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NASA NTRS2020

SCExAO/CHARIS Near-infrared Integral Field Spectroscopy of the HD 15115 Debris Disk

We present new, near-infrared (1.1–2.4 μm) high-contrast imaging of the debris disk around HD 15115 with the Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) system coupled with the Coronagraphic High Angular Resolution Imaging Spectrograph (CHARIS). The SCExAO/CHARIS resolves the disk down to ρ ∼ 0."2 (r(proj) ∼ 10 au), a factor of ∼3–5 smaller than previous recent studies. We derive a disk position angle of PA ∼ 279.°4–280.°5 and an inclination of i ∼ 85.°3–86.2.°. While recent SPHERE/IRDIS imagery of the system could suggest a significantly misaligned two-ring disk geometry, CHARIS imagery does not reveal conclusive evidence for this hypothesis. Moreover, optimizing models of both one- and two-ring geometries using differential evolution, we find that a single ring having a Hong-like scattering phase function matches the data equally well within the CHARIS field of view (ρ ≲ 1''). The disk's asymmetry, well evidenced at larger separations, is also recovered; the west side of the disk appears, on average, around 0.4 mag brighter across the CHARIS bandpass between 0farcs25 and 1''. Comparing Space Telescope Imaging Spectrograph (STIS) 50CCD optical photometry (2000–10500 Å) with CHARIS near-infrared photometry, we find a red (STIS/50CCD−CHARIS broadband) color for both sides of the disk throughout the 0farcs4–1'' region of overlap, in contrast to the blue color reported at similar wavelengths for regions exterior to ∼2''. Further, this color may suggest a smaller minimum grain size than previously estimated at larger separations. Finally, we provide constraints on planetary companions and discuss possible mechanisms for the observed inner disk flux asymmetry and color.

Kellen Lawson↗

NASA NTRS2019

The Type II superluminous SN 2008es at late times: near-infrared excess and circumstellar interaction

SN 2008es is one of the rare cases of a Type II superluminous supernova (SLSN), showing no narrow features in its early-time spectra, and therefore, its powering mechanism is under debate between circumstellar interaction (CSI) and magnetar spin-down. Late-time data are required for better constraints. We present optical and near-infrared (NIR) photometry obtained from Gemini, Keck, and Palomar Observatories from 192 to 554 d after explosion. Only broad H α emission is detected in a Gemini spectrum at 288 d. The line profile exhibits red-wing attenuation relative to the early-time spectrum. In addition to the cooling SN photosphere, an NIR excess with blackbody temperature ∼1500 K and radius ∼1016 cm is observed. This evidence supports dust condensation in the cool dense shell being responsible for the spectral evolution and NIR excess. We favour CSI, with ∼2–3 Mꙩ of circumstellar material (CSM) and ∼10–20 Mꙩ of ejecta, as the powering mechanism, which still dominates at our late-time epochs. Both models of uniform density and steady wind fit the data equally well, with an effective CSM radius ∼1015 cm, supporting the efficient conversion of shock energy to radiation by CSI. A low amount (≲0.4 Mꙩ) of 56Ni is possible but cannot be verified yet, since the light curve is dominated by CSI. The magnetar spin-down powering mechanism cannot be ruled out, but is less favoured because it overpredicts the late-time fluxes and may be inconsistent with the presence of dust.

Kornpob Bhirombhakdi↗

NASA NTRS2021

Derivation of the final OSIRIS-REx OVIRS in-flight radiometric calibration

The OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS) operates over the ∼0.4- to 4.3-μm wavelength range. Radiometric calibration over this broad range requires the use of multiple calibration sources. Initial OVIRS in-flight calibration coefficients were previously computed using ground calibration from visible integrating sphere and IR blackbody sources, cross-calibrated with Earth-observing satellites for visible wavelengths, and adjusted using the spectrum of the OSIRIS-REx mission’s target body, asteroid (101955) Bennu. As part of the final in-flight calibration, we determined that the best calibration method removes out-of-band IR signal leakage prior to radiometric calibration and updated the calibration coefficients accordingly. These final calibration coefficients work well for data where the field of view is filled, and we document the possible artifacts in underfilled spots.

Amy A. Simon↗

NASA NTRSDate not supplied

Application of Low & Mid Fidelity Tools to the Moog SureFly Vehicle

The results from a comprehensive acoustic analysis using low- and mid-fidelity tools to predict the acoustic signature of the Moog SureFly® UAM vehicle are presented and compared to experimental ground test data taken in 2019. The data presented is taken from a ground plate microphone at a distance of just under 100 feet from the propeller source. Simulations were performed for a single propeller and a coaxial pair. Results indicate that the first few blade passing frequency (BPF) harmonics match the experimental data reasonably well using both low- and mid-fidelity prediction toolchains.

Acoustics↗

NASA NTRS2022

One Year in the Extreme Isolation of Antarctica—Is This Enough to Modulate an “Allergic” Sensitization?

(1) Background: After spending a year wintering in Antarctica, individual expedition members have reported increased or even new allergic reactions to environmental allergens after their return. (2) Methods: Blood samples from five overwintering crews were analyzed using the chip based multiplex ALEX Allergy Explorer (MacroArray Diagnostics GmbH, Austria). (3) Results: About one third of the 39 participants displayed specific IgEs against pollen. In most individuals, kinetics showed a reduction in the specific IgE at the time about nine months after deployment to Antarctica. Five participants had the highest specific IgE levels after returning to the “normal” world. The examination of the specific IgE relative to house dust mites and storage mites showed different kinetics. Six out of 10 had the highest specific IgE concentrations at the inner Antarctic measurement time point. These data corresponded well to the general situation in the stations. At the stations themselves, there were almost no pollen particle load, especially at Concordia. (4) Conclusions: Antarctic long-term confinement can induce an altered immune function, which is in some individuals pronounced after return to the familiar allergen environment. Future prospective studies in larger cohorts are needed to further specify these first results.

Matthias Feuerecker↗

NASA NTRSDate not supplied

Trace Element Partitioning in the Presence of Sulfur Under Reduced Conditions

Oxygen fugacity (fO2) plays an important role in thephysicochemical properties of that system because fO2 has asubstantial impact on the partitioning behavior between andsolubility of elements in various phases. The reduced nature ofMercury and the aubrite parent bodies (APB) have raised manyquestions regarding the geochemical behavior of typicallylithophile, heat-producing, and rare-earth elements (REE) inmagmas at low fO2. In fact, interpretations of magmaticprocesses on reduced rocky bodies are difficult at presentbecause of the small number of experimental studies relevant tothe extremely low fO2 and high sulfur content of Mercury andthe APB, and our only natural analogs are the highly reducedenstatite chondrites and aubrites [e.g., 1]. Preliminaryobservations suggest that major and minor elements exhibitdifferent geochemical affinities in highly reduced, S-richsystems compared to terrestrial rocks. The partitioning behavior of major, minor, and traceelements between silicate melt, sulfide melt, and metal underhighly reduced conditions will be determined in a suite of super-liquidus experiments at a range of pressures (1 bar to 4 GPa) atNASA Johnson Space Center (JSC). Based on previous studies,heat-producing elements U and Th become more chalcophile,while K becomes less chalcophile, with more reducingconditions [2]. The nominally lithophile elements Mg and Cabecoming more chalcophile and appear as minor elements in(Fe,Mg,Ca)-S with more reducing conditions [3]. Additionally, itappears that nominally siderophile elements become moresiderophile and chalcophile with more reducing conditions,although the partitioning behavior into Mg- and Ca-bearingsulfide melts, rather than FeS, is less understood. Current workis focused on investigating elements for which we currently haveMESSENGER data as well as a host of geochemically relevanttrace elements such as REE.

Brendan A Anzures↗

NASA NTRS2022

Boulder County Disasters: Mapping Forest Carbon Stocks to Understand Carbon Implications of Treatment and Wildfire

In recent years, record-breaking wildfire activities in the western US illustrate the need for fire mitigation efforts, such as forest fuels reduction treatments. Forests serve as crucial carbon sinks that combat the increasing effects of climate change while fuels reduction treatments may remove carbon from forested systems. As a result, forest managers need to find a balance between fire mitigation and carbon preservation. This project partnered with Boulder County Parks and Open Space (BCPOS) and the University of Colorado, Denver to investigate the 2020 Cal-Wood fire in Boulder County, Colorado. Using remote sensing data from Landsat 8 OLI, SRTM, Sentinel-2 MSI, and LiDAR, we mapped post-fire forest carbon pools and compared these values with values derived from measurements from plots on the ground. Results indicate that the correlations are R2=0.76 for aboveground live carbon, R2=0.44 for standing carbon, and R2=0.43 for aboveground dead carbon (R2=0.43), and R2=0.35 for total carbon (R2=0.35). Additionally, 38.5% of total carbon was stored in dead carbon and 14.4% was stored in live carbon. We next compared the post-fire pools between treated and untreated areas. Our analysis suggests fuels reduction treatments did not reduce carbon loss in the presence of wildfire enough to clearly distinguish the post-fire carbon in the treated and untreated areas. However, our final carbon maps still provide BCPOS and researchers with an opportunity to explore carbon estimation models based on remotely sensed data as well as a framework to evaluate fuels reduction treatment effectiveness and impact on forest carbon stocks for future wildfire events.

Sarah Hettema↗

NASA NTRSDate not supplied

Mining the Gravity Mutants of Arabidopsis

Gravity mutants are a valuable resource for understanding gravity perception, signaling, and response in plants. A review of 190 publications resulted in a list of 97 loci with mutations that caused a gravitropic phenotype. While all these mutants show some form of gravity phenotype, several are also generally defective in growth. After removing these nonspecific mutants, 76 loci were deemed to have true gravity mutants. The gene list was then used to create a sortable database containing key factors of gravity signaling as well as data on methodologies and the development of mutant lines. Indexing this database has allowed us to pull out trends that were not visible in individual publications. For example, mutants that are unable to rearrange starch statoliths make up a larger proportion of the described inflorescence stems mutants than any other organ. Comparing these statolith mutants across organs shows that root and inflorescence stems consistently display different phenotypes for the same class of defect. The more severe gravity defects are most commonly described in root tissue while other tissues are more likely to show only a delayed or reduced response to gravity. The experience of members of the GeneLab plant Analytics Working Group (AWG) in data visualization and gene mapping have sparked new ideas for utilizing this database. Knowledge of shared traits, mutant development, and growth can provide a new resource for the production of seed lines specialized for their response to gravity.

gravitropism↗

NASA NTRSDate not supplied

On the Equivalence of Gas and Liquid Leak Flow Rates for Application to Propulsion and Propellant Transfer Systems

The equivalence of leak rates for gas flow and liquid flow through an arbitrary small leak size in pressurized systems has been investigated theoretically and experimentally. Measurements were taken for gaseous helium (GHe) rates and water flow issuing from the same leak configuration. The predictions for the correlation of GHe leak rates to water leak rates have been satisfactorily compared with present test data and those of other investigators over a wide range leak flow rates (many orders of magnitude) corresponding to a wide range of leak sizes (0.1 m to 0.1 mm). The results show that at extremely small leak sizes (sub-micron range), the effects of Knudsen number in the free molecular regime (rarefied gases) become important. By a proper scaling procedure, the measured flow rate for water could be applied to equivalent propellant leaks in flight operations. In the present tests the micro-channel range of the leak size is satisfactorily simulated by repeatable precision set needle position valve. Test results show that in general the theoretical model predicts the data reasonably well for GHe flow rates in the range of 0.001 to 1 sccs. Outside this range of GHe flow rates some adjustments (improvements) to the analytical model are required along with further testing.

Max Kandula↗

NASA NTRSDate not supplied

Mapping Forest Carbon Stocks to Understand Carbon Implications of Treatment on Wildfire for the Calwood Fire, Boulder County Colorado

Recent, record-breaking wildfire activity in the western U.S. illustrates the need for fire mitigation, such as forest fuels reduction treatments. Forests serve as crucial carbon sinks that combat the increasing effects of climate change, but fuels reduction treatments may remove carbon from forested systems. As a result, forest managers need to find a balance between fire mitigation and carbon preservation. This project partnered with Boulder County Parks and Open Space (BCPOS) and the University of Colorado, Denver to investigate the 2020 Cal-Wood fire in Boulder County, Colorado. Using remote sensing data from Landsat 8 Operational Land Imager, Shuttle Radar Topography Mission, Sentinel-2 MultiSpectral Imagery, and LiDAR, we mapped post-fire forest carbon pools and compared these values with values derived from field measurements. The analysis suggested that fuels reduction treatments did not reduce carbon loss in the presence of wildfire enough to clearly distinguish post-fire carbon between treated and untreated areas. However, the final carbon maps provide BCPOS and researchers with an opportunity to explore carbon estimation models based on remote sensing data as well as a framework to evaluate fuels reduction treatment effectiveness and impact on forest carbon stocks for future wildfire events.

Sarah Hettema↗

NASA NTRSDate not supplied

Cosmic Ray Exposure Ages, Bulk and Isotopic H, C, and N Compositions of Dominion Range (DOM) CO3 Carbonaceous Chondrites and Implications for Pairing

Over 20 CO3 chondrites have been re-covered in the Dominion Range (DOM) dense collection area (DCA) of the Transantarctic Mountains by ANSMET (Antarctic Search for Meteorites) across 6 field seasons. Because of the significant masses involved and huge community interest in the most primitive samples of all carbonaceous chondrite classes such as the CO3s, we have undertaken a de-tailed assessment of the pairings and petrologic types using field relations, macroscopic observations, petrography, olivine compositions, and bulk and isotopic H, C, N compositions, and noble gas abundances and isotopes for cosmic ray exposure (CRE) ages, for all specimens. Most recently, teams during the 2018-19 and 2019-20 seasons recovered 10 new CO3 samples. Here we report new H, C, and N bulk and isotopic data, as well as CRE ages, for these 10 samples and DOM 10900 (which has some unique properties and may not be a CO chondrite). This completes the characterization of all known CO3s from DOM, allowing a thorough assessment of possible pairing relations.

chondrite↗

NASA NTRS2023

Numerical Study of Solidification Crack Susceptibility in Novel Refractory Alloy Systems

Calculation of Phase Diagrams (CALPHAD) -based solidification computations, such as Scheil or equilibrium computations, have been utilized to propose crack solidification susceptibility indices (CSSIs) of cracking. These CSSIs have been proposed in order to predict the cracking susceptibility of an alloy in the solidification range, as a function of its solidification fraction and as dependent upon its wt.% elemental composition through the CALPHAD computation & via comparative methods between one composition & the next. Recently Kou at al. have proposed a novel CSSI where the gradient of the e.x. Scheil solidification curve is obtained in the critical solidification cracking region of greater than 0.95 fraction of solid. Therefore, a direct Temperature dependent metric is now available for the prediction, and presumably the control, of solidification cracking. In this TM, the researchers apply this Kou gradient method to refractory alloys for the first time & discuss justification for the approach via Spearman rank correlation with Varestraint cracking test data as well as by comparisons with Thermocalc based vulnerability time CSSI calculations. A Python Pycalphad module example of the approach is provided & can be utilized as an open-source resource that utilizes also open-source available thermodynamical databases, making the CSSI quantitative aspect of ICME more available and freely available to practitioners.

ICME integrated computational materials engineerin↗

NASA NTRSDate not supplied

Development of the Mod II X-57 Piloted Simulator and Flying Qualities Predictions

This paper discusses the development of the X-57 Mod II piloted simulator along with the predicted flight dynamics of the airplane. The piloted simulator models were initially based on data published by Tecnam on a P2006T airplane but were further improved upon through parameter identification of flight data as well as modeling tools such as computational fluid dynamics. In addition to having accurate flight models, a realistic cockpit was constructed to aid pilot training. From the piloted simulator, an understanding of how the airplane will behave throughout the flight envelope using established FAR and MIL standards is discussed. Using the simulation results, this paper will show that the airplane is predicted to be statically and dynamically stable as well as having Level 1 flying qualities.

Ryan Wallace↗

NASA NTRS2022

Measuring, mapping, and anticipating climate gentrification in Florida: Miami and Tampa case studies

This article introduces an experimental methodology to identify proxy indicators that are conceptually consistent with the processes of Climate Gentrification (“CG”), in which a change in demand preferences among consumers and investors drives the increased consumption for real estate, in part, on lower measures of physical risk from climate change. Evaluated through case studies in the state of Florida, this article builds on the integration of multiple datasets concerning rental properties, evictions, and socioeconomic data, as well as environmental risk indices to build a Climate Gentrification Risk Index (CGRI). In the Miami case study, we find that the CGRI identifies a hotly contested neighborhood that is already known to be in a state of transition consistent with the processes of CG. In the Tampa case, the index highlights a district that exhibits strong metrics for the future accelerated occurrence of CG. Our findings suggest that transitional land uses and flexible zoning in low-exposure areas are key elements for attracting new development consistent with CG and offer insight into the challenges that local governments face understanding the types and rates of change that may be catalyzed in the broader urban processes of public and private sector climate adaptation in the built environment.

Climate change↗

NASA NTRS2024

Lunar Terrain Mapping Using 3D Software and Modeling Techniques for the Glenn Research Center Communication Analysis Suite

As NASA prepares to return humans to the Moon as part of upcoming Artemis missions, engineers must examine the surface features and safety of lunar terrain at various locations. The Glenn Research Center Communication Analysis Suite (GCAS) includes visualization tools developed to aid scientists in this quest to comprehend lunar terrain data, as well as spatial communication information. Visual information and understanding will be highly useful to engineers as they use the GCAS to compare the topography of regions of interest for the Artemis III and future space travel missions. Not only can three-dimensional (3D) visualization display the intricacies of the lunar terrain, but it can also demonstrate relationships such as the presence or absence of communication links between Earth ground stations, lunar crew members, and rovers, and the presence of shadows on the lunar surface. In the future, the GCAS has the potential to support the planning of other space exploration missions as well. The emerging possibility of incorporating more planetary bodies becomes especially important as NASA plans not only to return to the Moon but to press onward to Mars.

Visualization↗

NASA NTRS2024

Kankakee River Water Resources: Monitoring Temperature and Vegetation to Detect River Flow Impediments at Energy Intake Structures

The goal of this tutorial is to provide a comprehensive and accessible guide for detecting aquatic vegetation within the Kankakee River using Earth Observation data as well as pairing these observations with environmental trends monitoring. By offering step-by-step instructions and insights into the latest remote sensing technologies, this tutorial aims to equip readers with the knowledge and tools necessary to identify and track aquatic vegetation within a river extent of their choice.

Marisa Smedsrud↗

NASA NTRSDate not supplied

Flow Visualization for Plume-Surface Interaction at Martian-Relevant Lander Environments

This paper describes a jet impingement experiment performed in a large-scale vacuum chamber at Martian-relevant ambient pressure conditions, with the motivation of studying plume-surface interaction (PSI) caused by the exhaust plume of a lander interacting with the planetary surface. Flow visualization of an inert supersonic jet was performed using planar laser-induced fluorescence (PLIF), which is a molecular-based, two-dimensional measurement technique. Representative instantaneous and time-averaged visualizations of the impinging jet at two different nozzle flow conditions corresponding to the underexpanded and overexpanded jet regimes are presented for up to six different dimensionless altitudes h/De. The time-averaged measured spatial distribution of impingement pressures at these conditions is also reported. The PLIF visualizations appear to be critical towards explaining unexpected behavior in the impingement pressure, such as a higher impingement pressure for the underexpanded condition at h/De = 10, compared to a lower altitude of h/De = 8. This behavior can be attributed to differences in the stagnation shock structure observed in the PLIF images. The PLIF images also reveal significant flow separation at the nozzle exit for the overexpanded jet conditions. Further analysis of the test data as well as combined flow visualization and surface diagnostics for future ground tests will help inform engineering designs for landings on the Martian surface while mitigating PSI risks.

PLIF↗

NASA NTRSDate not supplied

Flow Visualization for Plume-Surface Interaction at Martian-Relevant Lander Environments

PLIF↗