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At least 1,153 records · Page 64
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Cometary Dust: The Diversity of Primitive Matter

The connections between comet dust and primitive chondrites from asteroids has strengthened considerably over the past decade. Understanding the importance of the connections between Stardust samples and chondrites requires geochemistry lingo as well as a perspective of other cometary dust samples besides Stardust. We present the principal findings of an extensive review prepared for by us for the June 2016 "Cometary Science After Rosetta" meeting at The Royal Society, London.

asteroids↗
NASA NTRS2017

The Diverse Data, User Driven Services and the Power of Giovanni at NASA GES DISC

This presentation provides an overview of remote sensing and model data at GES (Goddard Earth Sciences) DISC (Data and Information Services Center); Overview of data services at GES DISC (Registration with NASA data system; Searching and downloading data); Giovanni (Geospatial Interactive Online VisualizationANd aNalysis Infrastructure): online data exploration tool; and NASA Earth Data and Information System.

model↗
NASA NTRS2017

Surveying Clay Mineral Diversity in the Murray Formation, Gale Crater, Mars

The CheMin XRD instrument aboard Mars Science Laboratory (MSL) has documented clay minerals in various drill samples during its traverse of Gale Crater's floor and ascent of Mt. Sharp. The most recent samples, named Marimba, Quela and Sebina were acquired from the Murray Formation in the Murray Buttes region of lower Mt. Sharp. Marimba and Quela come from a approx. 30 m package of finely laminated lacustrine mudstones. Sebina comes from an overlying package of heterolithic mudstone-sandstones. Clay minerals make up approx.15-25 wt.% of the bulk rock with similar contributions to XRD patterns in all three samples. Broad basal reflections at approx. 10deg 2(theta) CoK(alpha) indicate the presence of 2:1 group clay minerals. The 02(lambda) clay mineral band lies at approx. 22.9deg 2(theta), a region typically occupied by Fe-bearing dioctahedral 2:1 clay minerals like nontronite or Fe-illite. The low humidity within the CheMin instrument, which is open to the martian atmosphere, promotes loss of interlayer H2O and collapse of smectite interlayers making them difficult to distinguish from illites. However, based on the low K content of the bulk samples, it appears that smectitic clay minerals are dominant. Peak dehydroxylation of the Marimba sample measured by the SAM instrument on MSL occurred at 610C and 780C. Fe-bearing smectites are not consistent with these dehydroxylation temperatures. Thus, we suggest that a mixture of dioctahedral and trioctahedral smectite phases are present giving the appearance of intermediate octahedral occupancy in XRD. Dioctahedral smectites have not previously been reported in Gale Crater by MSL. Earlier in the mission, relatively clay mineral rich samples (approx. 20 wt.%) from lacustrine mudstones in Yellowknife Bay (YKB) were found to contain ferrian saponites. It is proposed that YKB saponites formed via isochemical aqueous alteration of detrital olivine close to the time of sediment deposition, under anoxic to poorly oxidizing conditions. In terrestrial settings where alteration sequences of basaltic rocks or sediments are observed, first-stage alteration clay minerals are typically trioctahedral smectite species, as reported from YKB. In later alteration stages trioctahedral clay minerals are replaced by dioctahedral clays as a result of removal and/or oxidation of Fe2+ and Mg. Observed changes in clay mineralogy between YKB and Murray Buttes samples correspond with differences in bulk mineralogy, including: 1) a transition from magnetite to hematite as the main Fe-oxide, 2) increasing abundances of Ca-sulfates and 3) a reduction in the quantity of reactive mafic minerals. This mineralogical change indicates an increasing degree of aqueous alteration and oxidation of mafic detritus in the upper part of the Murray Formation. These results broaden the spectrum of mineralogical facies documented by MSL. Together sedimentology and mineralogy indicate a long-lasting, dynamic fluvial-lacustrine system encompassing a range aqueous geochemical processes under varying redox conditions. Future work is needed to unravel the influence of global and local controls on the range of ancient conditions observed at Gale Crater.

MSL↗
NASA NTRS2016

In Situ Air Temperature and Humidity Measurements Over Diverse Land Covers in Greenbelt, Maryland, November 2013-November 2015

As our climate changes through time there is an ever-increasing need to quantify how and where it is changing so that mitigation strategies can be implemented. Urban areas have a disproportionate amount of warming due, in part, to the conductive properties of concrete and asphalt surfaces, surface albedo, heat capacity, lack of water, etc. that make up an urban environment. The NASA Climate Adaptation Science Investigation working group at Goddard Space Flight Center in Greenbelt, MD, conducted a study to collect temperature and humidity data at 15 min intervals from 12 sites at the center. These sites represent the major surface types at the center: asphalt, building roof, grass field, forest, and rain garden. The data show a strong distinction in the thermal properties of these surfaces at the center and the difference between the average values for the center compared to a local meteorological station. The data have been submitted to Oak Ridge National Laboratory Distributed Active Archive Center (ORNL-DAAC) for archival in comma separated value (csv) file format (Carroll et al.,2016) and can be found by following this link: http:daac.ornl.govcgi-bindsviewer.pl?ds_id1319.

Carroll, Mark L.↗
NASA NTRS2017

Evolved-Lithology Clasts in Lunar Breccias: Relating Petrogenetic Diversity to Measured Water Content

Studies of the inventory and distribution of water in lunar rocks have recently begun to focus on alkali suite samples as possible water repositories, particularly the most highly evolved granitoid lithologies. Although H analyses of feldspars in these rocks have so far pointed to 'low' (less than 20 ppm) H2O contents, there is sufficient variability in the dataset (e.g., 2-20 ppm) to warrant consideration of the petrogenetic factors that may have caused some granitoid-to-intermediate rocks to be dryer or wetter than others. Given that all examples of these rocks occur as clasts in complex impact breccias, the role of impact and other factors in altering water contents established by primary igneous processes becomes a major factor. We are supporting our ongoing SIMS studies of water in evolved lunar lithologies with systematic SEM and EPMA observations. Here we report a synthesis of the observations as part of developing discriminating factors for reconstructing the thermal, crystallization and shock history of these samples as compared with their water contents.

Christoffersen, R.↗
NASA NTRS2017

Hyper-Spectral Communications, Networking and ATM as Foundation for Safe and Efficient Future Flight: Transcending Aviation Operational Limitations with Diverse and Secure Multi-Band, Multi-Mode, and mmWave Wireless Links: Project Overview, Aviation Communications and New Signaling

NASA's Aeronautics Research Mission Directorate (ARMD) has recently solicited proposals and awarded funds for research and development to achieve and exceed the goals envisioned in the ARMD Strategic Implementation Plan (SIP). The Hyper-Spectral Communications and Networking for Air Traffic Management (ATM) (HSCNA) project is the only University Leadership Initiative (ULI) program to address communications and networking (and to a degree, navigation and surveillance). This paper will provide an overview of the HSCNA project, and specifically describe two of the project's technical challenges: comprehensive aviation communications and networking assessment, and proposed multi-band and multimode communications and networking. The primary goals will be described, as will be research and development aimed to achieve and exceed these goals. Some example initial results are also provided.

aeronautics↗
NASA NTRS2017

Diverse Long-Term Variability of Five Candidate High-Mass X-Ray Binaries from Swift Burst Alert Telescope Observations

We present an investigation of long-term modulation in the X-ray light curves of five little-studied candidate high-mass X-ray binaries using the Swift Burst Alert Telescope (SWIFT-BAT). IGR J14488-5942 and AX J1700.2-4220 show strong modulation at periods of 49.6 and 44 days, respectively, which are interpreted as orbital periods of Be star systems. For IGR J14488-5942, observations with the Swift X-ray Telescope show a hint of pulsations at 33.4 seconds. For AX J1700.2-4220, 54 second-pulsations were previously found with XMM-Newton. Swift J1816.7-1613 exhibits complicated behavior. The strongest peak in the power spectrum is at a period near 150 days, but this conflicts with a determination of a period of 118.5 days by La Parola et al. AX J1820.5-1434 has been proposed to exhibit modulation near 54 days, but the extended BAT observations suggest modulation at slightly longer than double this at approximately 111 days. There appears to be a long-term change in the shape of the modulation near 111 days, which may explain the apparent discrepancy. The X-ray pulsar XTE J1906+090,which was previously proposed to be a Be star system with an orbital period of approximately 30 days from pulse timing, shows peaks in the power spectrum at 81 and 173 days. The origins of these periods are unclear, although theymight be the orbital period and a superorbital period respectively. For all five sources, the long-term variability, together with the combination of orbital and proposed pulse periods, suggests that the sources contain Be starmass donors.

Corbet, Robin H. D.↗
NASA NTRS2017

Comparison of Two Bioinformatics Tools Used to Characterize the Microbial Diversity and Predictive Functional Attributes of Microbial Mats from Lake Obersee, Antarctica

In this study, using NextGen sequencing of the collective 16S rRNA genes obtained from two sets of samples collected from Lake Obersee, Antarctica, we compared and contrasted two bioinformatics tools, PICRUSt and Tax4Fun. We then developed an R script to assess the taxonomic and predictive functional profiles of the microbial communities within the samples. Taxa such as Pseudoxanthomonas, Planctomycetaceae, Cyanobacteria Subsection III, Nitrosomonadaceae, Leptothrix, and Rhodobacter were exclusively identified by Tax4Fun that uses SILVA database; whereas PICRUSt that uses Greengenes database uniquely identified Pirellulaceae, Gemmatimonadetes A1-B1, Pseudanabaena, Salinibacterium and Sinibacteraceae. Predictive functional profiling of the microbial communities using Tax4Fun and PICRUSt separately revealed common metabolic capabilities, while also showing specific functional IDs not shared between the two approaches. Combining these functional predictions using a customized R script revealed a more inclusive metabolic profile, such as hydrolases, oxidoreductases, transferases; enzymes involved in carbohydrate and amino acid metabolisms; and membrane transport proteins known for nutrient uptake from the surrounding environment. Our results present the first molecular-phylogenetic characterization and predictive functional profiles of the microbial mat communities in Lake Obersee, while demonstrating the efficacy of combining both the taxonomic assignment information and functional IDs using the R script created in this study for a more streamlined evaluation of predictive functional profiles of microbial communities.

Hyunmin Koo↗
NASA NTRS2018

RFID Reader Antenna with Multi-Linear Polarization Diversity

This paper describes an RFID reader antenna that offers reduced polarization loss compared to that typically associated with reader-tag communications involving arbitrary relative orientation of the reader antenna and the tag.

Fink, Patrick↗
NASA NTRS2018

A Flexible Control Center Architecture for Support of Diverse Spaceflight Missions

The Ames Multi-Mission Operations Center (MMOC) enables and supports flight and science operations for Ames' spaceflight missions. The MMOC is composed of the facilities, networks, information technology equipment, software, and system administration services needed by flight projects to effectively and efficiently perform all mission functions, including planning, scheduling, command, telemetry processing, and science analysis. The MMOC's ready-to-use services reduce start-up time, shorten procurement and provisioning and allow mission planning efforts to focus more on science and less on infrastructure. The architecture of the MMOC was designed from the start for flexibility, so that it can readily support multiple missions of greatly varying size and complexity while simultaneously keeping costs low.

Differding, Joan C.↗
NASA NTRS2018

Generalizing a Data Analysis Pipeline in the Cloud to Handle Diverse Use Cases in NASA's EOSDIS

NASA's Earth Observing System Data and Information System (EOSDIS) is tasked with archiving and distributing Earth Observation data across a range of disciplines, including atmospheric science, oceanography, land processes, natural hazards, solar radiance and even socioeconomic aspects relating to the environment. Driven by rapidly rising data volumes, EOSDIS is migrating to a cloud computing based archive over the next few years. Although this simplifies data management somewhat, the main aim is to provide the data in an environment where end users can bring their analysis to the data rather than attempting to download and manage ever-increasing volumes. To that end, a cloud-based analysis platform is being constructed to enable data transformations, analyses and visualization without egressing the data from the cloud. In this endeavor, we expect a wide variety of users, algorithms and use cases. Consequently, the architecture of this cloud analytics platform is expressly designed to be based on open services, thus fostering an ecosystem that enables the efficient combination of common components with data-specific or analysis-specific components. Reviewed and approved by Andrew Mitchell, ESDIS project manager.

Cloud computing↗
NASA NTRS2018

GrassPlot - a Database of Multi-Scale Plant Diversity in Palaearctic Grasslands

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG)and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001; ... 1,000 m_) and on nested-plot series withat least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata.However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetation plot databases, such as the European Vegetation Archive (EVA) and the global database "sPlot". Its main aim is to facilitate studies on the scale- and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board.

Dengler, Jurgen↗
NASA NTRS2019

A Diversity of Calcium-Rich Carbonates in EETA 79001

Carbonate minerals of martian origin are present in several martian meteorites in trace concentrations (less than 1 percent) and possess unique isotopic signatures that suggest that the martian environment and/or isotopic reservoirs are very different from the Earth’s. Carbonates are most common in the older martian meteorites (ALH 84001 and the nakhlites), however, there have been reports of carbonate in the younger shergottites including EETA 79001 (Mars meteorite Elephant Moraine 79001). Acidification studies of Zagami and Shergotty have shown that CO2 is released suggesting that carbonate phases are present in these meteorites, but the origin of these phases is controversial. The young ages of the shergottites makes them important samples for understanding the modern martian environment. The carbonates in EETA 79001 are the best-characterized secondary minerals in a shergottite, but their origin remains controversial. Gooding et al. argued that two types of carbonate occur with-in the glassy parts of the meteorite. One type, nearly pure CaCO3 associated with Ca-sulfate shows textural evidence for being present in the rock prior to it being shocked, suggesting formation on Mars. The second was more abundant and consists of Ca-rich carbonate, possibly with finely intergrown Mg-phosphate, but does not possess any textural relationships indicative of a martian origin. Carbon and oxygen isotopic studies of this carbonate yielded oxygen isotopes that potentially suggest a martian origin as well

Niles, P. B.↗
NASA NTRS2019

Remarkable Diversity of Refractory Inclusions in the Miller Range 090019 CO3.1 Chondrite

We have characterized the mineralogy, textures, bulk compositions, modal abundances and some mineral compositions in a suite of approximately 140 refractory inclusions from the MIL090019 carbonaceous chondrite. All of these 140 inclusions are found in a single thin section of this CO3.1 chondrite. These inclusions range from grossite- and hibonite-rich varieties, melilite-, spinel-, fassaite-diopside- and anorthite-rich types, and include a subset of aluminous AOAs (amoeboidal olivine aggregates). Grossite- and hibonite-bearing inclusions were discussed briefly in previous abstracts. X-ray mapping by energy dispersive spectrometry has permitted us to extract the bulk compositions of these inclusions from hyperspectral x-ray datasets. The bulk compositions of these inclusions represent the full range of recognized CAI (Calcium-Aluminum–rich Inclusions) types.

Ross, D. Kent↗
NASA NTRS2015

Modeling of Complex and Diverse Aircraft Trajectories with the Trajectory Synthesizer Generalized Profile Interface

A flexible method to describe and generate aircraft trajectories called GenProf was developed for the Center TRACON Automation System (CTAS) software research platform. Generally CTAS is used to prototype new air traffic management decision support tools and concepts. Beyond this purpose, the GenProf methodology has enabled a variety of research and validation tasks to be performed. This paper briefly describes the methodology and details these applications.

trajectory modelling↗
NASA NTRS2019

Microbial Monitoring of Astromaterials Curation Labs Reveals Inter-Lab Diversity

The Astromaterials Curation Division at NASA’s Johnson Space Center houses seven sample collections stored in separate clean rooms to avoid cross-contamination. Prior to receiving new sample collections from carbon rich asteroids, we instituted a monitoring program to characterize the microbial ecology of these labs and to understand how organisms could interact with and potentially contaminate current and future collections. Methods: Beginning in Oct. 2017 we sampled the Meteorite (ISO 7 equivalent) and Pristine Lunar (ISO 5 equivalent) labs on a monthly basis. Surface samples were collected using dry swabs. Air samples were collected using an impactor style air sampler. Cultivable organisms were identified and characterized. Aliquots of each sample were also preserved for DNA sequencing. For each sampling event recovery rate was calculated as the percentage of samples showing microbial growth1. Fungal colonies were selected for amino acid extraction and analysis via Ultra- Performance Liquid Chromatography with Fluorescence Detection and Mass Spectrometry.

Regberg, A. B.↗