Engineering topics

McCubbin, F. M.

Publications and source records attributed to McCubbin, F. M..

At least 37 records · Page 2

NASA NTRS2018

Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - Implications for Human Space Exploration

New initiatives to begin Lunar and Martian human surface operations within the next few decades are illustrative of the resurgence of interest in human space exploration. However, as with all exploration, there are risks. The previous manned missions to the Moon highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness.". It was further reported that the allergic response to the dust worsened with each exposure. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern.

Harrington, A. D.↗

NASA NTRS2018

Asymmetric Post-Magma Ocean Crust-Building on the Lunar Nearside

Mg-suite is a series of ancient plutonic rocks from the lunar crust with ages and com-positions indicating that they represent the first post-differentiation crust-building magmatism [1, 2]. Sam-ples of Mg-suite materials were found at every Apollo landing site except 11 and all exhibit geochemical characteristics indicating the involvement of KREEP in their petrogenesis [3-5]. This has led to the sugges-tion that the KREEP reservoir under the nearside was responsible for Mg-suite magmatism [e.g., 5, 6]. The lack of readily identifiable Mg-suite rocks in meteoritic regolith breccias sourced from outside the Procellarum KREEP Terrane (PKT) seemingly supports this interpretation.

Elardo, S. M.↗

NASA NTRS2018

Experimental Investigation of Chromium Behavior During Mercury's Differentiation

Mercury is the most reduced terrestrial planet with the largest core/mantle size ratio and highest sulfur concentration on the surface. The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft data allowed mapping of Mercury's surface elemental composition. Recent chromium mapping suggests Mercury's surface has on average 800 parts per million Cr with the highest values in the High Magnesium Region. These new data can give clues about Mercury's internal structure and the redox conditions under which it differentiated. In the present study, we present experimental data on the distribution of Cr among metal, silicate and sulfide liquids. We then combine them with data from previous studies and a model of planetary differentiation to discuss Mercury's bulk composition and its oxidation state.

Boujibar, A.↗

NASA NTRS2018

Heterogeneous Distribution of Chromium on Mercury

Measurements made with geochemical instruments on the MESSENGER spacecraft revealed that Mercury's crust is surprisingly rich in volatile elements, including S, Na, K, Cl, and C, and that it is enriched in Mg and depleted in Al, Ca, and Fe, relative to other terrestrial planets. Geochemical maps also indicated the presence of a number of distinct geochemical terranes. The MESSENGER X-ray Spectrometer (XRS) detected X-ray fluorescence, induced by incident solar X-rays, from the top approx. 10s of micrometers of Mercury's surface. Like Fe, Cr was only detectable by XRS during large solar flares. However, accurate Cr measurements are more susceptible to systematic errors than other elements measured by the XRS. Therefore, to date, Cr data have been published for only 11 XRS measurements, but we have recently derived a map of Cr/Si across Mercury's surface. This map is based on data acquired through the complete MESSENGER mission and reveals clear spatial heterogeneity in Cr.

Nittler, L. R.↗

NASA NTRS2018

Aubrite and Enstatite Chondrite Impact Melt Meteorites: Analogs to Mercury?

New data obtained during the MESSENGER mission has allowed us to better contrain the composition and mineralogy of the mercurian surface. One unique feature of Mercury is its extremely low oxygen fugacity (ƒO2) (Iron Wustite (IW) -7.3 to IW-2.6). At such extreme conditions, elements that exhibit lithophile behavior on Earth can exhibit chalcophile or siderophile behavior, leading to the formation of exotic sulfides and metals. As no samples have been returned from Mercury, it is critical to study meteorite analogs to better under-stand the formation conditions of the minerals present at the mercurian surface, as well as mercurian magmatic processes. Given the low fO2 on Mercury, we have selected to investigate potential meteoritic analogs for Mercury among the most reduced meteorite types, including the aubrites and enstatite chondrite impact melts. The aubrites are differentiated meteorites that show varying degrees of brecciation, have a similar ƒO2 to the mercurian surface and interior, and contain exotic sulfides that have been inferred to be present on the mercurian surface. The enstatite chondrite impact melts are from undifferentiated parent bodies, have a similar ƒO2 to the mercurian surface and interior, and contain exotic sulfides that have been inferred to be present on the mercurian surface. In this study, we present a comprehensive analysis of a representative suite of aubrites and enstatite chondrite impact melts and assess their relevance to under-standing magmatic processes on Mercury.

Wilbur, Z. E.↗

NASA NTRS2018

Perserving Samples and Their Scientific Integrity - Insights into MSR from the Astromaterials Acquisition and Curation Office at NASA Johnson Space Center

The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (JSC), in Houston, TX (henceforth Curation Office) manages the curation of all past, present, and future extraterrestrial samples returned by NASA missions and shared collections from international partners, preserving their integrity for future scientific study while providing the samples to the international community in a fair and unbiased way. The Curation Office also curates flight and non-flight reference materials and other materials from spacecraft assembly of sample return missions that would have the potential to cross-contaminate a present or future NASA astromaterials collection. These materials are primarily collected during the assembly, test, and launch operations (ATLO) phase and after flight during the recovery and curation phase. In addition, the Curation Office curates non-flight, flight-like, and flown witness plates for sample return missions. These reference materials and witness plates provide the scientific community with the fundamental ability to reconstruct the contamination/alteration history of the sample collection through the course of the mission, with the overall goal of strengthening the scientific conclusions drawn from the study of returned materials.

Harrington, A. D.↗

NASA NTRS2018

Seeking Signs of Life on Mars: A Strategy for Selecting and Analyzing Returned Samples from Hydrothermal Deposits

Highly promising locales for biosignature prospecting on Mars are ancient hydrothermal deposits, formed by the interaction of surface water with heat from volcanism or impacts. On Earth, they occur throughout the geological record (to at least approx. 3.5 Ga), preserving robust mineralogical, textural and compositional evidence of thermophilic microbial activity. Hydrothermal systems were likely present early in Mars' history, including at two of the three finalist candidate landing sites for M2020, Columbia Hills and NE Syrtis Major. Hydrothermal environments on Earth's surface are varied, constituting subaerial hot spring aprons, mounds and fumaroles; shallow to deep-sea hydrothermal vents (black and white smokers); and vent mounds and hot-spring discharges in lacustrine and fluvial settings. Biological information can be preserved by rapid, spring-sourced mineral precipitation, but also could be altered or destroyed by postdepositional events. Thus, field observations need to be followed by detailed laboratory analysis to verify potential biosignatures. See Attachment

Campbell, K. A.↗

NASA NTRS2018

Seeking Signs of Life on Mars: the Importance of Sedimentary Suites as Part of a Mars Sample Return Campaign

Seeking the signs of life on Mars is often considered the "first among equal" objectives for any potential Mars Sample Return (MSR) campaign. Among the geological settings considered to have the greatest potential for recording evidence of ancient life or its pre-biotic chemistry on Mars are lacustrine (and marine, if ever present) sedimentary depositional environments. This potential, and the possibility of returning samples that could meaningfully address this objective, have been greatly enhanced by investigations of an ancient redox stratified lake system in Gale crater by the Curiosity rover.

Mangold, N.↗

NASA NTRS2018

Priority Science Targets for Future Sample Return Missions Within the Inner Solar System Out to the Year 2061

The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (JSC) is re-sponsible for curating all of NASA's extraterrestrial samples. The NASA Curation Office plans for the requirements of future collections in an ''Advanced Curation'' program. Advanced Curation is tasked with developing procedures, technology, and data sets necessary for curating new types of collections as envisioned by NASA exploration goals. Here we review the science value of some potential targets for sample return missions from the inner solar system over the next 43 years.

McCubbin, F. M.↗

NASA NTRS2018

The Importance of Primary Martian Surface and Airfall Dust Sample Return for Toxicological Hazard Evaluations for Human Exploration

Manned missions to the Moon highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust 'storm' generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness" . It was further reported that the allergic response to the dust worsened with each exposure. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment.

Harrington, A. D.↗

NASA NTRS2018

The Importance of Contamination Knowledge in Curation - Insights into Mars Sample Return

The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (JSC), in Houston, TX (henceforth Curation Office) manages the curation of extraterrestrial samples returned by NASA missions and shared collections from international partners, preserving their integrity for future scientific study while providing the samples to the international community in a fair and unbiased way. The Curation Office also curates flight and non-flight reference materials and other materials from spacecraft assembly (e.g., lubricants, paints and gases) of sample return missions that would have the potential to cross-contaminate a present or future NASA astromaterials collection.

Harrington, A. D.↗

NASA NTRS2018

Aubrite and Impact Melt Enstatite Chondrite Meteorites as Potential Analogs to Mercury

The MESSENGER (MErcury Sur-face, Space ENvironment, GEochemistry and Ranging) orbiter measured the Mercurian surface abundances of key rock-forming elements to help us better understand the planet's surface and bulk geochemistry. A major discovery is that the Mercurian surface and interior are characterized by an extremely low oxygen fugacity (ƒO2; Iron-Wüstite (IW) -7.3 to IW-2.6. This is supported by low Fe and high S abundances on the surface. This low ƒO2 causes a different elemental partioning from what is observed on Earth. Using surface composition, it was shown that the Mercurian surface mainly consists of normative plagioclase, pyroxene, olivine, and exotic sulfides, such as niningerite ((Mg,Mn, Fe)S) and oldhamite (CaS).

Wilbur, Z. E.↗

NASA NTRS2018

Investigating Astromaterials Curation Applications for Dexterous Robotic Arms

The Astromaterials Acquisition and Curation office at NASA Johnson Space Center is currently investigating tools and methods that will enable the curation of future astromaterials collections. Size and temperature constraints for astromaterials to be collected by current and future proposed missions will require the development of new robotic sample and tool handling capabilities. NASA Curation has investigated the application of robot arms in the past, and robotic 3-axis micromanipulators are currently in use for small particle curation in the Stardust and Cosmic Dust laboratories. While 3-axis micromanipulators have been extremely successful for activities involving the transfer of isolated particles in the 5-20 micron range (e.g. from microscope slide to epoxy bullet tip, beryllium SEM disk), their limited ranges of motion and lack of yaw, pitch, and roll degrees of freedom restrict their utility in other applications. For instance, curators removing particles from cosmic dust collectors by hand often employ scooping and rotating motions to successfully free trapped particles from the silicone oil coatings. Similar scooping and rotating motions are also employed when isolating a specific particle of interest from an aliquot of crushed meteorite. While cosmic dust curators have been remarkably successful with these kinds of particle manipulations using handheld tools, operator fatigue limits the number of particles that can be removed during a given extraction session. The challenges for curation of small particles will be exacerbated by mission requirements that samples be processed in N2 sample cabinets (i.e. gloveboxes). We have been investigating the use of compact robot arms to facilitate sample handling within gloveboxes. Six-axis robot arms potentially have applications beyond small particle manipulation. For instance, future sample return missions may involve biologically sensitive astromaterials that can be easily compromised by physical interaction with a curator; other potential future returned samples may require cryogenic curation. Robot arms may be combined with high resolution cameras within a sample cabinet and controlled remotely by curator. Sophisticated robot arm and hand combination systems can be programmed to mimic the movements of a curator wearing a data glove; successful implementation of such a system may ultimately allow a curator to virtually operate in a nitrogen, cryogenic, or biologically sensitive environment with dexterity comparable to that of a curator physically handling samples in a glove box.

Snead, C. J.↗

NASA NTRS2018

Can Silicon-Smelting Contribute to the Low O/Si Ratio on the Surface of Mercury?

The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft collected data that provided important insights into the structure, chemical makeup, and compositional diversity of Mercury. Among the many discoveries about Mercury made by MESSENGER, several surprising compositional characteristics of the surface were observed. These discoveries include elevated sulfur abundances (up to 4 wt.%), elevated abundances of graphitic carbon (0-4.1 wt.% across the surface with an additional 1-3 wt.% graphite above the global average in low reflectance materials), low iron abundances (less than 2 wt.%), and low oxygen abundances (O/Si weight ratio of 1.20+/-0.1). These exotic characteristics likely have important implications for the thermochemical evolution of Mercury and point to a planet that formed under highly reducing conditions. In the present study, we focus specifically on the low O/Si ratio of Mercury, which is anomalous compared to all other planetary materials. A recent study that considered the geochemical implications of the low O/Si ratio reported that 12-20% of the surface materials on Mercury are composed of Si-rich, Si-Fe alloys. They further postulated that the origin of the metal is best explained by a combination of space weathering and graphite-induced smelting that was facilitated by interaction of graphite with boninitic and komatiitic parental liquids. The goal of the present study is to assess the plausibility of smelting on Mercury through experiments run at the conditions that McCubbin et al. indicated would be favorable for Si-smelting.

McCubbin, F. M.↗

NASA NTRS2018

The Need for Medical Geology in Space Exploration: Implications for the Journey to Mars and Beyond

The previous manned missions to the Moon represent milestones in human ingenuity, perseverance, and intellectual curiosity. They also highlight a major hazard for future human exploration of the Moon and beyond: surface dust. Not only did the dust cause mechanical and structural integrity issues with the suits, the dust "storm" generated upon reentrance into the crew cabin caused "lunar hay fever" and "almost blindness". It was further reported that the allergic response to the dust worsened with each exposure. The lower gravity environment exacerbated the exposure, requiring the astronauts to wear their helmet within the module in order to avoid breathing the irritating particles. Due to the prevalence of these high exposures, the Human Research Roadmap developed by NASA identifies the Risk of Adverse Health and Performance Effects of Celestial Dust Exposure as an area of concern. Extended human exploration will further increase the probability of inadvertent and repeated exposures to celestial dusts. Going forward, hazard assessments of celestial dusts will be determined through sample return efforts prior to astronaut deployment. However, even then the returned samples could also put the Curators, technicians, and scientists at risk during processing and examination.

Harrington, A. D.↗

NASA NTRS2018

The Opera Instrument: An Advanced Curation Development for Mars Sample Return Organic Contamination Monitoring

Mars Sample Return (MSR) requires strict organic contamination control (CC) and contamination knowledge (CK) as outlined by the Mars 2020 Organic Contamination Panel (OCP). This includes a need to monitor surficial organic contamination to a ng/sq. cm sensitivity level. Archiving and maintaining this degree of surface cleanliness may be difficult but has been achieved. MSR's CK effort will be very important because all returned samples will be studied thoroughly and in minute detail. Consequently, accurate CK must be collected and characterized to best interpret scientific results from the returned samples. The CK data are not only required to make accurate measurements and interpretations for carbon-depleted martian samples, but also to strengthen the validity of science investigations performed on the samples. The Opera instrument prototype is intended to fulfill a CC/CK role in the assembly, cleaning, and overall contamination history of hardware used in the MSR effort, from initial hardware assembly through post-flight sample curation. Opera is intended to monitor particulate and organic contamination using quartz crystal microbalances (QCMs), in a self-contained portable package that is cleanroom-compliant. The Opera prototype is in initial development capable of approximately 100 ng/sq. cm organic contamination sensitivity, with additional development planned to achieve 1 ng/sq. cm. The Opera prototype was funded by the 2017 NASA Johnson Space Center Innovation Charge Account (ICA), which provides funding for small, short-term projects.

Fries, M. D.↗

NASA NTRS2018

Advances in Small Particle Handling of Astromaterials in Preparation for OSIRIS-REx and Hayabusa2: Initial Developments

The Astromaterials Acquisition and Curation office at NASA Johnson Space Center has established an Advanced Curation program that is tasked with developing procedures, technologies, and data sets necessary for the curation of future astromaterials collections as envisioned by NASA exploration goals. One particular objective of the Advanced Curation program is the development of new methods for the collection, storage, handling and characterization of small (less than 100 micrometer) particles. Astromaterials Curation currently maintains four small particle collections: Cosmic Dust that has been collected in Earth's stratosphere by ER2 and WB-57 aircraft, Comet 81P/Wild 2 dust returned by NASA's Stardust spacecraft, interstellar dust that was returned by Stardust, and asteroid Itokawa particles that were returned by the JAXA's Hayabusa spacecraft. NASA Curation is currently preparing for the anticipated return of two new astromaterials collections - asteroid Ryugu regolith to be collected by Hayabusa2 spacecraft in 2021 (samples will be provided by JAXA as part of an international agreement), and asteroid Bennu regolith to be collected by the OSIRIS-REx spacecraft and returned in 2023. A substantial portion of these returned samples are expected to consist of small particle components, and mission requirements necessitate the development of new processing tools and methods in order to maximize the scientific yield from these valuable acquisitions. Here we describe initial progress towards the development of applicable sample handling methods for the successful curation of future small particle collections.

Snead, C. J.↗

NASA NTRS2018

Experimental Study into the Stability of Whitlockite and Hydroxylapatite in Basaltic Magmas

Apatite (Ca5(PO4)3(F,Cl,OH)), merrillite (Ca18Na2Mg2(PO4)14), and whitlockite (Ca9(Mg,Fe(2+))(PO4)6[PO3(OH)]) are the primary phosphate minerals found in most planetary materials including rocks from Earth, Moon, Mars, and asteroids. For many years, the terms merrillite and whitlockite have been used interchangeably in the meteorite literature. Much of the confusion regarding the relationship between terrestrial and extraterrestrial 'whitlockite' is based on the presence or absence of hydrogen in the mineral structure. Whitlockite has approximately 8500 ppm H2O, and the term 'merrillite' has been adopted to identify the hydrogen-free form of whitlockite. The atomic structures of merrillite and whitlockite were examined in detail by Hughes et al.. On Earth, whitlockite has been found in rocks from evolved pegmatitic systems and in some mantle rocks. Furthermore, terrestrial whitlockite has been shown to have some merrillite component. For the meteoritic and lunar materials that have been investigated, merrillite appears to be far more common than whitlockite, and it has been proposed that the whitlockite component is unique to terrestrial samples. There are some reports of 'whitlockite' in the meteorite literature; however, these may represent misidentifications of merrillite because there have been no reports of extraterrestrial whitlockite that have been verified through crystal structural studies or analyzed for their H contents. Hughes et al. reported the atomic arrangement of lunar merrillite and demonstrated that the phase is similar to meteoritic merrillite and, predictably, devoid of hydrogen. In a follow-up study, Hughes et al. reported the atomic arrangements of two natural samples of whitlockite, one synthetic whitlockite, and samples of synthetic whitlockite that were heated at 500 C or 1050 C for 24 h. The crystal chemistry and crystal structures of the phases were compared, and it was discovered that the latter treatment resulted in the dehydrogenation of whitlockite to form merrillite.

McCubbin, F. M.↗