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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
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NASA NTRS2017

A Large Ordinary Chondrite Shower in the Dominion Range

The US Antarctic Meteorite Program has visited the Dominion Range in the Transantarctic Mountains during several different seasons, including the 1985, 2003, 2008, 2010, and 2014 seasons. Total recovered meteorites from this region is over 2000. The 2008 and 2010 seasons have been fully classified and, respectively) revealing the presence of a large meteorite shower that comprises approximately 60% of all samples recovered in those two seasons. The oil immersion classification suggests that this shower is LL chondrite material, whereas published magnetic susceptibility (MS; log chi) measurements yield L chondrite values. However, usually random sampling of a large collection like this would uncover EOC material for which we have prepared thin sections. In this case, no LL chondrite materials have been found in thin section, suggesting that the shower might instead be an L chondrite. L and LL chondrites are notoriously difficult to distinguish using oil immersion techniques. To better characterize this large group of samples, we have decided to examine some of the large members of this group, using EMPA analysis of the olivines to verify the classifications. With a compositional link between this subset of samples, and the MS measurements, we can more confidently classify the samples making up this pairing group. Subsequently, more accurate and meaningful comparisons may be drawn between this pairing group and some other Antarctic pairing groups such as from the Queen Alexandra Range (QUE), and Lewis Cliffs Ice Tongue (LEW). electron microprobe analysis

Satterwhite, C. E.↗
NASA NTRS2019

Flight Readiness of Mochii S: Portable Spectroscopic Scanning Electron Microscope Facility on the International Space Station (ISS)

The ISS (International Space Station) currently lacks the capability to image and chemically analyze nano-to-micron scale particles from numerous engineering systems. To identify these particles, we must wait for a re-entry vehicle to return them from low earth orbit for ground-based SEM (Scanning Electron Microscope) / EDS (Energy Dispersive X-Ray Spectroscopy) analysis. This may take months, potentially delaying the affected system. Having an EDS-equipped SEM (Mochii S) aboard the ISS will accelerate response time thereby enhancing crew and vehicle safety by rapid and accurate identification of microscopic threats, especially in time-critical situations.The Mochii S payload will be stationed in the Japanese Experiment Module (JEM) powered by 120 VAC (Volts Alternating Current) inverter and connected to station Ethernet and WiFi (Fig. 1). To date the Mochii S payload has undergone testing for command and data handling, power quality, flight vibration, and radiation testing at Johnson Space Center (JSC). Mochii's high-RPM (Revolutions Per Minute) rotating vacuum pumps and high voltage systems have been reviewed to meet safety standards by JSC (Johnson Space Center) Engineering. Topology of the system in the JEM module has been baselined by ISS Safety and JAXA (Japan Space Exploration Agency). Digital controls to and from ISS over Joint Station LAN (Local Area Network) uplink have been simulated and the latencies and data rates have been found to be sufficient for successful operation of the payload from ground.Transporting sensitive electron optical instruments aboard a rocket that sustains 7G acceleration for 8 minutes and then operating it the unique microgravity (micro-g) environment is no trivial matter. To meet strict safety requirements and increase robustness for mission success, over 500 unique verifications must be completed before the payload is certified for spaceflight. Two of which will be discussed in detail are: vibroacoustic testing and magnetic susceptibility shielding and validation.

Mochii↗
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 NTRSDate not supplied

Petrologic Sub-types, Sub-groups, and Pairing for CV Chondrites in the US Antarctic Meteorite Collection

Carbonaceous chondrites of the Vigarano group (CV) are primitive meteorites that provide a wealth of information about the early solar system, including constraints on chondrule formation, origin of calcium-aluminum inclusions, stability of organic compounds, and redox conditions. The US Antarctic meteorite collection contains 119 CV samples from 15 dense collection areas (DCAs) from the Trans-Antarctic Mountains. These samples have been assigned a preliminary classification as CVs, but have not been assigned to the subgroups Oxidized A, Oxidized B, and Reduced. Additionally, variation in petrologic grade can be determined non-destructively using Raman spectroscopy. In order to update classification of both subgroups and petrologic types in the collection, we have acquired magnetic susceptibility, metal and sulfide compositions, and Raman spectra, for as many samples as possible. We use the recent assessment and delineation of CV sub-groups of as a guide.

solar nebula↗
NASA NTRSDate not supplied

Quantitative Characterization of Lunar Regolith Simulants for Direct Comparison to Apollo Soil Samples

Introduction: Sustained characterization efforts of lunar regolith simulant properties are not only integral for verification of commercially-produced material designed for a wide array of testing applications but are also necessary in establishing a comprehensive comparison to a lunar reference source. As a resource for the lunar science and engineering communities, the Simulant Development Lab (SDL) within the Astromaterials Research & Exploration Science (ARES) division at the Johnson Space Center (JSC) is actively pursuing closure of existing knowledge gaps in fundamental simulant attributes, including chemistry, mineralogy, particle size distribution, particle geometry, bulk and relative density, magnetic susceptibility, and shear strength (i.e., cohesion and angle of internal friction), as well as producing Figures of Merit for comparison of lunar simulants to Apollo regolith samples.

R. Kovtun↗
NASA NTRS2020

The Old, Unique C1 Chondrite Flensburg – Insight Into the First Processes of Aqueous Alteration, Brecciation, and the Diversity of Water-Bearing Parent Bodies and Lithologies

On September 12, 2019 at 12:49:48 (UT) a bolide was observed by hundreds of eye-witnesses from the Netherlands, Germany, Belgium, Denmark and the UK. One day later a small meteorite stone was found by accident in Flensburg. The presence of short-lived cosmogenic radionuclides with half-lives as short as 16 days proves the recent exposure of the found object to cosmic rays in space linking it clearly to the bolide event. An exceptionally short exposure time of ∼5000 years was determined. The 24.5 g stone has a fresh black fusion crust, a low density of <2 g/cm(exp 3), and a magnetic susceptibility of logχ = 4.35 (χ in 10−9 m(exp 3)/kg). The rock consists of relict chondrules and clusters of sulfide and magnetite grains set in a fine-grained matrix. The most abundant phases are phyllosilicates. Carbonates (∼3.9 vol.%) occur as calcites, dolomites, and a Na-rich phase. The relict chondrules (often surrounded by sulfide laths) are free of anhydrous silicates and contain abundant serpentine. Lithic clasts are also surrounded by similar sulfide laths partly intergrown with carbonates. Mn-53-Cr-53 ages of carbonates in Flensburg indicate that brecciation and contemporaneous formation of the pyrrhotite-carbonate intergrowths by hydrothermal activities occurred no later than 4564.6 ± 1.0 Ma (using the angrite D'Orbigny as the Mn-Cr age anchor). This corresponds to 2.6 ± 1.0 or 3.4 ± 1.0 Ma after formation of CAIs, depending on the exact absolute age of CAIs. This is the oldest dated evidence for brecciation and carbonate formation, which likely occurred during parent body growth and incipient heating due to decay of Al-26. In the three oxygen isotope diagram, Flensburg plots at the 16O-rich end of the CM chondrite field and in the transition field to CV-CK-CR chondrites. The mass-dependent Te isotopic composition of Flensburg is slightly different from mean CM chondrites and is most similar to those of the ungrouped C2 chondrite Tagish Lake. On the other hand, Ti-50 and Cr-54 isotope anomalies indicate that Flensburg is similar to CM chondrites, as do the ∼10 wt.% H2O of the bulk material. Yet, the bulk Zn, Cu, and Pb concentrations are about 30% lower than those of mean CM chondrites. The He, Ne, and Ar isotopes of Flensburg show no solar wind contribution; its trapped noble gas signature is similar to that of CMs with a slightly lower concentration of Ne(sub tr)-20. Based on the bulk H, C, and N elemental abundances and isotopic compositions, Flensburg is unique among chondrites, because it has the lightest bulk H and N isotopic compositions of any type 1 or 2 chondrite investigated so far. Moreover, the number of soluble organic compounds in Flensburg is even lower than that of the brecciated CI chondrite Orgueil. The extraordinary significance of Flensburg is evident from the observation that it represents the oldest chondrite sample in which the contemporaneous episodes of aqueous alteration and brecciation have been preserved. The characterization of a large variety of carbonaceous chondrites with different alteration histories is important for interpreting returned samples from the OSIRIS-REx and Hayabusa 2 missions.

C1 chondrite↗
NASA NTRSDate not supplied

MSR Curation Technology Development – Developing Protocols for Pre-Basic Characterization Measurements

The joint NASA/ESA Mars Sample Return (MSR) campaign could deliver to Earth the first pristine Mar-tian rock and regolith samples, collected by the Mars2020 science mission, Perseverance. In preparation for their arrival, the NASA/ESA Joint Curation Office (JCO) within the Sample Receiving Project (SRP) is developing curation technology needed to perform initial characterization of the samples while isolating samples from the Earth’s biosphere and protecting the samples from terrestrial contamination. (RSTA; Fig. 1). The Mars Sample Return Planning Group 2 (MSPG2) identified methods for achieving an array of potential science objectives for MSR outlined by the International MSR Objectives and Samples Team (iMOST) [1]. One category of methods, called Pre-Basic Characterization, recommends potential analyses that would happen before the Returnable Sample Tube Assemblies (RSTA; Figure 1) are opened: 1) Magnetometer & Magnetic Susceptibility; 2) X-ray Computed Tomography (XCT) Scanner [2]. To be in compliance with planetary protection requirements, and to limit the amount of time sample tubes are out-side of an isolated contamination-controlled environment, secondary containment is necessary. A Sample Tube Isolation Container (STIC) and Secondary Outer Containment Case (SOCC) is currently being developed at NASA JPL under the direction of the SRP JCO.

V Tu↗
NASA NTRS2024

Characterization of NUW-LHT-5m, A Lunar Highland Simulant

A new simulant of the lunar highlands regolith, NUW-LHT-5M, was designed by NASA and manufactured by Washington Mills. The simulant was based on Apollo 16 data and is a member of the NU-LHT-series. NASA’s Marshall Space Flight Center and Johnson Space Center have already purchased 3 metric tons of the simulant for advanced engineering work. In support of engineering uses of the simulant, we provided measurements of the simulant including: mineral abundance and composition, liberation, X-ray fluorescence (XRF), ferrous iron, carbon, sulfur, 60 element inductively coupled plasma (ICP), loss on ignition, particle size, both 2D and 3D particle shape, specific surface area, shear, cohesion, internal friction, helium pycnometry, minimum index density, tap density, magnetic susceptibility, cryogenic and high temperature permittivity, visible and near-infrared (VNIR) and middle infra-red spectroscopy (MIR), differential scanning calorimetry (DSC), viscosity, thermal diffusivity, thermal conductivity, thermal gravimetric analysis (TGA), evolved gas analysis (EGA), and spark sintering. For the crystalline components the design of the simulant called for two rocks from the Stillwater Complex, Montana: 17.6 wt% norite, 37.7% anorthosite, and 4.7 wt% olivine from an unspecified commercial source. The other 40% of the simulant was a high calcium (An100), vesicular glass that Washington Mills made specifically for the simulant. Fabrication and quality control processes for both the glass and the simulant are described. Importantly, most of the graphs and tables presented herein provide values for both the new simulant and data for the older NASA mare simulant, JSC-1A. Finally, we discussed the current limitations of NUW-LT-5M and most other lunar regolith simulants to replicate the lunar material.

lunar regolith simulant↗
NASA NTRS1995

Forced three-dimensional magnetic reconnection due to linkage of magnetic flux tubes

During periods of southward interplanetary magnetic field (IMF) orientation the magnetic field geometry at the dayside magnetopause is susceptible to magnetic reconnection. It has been suggested that reconnection may occur in a localized manner at several patches on the magnetopause. A major problem with this picture is the interaction of magnetic flux ropes which are generated by different reconnection processes. An individual flux rope is bent elbowlike where it intersects the magnetopause and the magnetic field changes from magnetospheric to interplanetary magnetic field orientation. Multiple patches of reconnection can lead to the formation of interlinked magnetic flux tubes. Although the corresponding flux is connected to the IMF the northward and southward connected branches are hooked into each other and cannot develop independently. We have studied this problem in the framework of three-dimensional magnetohydrodynamic simulations. The results indicate that a singular current sheet forms at the interface of two interlinked flux tubes if no resistivity is present in the simulation. This current sheet is strongly tilted compared to the original current sheet. In the presence of resistivity the interaction of the two flux tubes forces a fast reconnection process which generates helically twisted closed magnetospheric flux. This linkage induced reconnection generates a boundary layer with layers of open and closed magnetospheric flux and may account for the brightening of auroral arcs poleward of the boundary between open and closed magnetic flux.

Otto, A.↗
NASA NTRS1974

Possible magnetic effects due to fine particle metal and intergrown phases in lunar samples

The characteristics and forms of existence for alpha iron and gamma iron are considered along with experimental observations concerning the alpha to gamma iron transformation. Attention is given to iron-copper precipitation alloys, the origin of rotational hysteresis in lunar samples, questions of paleointensity, and results obtained in the study of lunar samples. It is pointed out that the presence of gamma iron as a significant component in lunar fines and breccia samples would make it necessary to include the gamma iron component in an interpretation of the magnetic susceptibility-temperature curves.

Wasilewski, P.↗
NASA NTRS1974

The magnetic anomaly of the Ivreazone

A magnetic field survey was made in the Ivreazone in 1969/70. The results were: significant anomaly of the vertical intensity is found. It follows the basic main part of the Ivrea-Verbano zone and continues to the south. The width of the anomaly is about 10 km, the maximum measures about +800 gamma. The model interpretation shows that possibly the anomaly belongs to an amphibolitic body, which in connection with the Ivrea-body was found by deep seismic sounding. Therefore, the magnetic anomaly provides further evidence for the conception that the Ivrea-body has to be regarded as a chip of earthmantle material pushed upward by tectonic processes.

Vertical Intensity of Magnetic Field↗
NASA NTRS1981

Broad-band polarization in molecular spectra

The rotational lines of the CN(0,0) red system have been observed to show a strongly asymmetric Zeeman profile. Certain molecules are very susceptible to magnetic perturbation because of the weakness of their spin-rotation coupling; a fairly weak magnetic field can cause a complete Paschen-Back effect. The calculation of transition probabilities incorporating this effect into the Hamiltonian is discussed, and the detailed calculation is then given. The resulting transition probabilities are transformed into synthetic line profiles by using the Unno (1956) model of polarized radiation transfer. The dependence of the net polarized flux on magnetic field and equivalent width is investigated. It is shown that entire band systems may be significantly polarized. Broad-band circular polarization of sunspots may be due, in part, to molecular bands. Analysis of the CH G band indicates a magnetic field of 0.25-0.50 x 10 to the 6th gauss in the white dwarf G99-37, an order of magnitude lower than previous estimates.

Illing, R. M. E.↗
NASA NTRS1974

Magnetization and magnetic entropy of Dy2Ti2O7

Isothermal measurements of the magnetic entropy, magnetization, and differential susceptibility of Dy2Ti2O7 have been made. Absolute values of magnetic entropy have been determined as a function of applied magnetic field for several temperatures in the range 2-20 K, and several isofield lines in the magnetic entropy-temperature plane have been determined. Magnetization measurements, which extended into the saturation region, yield a powder-average magnetic moment of about 4.7 Bohr magnetons per ion. A van Vleck contribution to M was also observed. The results are consistent with the assumption of a nearly pure Jz equals + or - 15/2 ground-state Kramers doublet for the Dy(+++) ion. Comments on the suitability of Dy2Ti2O7 for use in a magnetic refrigerator cycling between 4.2 and 20 K are included.

Flood, D. J.↗