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Graff, Trevor G.

Publications and source records attributed to Graff, Trevor G..

15 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Perseverance’s Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) Investigation

The Scanning Habitable Environments with Raman and Luminescence for Organics and Chemicals (SHERLOC) is a robotic arm-mounted instrument on NASA’s Perseverance rover. SHERLOC has two primary boresights. The Spectroscopy boresight generates spatially resolved chemical maps using fluorescence and Raman spectroscopy coupled to microscopic images (10.1 μm/pixel). The second boresight is a Wide Angle Topographic Sensor for Operations and eNgineering (WATSON); a copy of the Mars Science Laboratory (MSL) Mars Hand Lens Imager (MAHLI) that obtains color images from microscopic scales (~13 μm/pixel) to infinity. SHERLOC Spectroscopy focuses a 40 μs pulsed deep UV neon-copper laser (248.6 nm), to a ~100 μm spot on a target at a working distance of ~48 mm. Fluorescence emissions from organics, and Raman scattered photons from organics and minerals, are spectrally resolved with a single diffractive grating spectrograph with a spectral range of 250 to ~370 nm. Because the fluorescence and Raman regions are naturally separated with deep UV excitation (<250 nm), the Raman region ~ 800 – 4000 cm -1 (250 to 273 nm) and the fluorescence region (274 to ~370 nm) are acquired simultaneously without time gating or additional mechanisms. SHERLOC science begins by using an Autofocus Context Imager (ACI) to obtain target focus and acquire 10.1 μm/pixel greyscale images. Chemical maps of organic and mineral signatures are acquired by the orchestration of an internal scanning mirror that moves the focused laser spot across discrete points on the target surface where spectra are captured on the spectrometer detector. ACI images and chemical maps (< 100 μm/mapping pixel) will enable the first Mars in situ view of the spatial distribution and interaction between organics, minerals, and chemicals important to the assessment of potential biogenicity (containing CHNOPS). Single robotic arm placement chemical maps can cover areas up to 7x7 mm in area and, with the < 10 min acquisition time per map, larger mosaics are possible with arm movements. This microscopic view of the organic geochemistry of a target at the Perseverance field site, when combined with the other instruments, such as Mastcam-Z, PIXL, and SuperCam, will enable unprecedented analysis of geological materials for both scientific research and determination of which samples to collect and cache for Mars sample return.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS2020

Flight Readiness of Mochii ISS-NL Portable Spectroscopic Electron Microscope

Electron microscopes (EM’s), are workhorse tools serving diverse fields such as materials science, biological science, and engineering. Scanning EM’s (SEM’s) in particular enable high magnification study and pinpoint chemical analyses of structures down to the nanoscale by providing a powerful blend of strong optical scattering, high native resolution, large depth of focus, and energy-dispersive X-ray spectroscopy (EDS). Mochii is the world’s smallest production electron microscope, scheduled to travel to the International Space Station (ISS) this spring where it will serve as an ISS National Laboratory (ISSNL) microgravity facility on successful demonstration. We previously reported on progress preparing Mochii for space flight, in particular flight integration verifications and science application testing. These included standard integration testing such as electromagnetic interference and flight vibration, and extend to unique functional testing such as magnetic susceptibility and extreme analog environment testing under the sea. Presently, Mochii payload flight hardware has completed testing and was handed over to NASA’s ISS payload processing facility in Houston. It will make its way to the the east coast for launch currently scheduled on Space-X CRS-20 for Mission increment 62 in March 2020.

Own, C. S.↗
NASA NTRS2018

Field Camp for Astronauts: NASA's Geoscience Training Program for Planetary Exploration

Fifty years ago Apollo astronauts walked on the Moon to explore the geology and collect samples for Earth return. Several authors have discussed the strategic planning and training that enabled the Apollo successes, and assembled recommendations regarding today’s lunar science objectives and astronaut training required to achieve those science goals. Since the 1980s, geoscience training for astronauts focused on observing the Earth from orbit. Today, we are building a geoscience training program to support informed Earth observations as well as the exploration culture for future human missions to the Moon and Mars. Our team partnered with JSC’s crew training and astronaut offices to develop our 4-week geoscience program for the 2017 astronaut class. Because the astronauts have a variety of professional backgrounds, we provide a broad introduction to Earth and planetary sciences. But our prime focus is 2 weeks of intensive field work, a methodology introduced with the 2013 astronaut class. We completed the first half of the training – a field trip to observe hurricane deposits along Galveston Bay; keynotes by Apollo colleagues highlighting Apollo experiences; a tightly-integrated week of introductory geology in the classroom followed by a week of fieldwork in the Rio Grande del Norte National Monument. The classroom included interactive map exercises that allowed the students to progressively build a base map of the field area that they used as a starting point for their week-long mapping exercise. We divided the class into small mapping groups to conduct their observations, mapping and interpretation of the geology. In addition to learning geological field work, our field training provided the platform for practicing expeditionary leadership, a key skill set valued by NASA for astronaut crews. Next summer the capstone fieldwork for the 2017 astronauts will include both mapping and rock sampling. Throughout the mapping, the class will collect additional data to help inform field and sampling decisions using diagnostic field instruments that are being tested in analog settings for their operational efficacy for future planetary exploration.

Evans, Cynthia A.↗
NASA NTRS2017

Integration of an Earth-Based Science Team During Human Exploration of Mars

NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. A mission was undertaken in 2016, NEEMO 21, at the Aquarius undersea research habitat. During the mission, the effects of varied oper-ations concepts with representative communication latencies as-sociated with Mars missions were studied. Six subjects were weighed out to simulate partial gravity and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) who provided input and direction during exploration activities. Exploration traverses were planned in advance based on precursor data collected. Subjects completed science-related tasks including presampling surveys and marine-science-based sampling during saturation dives up to 4 hours in duration that simulated extravehicular activity (EVA) on Mars. A communication latency of 15 minutes in each direction between space and ground was simulated throughout the EVAs. Objective data included task completion times, total EVA time, crew idle time, translation time, ST assimilation time (defined as time available for the science team to discuss, to review and act upon data/imagery after they have been collected and transmitted to the ground). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. In addition, comments from both the crew and the ST were captured during the post-mission debrief. Here, we focus on the acceptability of the operations concepts studied and the capabilities most enhancing or enabling in the operations concept. The importance and challenges of designing EVA time-lines to account for the length of the task, level of interaction with the ground that is required/desired, and communication latency, are discussed.

Chappell, Steven P.↗
NASA NTRS2016

Is Tridymite at Gale Crater Evidence for Silicic Volcanism on Mars?

The X-ray diffraction (XRD) instrument (CheMin) onboard the MSL rover Curiosity detected 17 wt% of the SiO2 polymorph tridymite (relative to bulk sample) for the Buckskin drill sample (73 wt% SiO2) obtained from sedimentary rock in the Murray formation at Gale Crater, Mars. Other detected crystalline materials are plagioclase, sanidine, cristobalite, cation-deficient magnetite, and anhydrite. XRD amorphous material constitutes approx. 60 wt% of bulk sample, and the position of its broad diffraction peak near approx. 26 deg. 2-theta is consistent with opal-A. Tridymite is a lowpressure, high-temperature mineral (approx. 870 to 1670 deg. C) whose XRD-identified occurrence on the Earth is usually associated with silicic (e.g., rhyolitic) volcanism. High SiO2 deposits have been detected at Gale crater by remote sensing from martian orbit and interpreted as opal-A on the basis H2O and Si-OH spectral features. Proposed opal-A formation pathways include precipitation of silica from lake waters and high-SiO2 residues of acid-sulfate leaching. Tridymite is nominally anhydrous and would not exhibit these spectral features. We have chemically and spectrally analyzed rhyolitic samples from New Mexico and Iwodake volcano (Japan). The glassy (by XRD) NM samples have H2O spectral features similar to opal-A. The Iwodake sample, which has been subjected to high-temperature acid sulfate leaching, also has H2O spectral features similar to opal-A. The Iwodake sample has approx. 98 wt% SiO2 and 1% wt% TiO2 (by XRF), tridymite (>80 wt.% of crystalline material without detectable quartz by XRD), and H2O and Si-OH spectral features. These results open the working hypothesis that the opal-A-like high-SiO2 deposits at Gale crater detected from martian orbit are products of alteration associated with silicic volcanism. The presence or absence of tridymite will depend on lava crystallization temperatures (NM) and post crystallization alteration temperatures (Iwodake).

Morris, Richard V.↗
NASA NTRS2016

The Miniaturized Mossbauer Spectrometer MIMOS II for the Asteroid Redirect Mission (ARM): Quantitative Iron Mineralogy and Oxidation States

The miniaturized Mossbauer spectrometer MIMOS II is an off-the-shelf instrument, which has been successfully deployed during NASA's Mars Exploration Rover (MER) mission and was on-board the ESA/UK Beagle 2 Mars lander and the Russian Phobos-Grunt sample return mission. We propose to use a fully-qualified flight-spare MIMOS II instrument available from these missions for in situ asteroid characterization with the Asteroid Redirect Robotic Mission (ARRM).

Schroder, Christian↗
NASA NTRS2016

A Review of the Handheld X-Ray Fluorescence Spectrometer as a Tool for Field Geologic Investigations on Earth and in Planetary Surface Exploration

X-ray fluorescence (XRF) spectroscopy is a well-established and commonly used technique in obtaining diagnostic compositional data on geological samples. Recently, developments in X-ray tube and detector technologies have resulted in miniaturized, field-portable instruments that enable new applications both in and out of standard laboratory settings. These applications, however, have not been extensively applied to geologic field campaigns. This study investigates the feasibility of using developing handheld XRF (hXRF) technology to enhance terrestrial field geology, with potential applications in planetary surface exploration missions. We demonstrate that the hXRF is quite stable, providing reliable and accurate data continuously over a several year period. Additionally, sample preparation is proved to have a marked effect on the strategy for collecting and assimilating hXRF data. While the hXRF is capable of obtaining data that are comparable to laboratory XRF analysis for several geologically-important elements (such as Si, Ca, Ti, and K), the instrument is unable to detect other elements (such as Mg and Na) reliably. While this limits the use of the hXRF, especially when compared to laboratory XRF techniques, the hXRF is still capable of providing the field user with significantly improved contextual awareness of a field site, and more work is needed to fully evaluate the potential of this instrument in more complex geologic environments.

Young, Kelsey E.↗
NASA NTRS2016

NEEMO 18-20: Analog Testing for Mitigation of Communication Latency During Human Space Exploration

NASA Extreme Environment Mission Operations (NEEMO) is an underwater spaceflight analog that allows a true mission-like operational environment and uses buoyancy effects and added weight to simulate different gravity levels. Three missions were undertaken from 2014-2015, NEEMO's 18-20. All missions were performed at the Aquarius undersea research habitat. During each mission, the effects of communication latencies on operations concepts, timelines, and tasks were studied. METHODS: Twelve subjects (4 per mission) were weighed out to simulate near-zero or partial gravity extravehicular activity (EVA) and evaluated different operations concepts for integration and management of a simulated Earth-based science team (ST) to provide input and direction during exploration activities. Exploration traverses were preplanned based on precursor data. Subjects completed science-related tasks including pre-sampling surveys, geologic-based sampling, and marine-based sampling as a portion of their tasks on saturation dives up to 4 hours in duration that were designed to simulate extravehicular activity (EVA) on Mars or the moons of Mars. One-way communication latencies, 5 and 10 minutes between space and mission control, were simulated throughout the missions. Objective data included task completion times, total EVA times, crew idle time, translation time, ST assimilation time (defined as time available for ST to discuss data/imagery after data acquisition). Subjective data included acceptability, simulation quality, capability assessment ratings, and comments. RESULTS: Precursor data can be used effectively to plan and execute exploration traverse EVAs (plans included detailed location of science sites, high-fidelity imagery of the sites, and directions to landmarks of interest within a site). Operations concepts that allow for pre-sampling surveys enable efficient traverse execution and meaningful Mission Control Center (MCC) interaction across communication latencies and can be done with minimal crew idle time. Imagery and contextual information from the EVA crew that is transmitted real-time to the intravehicular (IV) crewmember(s) can be used to verify that exploration traverse plans are being executed correctly. That same data can be effectively used by MCC (across comm latency) to provide meaningful feedback and instruction to the crew regarding sampling priorities, additional tasks, and changes to the EVA timeline. Text / data capabilities are preferred over voice capabilities between MCC and IV when executing exploration traverse plans over communication latency.

Chappell, Steven P.↗
NASA NTRS2014

Water in the Cratonic Mantle: Insights from FTIR Data on Lac De Gras Xenoliths (Slave Craton, Canada)

The mantle lithosphere beneath the cratonic part of continents is the deepest (> 200 km) and oldest (>2-3 Ga) on Earth, remaining a conundrum as to how these cratonic roots could have resisted delamination by asthenospheric convection over time. Water, or trace H incorporated in mineral defects, could be a key player in the evolution of continental lithosphere because it influences melting and rheology of the mantle. Mantle xenoliths from the Lac de Gras kimberlite in the Slave craton were analyzed by FTIR. The cratonic mantle beneath Lac de Gras is stratified with shallow (<145 km) oxidized ultradepleted peridotites and pyroxenites with evidence for carbonatitic metasomatism, underlain by reduced and less depleted peridotites metasomatized by kimberlite melts. Peridotites analyzed so far have H O contents in ppm weight of 7-100 in their olivines, 58 to 255 in their orthopyroxenes (opx), 11 to 84 in their garnet, and 139 in one clinopyroxene. A pyroxenite contains 58 ppm H2O in opx and 5 ppm H2O in its olivine and garnet. Olivine and garnet from the deep peridotites have a range of water contents extending to higher values than those from the shallow ones. The FTIR spectra of olivines from the shallow samples have more prominent Group II OH bands compared to the olivines from the deep samples, consistent with a more oxidized mantle environment. The range of olivine water content is similar to that observed in Kaapvaal craton peridotites at the same depths (129-184 km) but does not extend to as high values as those from Udachnaya (Siberian craton). The Slave, Kaapvaal and Siberian cratons will be compared in terms of water content distribution, controls and role in cratonic root longevity.

Peslier, Anne H.↗
NASA NTRS2013

Moessbauer/XRF MIMOS Instrumentation and Operation During the 2012 Analog Field Test on Mauna Kea Volcano, Hawaii

Field testing and scientific investigations were conducted on the Mauna Kea Volcano, Hawaii, as part of the 2012 Moon and Mars Analog Mission Activities (MMAMA). Measurements were conducted using both stand-alone and rover-mounted instruments to determine the geophysical and geochemical properties of the field site, as well as provide operational constraints and science considerations for future robotic and human missions [1]. Reported here are the results from the two MIMOS instruments deployed as part of this planetary analog field test.

Graff, Trevor G.↗
NASA NTRS2012

Chemical and Mineralogical Characterization of Acid-Sulfate Alteration of Basaltic Material on Mauna Kea Volcano, Hawaii: Jarosite and Hydrated Halloysite

Sulfates have been identified on the martian surface during robotic surface exploration and by orbital remote sensing. Measurements at Meridiani Planum (MP) by the Alpha-Particle X-ray Spectrometer (APXS) and Mossbauer (MB) instruments on the Mars Exploration Rover Opportunity document the presence of a ubiquitous sulfate-rich outcrop (20-40% SO3) that has jarosite as an anhydrous Fe3+-sulfate [1- 3]. The presence of jarosite implies a highly acidic (pH <3) formation environment [4]. Jarosite and other sulfate minerals, including kieserite, gypsum, and alunite have also been identified in several locations in orbital remote sensing data from the MEx OMEGA and MRO CRISM instruments [e.g. 5-8]. Acid sulfate weathering of basaltic materials is an obvious pathway for formation of sulfate-bearing phases on Mars [e.g. 4, 9, 10]. In order to constrain acid-sulfate pathways on Mars, we are studying the mineralogical and chemical manifestations of acid-sulfate alteration of basaltic compositions in terrestrial environments. We have previously shown that acidsulfate alteration of tephra under hydrothermal conditions on the Puu Poliahu cone (summit region of Mauna Kea volcano, Hawaii) resulted in jarosite and alunite as sulfate-bearing alteration products [11-14]. Other, more soluble, sulfates may have formed, but were leached away by rain and melting snow. Acidsulfate processes on Puu Poliahu also formed hematite spherules similar (except in size) to the hematite spherules observed at MP as an alteration product [14]. Phyllosilicates, usually smectite }minor kaolinite are also present as alteration products [13]. We discuss here an occurrence of acid-sulfate alteration on Mauna Kea Volcano (Hawaii). We report VNIR spectra (0.35-2.5 microns ASD spectrometer), Mossbauer spectra (MER-like ESPI backscatter spectrometer), powder XRD (PANalytical), and major element chemical compositions (XRF with LOI and Fe redox) for comparison to similar data acquired or to be acquired by MRO-CRISM and MEx OMEGA, MERMB, MSL-CheMin, and MER and MSL APXS, respectively.

Graff, Trevor G.↗
NASA NTRS2012

Moon and Mars Analog Mission Activities for Mauna Kea 2012

Rover-based 2012 Moon and Mars Analog Mission Activities (MMAMA) scientific investigations were recently completed at Mauna Kea, Hawaii. Scientific investigations, scientific input, and science operations constraints were tested in the context of an existing project and protocols for the field activities designed to help NASA achieve the Vision for Space Exploration. Initial science operations were planned based on a model similar to the operations control of the Mars Exploration Rovers (MER). However, evolution of the operations process occurred as the analog mission progressed. We report here on the preliminary sensor data results, an applicable methodology for developing an optimum science input based on productive engineering and science trades discussions and the science operations approach for an investigation into the valley on the upper slopes of Mauna Kea identified as "Apollo Valley".

Graham, Lee D.↗
NASA NTRS2011

Visible and Near-IR Reflectance Spectra of Smectite Acquired Under Dry Conditions for Interpretation of Martian Surface Mineralogy

Visible and near-IR (VNIR) spectra from the MEx OMEGA and the MRO CRISM hyper-spectral imaging instruments have spectral features associated with the H2O molecule and M OH functional groups (M = Mg, Fe, Al, and Si). Mineralogical assignments of martian spectral features are made on the basis of laboratory VNIR spectra, which were often acquired under ambient (humid) conditions. Smectites like nontronite, saponite, and montmorillionite have interlayer H2O that is exchangeable with their environment, and we have acquired smectite reflectance spectra under dry environmental conditions for interpretation of martian surface mineralogy. We also obtained chemical, Moessbauer (MB), powder X-ray diffraction (XRD), and thermogravimetric (TG) data to understand variations in spectral properties. VNIR spectra were recorded in humid lab air at 25-35C, in a dynamic dry N2 atmosphere (50-150 ppmv H2O) after exposing the smectite samples (5 nontronites, 3 montmorillionites, and 1 saponite) to that atmosphere for up to approximately l000 hr each at 25-35C, approximately 105C, and approximately 215C, and after re-exposure to humid lab air. Heating at 105C and 215C for approximately 1000 hr is taken as a surrogate for geologic time scales at lower temperatures. Upon exposure to dry N2, the position and intensity of spectral features associated with M-OH were relatively insensitive to the dry environment, and the spectral features associated with H2O (e.g., approximately 1.90 micrometers) decreased in intensity and are sometimes not detectable by the end of the 215C heating step. The position and intensity of H2O spectral features recovered upon re-exposure to lab air. XRD data show interlayer collapse for the nontronites and Namontmorillionites, with the interlayer remaining collapsed for the latter after re-exposure to lab air. The interlayer did not collapse for the saponite and Ca-montmorillionite. TG data show that the concentration of H2O derived from structural OH was invariant to the dry N2 treatment for saponite and the montmorillionites, but the nontronites had additional structural OH after treatment. Upon exposure to dry N2, the VNIR spectra also acquired a red slope with decreasing albedo between approximately 0.4 and approximately 2.0 micrometers. The magnitude of the effects covaries with exposure time to dry N2 and heating temperature. Upon re-exposure to lab air, the slope and albedo do not completely recover to pre-exposure values. MB data show that these effects do not result from partial reduction of ferric to ferrous iron, and TG data show they do not result from loss of structural OH. Possible explanations include formation of small clusters of (superparamagnetic) ferric oxide and reduced smectite crystallinity. The difference in spectral properties between spectra acquired in humid lab air and under dry conditions are consequential for interpretation of CRISM and OMEGA spectra. For example, nontronite by itself and not nontronite plus ferrihydrite can account for the red spectral slope in martian spectra where nontronite is indicated by the Fe-OH spectral features.

Morris, Richard V.↗
NASA NTRS1999

Spectroscopic Properties of Metamorphosed Mafic Rocks: Remote Sensing Applications on Mars

Reflectance spectroscopy in the visible and near-infrared wavelengths, between 420 mn to 2588 nm. was utilized on a suite of hydrothermally metamorphosed mafic rocks from the Smartville complex in the northern Sierra Nevada mountains in California. A detailed data base of 102 samples was compiled in order to distinguish differences in mineralogy, petrology, and degree of metamorphism for remote sensing applications. Study was limited to metaigneous and metasedimentary rocks in an attempt to spectrally characterize terrestrial rocks analogous to the possible surface of Mars, for a better understanding and possible detection of the geologic features on the remote surface. Diagnostic absorption bands of iron, water, and hydroxyl produced the majority of discernible features in this study. Mossbauer spectroscopy was performed in order to determine specific iron sites. The resulting spectral data base along with thin section mineral identification, metamorphic zone, rock type and location were recorded and available for future application and research. Continued exploration of Mars in the advancing years, will further advance our understanding of the geology of Mars. Spectroscopic techniques will undoubtedly be integral parts of these future missions. Work on terrestrial analogs to the Martian surface must continue, in order to produce extensive data bases and broaden our knowledge of spectral features.

Graff, Trevor G.↗