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E. B. Rampe

Publications and source records attributed to E. B. Rampe.

18 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Evolved Gas Analyses of Sedimentary Rocks from the Glen Torridon Clay-Bearing Unit, Gale Crater, Mars: Results From the Mars Science Laboratory Sample Analysis at Mars Instrument Suite

Evolved gas analysis (EGA) data from the Sample Analysis at Mars (SAM) instrument suite indicated Fe-rich smectite, carbonate, oxidized organics, Fe/Mg sulfate, and chloride in sedimentary rocks from the Glen Torridon (GT) region of Gale crater that displayed phyllosilicate spectral signatures from orbit. SAM evolved H2O data indicated that the primary phyllosilicate in all GT samples was an Fe-rich dioctahedral smectite (e.g., nontronite) with lesser amounts of a phyllosilicate such as mixed layer talc-serpentine or greenalite-minnesotaite. CO(2) data supported the identification of siderite in several samples, and CO(2) and CO data was also consistent with trace oxidized organic compounds such as oxalate salts. SO(2) data indicated trace and/or amorphous Fe sulfates in all samples and one sample may contain Fe sulfides. SO(2) data points to significant Mg sulfates in two samples, and lesser amounts in several other samples. A lack of evolved O(2) indicated the absence of oxychlorine salts and Mn3+/Mn4+ oxides. The lack of, or very minor, evolved NO revealed absent or very trace nitrate/nitrite salts. HCl data suggested chloride salts in GT samples. Constraints from EGA data on mineralogy and chemistry indicated that the environmental history of GT involved alteration with fluids of variable redox potential, chemistry and pH under a range of fluid-to-rock ratio conditions. Several of the fluid episodes could have provided habitable environmental conditions and carbon would have been available to any past microbes though the lack of significant N could have been a limiting factor for microbial habitability in the GT region.

A. C. McAdam↗
NASA NTRS2022

X-Ray Amorphous Sulfur-Bearing Phases in Sedimentary Rocks of Gale Crater, Mars

The Curiosity rover in Gale crater is investigating a mineral transition observed from orbit—an older “clay unit” to a younger “sulfate unit”—hypothesized to reflect the aridification of Mars' climate. Below this transition, the rover detected crystalline Ca-sulfates with minor Fe-sulfates but also found that some fraction of a rock's bulk SO 3 is often in the poorly constrained X-ray amorphous component. Here, we characterize the abundances and compositions of the X-ray amorphous sulfur-bearing phases in 19 drilled samples using a mass balance approach, and in a subset of 5 samples using evolved SO 2 gas measured using the SAM instrument. We find that ∼20–90 wt% of a sample's bulk SO 3 is in the X-ray amorphous state and that X-ray amorphous sulfur-bearing phase compositions are consistent with mixtures of Mg-S, Fe-S, and possibly Ca-S phases, likely sulfates or sulfites. These phases reside in the bedrock, perhaps as cementing agents deposited with detrital sediments or during early diagenesis, and in diagenetic alteration halos deposited after lithification during late diagenesis. The likely presence of highly soluble Mg-sulfates in the rocks suggests negligible fluid flow through the bedrock post-Mg-sulfate deposition. The X-ray amorphous sulfur-bearing phases probably became amorphous through dehydration in the current Martian atmosphere or inside the CheMin instrument. X-ray amorphous sulfur-bearing materials likely contribute to orbital spectral detections of sulfates, and so our results help form multiple hypotheses to be tested in the sulfate unit and are important for understanding the evolution of the Martian surface environment at Gale crater.

R. J. Smith↗
NASA NTRS2020

Mineralogy of Vera Rubin Ridge from the Mars Science Laboratory CheMin Instrument

Vera Rubin ridge (VRR) is an erosion-resistant feature on the northwestern slope of Mount Sharp in Gale crater, Mars, and orbital visible/short-wave infrared measurements indicate it contains red-colored hematite. The Mars Science Laboratory Curiosity rover performed an extensive campaign on VRR to study its mineralogy, geochemistry, and sedimentology to determine the depositional and diagenetic history of the ridge and constrain the processes by which the hematite could have formed. X-ray diffraction (XRD) data from the CheMin instrument of four samples drilled on and below VRR demonstrate differences in iron, phyllosilicate, and sulfate mineralogy and hematite grain size. Hematite is common across the ridge, and its detection in a gray-colored outcrop suggested localized regions with coarse-grained hematite, which commonly forms from warm fluids. Broad XRD peaks for hematite in one sample below VRR and the abundance of FeOT in the amorphous component suggest the presence of nano-crystalline hematite and amorphous Fe oxides/oxyhydroxides. Well-crystalline akaganeite and jarosite are present in two samples drilled from VRR, indicating at least limited alteration by acid-saline fluids. Collapsed nontronite is present below VRR, but samples from VRR contain phyllosilicate with d(001) = 9.6 Å, possibly from ferripyrophyllite or an acid-altered smectite. The most likely cementing agents creating the ridge are hematite and opaline silica. We hypothesize late diagenesis can explain much of the mineralogical variation on the ridge, where multiple fluid episodes with variable pH, salinity, and temperature altered the rocks, causing the precipitation and crystallization of phases that are not otherwise in equilibrium.

E. B. Rampe↗
NASA NTRS2018

Reactive Transport and Mass Balance Modeling of the Stimson Sedimentary Formation and Altered Fracture Zones Constrain Diagenetic Conditions at Gale Crater, Mars

On a planet as cold and dry as present-day Mars, evidence of multiple aqueous episodes offers an intriguing view into very different past environments. Fluvial, lacustrine, and eolian depositional environments are being investigated by the Mars Science Laboratory Curiosity in Gale crater, Mars. Geochemical and mineralogical observations of these sedimentary rocks suggest diagenetic processes affected the sediments. Here, we analyze diagenesis of the Stimson formation eolian parent material, which caused loss of olivine and formation of magnetite. Additional, later alteration in fracture zones resulted in preferential dissolution of pyroxene and precipitation of secondary amorphous silica and Ca sulfate. The ability to compare the unaltered parent material with the reacted material allows constraints to be placed on the characteristics of the altering solutions. In this work we use a combination of a mass balance approach calculating the fraction of a mobile element lost or gained, tau, with fundamental geochemical kinetics and thermodynamics in the reactive transport code CrunchFlow to examine the characteristics of multiple stages of aqueous alteration at Gale crater, Mars. Our model results indicate that early diagenesis of the Stimson sedimentary formation is consistent with leaching of an eolian deposit by a near-neutral solution, and that formation of the altered fracture zones is consistent with a very acidic, high sulfate solution containing Ca, P and Si. These results indicate a range of past aqueous conditions occurring at Gale crater, Mars, with important implications for past martian climate and environments.

Gale↗
NASA NTRSDate not supplied

Mineralogy of the Greenheugh Pediment and Underlying Murray Formation from the Mars Science Laboratory CheMin Instrument

The Mars Science Laboratory Curiosity rover has been investigating a sequence of ancient fluvio-lacustrine and eolian units in Gale crater. For much of the mission, Curiosity has studied the fluvio-lacustrine deposits of the Murray formation. Curiosity has also studied the ancient eolian Stimson formation in a few locations, which unconformably overlies the Murray fm. The Stimson formation was previously studied at the Naukluft and Emerson Plateaus and recently studied at the Greenheugh pediment capping unit. The Curiosity science team also investigated the Murray formation directly underlying the pediment. Curiosity drilled the “Edinburgh” target within the pediment capping unit and the “Hutton” target in the Murray formation near the contact with the pediment and delivered these materials to the CheMin X-ray diffractometer to characterize bulk mineralogy. Edinburgh contains abundant plagioclase, pyroxene, magnetite, olivine, and X-ray amorphous materials, with 10 wt.% smectite and minor sanidine. The mineralogy of the Stimson at Greenheugh is distinct from the mineralogy of the Stimson at Naukluft and Emerson because previous Stimson targets did not contain olivine or clay minerals. This suggests sediments in the pediment may have a different source and/or different aqueous alteration history than those from Naukluft and Emerson. Hutton contains abundant plagioclase, pyroxene, magnetite, and X-ray amorphous materials, 6 wt.% smectite, and minor cristobalite, opal-CT, sanidine, hematite, fluorapatite, and anhydrite. Other Murray targets in the surrounding Glen Torridon region that are farther from the pediment contact contain ~30 wt.% smectite and lack cristobalite and opal-CT. Cristobalite and/or opal-CT are present in a few other targets elsewhere along the traverse, including the top of the nearby Vera Rubin ridge and the top of the Pahrump Hills outcrop. Stimson overlies the Pahrump Hills, and, based on projections of the pediment slope, the Stimson may have overlain Vera Rubin ridge. The proximity of the low-smectite and cristobalite- and/or opal-CT-bearing outcrops to the contact between the Murray and Stimson suggests the contact provided a conduit for diagenetic fluids that altered clay minerals and formed crystalline and paracrystalline silica.

E. B. Rampe↗
NASA NTRSDate not supplied

The Mineralogy and Sedimentary History of the Glen Torridon Region, Gale Crater, Mars

Gale crater was selected as Curiosity’s landing site largely because, from orbit, phyllosilicate-rich strata were identified on the slopes of Mt. Sharp. This phyllosilicate unit was later dubbed the Glen Torridon (GT) region, and the rover has been traversing this region since early January 2019. On Earth, phyllosilicates in the rock record preserve a history of aqueous conditions, overprinted with paleoclimate and environmental signatures. Thus, the GT is a highly anticipated region of exploration in Gale crater, and the mineralogy of its sedimentary rocks may provide clues to its ancient origin.

M. T. Thorpe↗
NASA NTRSDate not supplied

Characterizing Martian X-ray Amorphous Materials through Terrestrial Analogs

X-ray amorphous materials (i.e., lacking long-range crystallographic order) have been identified on the martian surface from orbit and in-situ. Initial models of orbital IR spectral data identified volcanic glasses [e.g., 1], but subsequent interpretations suggested that amorphous silicates are dominantly secondary in nature and formed from water-rock interactions [e.g., 2-4]. ThermalIR spectra from the Mini-Thermal Emission Spectrometer on the Spirit rover show evidence for the amorphous secondary product opaline silica[e.g., 5].X-ray diffraction (XRD) measurements by the CheMin instrument on the Mars Science Laboratory rover have identified 20-70 wt.% amorphous materials in every sample analyzed in Gale crater to date [e.g., 6]. Mass balance calculations using CheMin results and bulk elemental measurements by the Alpha Particle X-ray Spectrometer suggest the amorphous component in Gale crater is variably enriched in Si, Fe, and S[e.g., 7,8].The compositions are not consistent with pure volcanic glass, indicating water must have been involved in the formation of amorphous materials in Gale crater. We seek to better constrain the conditions under which amorphous materials on Mars formed by studying the composition and short-range atomic order of amorphous materials in terrestrial analog environments via XRD and transmission electron microscopy (TEM).

E. B. Rampe↗
NASA NTRSDate not supplied

Recent Mineralogical Discoveries in Gale Crater, Mars from the CheMin XRD Instrument

Curiosity landed in Gale crater in August 2012 and has traversed ~27 km through sedimentary rocks that comprise the lower slopes of a ~5 km-high mound, informally known as Mount Sharp, to investigate depositional/diagenetic environments and potential habitability. Orbital visible/short-wave infrared spectra revealed some strata on lower Mount Sharp contain mineral assemblages that are indicative of water-rock interactions (1-3), with sulfate-bearing units overlying phyllosilicate-bearing units. This mineralogical succession may mark the beginning of the transition from a relatively wet/warm to a very dry/cold Mars (e.g., 1, 4). Curiosity began studying the strata that show mineralogical signatures from orbit in 2018, with the investigation of Vera Rubin ridge. Here, we describe the mineralogical diversity in these strata using X-ray diffraction data collected by the CheMin instrument. We report on the mineral assemblages from the hematite-rich Vera Rubin ridge, the smectite-rich Glen Torridon region, and the transition from the smectite-bearing rocks to the sulfate-bearing unit. We will present hypotheses explaining the changes in mineralogy throughout the strata, including changes in depositional environment, diagenetic reactions with saline groundwater, and groundwater-lake water interactions (e.g., 5-7).

V. M. Tu↗
NASA NTRSDate not supplied

Importance of Sulfur for Phosphorus Mobility on the Martian Surface

Sulfur and phosphorus were mobile on the martian surface, and we present evidence that sulfate was likely a control on phosphate mobility. Mobility of the two elements on the martian surface is crucial for the habitability of Mars because their availability for biochemical reactions and biological structures is a major constraint on life. In the sedimentary rocks of Gale crater, the rover Curiosity has discovered evidence of mobile S and P with the alpha particle X-ray spectrometer (APXS). Sulfur-rich fluids are evident in ubiquitous Ca-sulfate veins that crosscut the bedrock. Compelling evidence of P mobility is in nodules, veins, crusts, and haloes with P2O5 enrichments (1.5-7.5 wt%) relative to the median bedrock (0.9-1.2 wt%) and average basaltic crust (~0.9 wt%). We have investigated phosphorus mobility in Hawaiian analogues, where the primary P2O5 (0.2-2.1 wt%) is contained in Ca-apatite. Four relevant processes have emerged: (1) In open-system, circumneutral regolith weathering profiles, we found up to 40% of the P was leached over 10s-100s ka. (2) Natural acid-sulfate alteration at the Maunakea summit resulted in the dissolution of apatite and mobilization of phosphate 10s-1000s µm to rock surfaces where it formed Al-phosphates and substituted into crystalline sulfates (alunite and jarosite). (3) Experimental results indicate that basaltic sediment chemisorbs phosphate (pH < 7). (4) In experimental systems containing water, basaltic sediment, and a starting pH = 2-7, phosphate has higher solubility in chloride-rich fluids, but significantly lower solubility in sulfate-rich fluids. For example, in water doped with phosphate (~100-500 mg/L), ~60-80% of the PO43- was removed from the sulfate-rich fluid, whereas ~20% of the PO43- was removed from the Cl-rich and pure water fluids (likely via adsorption). Gypsum precipitated from the sulfate-rich fluids; the fate of phosphate in the solid residue is unconfirmed. The potential for phosphate incorporation in martian sulfates is reflected in the enrichment of P2O5 in Gale Ca-sulfate veins, based on preliminary analyses of APXS data. Models for the mobility of phosphorus in Gale crater should consider these conflicting P characteristics: (1) P solubility may have been inhibited by sulfate and (2) P¬ is enriched in diagenetic features and was therefore mobile.

Jeff A. Berger↗
NASA NTRSDate not supplied

Mineralogical Evidence for Environmental Change in the Clay-Sulfate Transition at Gale Crater, Mars

A primary reason for selecting Gale crater as the Mars Science Laboratory (MSL) Curiosity rover landing site was a clear mineralogical transition from Fe/Mg smectite in older strata to hydrated Mg sulfate salts in younger strata observed in orbital visible/shortwave-infrared reflectance data. This transition has been observed in other early-Hesperian terrains on Mars and has been hypothesized to signal a planet-wide change in climate from relatively warm and wet to cold and dry. Curiosity studied the sedimentology and geochemical and mineralogical composition of rocks in this “clay-sulfate transition” region from sols 3052 to 3572 (i.e., March 2021 to August 2022), with arrival at the sulfate unit on sol 3574. Here, we report on the mineralogical measurements made by the CheMin X-ray diffractometer of the six drill targets in the clay-sulfate transition and the first drill target in the sulfate unit. We use compositional data and sedimentological observations to interpret depositional and diagenetic environments and present hypotheses to explain the transition from clay minerals to hydrated Mg sulfates.

E. B. Rampe↗
NASA NTRSDate not supplied

High Resolution Imaging and Analysis of Terrestrial Impact Glass: Amorphous Materials, Phyllosilicates and Everything in Between

Introduction: Impact cratering is one of the most ubiquitous geologic processes shaping the surface of all solid bodies in our solar system. Impacts are also a major source of clay minerals, poorly crystalline clay-like phases and amorphous (i.e., lacking long-range atomic order) materials on Earth and Mars. Phyllosilicates and amorphous materials have consistently formed a major component (~20-70 wt%) of every single drilled rock and soil sample in Gale Crater on Mars, as determined by the CheMin instrument on Curiosity. The origin of the amorphous component is speculative, but could be primary impact or volcanic-produced glass(es) deposited via aeolian or fluvial processes, secondary aqueous alteration products or chemical precipitates; it is likely to be a combination of all three possibilities. Efforts to determine the composition of these materials across the rover’s traverse through Gale Crater are ongoing. Naturally occurring amorphous phases are found in a variety of environments on Earth, and terrestrial analogue studies may help shed light on how they may have formed on Mars. Primary and altered impact glass are likely widespread on Mars and may have contributed to the amorphous component found throughout Gale Crater. In its pristine, unaltered state, impact glass (i.e., melt glass) is considered amorphous. However, truly unaltered glass is rarely preserved in crater fill impactites as it quickly alters in the post-impact environ-ment, commonly forming a mixture of hydrated aluminosilicate phases whose structures are not always discernable at the microscale (i.e., they may be amorphous or contain short-range order). These phases are part of an incredibly complex group of materials; differences in their composition and crystalline structure (or lack thereof) and genetic relationship to the more well-crystalline clay minerals are often only discernable at the nanoscale, beyond the resolution of traditional X-ray diffractometers (XRD) and scanning electron microscopes/microprobes (SEM/EPMA) alone. In this contribution, we summarize recent results from ongoing characterization of clay minerals, poorly crystalline clay-like phases, and amorphous materials preserved in altered terrestrial impact glass from the Chicxulub (~66 Ma) and Ries (~15 Ma) impact structures. This work has been performed using a combination of high-resolution transmission electron microscopy (HR-TEM), SEM, microprobe/EPMA, Raman spectroscopy and XRD.

Impact crater↗
NASA NTRSDate not supplied

Warm-Based Glacial Landforms and Past Climate Signals: Icelandic Eskers as Proxies for Small Sinuous Ridges on Mars

The surface of Mars exhibits plentiful geomorphic evidence for glacial processes, but the history of the cryosphere on Mars remains debated [e.g., 1, 2]. Recent hydrological modeling predicts that warm-based ice sheets on Mars may have resulted in subglacial incised channels (e.g., valley networks) and eskers [3]. Evidence on Mars for warm-based glaciation includes candidate moraines, bedrock channels, and candidate eskers [e.g., 4-6]. Eskers are sinuous ridges comprising glaciofluvial sediments deposited by meltwater flowing through tunnels at the bed of warm-based large glaciers [e.g., 7, 8]. They provide direct evidence of basal melting of ice and preserve glaciofluvial sediments. Warm-based glacial transport is primarily driven by meltwater and can chemically weather the underlying bedrock. An alternative signature of past climate on Mars may thus be the geochemical record, due to alteration by interactions with glacial meltwater, preserved in esker sediments and strata. At present, the sedimentology and stratigraphy of terrestrial eskers is poorly understood. This study will combine sedimentology, geochemistry, and geomorphology to better constrain the unique properties of eskers resulting from warm-based glaciation on Mars-like substrates by leveraging a natural laboratory in Iceland.

A. M. Rutledge↗
NASA NTRSDate not supplied

Hematite Formation and Growth in Gale Crater Seen Through MSL Chemin X-Ray Diffraction Data

For more than 10 Earth years, the Mars Science Laboratory (MSL) Curiosity rover has been studying modern sediments and ancient sedimentary rocks deposited by lacustrine, fluvial, deltaic, and eolian processes in Gale crater. The mineral and X-ray amorphous abundances in rocks and sediments have been quantified via X-ray diffraction (XRD) data from the CheMin instrument. The received data demonstrate significant mineralogical variations within the stratigraphy, including changes in the type and abundances of Fe-oxides/oxyhydroxides silica polymorphs, phyllosilicates, and sulfate minerals. Characterizing Fe-oxides/oxyhydroxide minerals in Gale crater is especially important for constraining past aqueous environments because their formation depends on a variety of conditions, including pH, Eh, temperature, and salinity. Hematite, magnetite, goethite, and akaganeite have been identified by CheMin in different portions of the stratigraphic section. Hematite is the most prevalent Fe-bearing oxide mineral and has been detected (>1 wt.%) in 34 of the studied 36 drill targets. Variations in hematite crystallite size were reported in association with Vera Rubin ridge, which has a strong hematite signature in orbital reflectance spectroscopy. Here, we calculate hematite crystallite sizes and shapes for the entire stratigraphic section to date, to characterize trends and evaluate the processes by which hematite formed and transformed in Gale crater.

M. Szczerba↗
NASA NTRSDate not supplied

Using Mineralogy to Interpret Martian Geologic History

The surface mineralogy of Mars is key to interpreting the planet’s geologic history and constraining when and where Mars may have been habitable to microbial life. Orbital mineralogical data from infrared spectrometers collected over the last two decades have demonstrated that Mars is more than a basaltic planet. Thermal infrared (TIR) emission spectrometers have identified regional variations in igneous minerals, iron oxides, and chloride salts, showing evidence for magmatic evolution and aqueous alteration. Orbital visible/shortwave infrared reflectance spectra provide detailed information about the aqueous history of Mars through the identification of clay minerals, sulfates, carbonates, zeolites, and amorphous materials in ancient ~3-4-billion-year-old terrains. Mineralogical data from rovers allow us to better characterize mineral formation mechanisms by identifying mineral assemblages and placing them in geologic context using outcrop- to grain-scale images. TIR and Mössbauer data from the Mars Exploration Rovers helped identify an ancient dune-interdune playa environment with multiple episodes of groundwater at Meridiani Planum and volcanism-induced hydrothermalism at Gusev crater. The CheMin X-ray diffractometer on the Mars Science Laboratory Curiosity rover in Gale crater is the first fully quantitative mineralogical instrument sent to another planetary surface. CheMin data allow the quantification of minerals and X-ray amorphous materials with a mineral detection limit of <1 wt.% and provide crystal chemistry of major phases from refined unit-cell parameters. CheMin has revealed local mineralogical changes in ancient sedimentary rocks not seen from orbit and helped identify habitable environments. Throughout the 600+ m of vertical stratigraphy studied so far, changes in clay mineralogy, Fe-oxides/oxyhydroxides, sulfates, and carbonates demonstrate a long history of surface and groundwater at Gale crater with variable salinity, pH, Eh, and temperature. Recent CheMin data document a decrease in clay minerals and an increase in sulfate minerals in younger strata that corresponds with a change from fluvio-lacustrine to eolian depositional environments, potentially documenting a change to a drier climate across the planet.

E. B. Rampe↗
NASA NTRSDate not supplied

Advances in X-ray Instruments to Support Mars Sample Return

The Mars 2020 Perseverance rover is currently collecting drill cores of ancient igneous and sedimentary rock in and around Jezero crater for potential transport to Earth. These samples from the martian surface will enable detailed mineralogical, geochemical, and petrological measurements to characterize ancient depositional and diagenetic environments, quantitatively age-date the samples, and identify the building blocks for life or evidence for life itself. Furthermore, these drill cores are especially precious because they may represent the most pristine samples from the martian surface and our best chance at identifying martian life, as future sample return missions may be conducted by humans that can introduce biological contaminants to the samples. Because of the importance of these samples, we must take great care in their handling, curation, and preliminary analyses so that they are preserved for scientific measurements for decades to come. In-situ measurements by Perseverance have identified minerals that further warrant special treatment of the returned samples. Hydrated sulfate carbonate, swelling clay minerals, and oxychlorine salts are extremely sensitive to changes in temperature and relative humidity. The structures of hydrated sulfates and oxychlorine minerals, in particular, readily change when exposed to different conditions, meaning the mineral assemblage of the as-returned samples may be lost if the samples aren’t handled properly. Characterizing the as-returned mineral assemblage, particularly of the salts, is essential for reconstructing past aqueous conditions and habitability. To characterize the as-returned mineral assemblage, the samples must be analyzed rapidly before phase changes occur and/or under controlled conditions (e.g., within a glove box). Significant recent advances in X-ray instrumentation for robotic exploration of the solar system have resulted in high-resolution miniaturized instruments that would provide mineralogical, geochemical, and petrological information on the returned martian samples without degradation of the mineral assemblage. Here, we describe a combined X-ray diffractometer/X-ray fluorescence spectrometer (XRD/XRF), an X-ray computed tomographic (XCT) instrument, and a scanned beam XRF mapping instrument that could be used in a glove box so that the martian samples remain under controlled conditions.

E. B. Rampe↗
NASA NTRSDate not supplied

Mineralogical, Elemental, and Tomographic Reconnaissance Investigation for CLPS (METRIC): A Payload Designed for Exploration of Terrestrial Planetary Bodies

Geological materials (indeed, all solid objects) are characterized by their crystal structure, elemental composition, and morphology. The Mineralogical, Elemental, and Tomographic Reconnaissance Investigation for CLPS (METRIC) instrument suite quantifies all three. These measurements address fundamental science questions (e.g., the origin and evolution of planetary bodies) and support the human exploration of space (e.g., the characterization of regolith for ISRU and the constraint of its geotechnical properties). METRIC comprises an X-ray Diffraction/X-ray Fluorescence instrument (XRD: mineral structure and XRF: elemental composition), an X-ray micro-Computed Tomography instrument (XCT: 3D internal micromorphology), and a hyperspectral imaging infrared spectrometer (IRS) to provide local/regional mineralogic context for these measurements. METRIC XRD/F draws heritage from the highly successful Mars Science Laboratory CheMin instrument. The METRIC XRD/F employs two separate sample cells, one optimized for XRD and one for XRF, resulting in more rapid XRD analysis (tens of minutes vs. tens of hours for CheMin) and an orders-of-magnitude improvement in XRF detection. XCT has not been deployed in space, so the METRIC XCT represents a new capability for solar system exploration. The XCT uses the same basic high-TRL components as METRIC XRD/F, decreasing its development cost for flight. The METRIC IRS is a derivative of the NASA Earth Science Technology Office funded Hyperspectral Thermal Imager instrument and utilizes the NASA Technology Transfer Program to incorporate a commercial-of-the-shelf infrared camera ruggedized for space by NASA Marshall Space Flight Center. The IRS spectral range (8–14 µm) and resolution (10.8 cm -1 ) are tailored to quantify mineralogy in rocks using their characteristic Reststrahlen bands and to characterize mineralogy of soils using the position of the Christensen Feature. The METRIC payload is currently designed for deployment to the Moon on a Commercial Lunar Payload Services (CLPS) mission, where the XRD/F and XCT would be located on a lander and the IRS would be on deployed on a companion rover to evaluate the mineralogical diversity of the landing site. A pneumatic drill designed by Honeybee Robotics would excavate regolith up to 50 cm below the lander and deliver multiple aliquots of regolith to the XRD/F and XCT. The METRIC payload could also be deployed on a rover. In this case, a sample handling system on a robotic arm could scoop regolith and/or drill rocks and deliver powder to the XRD/F and XCT located in the rover’s interior. Alternatively, METRIC instruments could be used singly or in combination on human space missions. The XRD/F and XCT could be used to characterize samples in a rover or in a science laboratory within a habitat. These data could help astronauts identify resource-enriched rocks and regolith and triage geologic samples to return samples of high interest for analysis in terrestrial laboratories. The IRS could be attached to a human-navigated rover to collect mineralogical data along a traverse and identify high-priority science samples.

E. B. Rampe↗