometeoroids during entry heating that indicate that large thermal gradients cannot arise simply as a result of the non-steady state heating of particles. The generation of thermal gradients resulting in melted rims may occur in fine-grained micrometeorites due to energy losses at the melt-core boundary due to the endothermic decomposition of volatile-bearing phases. However, the occurrence of melted rims on many coarse-grained particles that lack such low-temperature phases suggests this is not the primary cause of the temperature differences. Large mass losses due to vaporisation and energy losses due to fusion may therefore be involved in the generation of melted rims. The presence of thermal gradients in Micrometeoroids during atmospheric entry increases the likelihood that low-temperature primary phases such as abiotic carbonaceous compounds will survive atmospheric entry heating.
David J. Loftus - One of the best experts on this subject based on the ideXlab platform.
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hypervelocity impact performance of biopolymer bound soil composites for space construction
Journal of Aerospace Engineering, 2020Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, Joshua E Miller, David J. LoftusAbstract:AbstractEstablishing a lunar base requires the design and construction of infrastructure that can withstand the Moon’s hazardous environment. This study explores the effects of micrometeoroid impac...
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hypervelocity impact performance of biopolymer bound soil composites for space construction
Journal of Aerospace Engineering, 2020Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, J.e. Miller, David J. LoftusAbstract:AbstractEstablishing a lunar base requires the design and construction of infrastructure that can withstand the Moon’s hazardous environment. This study explores the effects of micrometeoroid impac...
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prediction of micrometeoroid damage to lunar construction materials using numerical modeling of hypervelocity impact events
International Journal of Impact Engineering, 2019Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, J.e. Miller, David J. LoftusAbstract:Abstract The use of Lunar regolith for the creation of construction materials to build habitats and other infrastructure required for a Lunar base is an example of in situ resource utilization (ISRU), an important strategy for minimizing the launch mass associated with a NASA mission to the Moon. One class of solidified regolith, Biopolymer-bound Soil Composites (BSC), consists of regolith mixed with a small amount of biopolymer binding agent (10% w/w). This paper characterizes BSC's micrometeoroid impact performance using experimental and numerical methods. Micrometeoroids are a notable hazard of the Lunar environment and pose a challenging design consideration. A total of 17 hypervelocity impact experiments were conducted on BSC targets at NASA's White Sands Testing Facility. Numerical simulations of the hypervelocity impact experiments were carried out using CTH, a shock physics code developed by Sandia National Laboratories. Comparisons between the experimental craters and the simulation results indicate that there is good agreement between crater dimensions of the hypervelocity impact experiments and the CTH model. The CTH model developed in this paper provides (1) a damage prediction tool that allows for the necessary extrapolation of micrometeoroid impact velocities beyond what is experimentally achievable and into the velocity regime that is relevant for Micrometeoroids and (2) a material design tool that is capable of varying material parameters computationally, ultimately allowing for the engineering and optimization of BSC's performance under impact loading.
James Ira Thorpe - One of the best experts on this subject based on the ideXlab platform.
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Micrometeoroid Events in LISA Pathfinder
The Astrophysical Journal, 2019Co-Authors: James Ira Thorpe, Tyson Littenberg, John G. Baker, J. Slutsky, Sophie Hourihane, Nicole Pagane, Petr Pokorny, Diego Janches, Michele Armano, H. AudleyAbstract:The zodiacal dust complex, a population of dust and small particles that pervades the Solar System, provides important insight into the formation and dynamics of planets, comets, asteroids, and other bodies. Here we present a new set of data obtained using a novel technique: direct measurements of momentum transfer to a spacecraft from individual particle impacts. This technique is made possible by the extreme precision of the instruments flown on the LISA Pathfinder spacecraft, a technology demonstrator for a future space-based gravitational wave observatory that operated near the first Sun-Earth Lagrange point from early 2016 through Summer of 2017. Using a simple model of the impacts and knowledge of the control system, we show that it is possible to detect impacts and measure properties such as the transferred momentum (related to the particle's mass and velocity), direction of travel, and location of impact on the spacecraft. In this paper, we present the results of a systematic search for impacts during 4348 hours of Pathfinder data. We report a total of 54 candidates with momenta ranging from 0.2$\,\mu\textrm{Ns}$ to 230$\,\mu\textrm{Ns}$. We furthermore make a comparison of these candidates with models of micrometeoroid populations in the inner solar system including those resulting from Jupiter-family comets, Oort-cloud comets, Hailey-type comets, and Asteroids. We find that our measured population is consistent with a population dominated by Jupiter-family comets with some evidence for a smaller contribution from Hailey-type comets. This is in agreement with consensus models of the zodiacal dust complex in the momentum range sampled by LISA Pathfinder.
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micrometeoroid events in lisa pathfinder
The Astrophysical Journal, 2019Co-Authors: James Ira Thorpe, Tyson Littenberg, John G. Baker, J. Slutsky, Sophie Hourihane, Nicole Pagane, Petr PokornyAbstract:The zodiacal dust complex, a population of dust and small particles that pervades the solar system, provides important insight into the formation and dynamics of planets, comets, asteroids, and other bodies. We present a new set of data obtained from direct measurements of momentum transfer to a spacecraft from individual particle impacts. This technique is made possible by the extreme precision of the instruments flown on the LISA Pathfinder spacecraft, a technology demonstrator for a future space-based gravitational wave observatory. Pathfinder employed a technique known as drag-free control that achieved rejection of external disturbances, including particle impacts, using a micropropulsion system. Using a simple model of the impacts and knowledge of the control system, we show that it is possible to detect impacts and measure properties such as the transferred momentum, direction of travel, and location of impact on the spacecraft. In this paper, we present the results of a systematic search for impacts during 4348 hr of Pathfinder data. We report a total of 54 candidates with transferred momenta ranging from 0.2 to 230 μNs. We furthermore make a comparison of these candidates with models of micrometeoroid populations in the inner solar system, including those resulting from Jupiter-family comets (JFCs), Oort Cloud comets, Halley-type comets, and asteroids. We find that our measured population is consistent with a population dominated by JFCs, with some evidence for a smaller contribution from Halley-type comets, in agreement with consensus models of the zodiacal dust complex in the momentum range sampled by LISA Pathfinder.
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Detection and Characterization of Micrometeoroids with LISA Pathfinder
Astronomy & Astrophysics, 2016Co-Authors: James Ira Thorpe, Cameron Parvini, Josep M. Trigo-rodríguezAbstract:The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. In this paper, we describe an approach for using the LISA Pathfinder (LPF) mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launching in late 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as $4\times 10^{-8}\,\textrm{N}\cdot\textrm{s}$. We then estimate the rate of such impulses resulting from impacts of Micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses $> 10^{-9}\,$g during LPF's roughly six-month science operations phase in a $5\times 10^5\,\textrm{km}$ by $8\times 10^5\,\textrm{km}$ Lissajous orbit around L1. In addition, we estimate the ability of LPF to characterize individual impacts by measuring quantities such as total momentum transferred, direction of impact, and location of impact on the spacecraft. Information on flux and direction provided by LPF may provide insight as to the nature and origin of the individual impact and help constrain models of the interplanetary dust complex in general. Additionally, this direct in-situ measurement of micrometeoroid impacts will be valuable to designers of future spacecraft targeting the environment around L1.
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Detection and measurement of Micrometeoroids with LISA Pathfinder
EDP Sciences, 2016Co-Authors: James Ira Thorpe, Cameron Parvini, Josep M. Trigo-rodríguezAbstract:The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. In this paper, we describe an approach for using the LISA Pathfinder (LPF) mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launched on Dec. 3rd, 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as 4 × 10-8 N s. We then estimate the rate of such impulses resulting from impacts of Micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses >10-9g during LPF’s roughly six-month science operations phase in a 5 × 105 km by 8 × 105 km Lissajous orbit around L1. In addition, we estimate the ability of LPF to characterize individual impacts by measuring quantities such as total momentum transferred, direction of impact, and location of impact on the spacecraft. Information on flux and direction provided by LPF may provide insight as to the nature and origin of the individual impact and help constrain models of the interplanetary dust complex in general. Additionally, this direct in situ measurement of micrometeoroid impacts will be valuable to designers of future spacecraft targeting the environment around L1
Sophie Hourihane - One of the best experts on this subject based on the ideXlab platform.
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Micrometeoroid Events in LISA Pathfinder
The Astrophysical Journal, 2019Co-Authors: James Ira Thorpe, Tyson Littenberg, John G. Baker, J. Slutsky, Sophie Hourihane, Nicole Pagane, Petr Pokorny, Diego Janches, Michele Armano, H. AudleyAbstract:The zodiacal dust complex, a population of dust and small particles that pervades the Solar System, provides important insight into the formation and dynamics of planets, comets, asteroids, and other bodies. Here we present a new set of data obtained using a novel technique: direct measurements of momentum transfer to a spacecraft from individual particle impacts. This technique is made possible by the extreme precision of the instruments flown on the LISA Pathfinder spacecraft, a technology demonstrator for a future space-based gravitational wave observatory that operated near the first Sun-Earth Lagrange point from early 2016 through Summer of 2017. Using a simple model of the impacts and knowledge of the control system, we show that it is possible to detect impacts and measure properties such as the transferred momentum (related to the particle's mass and velocity), direction of travel, and location of impact on the spacecraft. In this paper, we present the results of a systematic search for impacts during 4348 hours of Pathfinder data. We report a total of 54 candidates with momenta ranging from 0.2$\,\mu\textrm{Ns}$ to 230$\,\mu\textrm{Ns}$. We furthermore make a comparison of these candidates with models of micrometeoroid populations in the inner solar system including those resulting from Jupiter-family comets, Oort-cloud comets, Hailey-type comets, and Asteroids. We find that our measured population is consistent with a population dominated by Jupiter-family comets with some evidence for a smaller contribution from Hailey-type comets. This is in agreement with consensus models of the zodiacal dust complex in the momentum range sampled by LISA Pathfinder.
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micrometeoroid events in lisa pathfinder
The Astrophysical Journal, 2019Co-Authors: James Ira Thorpe, Tyson Littenberg, John G. Baker, J. Slutsky, Sophie Hourihane, Nicole Pagane, Petr PokornyAbstract:The zodiacal dust complex, a population of dust and small particles that pervades the solar system, provides important insight into the formation and dynamics of planets, comets, asteroids, and other bodies. We present a new set of data obtained from direct measurements of momentum transfer to a spacecraft from individual particle impacts. This technique is made possible by the extreme precision of the instruments flown on the LISA Pathfinder spacecraft, a technology demonstrator for a future space-based gravitational wave observatory. Pathfinder employed a technique known as drag-free control that achieved rejection of external disturbances, including particle impacts, using a micropropulsion system. Using a simple model of the impacts and knowledge of the control system, we show that it is possible to detect impacts and measure properties such as the transferred momentum, direction of travel, and location of impact on the spacecraft. In this paper, we present the results of a systematic search for impacts during 4348 hr of Pathfinder data. We report a total of 54 candidates with transferred momenta ranging from 0.2 to 230 μNs. We furthermore make a comparison of these candidates with models of micrometeoroid populations in the inner solar system, including those resulting from Jupiter-family comets (JFCs), Oort Cloud comets, Halley-type comets, and asteroids. We find that our measured population is consistent with a population dominated by JFCs, with some evidence for a smaller contribution from Halley-type comets, in agreement with consensus models of the zodiacal dust complex in the momentum range sampled by LISA Pathfinder.
Maria I Allende - One of the best experts on this subject based on the ideXlab platform.
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hypervelocity impact performance of biopolymer bound soil composites for space construction
Journal of Aerospace Engineering, 2020Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, Joshua E Miller, David J. LoftusAbstract:AbstractEstablishing a lunar base requires the design and construction of infrastructure that can withstand the Moon’s hazardous environment. This study explores the effects of micrometeoroid impac...
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hypervelocity impact performance of biopolymer bound soil composites for space construction
Journal of Aerospace Engineering, 2020Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, J.e. Miller, David J. LoftusAbstract:AbstractEstablishing a lunar base requires the design and construction of infrastructure that can withstand the Moon’s hazardous environment. This study explores the effects of micrometeoroid impac...
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prediction of micrometeoroid damage to lunar construction materials using numerical modeling of hypervelocity impact events
International Journal of Impact Engineering, 2019Co-Authors: Maria I Allende, Alan B Davis, Eric L. Christiansen, Michael D Lepech, J.e. Miller, David J. LoftusAbstract:Abstract The use of Lunar regolith for the creation of construction materials to build habitats and other infrastructure required for a Lunar base is an example of in situ resource utilization (ISRU), an important strategy for minimizing the launch mass associated with a NASA mission to the Moon. One class of solidified regolith, Biopolymer-bound Soil Composites (BSC), consists of regolith mixed with a small amount of biopolymer binding agent (10% w/w). This paper characterizes BSC's micrometeoroid impact performance using experimental and numerical methods. Micrometeoroids are a notable hazard of the Lunar environment and pose a challenging design consideration. A total of 17 hypervelocity impact experiments were conducted on BSC targets at NASA's White Sands Testing Facility. Numerical simulations of the hypervelocity impact experiments were carried out using CTH, a shock physics code developed by Sandia National Laboratories. Comparisons between the experimental craters and the simulation results indicate that there is good agreement between crater dimensions of the hypervelocity impact experiments and the CTH model. The CTH model developed in this paper provides (1) a damage prediction tool that allows for the necessary extrapolation of micrometeoroid impact velocities beyond what is experimentally achievable and into the velocity regime that is relevant for Micrometeoroids and (2) a material design tool that is capable of varying material parameters computationally, ultimately allowing for the engineering and optimization of BSC's performance under impact loading.