56 research outputs found

    The Downward Spiral: A Look at the Depiction of Lawyers in Movies

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    Development of Low-Cost Micromanipulation Systems for Small Extraterrestrial Samples

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    The analysis of microscale to mm-scale astromaterials often involves the transfer of samples from storage or collection substrates to analytical substrates. These transfers are accomplished by hand (via tweezers or fine-tipped needles) or by utilizing micromanipulation instruments. Freehand manipulation of small particles is extremely challenging due to involuntary hand tremors on the order of 100m and due to the triboelectric charging induced by frequent contact between the manipulation tool and the support substrate. Months or years of practice may be required before an investigator develops the necessary experience to confidently transfer a 10-20m particle in this manner. Handling even mm-sized particles with fine-tipped tweezers can be challenging, due to the inability to precisely control the force with which grains are being held. Mechanical, hydraulic, and motorized/electrical micromanipulators enable the precise handling of microscale samples and are often utilized in laboratories where frequent small sample preparation is required. However, the price of such instruments (~ 10,000to10,000 to 100,000) makes them cost-prohibitive for some institutions. Graduate students or early-career scientists interested in conducting research on interplanetary dust particles, Itokawa particles returned by Hayabusa, or future samples returned by OSIRIS-REx or Hayabusa2 may experience difficulty in justifying the expense of a micromanipulator to their advisors or principle investigators. Johnson Space Centers Astromaterials Acquisition and Curation Office and the Lunar and Planetary Institute conduct annual training for early career scientists and for investigators that require experience with handling of small extraterrestrial samples. In support of this training, we have been developing low-cost mechanical alternatives to expensive micromanipulators that training participants can implement in their respective facilities

    Advanced Curation Development of Tools and Methods for Microparticle Curation

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    The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center is currently developing new tools and methods for the collection, storage, handling and characterization of particles less than 100 microns in diameter, or microparticles. Astromaterials Curation currently maintains four microparticle collections: Cosmic Dust that has been collected in Earths stratosphere by ER2 and WB-57 aircraft, Comet 81P/Wild 2 dust returned by NASAs Stardust spacecraft, interstellar dust that was returned by Stardust, and asteroid Itokawa particles that were returned by the JAXA (Japan Aerospace Exploration Agency)s Hayabusa spacecraft. NASA Curation is currently preparing for the anticipated return of two new astromaterials collections asteroid Ryugu regolith to be collected by Hayabusa II spacecraft in 2021 (samples will be provided by JAXA as part of an international agreement), and asteroid Bennu regolith to be collected by the OSIRIS-REx (Origins Spectral Interpretation Resource Identification Security - Regolith Explorer) spacecraft in 2023. In order to maximize the scientific yield from these valuable acquisitions, it will be necessary to develop methods that extend our current microsample handling capabilities. Here we describe recent progress in the development of sample handling techniques that will enhance our microparticle curation capabilities. Further described are: Six-Axis Robot Arms for Particle Manipulation, and Charge-Dissipative Substrates

    Water-Rock Interactions in Outer Solar System Bodies: Evidence from the Coordinated Analysis of Interplanetary Dust

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    NASA has an ongoing program of collecting interplanetary dust particles (IDPs) in the stratosphere using high altitude research aircraft. The collected IDPs are derived from asteroids and comets and here we report studies of a subset of hydrated IDPs rich in carbonaceous matter that are proposed to have a cometary origin. Our studies are aimed at understanding the evolution of oxygen reservoirs in the Solar System and their interaction with cometary minerals and organic matter. The small size (<20 m) and fragility of these IDPs present a number of analytical challenges. We have pioneered techniques for performing chemical, mineralogical, isotopic, and spectroscopic measurements on the same sample in a carefully coordinated sequence. Coordinated analyses of nanogram-size samples is made possible by several delicate sample preparation techniques. To avoid organic contamination, we embed IDPs in elemental sulfur and use ultramicrotomy to partly section the particles (the first few micrometers). Multiple thin sections (50-70 nm thick) are placed on different substrates depending on the analysis technique. We use a JEOL 2500SE scanning, transmission electron microscope (STEM) to determine the mineralogy, microstructure, and elemental compositions of constituent minerals in the thin sections through a combination of high resolution imaging, electron diffraction, quantitative energy-dispersive x-ray mapping, and electron energy-loss spectroscopy. Following the STEM analyses, we use a NanoSIMS 50L for high spatial resolution isotopic measurements of H, C, N, and O to search for presolar grains and to understand the origin of the indigenous organic matter. The isotopic analyses are performed on the same sections analyzed in the STEM in order to correlate isotopic properties with the elemental and mineralogical data. We reserve other thin sections for non-destructive analyses utilizing synchrotron-based techniques including Fourier-transform infrared (FTIR) micro-spectroscopy and X-ray absorption near-edge structure (XANES) analyses, especially for functional group analysis of organic matter in the particles. The remainder of the IDP is extracted from the sulfur bead that was used for microtomy and is pressed into Au foil for quantitative analysis (including light elements) using a JEOL 8530F field emission electron probe microanalyzer (EPMA). After the EPMA measurements, high precision oxygen isotopic analyses are obtained using Cameca IMS1270/1290 instruments at UCLA. The hydrated IDPs in this study are dominated by saponitic clays, with minor magnetite, carbonate and abundant organic matter. The remarkable oxygen isotopic compositions, high carbon contents, and the abundance of isotopically anomalous organic matter, together suggest that the high carbon, hydrated IDPs are derived from primitive sources not yet represented in meteorite collections such as outer main belt P- and D-type asteroids or comets

    NASA Curation Preparation for Ryugu Sample Returned by JAXA's Hayabusa2 Mission

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    The NASA OSIRIS-REx and JAXA Hayabusa2 missions to near-Earth asteroids Bennu and Ryugu share similar mission goals of understanding the origins of primitive, organic-rich asteroids. Under an agreement between JAXA and NASA, there is an on-going and productive collaboration between science teams of Hayabusa2 and OSIRIS-REx missions. Under this agreement, a portion of each of the returned sample masses will be exchanged between the agencies and the scientific results of their study will be shared. NASAs portion of the returned Hayabusa2 sample, consisting of 10% of the returned mass, will be jointly separated by NASA and JAXA. The sample will be legally and physically transferred to NASAs dedicated Hayabusa2 curation facility at Johnson Space Center (JSC) no later than one year after the return of the Hayabusa2 sample to Earth (December 2020). The JSC Hayabusa2 curation cleanroom facility design has now been completed. In the same manner, JAXA will receive 0.5% of the total returned OSIRIS-REx sample (minimum required sample to return 60 g, maximum sample return capacity of 2 kg) from the rest of the specimen. No later than one year after the return of the OSIRIS-REx sample to Earth (September 2023), legal, physical, and permanent custody of this sample subset will be transferred to JAXA, and the sample subset will be brought to JAXAs Extraterrestrial Sample Curation Center (ESCuC) at Institute of Space and Astronautical Science, Sagamihara City Japan

    Stardust@home: A Massively Distributed Public Search for Interstellar Dust in the Stardust Interstellar Dust Collector

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    In January 2006, the Stardust mission will return the first samples from a solid solar system body beyond the Moon. Stardust was in the news in January 2004, when it encountered comet Wild2 and captured a sample of cometary dust. But Stardust carries an equally important payload: the first samples of contemporary interstellar dust ever collected. Although it is known that interstellar (IS) dust penetrates into the inner solar system [2, 3], to date not even a single contemporary interstellar dust particle has been captured and analyzed in the laboratory. Stardust uses aerogel collectors to capture dust samples. Identification of interstellar dust impacts in the Stardust Interstellar Dust Collector probably cannot be automated, but will require the expertise of the human eye. However, the labor required for visual scanning of the entire collector would exceed the resources of any reasonably-sized research group. We are developing a project to recruit the public in the search for interstellar dust, based in part on the wildly popular SETI@home project, which has five million subscribers. We call the project Stardust@home. Using sophisticated chemical separation techniques, certain types of refractory ancient IS particles (so-called presolar grains) have been isolated from primitive meteorites (e.g., [4] ). Recently, presolar grains have been identified in Interplanetary Dust Particles[6]. Because these grains are not isolated chemically, but are recognized only by their unusual isotopic compositions, they are probably less biased than presolar grains isolated from meteorites. However, it is entirely possible that the typical interstellar dust particle is isotopically solar in composition. The Stardust collection of interstellar dust will be the first truly unbiased one

    Mineralogy and petrology of comet 81P/wild 2 nucleus samples

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    The bulk of the comet 81P/Wild 2 (hereafter Wild 2) samples returned to Earth by the Stardust spacecraft appear to be weakly constructed mixtures of nanometer-scale grains, with occasional much larger (over 1 micrometer) ferromagnesian silicates, Fe-Ni sulfides, Fe-Ni metal, and accessory phases. The very wide range of olivine and low-Ca pyroxene compositions in comet Wild 2 requires a wide range of formation conditions, probably reflecting very different formation locations in the protoplanetary disk. The restricted compositional ranges of Fe-Ni sulfides, the wide range for silicates, and the absence of hydrous phases indicate that comet Wild 2 experienced little or no aqueous alteration. Less abundant Wild 2 materials include a refractory particle, whose presence appears to require radial transport in the early protoplanetary disk

    Ion Probe Measurements of Comet Dust: Investigating Oxygen Isotope Heterogeneity in the Solar System

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    The abundances of the stable isotopes of oxygen vary in terrestrial materials in ways that can be explained by mass-dependent fractionation. Refractory inclusions and chondrules in meteorites, however, have oxygen isotopic compositions that are suggestive of a mixing between isotopically separated reservoirs. Understanding the processes that produced 16O-rich and 17,18O-rich reservoirs has been a major objective of cosmochemical research for several decades. One complication of investigations into the nature of oxygen isotope heterogeneity has been the alteration of chondritic components on asteroidal parent bodies, which modify the original isotopic signatures of primordial dust. Comets accreted in distal cold regions of the solar nebula, and dust from comets probably experienced minimal parent body processing relative to asteroidal samples. Much of the dust collected in the stratosphere likely has cometary origins, but until the return of samples from NASA’s Stardust spacecraft, definitive links to comets had not been established. Stardust successfully returned particles from a known comet 81P/Wild 2, but the silica aerogel collectors severely altered the oxygen isotope compositions of the fine-grained dust component. Impacts of Wild 2 dust into aluminum foils produced craters that retained material as a melt residue, providing an opportunity to measure the oxygen isotopic composition of coarse and fine-grained components of comet dust.This dissertation describes oxygen isotope measurements of Wild 2 impact crater residues via Secondary Ion Mass Spectrometry (SIMS). Hypervelocity experiments that simulated the collection conditions of Wild 2 dust were preformed using minerals of known oxygen isotope composition; the resulting craters were used to develop analytical techniques, to assess modification to the oxygen isotope composition due to hypervelocity capture, and as standards for oxygen isotope measurements of Wild 2 craters. This dissertation also describes the oxygen isotope measurements of interplanetary dust particles with hydrated mineralogy, in an attempt to observe 17,18O-enriched water that is predicted to be a consequence of some proposed mechanisms for producing observed oxygen isotope heterogeneity. Relationships between interplanetary dust particles, comet dust, and carbonaceous chondrites are examined, and implications for models of comet formation and oxygen isotope heterogeneity are discussed

    Banneker Industries, Inc. - Your Strategic Sourcing Solution

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    The color of the skin is in no way connected with the strength of the mind or intellectual powers. - Benjamin Banneker (1731-1806) For many years, Cheryl Watkins Snead had been providing value added services for her customers. As President and CEO, she was the driving force behind Banneker Industries, Inc. (Banneker), a provider of outsourcing solutions for her customers. The quality-minded and participative management style of Cheryl Snead converted a failing machine shop into a vibrant and innovative supply chain management (SCM) company whose core strengths focus on strategic sourcing. Due to a downturn in the economy, businesses were increasingly outsourcing their routine duties to Banneker in order for them to focus on their primary business functions. While this has kept Banneker busy and solvent, they have not grown at the rate that they anticipated. Cheryl pondered her successes with her business during the tough economic times but looked to the future for opportunities where Banneker could flourish
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