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NASA NTRS2015

Major Volatiles from MSL SAM Evolved Gas Analyses: Yellowknife Bay Through Lower Mount Sharp

The Sample Analysis at Mars (SAM) and Chemistry and Mineralogy (CheMin) instruments on the Mars Science Laboratory (MSL) analysed several subsamples of <150 μm fines from five sites at Gale Crater. Three were in Yellowknife Bay: the Rocknest aeolian bedform ("RN") and drilled Sheepbed mudstone from sites John Klein ("JK") and Cumberland ("CB"). One was drilled from the Windjana ("WJ") site on a sandstone of the Kimberly formation investigated on route to Mount Sharp. Another was drilled from the Confidence Hills ("CH") site on a sandstone of the Murray Formation at the base of Mt. Sharp (Pahrump Hills). Outcrops are sedimentary rocks that are largely of fluvial or lacustrine origin, with minor aeolian deposits.. SAM's evolved gas analysis (EGA) mass spectrometry detected H2O, CO2, O2, H2, SO2, H2S, HCl, NO, and other trace gases, including organic fragments. The identity and evolution temperature (T) of evolved gases can support CheMin mineral detection and place constraints on trace volatile-bearing phases or phases difficult to characterize with XRD (e.g., X-ray amorphous phases). They can also give constraints on sample organic chemistry. Here, we discuss trends in major evolved volatiles from SAM EGA analyses to date.

McAdam, A. C.↗
NASA NTRS2015

Constraining the Texture and Composition of Pore-Filling Cements at Gale Crater, Mars

The Mars Science Laboratory (MSL) rover Curiosity has encountered a wide variety of sedimentary rocks deposited in fluvio-lacuestrine sequences at the base of Gale Crater. The presence of sedimentary rocks requires that initial sediments underwent diagenesis and were lithified. Lithification involves sediment compaction, cementation, and re-crystallization (or authigenic) processes. Analysis of the texture and composition of the cement can reveal the environmental conditions when the cements were deposited, enabling better understanding of early environments present within Gale Crater. The first step in lithification is sediment compaction. The Gale crater sediments do not show evidence for extensive compaction prior to cementation; the Sheepbed mudstone in Yellowknife Bay (YKB) has preserved void spaces ("hollow nodules"), indicating that sediments were cemented around the hollow prior to compaction, and conglomerates show imbrication, indicating minimal grain reorganization prior to lithification. Furthermore, assuming the maximum burial depth of these sediments is equivalent to the depth of Gale Crater, the sediments were never under more than 1 kb of pressure, and assuming a 15 C/km thermal gradient in the late Noachian, the maximum temperature of diagenesis would have been approximately 75 C. This is comparable to shallow burial diagenetic conditions on Earth. The cementation and recrystallization components of lithification are closely intertwined. Cementation describes the precipitation of minerals between grains from pore fluids, and recrystallization (or authigenesis) is when the original sedimentary mineral grains are altered into secondary minerals. The presence of authigenic smectites and magnetite in the YKB formation suggests that some recrystallization has taken place. The relatively high percentage of XRD-amorphous material (25-40%) detected by CheMin suggests that this recrystallization may be limited in scope, and therefore may not contribute significantly to the cementing material. However, relatively persistent amorphous components could exist in the Martian environment (e.g. amorphous MgSO4), so recrystallization, including loss of crystallinity, cannot yet be excluded as a method of cementation. In order to describe the rock cementation, both the rock textures and their composition must be considered. Here, we attempt to summarize the current understanding of the textural and compositional aspects of the cement across the rocks analyzed by Curiosity to this point.

Siebach, K. L.↗
NASA NTRS2013

MSL Chemistry and Mineralogy X-Ray Diffraction X-Ray Fluorescence (CheMin) Instrument

This paper provides an overview of the Mars Science Laboratory (MSL) Chemistry and Mineralogy Xray Diffraction (XRD), X-ray Fluorescence (XRF) (CheMin) Instrument, an element of the landed Curiosity rover payload, which landed on Mars in August of 2012. The scientific goal of the MSL mission is to explore and quantitatively assess regions in Gale Crater as a potential habitat for life - past or present. The CheMin instrument will receive Martian rock and soil samples from the MSL Sample Acquisition/Sample Processing and Handling (SA/SPaH) system, and process it utilizing X-Ray spectroscopy methods to determine mineral composition. The Chemin instrument will analyze Martian soil and rocks to enable scientists to investigate geophysical processes occurring on Mars. The CheMin science objectives and proposed surface operations are described along with the CheMin hardware with an emphasis on the system engineering challenges associated with developing such a complex instrument.

sample chemistry↗
NASA NTRS2015

Additive Manufacturing of SiC Based Ceramics and Ceramic Matrix Composites

Silicon carbide (SiC) ceramics and SiC fiber reinforcedSiC ceramic matrix composites (SiCSiC CMCs) offer high payoff as replacements for metals in turbine engine applications due to their lighter weight, higher temperature capability, and lower cooling requirements. Additive manufacturing approaches can offer game changing technologies for the quick and low cost fabrication of parts with much greater design freedom and geometric complexity. Four approaches for developing these materials are presented. The first two utilize low cost 3D printers. The first uses pre-ceramic pastes developed as feed materials which are converted to SiC after firing. The second uses wood containing filament to print a carbonaceous preform which is infiltrated with a pre-ceramic polymer and converted to SiC. The other two approaches pursue the AM of CMCs. The first is binder jet SiC powder processing in collaboration with rp+m (Rapid Prototyping+Manufacturing). Processing optimization was pursued through SiC powder blending, infiltration with and without SiC nano powder loading, and integration of nanofibers into the powder bed. The second approach was laminated object manufacturing (LOM) in which fiber prepregs and laminates are cut to shape by a laser and stacked to form the desired part. Scanning electron microscopy was conducted on materials from all approaches with select approaches also characterized with XRD, TGA, and bend testing.

3-D printing↗
NASA NTRS2016

Diagenesis in the Murray Formation, Gale Crater, Mars

The Mars Science Laboratory (MSL) Curiosity rover began investigating the rocks of Mt. Sharp in September 2014. The Murray formation is the lowermost unit, which is mostly comprised of finely laminated mudstones, suggesting these sediments were deposited in a lacustrine environment. It is important to characterize the geochemical and mineralogical trends throughout the Murray Fm to interpret the aqueous conditions of the ancient lake, the sources of the lake sediments, and post-depositional alteration processes. Four samples have been drilled from the Murray Fm so far: Confidence Hills, Mojave 2, and Telegraph Peak were collected from the Pahrump Hills member - the basal portion of the Murray Fm, and Buckskin was collected in the Marias Pass region (Fig. 1). The drill fines were delivered to the instruments inside the rover, including the CheMin instrument, a combination X-ray diffractometer and X-ray fluorescence spectrometer. Rietveld refinements and FULLPAT analyses of 1D CheMin XRD patterns were performed to determine quantitative abundances of minerals and amor-phous phases and the unit cell parameters of minerals present in abundances greater than 4-5 wt.%.

Rampe, E. B.↗
NASA NTRS2016

Cementation and Aqueous Alteration of a Sandstone Unit Under Acidic Conditions in Gale Crater, Mars

The Curiosity rover landed on Mars in August 2012 to explore the sedimentary history and to assess the habitability of Gale Crater. After 1200 sols of surface operations and over 12 km of traverse distance, the mineralogy of 10 samples has been determined by the CheMin X-ray diffractometer (XRD) and the chemical composition of nearly 300 targets has been established by the Alpha Particle X-ray Spectrometer (APXS). Light-toned fracture zones containing elevated concentrations of silica have been studied by Curiosity's instruments to determine the nature of the fluids that resulted in the enrichment of SiO2. Multiple fluid exposures are evident, and the chemistry and mineralogy data indicate at least two aqueous episodes may have occurred under acidic conditions.

Yen, A. S.↗
NASA NTRS2016

Additive Manufacturing of Silicon Carbide-Based Ceramic Matrix Composites: Technical Challenges and Opportunities

Advanced SiC-based ceramic matrix composites offer significant contributions toward reducing fuel burn and emissions by enabling high overall pressure ratio (OPR) of gas turbine engines and reducing or eliminating cooling air in the hot-section components, such as shrouds, combustor liners, vanes, and blades. Additive manufacturing (AM), which allows high value, custom designed parts layer by layer, has been demonstrated for metals and polymer matrix composites. However, there has been limited activity on additive manufacturing of ceramic matrix composites (CMCs). In this presentation, laminated object manufacturing (LOM), binder jet process, and 3-D printing approaches for developing ceramic composite materials are presented. For the laminated object manufacturing (LOM), fiber prepreg laminates were cut into shape with a laser and stacked to form the desired part followed by high temperature heat treatments. For the binder jet, processing optimization was pursued through silicon carbide powder blending, infiltration with and without SiC nano powder loading, and integration of fibers into the powder bed. Scanning electron microscopy was conducted along with XRD, TGA, and mechanical testing. Various technical challenges and opportunities for additive manufacturing of ceramics and CMCs will be presented.

ceramic matrix composites↗
NASA NTRS2016

MSL SAM-Like Evolved Gas Analyses of Si-rich Amorphous Materials

Chemical and mineralogical analyses of several samples from Murray Formation mudstones and Stimson Formation sandstones by the Mars Science Laboratory (MSL) revealed the presence of Si-rich amorphous or poorly ordered materials. It is possible to identify the presence of high-SiO2 vs. lower SiO2 amorphous materials (e.g., basaltic glasses), based on the position of the resulting wide diffraction features in XRD patterns from the Chemistry and Mineralogy (CheMin) instrument, but it is not possible to distinguish between several candidate high-SiO2 amorphous materials such as opal-A or rhyolitic glass. In the Buckskin (BS) sample from the upper Murray Formation, and the Big Sky (BY) and Greenhorn (GH) samples from the Stimson Formation, analyses by the Sample Analysis at Mars (SAM) instrument showed very broad H2O evolutions during sample heating at temperatures >450-500degC which had not been observed from previous samples. BS also had a significant broad evolution <450-500degC. We have undertaken a laboratory study targeted at understanding if the data from SAM can be used to place constraints on the nature of the amorphous phases. SAM-like evolved gas analyses have been performed on several opal and rhyolitic glass samples. Opal-A samples exhibited wide <500degC H2O evolutions, with lesser H2O evolved above ~500degC. H2O evolution traces from rhyolitic glasses varied, having either two broad H2O peaks, <300degC and >500degC, or a broad peak centered around 400degC. For samples that produced two evolutions, the lower temperature peak is more intense than the higher temperature peak, a trend also exhibited by opal-A. This trend is consistent with data from BS, but does not seem consistent with data from BY and GH which evolved most of their H2O >500degC. It may be that dehydration of opal-A and/or rhyolitic glass can result in some preferential loss of lower temperature H2O, to produce traces that more closely resemble BY and GH. This is currently under investigation and results will be reported.

McAdam, Amy↗
NASA NTRS2017

Calcium Sulfates at Gale Crater and Limitations on Gypsum Stability

The Mars Science Laboratory rover has been exploring sedimentary rocks of the Bradbury group and overlying Murray formation, as well as the unconformably overlying Stimson formation. Early in exploration, and continuing to present, there have been observations of many Ca-sulfate veins that cut all three stratigraphic units. The CheMin XRD instrument on Curiosity provides complete mineralogy for drilled or scooped samples, with explicit identification of gypsum, bassanite, and anhydrite (crystal structure of so-called "soluble anhydrite," or gamma-CaSO4, is so similar to bassanite that it can't be distinguished at CheMin 2-theta resolution; here we refer to these similar dehydrated forms simply as bassanite).

Vantiman, D. T.↗
NASA NTRS2017

A New Method of Absorption-Phase Nanotomography for 3D Observation of Mineral-Organic-Water Textiles and its Application to Pristine Carbonaceous Chondrites

Pristine carbonaceous chondrites contain fine-grained matrix, which is composed largely of amorphous silicates, sub-micron silicate and sulfide crystals, and organic materials. They are regarded as primitive dust in the early Solar System that have suffered minimal alteration in their parent bodies. The matrix generally has different lithologies; some of them are unaltered but some are more or less aqueously altered. Their textures have been examined in 2D usually by FE-SEM/EDS, TEM/EDS, nano-SIMS and micro-XRD. Observation of their complex fine textures, such as spatial relation between different lithologies in 3D, is important for understanding aggregation and alteration processes. Synchrotron radiation (SR)-based X-ray tomography reveals 3D structures nondestructively with high spatial resolution of approximately greater than 100 nm. We have developed a new technique using absorption contrasts called "dual-energy tomography" (DET) to obtain 3D distribution of minerals at SPring-8, SR facility in Japan, and applied successfully to Itokawa particles. Phase and absorption contrast images can be simultaneously obtained in 3D by using "scanning-imaging x-ray microscopy" (SIXM) at SPring-8, which can discriminate between void, water and organic materials. We applied this technique combined with FIB micro-sampling to carbonaceous chondrites to search for primitive liquid water. In this study, we combined the DET and SIXM to obtain three dimensional submicron-scale association between minerals, organic materials and water and applied this to pristine carbonaceous chondrites.

Tsuchiyama, A.↗
NASA NTRS2017

Mineralogical Changes in a Predominantly Fluviolacustrine Succession at Gale Crater, Mars

The Mars Science Laboratory Curiosity rover landed in Gale crater in August 2012 to investigate the strata of lower Aeolis Mons (i.e., Mount Sharp) and characterize their depositional and diagenetic environments. Visible/short-wave infrared spectra from orbit of these strata show variations in phyllosilicate, sulfate, and Fe-oxide minerals, suggesting these units record environmental changes that occurred during the early Hesperian. Curiosity has traversed over 15 km and has climbed through Approx. 200 m of stratigraphic section, made up of predominantly fluviolacustrine (i.e., the Bradbury group and the Murray formation) and aeolian (i.e., the Stimson formation) units. Multiple geochemical and mineralogical instruments are onboard Curiosity to study these ancient rocks, including the Chemistry and Mineralogy (CheMin) instrument, which is an X-ray diffractometer (XRD) and X-ray fluorescence spectrometer, and the Alpha Particle X-ray Spectrometer (APXS).

Rampe, E. B.↗
NASA NTRS2017

Chemical, Structural, and Microstructural Changes in Metallic and Silicon-Based Coating Materials Exposed to Iodine Vapor

The chemical, structural and microstructural behavior of steels (304, 316 and A36), titanium-aluminum alloy (Ti-Al, (6Al-4V)), aluminum-magnesium alloy (Al-Mg, 6061), and coatings (Silcolloy and Dursan (SilcoTek Corporation)) were probed after exposure to iodine laminar flow. Exposures were carried out in a custom-built Iodine Vapor RIG (IVR) at 300 degrees C to an iodine laminar vapor flow of 1 mg min(exp. -1), carried by 145 mL-min(exp. -1) argon gas, for 5, 15 and 30 days. Samples were characterized before and after the experiment by gravimetric analysis, X-ray diffraction (XRD) and cross section electron microscopy analysis coupled with energy dispersive X-ray spectroscopy (EDS). All steels exposed for 30 days formed scales consisting mainly of metal (Cr, Fe, Ni) oxides showing different chemistry, microstructure and crystalline phases. Elemental iodine was only detected by EDS analysis in the scales of stainless steels 304 and 316. After 30 days, the Ti-Al exhibited no detectable scale, suggesting only a very thin film was formed. A scale consisting mainly of aluminum, iodine, and oxygen formed on the Al-Mg sample exposed to 30 days. Some pockets rich in magnesium, iodine and oxygen also formed in this Al-Mg alloy. Stainless steel 316, low carbon steel A36 and Ti-Al alloy coated with Silcolloy and stainless steel 304 coated with Dursan that were exposed for 30 days exhibited no oxidation. Stainless steel 304 coated with Silcolloy exposed for 30 days did not exhibit corrosion although the sample gained weight and the coating exhibited expansion. The weight gain per area performance of the materials exposed in iodine lamina flow containing oxygen at impurity level for 10, 15 and 30 days are reported from the lowest to the highest weight gain per area as follows: Steels: Less than 316 less than 304 less than A36; Ti-Al-Mg based alloys: Al-Mg less than Ti-Al: Considering the experimental uncertainties, no weight change was observed for Stainless steel 316, low carbon steel A36 and Ti-Al alloy coated with Silcolloy and stainless steel 304 coated with Dursan. The corrosion of the alloys is catalyzed by iodine in the presence of oxygen as impurity.

Costa, Gustavo C. C.↗
NASA NTRS2017

Amino Acid Contents of Meteorite Mineral Separates

Indigenous amino acids have been found indigenous all 8 carbonaceous chondrite groups. However, the abundances, structural, enantiomeric and isotopic compositions of amino acids differ significantly among meteorites of different groups and petrologic types. This suggests that parent-body conditions (thermal or aqueous alteration), mineralogy, and the preservation of amino acids are linked. Previously, elucidating specific relationships between amino acids and mineralogy was not possible because the samples analyzed for amino acids were much larger than the scale at which petrologic heterogeneity is observed (sub mm-scale differences corresponding to sub-mg samples). Recent advances in amino acid measurements and application of techniques such as high resolution X-ray diffraction (HR-XRD) and scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) for mineralogical characterizations allow us to perform coordinated analyses on the scale at which mineral heterogeneity is observed.

Berger, E. L.↗
NASA NTRS2017

Sintered Cathodes for All-Solid-State Structural Lithium-Ion Batteries

All-solid-state structural lithium ion batteries serve as both structural load-bearing components and as electrical energy storage devices to achieve system level weight savings in aerospace and other transportation applications. This multifunctional design goal is critical for the realization of next generation hybrid or all-electric propulsion systems. Additionally, transitioning to solid state technology improves upon battery safety from previous volatile architectures. This research established baseline solid state processing conditions and performance benchmarks for intercalation-type layered oxide materials for multifunctional application. Under consideration were lithium cobalt oxide and lithium nickel manganese cobalt oxide. Pertinent characteristics such as electrical conductivity, strength, chemical stability, and microstructure were characterized for future application in all-solid-state structural battery cathodes. The study includes characterization by XRD, ICP, SEM, ring-on-ring mechanical testing, and electrical impedance spectroscopy to elucidate optimal processing parameters, material characteristics, and multifunctional performance benchmarks. These findings provide initial conditions for implementing existing cathode materials in load bearing applications.

Ceramics↗
NASA NTRS2018

The Composition of Amorphous Phases in Soils and Sediments on Earth and Mars

Amorphous phases are major components (~15-70 wt%) of all rock and soil samples measured thus far by the CheMin X-ray diffractometer (XRD) instrument on the MSL rover in Gale crater, Mars. The nature of these phases is not well understood and could be any combination of primary (e.g., glass) and secondary (e.g., silica, errihydrite) phases. Secondary amorphous phases are frequently found as weathering products in soils on Earth, but these materials remain poorly characterized, and it is not certain how properties like composition and structure change with formation environment.

Smith, R. J.↗
NASA NTRS2018

Collapsed Smectite in Gale Crater: Martian Clay Minerals May Have Been on Acid

The Mars Science Laboratory (MSL) rover Curiosity began investigating the layered deposits of Gale Crater, Mars, in August 2012. Among the many science instruments on the rover, the CheMin (Chemistry and Mineralogy) X-ray diffractometer (XRD) has been useful in definitively characterizing the mineralogy of samples collected by the rover.

Craig, P. I.↗
NASA NTRS2018

Investigation of Alpha Silicon Carbide / Carbon Fiber Proposed (2H & 6H-SiC) / C

A commercially available alpha silicon carbide coated carbon 12k fiber tow was subjected to rigorous inspection and testing. The pyrolized polyacrylonitrile (PAN) fiber had gone through a conversion process that resulted in a thin layer of SiC forming on the exterior of the fiber. The fibers? surface was characterized by x-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). Powdered x-ray diffraction (XRD) examined the bulk material properties. Transmission electron microscopy (TEM) coupled with energy-dispersive X-ray spectroscopy (EDS) examined the crystallinity of the SiC. A number of pristine samples were used to determine elongation rate and tensile strength.

Trunek, Andrew↗
NASA NTRS2018

The Planetary Materials Database

NASA provides funds for a variety of research programs whose principal focus is to collect and analyze terrestrial analog materials. These data are used to (1) understand and interpret planetary geology; (2) identify and characterize habitable environments and pre-biotic/biotic processes; (3) interpret returned data from present and past missions; and (4) evaluate future mission and instrument concepts prior to selection for flight. Data management plans are now required for these programs, but the collected data are still not generally available to the community. There is also little possibility to re-analyze the collected materials by other techniques, since there is no requirement to archive collected samples. The Planetary Materials Database (PMD) is a central, high-quality, long-term data repository, which aims to promote the field of astrobiology and increase scientific returns from NASA funded research by enabling data sharing, collaboration and exposure of non-NASA scientists to NASA research initiatives and missions. The PMD is a linked collection of databases developed using the Open Data Repository (ODR) system. The PMD will include detailed descriptions of terrestrial analog planetary materials as well as data from the instruments used in their analysis. The goal is to provide example patterns/spectra/analyses, etc. and background information suitable for use by the Space Science community. An early example showing the utility of these databases (although not in the ODR format) is the RRUFF mineral database. RRUFF, comprising 4,000+ pure mineral standards, is the most popular and widely used dataset of minerals and receives more than 180,000 queries per week from geologists and mineralogists worldwide. The PMD will be patterned after the CheMin database [3], a resource that contains all of the data collected by the MSL CheMin XRD instrument on Mars. Raw and processed CheMin data can be viewed, downloaded, reprocessed and reanalyzed using cloud-based “applications” linked to the data.

Blake, David↗