Mallory E. DeCoster
A5076022692- Astro and Planetary Science
- Planetary Science and Exploration
- Space Satellite Systems and Control
- Conducting polymers and applications
- Organic Electronics and Photovoltaics
- Thermal properties of materials
- High-Velocity Impact and Material Behavior
- High-pressure geophysics and materials
- Advanced Thermoelectric Materials and Devices
- Machine Learning in Materials Science
- Metal-Organic Frameworks: Synthesis and Applications
- Spectroscopy and Chemometric Analyses
- Perovskite Materials and Applications
- Remote-Sensing Image Classification
- Electromagnetic Launch and Propulsion Technology
- Geological and Geochemical Analysis
- Transition Metal Oxide Nanomaterials
- Covalent Organic Framework Applications
- Advanced Chemical Sensor Technologies
- Transportation Safety and Impact Analysis
- Electronic and Structural Properties of Oxides
- Phase Equilibria and Thermodynamics
- Stellar, planetary, and galactic studies
- Thermal Radiation and Cooling Technologies
- Spectroscopy Techniques in Biomedical and Chemical Research
Johns Hopkins University Applied Physics Laboratory
2015-2025
Johns Hopkins University
2022-2024
University of Virginia
2017-2022
Arizona State University
2021
Abstract Although no known asteroid poses a threat to Earth for at least the next century, catalogue of near-Earth asteroids is incomplete objects whose impacts would produce regional devastation 1,2 . Several approaches have been proposed potentially prevent an impact with by deflecting or disrupting 1–3 A test kinetic technology was identified as highest-priority space mission related mitigation 1 NASA’s Double Asteroid Redirection Test (DART) full-scale technology. The mission’s target...
Abstract The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of binary (65803) Didymos, at 23:14 UTC 26 September 2022 as planetary defence test 1 . DART was first hypervelocity experiment an size and velocity scales relevant to defence, intended validate means deflection. Here we report determination momentum transferred by impact. On basis change in orbit period 2 , find instantaneous reduction Dimorphos’s along-track...
Abstract Whether the presence of adsorbates increases or decreases thermal conductivity in metal-organic frameworks (MOFs) has been an open question. Here we report observations transport framework HKUST-1 various liquid adsorbates: water, methanol, and ethanol. Experimental thermoreflectance measurements were performed on single crystals thin films, theoretical predictions made using molecular dynamics simulations. We find that by 40 – 80% depending adsorbate, a result cannot be explained...
Abstract NASA's Double Asteroid Redirection Test (DART) mission was the first to demonstrate asteroid deflection, and mission's Level 1 requirements guided its planetary defense investigations. Here, we summarize DART's achievement of those requirements. On 2022 September 26, DART spacecraft impacted Dimorphos, secondary member Didymos near-Earth binary system, demonstrating an autonomously navigated kinetic impact into with limited prior knowledge for defense. Months subsequent Earth-based...
Air-stable and soluble tetrabutylammonium fluoride (TBAF) is demonstrated as an efficient n-type dopant for the conjugated polymer ClBDPPV. Electron transfer from F- anions to π-electron-deficient ClBDPPV through anion-π electronic interactions strongly corroborated by combined results of electron spin resonance, UV-vis-NIR, ultraviolet photoelectron spectroscopy. Doping with 25 mol% TBAF boosts electrical conductivity up 0.62 S cm-1 , among highest conductivities that have been reported...
Four p-type polymers were synthesized by modifying poly(bisdodecylquaterthiophene) (PQT12) to increase oxidizability p-dopants. A sulfur atom is inserted between the thiophene rings and dodecyl chains, and/or 3,4-ethylenedioxy groups are appended of PQT12. Doped with NOBF4, PQTS12 (with in side chains) shows a conductivity 350 S cm-1, highest reported nonionic among films made from dopant-polymer solutions. tetrafluorotetracyanoquinodimethane (F4TCNQ), PDTDE12 on rings) 140 cm-1. The...
Abstract The Double Asteroid Redirection Test (DART) spacecraft will impact into the asteroid Dimorphos on 2022 September 26 as a test of kinetic impactor technique for planetary defense. efficiency deflection following can be represented using momentum enhancement factor, β , which is dependent factors such geometry and specific target material properties. Currently, very little known about its properties, introduces uncertainty in results observables, including crater formation, ejecta...
The DART spacecraft will impact Didymos's secondary, Dimorphos, at the end of 2022 and cause a change in orbital period secondary. For simplicity, most previous numerical simulations used spherical projectile geometry to model spacecraft. To investigate effects alternative, simple geometries on outcome we iSALE shock physics code two thee-dimensions vertical impacts projectiles with mass speed equivalent nominal impact, into porous basalt targets. We found that investigated here have minimal...
We experimentally and theoretically investigate the thermal conductivity mechanical properties of polycrystalline HKUST-1 metal-organic frameworks (MOFs) infiltrated with three guest molecules: tetracyanoquinodimethane (TCNQ), 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ), (cyclohexane-1,4-diylidene)dimalononitrile (H4-TCNQ). This allows for modification interaction strength between host, presenting an opportunity to study fundamental atomic scale mechanisms how molecules...
Abstract The Double Asteroid Redirection Test (DART) mission impacted Dimorphos, the moonlet of binary asteroid 65803 Didymos, on 2022 September 26 and successfully tested a kinetic impactor as an deflection technique. success was partly due to momentum excavated ejecta material, which provided extra push change Dimorphos’s orbital period. Preimpact images constraints surface but not subsurface morphology Dimorphos. DART observations indicated that Dimorphos contained boulder-strewn surface,...
We present two new polythiophene isomers, PQTC16-TT and PQTSC16-TT, with more separation lower side chain density on the backbone compared typical polythiophenes, such as PQT(S)12 PBTTT(S)12. The introduction of spacer subunits to separate chains improves accommodation dopant molecules close polymer backbone. Therefore, lamellar structure π–π stacking polymers were negligibly disturbed by dopants; in fact, improved ordering closer π-stacking observed after chemical doping. Furthermore,...
Abstract NASA’s Double Asteroid Redirection Test (DART) is the first full-scale test of an asteroid deflection technology. Results from hypervelocity kinetic impact and Earth-based observations, coupled with LICIACube later Hera mission, will result in measurement momentum transfer efficiency accurate to ∼10% characterization Didymos binary system. But DART a single experiment; how could these results be used future planetary defense necessity involving different asteroid? We examine what...
Abstract On 2022 September 26, the Double Asteroid Redirection Test (DART) spacecraft intentionally collided with Dimorphos, moon of binary asteroid system 65803 Didymos. This collision provided first full-scale test a kinetic impactor for planetary defense. Images from DART’s DRACO camera revealed Dimorphos to be an oblate spheroid covered in boulders varying sizes and shapes. Very little was known about prior impact, including its shape, structure, material properties. Approach...
Abstract The DART (Double Asteroid Redirection Test) mission will impact a spacecraft on the secondary (Dimorphos) of binary asteroid system Didymos in 2022 September, with goal altering orbital period Dimorphos about sufficiently to be observed from ground-based observations. Numerical modeling is crucial component understanding outcome experiment, and while many have investigated effects target properties, such as material strength porosity (which remain unknown), an often overlooked...
Abstract This work studies the thermal conductivity and phonon scattering processes in a series of n‐type lead telluride‐lead selenide (PbTe–PbSe) nanostructured thin films grown by atomic layer deposition (ALD). The ALD growth PbTe–PbSe samples this results nonepitaxial directly on native oxide/Si substrates, where Volmer–Weber mode promotes grains with preferred columnar orientation. these lead‐rich PbTe, PbSe, secondary oxide phases, along an increase microstructural quality increased...
Abstract Understanding how to deflect an incoming asteroid is of great importance and a focus research undertaken internationally by the planetary defense community. Deflection kinetic impactor one such mitigation method that has high degree technological maturity. In 2022, NASA’s mission, Double Asteroid Redirection Test (DART), will provide first full-scale technology demonstration impactor. However, DART mission just single test design, prompting question: Is it possible optimize design...
<title>Abstract</title> Kinetic deflection is a planetary defense technique that delivers spacecraft momentum to small body deviate its course from Earth. The efficiency depends strongly on the impactor and target. Among them, contribution of global curvature was poorly understood. ejecta plume created by NASA's DART impact target asteroid, Dimorphos, exhibited an elliptical shape almost aligned along north-south direction. Here, we identify this resulted target’s curvature, reducing...
Abstract The NASA Double Asteroid Redirection Test (DART) mission performed a kinetic impact on asteroid Dimorphos, the satellite of binary (65803) Didymos, at 23:14 UTC September 26, 2022 as planetary defense test 1 . DART was first hypervelocity experiment an size and velocity scales relevant to defense, intended validate means deflection. Here we report determination momentum transferred by impact. Based change in orbit period 2 , find instantaneous reduction Dimorphos’s along-track...
Abstract Rubble pile asteroids consist of reassembled fragments once larger monolithic asteroid parent bodies. Recent spacecraft missions to like Itokawa, Ryugu, Bennu, and Dimorphos suggest that rubble are common in the population, piles could be a likely structure among potentially hazardous objects. Therefore, it is important understand response targets kinetic impacts for potential future deflection needs. The recent Double Asteroid Redirection Test (DART) mission motivates an...
View Video Presentation: https://doi.org/10.2514/6.2023-1118.vid Recent decades have seen increased interest in the Moon and cislunar operations. To ensure safety of flight peace operations domain, space traffic management is required, which, turn, necessitates a dedicated situational awareness (SSA) system. However, SSA domain notoriously difficult to achieve due inherently large volume chaotic nature orbits regime. These characteristics produce challenges establishing persistent monitoring...
A concerted national effort to establish a modeling pipeline, with standardized, well-defined interfaces at every step, would make the USA better equipped assess and mitigate global Near-Earth Object (NEO) impact threats, having coherent unified among US response will facilitate clearer international communication collaboration (e.g., Yang et al., 2020).The creation of database organize retain simulation results relevant variety potential threats enable timely analysis future hazards, deeper...
Linear unmixing is a method of decomposing mixed signature to determine the component materials that are present in sensor's field view, along with abundances at which they occur. assumes energy from view linear fashion across spectrum interest. Traditional methods can take advantage adjacent pixels decomposition algorithm, but not case for point sensors. This paper explores several iterative and non-iterative unmixing, examines their effectiveness identifying individual signatures make up...
In the spectral science community, numerous signatures are stored in databases representative of many sample materials collected from a variety spectrometers and spectroscopists. Due to variability spectra that comprise databases, it is necessary establish metric for validating quality signatures. This has been an area great discussion debate community. paper discusses method independently validates two different aspects signature arrive at final qualitative assessment; textual meta-data...