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NASA NTRS2023

Evaluation of the Interference of Tenax®TA Adsorbent With Dimethylformamide Dimethyl Acetal Reagent for Gas Chromatography-Dragonfly Mass Spectrometry and Future Gas Chromatography-Mass Spectrometry in Situ Analysis

Among future space missions, national aeronautics and space administration (NASA) selected two of them to analyze the diversity in organic content within Martian and Titan soil samples using a gas chromatograph – mass spectrometer (GC–MS) instrument. The Dragonfly space mission is planned to be launched in 2027 to Titan's surface and explore the Shangri-La surface region for years. One of the main goals of this mission is to understand the past and actual abundant prebiotic chemistry on Titan, which is not well characterized yet. The ExoMars space mission is planned to be launched in 2028 to Mars’ surface and explore the Oxia Planum and Mawrth Vallis region for years. The main objectives focus on the exploration of the subsurface soil samples, potentially richer in organics, that might be relevant for the search of past life traces on Mars where irradiation does not impact the matrices and organics. One recently used sample pre-treatment for gas chromatography – mass spectrometry analysis is planned on both space missions to detect refractory organic molecules of interest for astrobiology. This pre-treatment is called derivatization and uses a chemical reagent – called dimethylformamide dimethyl acetal (DMF-DMA) – to sublimate organic compounds keeping them safe from thermal degradation and conserving the chirality of the molecules extracted from Titan or Mars’ matrices. Indeed, the detection of building blocks of life or enantiomeric excess of some organics (e.g. amino acids) after DMF-DMA pre-treatment and GC–MS analyses would be both bioindicators. The main results highlighted by our work on DMF-DMA and Tenax®TA interaction and efficiency to detect organic compounds at ppb levels in a fast and single preparation are first that Tenax®TA did not show the onset of degradation until after 150 experiments – a 120 h at 300 °C experiment – which greatly exceeds the experimental lifetimes for the DraMS and GC-space in situ investigations. Tenax®TA polymer and DMF-DMA produce many by-products (about 70 and 46, respectively, depending on the activation temperature). Further, the interaction between the two leads to the production of 22 additional by-products from DMF-DMA degradation, but these listed by-products do not prevent the detection of trace-level organic molecules after their efficient derivatization and volatilization by DMF-DMA in the oven ahead the GC–MS trap and column.

DraMS-Dragonfly mission↗

NASA NTRSDate not supplied

Mars Sample Receiving Facility Research and Development to Enable Preservation, Safe Containment, and Scientific Research of Martian Samples on Earth

NASA and ESA are working together to plan a joint campaign to potentially bring back the first Martian samples to Earth in the early 2030s. On the surface of Mars, the Mars 2020Perseverance Rover is selecting and packaging samples that could be returned to Earth for careful examination by an international team of scientists. In preparation for this historic sample return, advance planning is underway to design and build a Mars Sample Receiving Facility (SRF) in the mid-2020s. In 2022, a Mars Sample Receiving Facility Assessment Study(MSAS) will be conducted to further define construction modality and capability options for a facility in the conterminous United States. Since Mars Sample Return (MSR) is currently categorized as a planetary protection restricted Earth return, this new facility would feature biosafety level 4 (BSL-4)-like high containment to protect Earth’s biosphere from any potential hazard. In addition, the facility also requires integration of cleanroom technologies to mitigate against terrestrial contamination and preserve sample integrity for science investigations. The integration of both clean handling and high containment requires significant technology research and development (R&D) by the mid-2020s to support the definition and planning of a SRF before commencing the site specific design phase. The SRF project will need to solidify the inorganic, organic, and biological contamination control (CC) requirements for the facility. This could entail a translation of Mars 2020 mission CC requirements for geologic material to engineering requirements for surfaces and airborne molecular contamination inside isolators and cleanrooms. In tandem, the project will need to determine precision cleaning and sterilization approaches for cleanrooms, isolators, equipment, and tools. Initial material selections for the facility construction materials, cleanrooms, isolators, and BSL-4 suits/garments are an important activity. The recent construction of the OSIRIS-REx and Hayabusa2 curation cleanroom laboratories greatly benefited from early materials testing, before the design phase, to reduced organic outgassing and particulate shedding inside the laboratory. While the early biohazard investigations in the SRF may deem the samples safe to release to laboratories throughout the world, sterilization methods need to be defined to safely release Martian samples. One key aspect of enabling simultaneous sample containment and cleanliness is the concept of a Double-Walled Isolator (DWI) that ESA has been pursuing. Further R&D is needed about DWIs, sample handling, and instrumentation interfaces before beginning the SRF site specific design phase. A working isolator/DWI engineering model should be developed and fabricated. Isolator sizes, connections, pass-through antechambers, and configurations and basic interfaces with instruments and tools as well as the use of robotic, mechanical, and/or human manipulation need to be considered. Inert high purity gas supply (one-pass or recirculation) and other isolator utilities must be determined. Special accommodations for large instruments (e.g., XCT,SEM, etc.) need to be developed. Techniques for opening the sample tubes packaged by M2020and extracting the headspace gas while keeping samples pristine will be challenging, requiring additional R&D, and engagement of the M2020 project. In addition, careful micromanipulation for subdivision and packaging of samples will also need to be included. These combined R&D activities are important before commencing the SRF design phase to ensure safe biohazard containment, sample preservation, and science integrity for the samples that would be studied in the SRF and in laboratories around the world.

mars sample return↗

NASA NTRSDate not supplied

Operational Workflow in a Sample Receiving Facility: Input from the MSR Operation Definition Team

The return of scientifically selected samples from Mars would provide a rare opportunity for investigation with the full range of the latest technology available. To take full advantage of this opportunity, it is important to plan ahead to ensure the pristine nature of the samples upon arrival within the Earth environment until scientific investigations can begin. The NASA/ESA science community-driven MSR Science Planning Group – Phase 2 (MSPG2) delivered recommendations and guidance regarding curation (1) and science (2,3) activities to be performed on the samples under containment. High-level requirements for the infrastructure were also developed by MSPG2 (4). In order to prepare infrastructure-targeted input for the ESA and NASA facility studies planned in the 2022-2023 timeframe, the MSR agency-led Operational Scenarios Definition Team (MOSDT) was assembled to conceptualize the sample operations that will inform future architecture teams. Emphasis was placed on the responsibility of MOSDT to use community-defined requirements and to represent the view of the international scientific community. The main deliverable of MOSDT was an operational workflow for a Sample Receiving Facility (SRF). Two other deliverables were produced: a report to narrate the workflow, and a list of instruments (see Hutzler et al., this conference). Activities described in the main sequence of the workflow range from engineering operations to curation to science, with the latter term being used here as the science to be done within a SRF. Side sequences (e.g. engineering inspection of hardware, head gas extraction) were also identified, and detailed when they would have a significant impact on the infrastructure of a SRF. It was necessary for the MOSDT to rely on assumptions for some steps and activities, and though these were kept to a minimum (and are described in both the report supporting the workflow and in the full presentation), in general, the assumptions and overall work were very conservative, as the impact of underestimating the scope of the SRF infrastructure was considered more detrimental than overestimating it. It is expected that future work will be able to confirm or inform these assumptions. The community was consulted during the course of the MOSDT work. This abstract’s aim is two-fold: on one hand, inform the scientific community and overall MSR stakeholders, to make the infrastructure studies and trade-off more understandable; on the other hand, to solicit feedback from a larger community audience for the next iterations planning for SRF design and activities.

Mars Sample Return↗

NASA NTRSDate not supplied

Laboratory Investigation of the Effect of Venusian Weathering on Mineral Spectra

Introduction: The recent selection of two missions to Venus has renewed the importance of deter-mining weathering reactions between minerals and the Venusian atmosphere, and the spectral signatures of minerals before, during, and after these reactions. The rate at which weathering reactions progress also constrain show long unstable minerals will be present on the surface (e.g., [1]), and enables the use of mineralogy as a constraint on surface age(e.g., [2-3]).In order to gain an understanding of how mineral compositions and spectra change with weathering, we have begun conducting experiments in a 1 atm experimental setup at Wesleyan University. This setup exposes minerals to the temperature and most abundant gases of the Venus atmosphere (CO2, SO2, N2).We conducted initial experiments using biotite, calcite, and montmorillonite in order to test our methodology with minerals that may be relevant to recording the history of water on Venus. Methods: Experiments were conducted in Thermo Fisher Scientific Lindberg/Blue M Mini-Mite horizontal tube furnaces at Wesleyan University. Experiments used natural mineral chips and powders, and were conducted at 1 atmosphere and 460 °C under pre-mixed gases provided by Air Gas(Table 1). The furnaces are set up in a flow through configuration so that solid samples are exposed to a fixed gas composition, and quartz glass process tubes were used in all experiments (1/4” diameter for experiment V4, ½” diameter for all others). These conditions were maintained for the du-rations listed in Table 1, at which point the furnace was turned off with gas flowing until the sample was cool enough to extract under N2and be placed in a desiccator for storage. Run products were carbon coated and examined using a Hitachi SU5000 Field Emission Gun Scanning Electron Microscope (SEM) equipped with an EDAX Octane Pro EDS detector located at Wesley-an University. Visible-Near Infrared Spectroscopy (VNIR) analysis was performed on powdered samples under a nitrogen atmosphere using an ASD Fieldspec Proover the 350-2500 nm range. Powdered mineral samples were milled to a particle size of < 45μm and were spiked with an internal standard (Al2O3, corundum) to obtain quantitative mineralogy. Samples were analyzed using a Panalytical X’Pert pro X-ray Diffractometer (XRD), with an X’Celerator high speed detector and Co Kα radiation, with data collected at a step size of 0.02 ̊/minute step counting rate from 2 to 80 degrees 2θ at 45 mA/40kV in the X-ray Diffraction Laboratory located at NASA Johnson Space Center. Materials Data Inc (MDI) software suite, JadeTMv9 was used for Rietveld refinement to determine phase abundances and mineral identification by comparing XRD patterns to International Center for Diffraction Data (ICDD) database patterns. Table 1: Experimental matrix. Experiment Name Duration (Days)Gas Com-position (trace gas)MineralsV487SO2/N2(1.4%)Montmorillonite, biotiteV519SO2/N2(1.4%)CalciteV619CO2/SO2/N2(1.4% SO2, 2.1% N2)Montmorillonite, biotiteV828SO2/N2(1.4%)Biotite, calcite Results: Calcite. In both experiments, calcite was exposed to the SO2/N2gas mixture, and in both experimental run products, XRD analysis detected anhydrite, which is consistent with EDS measurements conducted in the SEM. The XRD analyses show greater amounts of anhydrite present after 28 days than 19, suggesting the calcite reaction progressed further given longer duration. Grain surface morphology as seen in the SEM also shows secondary mineral growth (Fig. 1). VNIR spectra show no change, as expected since anhydrite lacks spectral features in this wavelength range. Montmorillonite. Montmorillonite was exposed to two different gas mixtures, the SO2/N2mix and CO2/SO2/N2mix over different durations (87 and 19 days, respectively). VNIR analyses of both run products show a reduction in the 1441and1910 nm water features as well as a shift of the 1411 and 2011 nm features to shorter wavelengths that may indicate re-structuring in the crystal lattice and the production of amorphous phases [4]. XRD results are consistent with this, showing a shift of the 001 peak from 15Åto 10Åin both run products. The amount of X-ray amorphous material in the montmorillonite run products was greater than that present in the unreacted clay, being the greatest in the 87 day V4 experiment. No other secondary phases were detected in the run products, however sulfur was present in EDS analyses of powder samples.

A R Santos↗

NASA NTRS2024

Current Status of Martian Moons eXploration (MMX) Contamination Control and Curation Activity

Martian Moons eXploration (MMX) is a sample return mission from the Martian moon Phobos. The MMX spacecraft is scheduled to launch in 2026 and return to Earth in 2031. The main science goals of MMX are “to reveal the origin of the Martian moons and make progress in the understanding of planetary system formation and material transport in the solar system, and to observe processes that impact the circumplanetary and surface environments of Mars”. MMX has two sampling systems: coring (C)-sampler and pneumatic (P)-sampler and plans to bring back >10 g of Phobos sample. The retuned sample in the sample capsule will be transferred to the curation facility in ISAS/JAXA for sample curation and subsequent sample analysis. Contamination control of the sample return mission requires special care to prevent terrestrial contamination to the spacecraft, which would ruin the scientific value of the returned sample. Retaining the pristineness of the retuned sample is an important task of the MMX Curation and Sampler Science teams. The basis of the contamination control is (1) to minimize and understand the nature and amount of contaminants, (2) to perform contamination assessment and evaluate the effect of contaminants in the spacecraft on the retuned sample, (3) to employ a contamination knowledge (CK) material coupon in the spacecraft to identify the contaminants in the returned samples. In the MMX contamination control plan, the allowable contamination level for each contaminant is carefully defined. They are mostly set to be 1/1000 of the expected amount of each material in the returned sample and are divided into two main categories: organic and inorganic. The allowable atmospheric leakage rate to the sample container is also defined. The allowable contamination level of the organic materials is based on the composition of carbonaceous chondrites. The target contaminants are amino acids, aliphatic and aromatic hydrocarbons, carboxylic acids, etc. In case of the inorganic materials, the target contaminants are important elements to permit distinguishing the origin of the Martian moon by nucleosynthetic isotope anomalies (Cr, Ti, and Mo) and to reveal the evolution of the Martian moon by chronology (Hf, W, U, Pb, Rb, Sr, Sm, and Nd). The key instrument of contamination control in the sample return mission is the sampler system. The C-sampler has been developed by JAXA and the P-sampler was provided by Honeybee/NASA. In MMX, materials used in the two samplers (C- and P- sampler) were carefully selected to avoid potential contamination from the design stage of the system. The individual parts of the C-sampler FM (Flight Model) were thoroughly cleaned at the curation facility in ISAS/JAXA by the full-course cleaning procedure, which is an ultrasonic cleaning with organic solvents and ultrapure water in several steps. The equivalent level of cleaning was also carried out on the P-Samper FM as well by Honeybee Robotics in the USA. Now, MMX is in the critical phase for contamination control called ATLO: Assembly, Test, and Launch Operations. During the ATLO phase, sampler FM is constantly purged with nitrogen gas and maintained at positive pressure to prevent environmental contamination. The surrounding environments of the sampler FM are also simultaneously monitored using the CK Monitoring Coupon Set, which consists of several witness materials such as a glass petri dish, sapphire glass disk, and carbon adhesive tape (Figure 1). The detailed environmental assessment of each clean room used for the assembly and test of the sampler FM has also been conducted. This assessment includes microbial analysis, which was performed for OSIRIS-REx. Regarding the sample recovery and sample curation, we have started the designing of Sample Container Disassembling Instrument for the sample recovery from the sample container and the MMX curation chamber for sample curation. The curation protocol for the Phobos returned sample has also been discussed by the MMX Sample Analysis Working Team (SAWT). The MMX curation protocol consists of three phases: (1) quick analysis, (2) pre-basic characterization, and (3) basic characterization. (1) is extraction of the sample gas from the sample container and analysis by mass spectrometry, (2) is observation in bulk level, and (3) is observation in grain level and allocation of the sample aliquots. In parallel with the curation protocol, the returned sample undergoes preliminary examination for scientific investigations to achieve science goals. In addition, the CK witness plates made of sapphire glass are on board the sampler system. The CK witness plates will be recovered from the sampler system and analyzed by SAWT for the assessment of in-flight contamination.

Haruna Sugahara↗

NASA NTRSDate not supplied

Technology Assessment for Producing Propellant From Lunar Water

Introduction: The presence of water ice in permanently shadowed regions (PSRs) on the lunar surface may enable a sustained human presence on the Moon with minimal need for consumables. One of the most valuable uses of lunar water is to produce rocket propellant. A sustained human presence on the Moon will re-quire frequent launches from the lunar surface, and each launch will require tons of propellant. However, many other volatiles are likely to be present in the areas where lunar water is stable1. Producing propellant from lunar water in-situ will require the separation and purification of water before it can be electrolyzed into oxygen and hydrogen gas. The Resource Exploration and Science of OUR Cosmic Environment (RESOURCE) project, funded by the Solar System Exploration Research Virtual Institute (SSERVI) program, includes a task to demonstrate the end-to-end process of water extraction, capture, purification and electrolysis to produce pure/dry oxygen gas sourced from an icy regolith mixture. Water Purification: The requirements for water purity are driven by the type of water electrolyzer used. For example, the water electrolyzer currently used on the International Space Station is based on proton ex-change membrane (PEM) technology. PEM-based electrolyzers require water to be ultrapure and deionized (>10 MegaOhm-cm) so that electrical conductivity is limited to the membranes themselves, where electrical current is used to convert H2O into H2 and O2.. A practical first step toward purifying water that is sourced from a lunar PSR is to use freeze distillation to separate water from other volatiles2. A sub-micronic filter can also be used to ensure that a minimal amount of dust is present in any lunar water that is captured. The combination of freeze distillation and sub-micronic filtration will result in relatively pure water but would require a deionization step if being fed into a PEM electrolyzer. Water Electrolysis: An alternative to PEM electrolysis is to use a Solid Oxide Electrolyzer (SOE). This technology operates at a much higher operating temperature (~800oC) and has a limited pressure range but does not require water to be ultrapure and deionized. Another advantage of SOE technology is that it produces pure dry oxygen gas without the need of an additional drying step. PEM electrolyzers produce humid oxygen gas and the humidity must be removed prior to liquefaction. Assessment: In order to compare PEM and SOE technologies side-by-side, they must be compared at a system level that includes water purification and gas drying steps. Engineers at the Johnson Space Center up-dated and utilized a detailed In-Situ Resource Utilization (ISRU) system model to compare and select the best option for the RESOURCE project which will conclude with a laboratory demonstration of the process of producing pure/dry oxygen from an icy regolith mixture in 2025.

A.J. Paz↗

NASA NTRSDate not supplied

Technology Assessment for Producing Propellant From Lunar Water

ISRU↗

NASA NTRSDate not supplied

Identification and Study of Validation Level Test Cases for Computational Modeling of Non-Charring Ablators

Computational modeling of Thermal Protection System (TPS) materials, used for aerospace applications, provides numerous advantages in preliminary selection and design of a heatshield material and shape for atmospheric entry vehicles. However, to serve as a reliable tool for prediction of material thermal and ablative behavior, the modeling approach needs to be validated against real experimental and flight data, preferably at a range of applied conditions. The validation study is typically very complex as it requires reliable measured data not only for the material thermal response and surface recession, but also well characterized environmental conditions. The validation problem becomes even more complex when the material thermal response is dictated by multi-physics effects such as solid conduction, in-depth thermal decomposition, pyrolysis gas flow and chemical reactions. The multi-physics effects complicate not only the modeling effort, but also the experimental measurement for validation of various aspects of the highly coupled problem. In this study, an attempt is made to identify suitable experimental data that could serve as a source for validation of material thermal response modeling tools. To reduce the computational complexity, this study focuses only on non-charring ablators, where the material thermal response could be modeled with a single governing equation for solid conduction and the ablation is limited only to the surface of the material. With a well characterized and publicly available experimental data being sparse, the study is limited in presenting test cases for only three materials: camphor, graphite and FiberForm® in the sequence of increased modeling complexity. Graphite is a commonly used TPS material for aerospace applications, both for leading edges of high-speed vehicles and internal insulation of solid rocket motors. FiberForm® is a porous carbon pre-form used in preparation of the well known PICA material Tran et al. [1996]. Inclusion of camphor into the list is conditioned with the relative simplicity in modeling the material thermal and chemical response and the low-enthalpy flow environment. In addition, camphor has been used as a simple test material for study of flow transition behavior by Stock and Ginoux [1973] and assessment of a heatshield shape change at flight relevant conditions by Rotondi et al. [2022]. In this work, the identified experimental data was extracted from the public literature and test cases that yet have been published. As it was found from the review, not a single test case contains an exhaustive set of data that would validate every aspect of the material physics. However, in the data collected, various aspects of the material behavior can be still validated, such as surface and in-depth temperature, amount of recession and a shape change. The identified experimental data for each case is accompanied with a characterized flow environment and simulated boundary conditions predicted by a Data-Parallel Line Relaxation (DPLR) code Wright et al. [1998]. In addition, material thermal response numerical simulations in each test case are performed with Kentucky Aerothermodynamics and Thermal Response System (KATS-MR) Zibitsker et al. [2022] providing a comparative study and a sanity check for the proposed validation data. Sample results from the performed numerical study are shown below. Figure 1 shows distribution of surface heat flux and pressure values on a hemi-cylinder model made of FiberForm® and tested in HyMETS arc-jet facility. The results are shown for the high pressure condition among the two tests. Flow simulation was performed with DPLR code on a quarter of original geometry. In the figure, the quarter shape was mirrored across zx and xy planes to show the complete distribution. Figure 2 shows the material response results for the high pressure case (7500 Pa), simulated with KATS-MR and a comparison to the experimental data for the surface temperature and shape shape. The simulation was performed on a 2-D slice, extracted in the xy plane at the middle of the sample. Figure 3 shows the material response simulation for the low pressure case (3500 Pa) and a comparison to the experimental data for surface temperature and shape change.

ablation↗

NASA NTRSDate not supplied

A Transmission Electron Microscopy Study of a Refractory Metal Grain from a Calcium-Aluminum-Rich Inclusion in the Leoville CV3 Chondrite

Introduction: Calcium-aluminum-rich inclusions (CAIs) are an important component of chondritic meteorites. They can contain materials that are thermodynamically predicted and isotopically age dated to be among the first-formed solids in our solar system [1-5]. Observed in some CAIs are micron to sub-micron sized inclusions rich in Fe, Ni, and high-Z elements such as Pt, Os, Ir and W, in the form of refractory metal nuggets (RMNs), fremdlinges, and ‘nugget like objects’ (NLOs) [1,6]. Refractory siderophile elements such as Os, Ir and Ru are thermodynamically predicted to condense at temperatures well in excess of the major CAI phases such as melilite, perovskite, spinel and hibonite [2,7-9]. These refractory metal inclusions in CAIs can therefore serve as probes into the thermodynamic landscape of the early solar protoplanetary disk. Here we report on a refractory grain identified in a CAI of the Leoville CV3 chondrite. This work is part of an ongoing effort to gain insight into the thermochemistry of the early solar system through systematic analyses of the structure and chemistry of various components in CAIs [10-13]. Sample and Analytical Techniques: A fluffy type A CAI (Fig. 1A) was identified in a section of the Leoville, CV3 chondrite (Center for Meteorite Studies, Arizona State University collection, #821_C_3) using a JOEL-JXA 8530F electron microprobe at Arizona State University. Backscattered electron (BSE) imaging and energy-dispersive X-ray spectroscopy (EDS) were used to identify refractory metal grains in the CAI using a Thermo Fisher (formerly FEI) Helios NanoLab 660 G3 focused-ion-beam scanning-electron microscope (FIBSEM) located at the Kuiper Materials Imaging and Characterization Facility (KMICF) at the Lunar and Planetary Laboratory, University of Arizona. The FIB is equipped with an EDAX EDS system. We selected one of the larger (micron-sized) refractory metal grains, designated as ‘Spud’ (Fig. 1B) for further analysis. ‘Spud’ was extracted and thinned to electron transparency (<100 nm) using the FIB-SEM located in KMICF, following methods described by [14- 15]. The FIB section was analyzed using a 200 keV Hitachi HF5000 scanning transmission electron microscope (S/TEM) located at KMICF. The HF5000 is equipped with cold-field emission gun, 3rd-order spherical aberration corrector for STEM imaging, and an Oxford Instruments X-Max N 100 TLE energydispersive spectroscopy (EDS) system with dual 100 mm2 windowless silicon-drift detectors (Ω = 2.0 sr). Selected-area electron-diffraction (SAED) patterns were acquired to aid in determination of crystallinity and phase. Results: The mineralogy, texture, and morphology of the CAI are consistent with that of a fluffy type A (FTA) CAI [16]. BSE imaging at high magnifications revealed grains with high contrast, indicative of compositions rich in elements of higher atomic number relative to surrounding material. These high-Z grains have sizes that range from ∼250 nm to 4 µm. EDS analyses confirm that the bright grains are metal-rich inclusions. A minor fraction of the grains are composed of only Fe and Ni, but the majority (∼60%) of the identified inclusions also contained various refractory siderophiles including Os, Ru, Zr, Ir and Mo. EDS analysis on the FIB-SEM of Spud shows that it contains Fe, Ni, Mo and Ru. High-angle annular dark-field (HAAFD) imaging and EDS mapping in the TEM (Fig. 2) show that Spud occurs in melilite (Ca1.9Al1.99Si1.06O7). Spud contains a subhedral to anhedral morphology and is compositionally heterogenous (polyphasic, Fig. 2). Local spatial correlation occurs among Fe, Ni, and Pt, and also among Os, Ru, and Mo. SAED patterns show that the Fe-Ni-Pt, Fe-Os-Mo-Ru and Fe-Pt regions are crystalline. Discussion: CAIs can contain various types of inclusions rich in Fe, Ni and refractory siderophiles such as Os, Ru, W and Pt [1]. RMNs are micron-sized, single phase alloy grains and can contain Os, Ir, Ru and Rh [1,7,17]. NLOs are also micron-sized inclusions, but contain two phases, a refractory metal, and an oxide [6]. Fremdlinge are the largest of such inclusions (tens of microns in size) and are complex aggregates of Fe-Ni alloy, silicates, oxides, and sulfides [1,17]. While the size of Spud matches previous descriptions of RMNs and NLOs, Spud is neither a single-phase alloy like RMNs, nor does it contain one metal phase and one oxide like NLOs. Spud does not match the above described categories of refractory metal inclusions. The presence of refractory siderophiles such as Mo, Os, Ru, and Pt suggests a high-temperature origin. Thermodynamic modelling by [7] indicates condensation temperatures of 1917 K, 1693 K, 1613 K and 1415 K for Os, Mo, Ru and Pt respectively. These models also show that following the initial condensation of a refractory metal, alloying of solutes such as Fe, Ni and W, occurs in levels proportional to their partial pressures in the surrounding gas. Such alloying occurs at temperatures above the condensation temperatures of common CAI phases such as melilite (1529 K), perovskite (1441 K), spinel (197 K) and forsterite (1354 K) [2]. The polyphasic nature of Spud could be the result of such high-temperature alloying, possibly shortly after the condensation of Mo and Ru at 1693 K and 1613 K respectively. That Spud occurs as an inclusion is consistent with it having formed prior to and at temperature above that of its host melilite in this FTA CAI, which is qualitatively consistent with such prior thermodynamic modeling. Further, the polyphasic nature of Spud is similar to refractory grains from a FTA CAI in the Northwest Africa (NWA) 8323, CV3 chondrite [11-13]. These data suggest that such refractory metal grains could have been widespread in the inner and early solar protoplanetary disk and represent some of the earliest formed solids to have condensed. Acknowledgments: Research and instrumentation supported by NASA grants #NNX12AL47G, #NNX15AJ22G and #80NSSC19K0509, and NSF grants #1531243 and #0619599. Fig 2. STEM data on ‘Spud’. HAADF Image (Top) False-color EDS Maps (Bottom) References: [1] MacPherson G. J. (2014) T. of Geochem. Vol I: Met. And Cosmochem. Processes, 139-179. [2] Lodders K. (2003) ApJ, 591, 1220-1247. [3] Ebel D. S. (2006) Met. & the Early S. Sys. II., 253- 277. [4] Amelin Y. (2002) Science, 297, 1678-1683. [5] Connelly J.N. et.al. (2012) Science, 338, 651-655. [6] Schwander D. et al. (2015) GCA, 18, 70-87. [7] Palme H. and Wlotzka F. (1976) EPSL, 33, 45-60. [8] Berg T. et al. (2009) ApJ, 702, 172-176. [9] Liffman K. et al. (2021) Icarus, 221, 89-105. [10] Zega T.J. et al. (2021) PSJ, 2, 115. [11] Ramprasad T. et al. (2020) LPSC LI, Abstract #2472. [12] Ramprasad T. et al. (2021) Microscopy & Microanalysis, S1, 2792-2794. [13] Ramprasad T. et al. (2021) 84th MetSoc, Abstract #6123. [14] Zega T.J. et al. (2007) MAPS, 42, 1373-1386. [15] Ramprasad T. et al. (2022) MAPS, in revision. [16] Grossman L. (1975), GCA, 39, 433-454. [17] El Goresy A. et al. (1978) LPSC IX, Abstract#1100

T. Ramprasad↗