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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Reduced Organic Outgassing in the NASA Osiris-Rex and Hayabusa2 Curation Facility by Careful Selection and Implementation of Cleanroom Construction Materials

In October 2021, NASA Johnson Space Center (JSC) Astromaterials Acquisition and Cu-ration Office in JSC bldg. 31 completed construction and commissioning of the OSIRIS-REx and Hayabusa2cleanroom laboratory suites along with new precision cleaning and advanced curation laboratories: •OSIRIS-REx Curation Cleanroom: ISO Class 5•Hayabusa2 Curation Cleanroom: ISO Class 5•Final Precision Cleaning Cleanroom: ISO Class 5•Advanced Precision Cleaning Cleanroom: ISO Class 6•PreClean Precision Cleaning Cleanroom: ISO Class 6•Advanced Curation Cleanroom: ISO Class 7The new curation facilities are designed for initial receiving, basic characterization, curation processing, and preliminary examination of carbonaceous asteroidal material. The facilities are also designed to enable long-term pristine sample storage to preserve the scientific integrity of each sample to enable decades of future re-search by the international science community. The scientific study of organics in general is critical for both missions. The OSIRIS-REx mission executed a stringent contamination control plan [1] where all sample hardware at time of sample acquisition would be at Level 100 A/2 per IEST-STD-CC1246D (non-volatile residue (NVR) < 500 ng/cm2). In addition, the mission imposed a requirement of <180 ng/cm2 for amino acids (and hydrazine) [1]. Given these mission requirements, long-term storage preservation requirements, and information from the Organic Contamination Baseline Study at JSC [2], the JSC Curation team decided to carefully select cleanroom construction materials that would not hinder the scientific search for amino acids and the study of organics in the samples [3].

astromaterials curation↗
NASA NTRS1993

The EET87513 clast N: A CM2 fragment in an HED polymict breccia

Xenoliths of material resembling carbonaceous chondrites have been found in several HED polymict breccias. Most workers concluded that these clasts are related to CM2 meteorites on the basis of texture, bulk composition, and mineralogy. Data on clast N, a carbonaceous chondrite fragment from the howardite EET87513 large enough (approximately 4x5mm on the surface of the slab from which it was separated) to extract bulk samples for INAA and oxygen isotope analysis and to provide a thin section for electron microprobe, SEM, and TEM analysis is reported. Preliminary data for this clast were previously reported. INAA was performed at Oregon State University and bulk oxygen isotopic composition was determined at the University of Chicago. These data confirm that EET87513 clast N is a fragment of CM2 material.

Buchanan, P. C.↗
NASA NTRS2024

Identifying Solar Wind and Other Volatiles in Space-Weathered Samples From Asteroid Bennu

On September 24, 2023, NASA’s Origins, Spectral Interpretation, Resource Identification, and Security–Regolith Explorer (OSIRIS-REx) mission returned >70 g of material from asteroid Bennu to Earth. The Sample Return Capsule was opened at NASA Johnson Space Center (JSC), and a spillover sample was collected from the avionics deck to perform quick-look (QL) analyses. In addition to providing a reconnaissance investigation of its mineralogy, the sample was also examined for evidence of surface exposure on asteroid Bennu by identifying signatures of space weathering. Space weathering changes the morphology, microstructure, and chemistry of regolith on the surfaces of airless bodies. Driven by micrometeoroid bombardment and solar wind irradiation, our understanding of how space weathering modifies particles on the surfaces of carbonaceous asteroids is still developing. To bolster the interpretation of remote sensing data and to further address driving Hypothesis 10, we must investigate the nanoscale structural and chemical changes in returned samples from Bennu to understand how space weathering affects carbonaceous surface materials. Here we explore evidence for solar wind irradiation in QL samples from asteroid Bennu.

M S Thompson↗
DOE OSTI2025

Spontaneous sodium ion storage behaviors of reduced graphene oxide anodes exceeding 100% Coulombic efficiency by modulated ion solvation

Rechargeable batteries are essential energy storage devices that power portable devices and electrical vehicles throughout the world. In general, it is thought that the electrochemical performance of rechargeable batteries is mostly determined by the electrodes within them and that the electrolyte plays a relatively passive role. However, ion transport and storage can be greatly influenced by the electrolyte solution structure, specifically, ion solvation within the bulk and ion desolvation across the electrode/electrolyte interfaces. Herein, we studied the role of the electrolyte as an active component of electrochemical energy storage devices. We found that with an appropriate electrolyte formulation, ion storage in disordered carbonaceous anode materials can occur spontaneously without externally supplied electrical energy. Reduced graphene oxide (RGO) in an ether-based electrolyte demonstrates ‘spontaneous' ion storage behaviors of adsorbing and inserting the solvated ions utilizing facilitated permeability and wettability of RGO, which results in Coulombic efficiency of ~145% due to additional charging capacity of ~180 mAh g -1 during electrochemical processes. The unexpected spontaneous ion storage behavior was extensively investigated using a combination of electrochemical analyses and diagnostics, advanced characterizations, and computational simulation. In conclusion, we believe the spontaneous ion storage behavior offers a new way to further improve the energy efficiency of practical rechargeable batteries.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

A Relief Zone Architecture for Enhanced Durability of Ultrathin Membranes in Electrochemical Conversion Devices

Premature cell failures in electrochemical conversion systems often result when membrane electrode assemblies (MEAs) are prepared with ultra-thin (= 15 micrometer-thick) polymer electrolyte membranes (PEMs). These high-performance PEMs are susceptible to mechanical degradation from stress concentrations arising from component and device-level integration. Herein, a relief zone was developed to mitigate mechanical degradation by alleviating excess and non-uniform compression across the active area. Relief zones, created through the ablation of carbonaceous diffusion material achieves a seamless adaptation across a range of MEA dimensions and electrochemical applications without need for costly hardware modifications. This concept was demonstrated using fuel cells as a case study. Accelerated stress test (AST) validations yielded a 6-fold improvement for MEAs prepared with relief zones (i.e., lifetime approximately 1500 h) compared to those fabricated using conventional edge-protection techniques, showcasing the utility of this technique in decoupling integration and device-level engineering effects from intrinsic material limitations for durable electrochemical devices.

14 SOLAR ENERGY↗
NASA NTRS1974

Io - A surface evaporite deposit

A model is suggested for Io's surface composition involving evaporite salt deposits, rich in sodium and sulfur. According to this model, these deposits were produced as a result of the migration of salt-saturated aqueous solutions to Io's surface from a warm or hot interior followed by loss of the water to space. This model satisfies cosmochemical constraints based on Io's initial composition, current density, and thermal history. Salt-rich assemblages are easily derivable from the leaching of carbonaceous chondritic material. The chemical and optical properties of such deposits, after modification by irradiation, can be used to explain Io's overall albedo and spectral reflectance, its dark reddish poles, and the observed sodium emission as well as or better than other currently suggested materials.

Fanale, F. P.↗
NASA NTRS1975

Evidence for frost on Rhea's surface

We have observed Rhea (S5) at 1.6 and 2.2 microns at Mt. Wilson using the Caltech photometer on the 1.52 m and 2.54 m telescopes. The infrared spectral reflectances relative to 0.55 micron are 0.8 at 1.65 micron and 0.6 at 2.2 microns. Such absorption bands in the near infrared are not consistent with spectra of most rocks or minerals; even carbonaceous chondritic materials have nearly flat reflectances over this spectral region. Frosts, however, have strong absorption bands in the 1-3 microns region. In particular, the broadband infrared reflectances of Rhea are similar to those of the Galilean satellites Europa (J2) and Ganymede (J3) and also the rings of Saturn. Rhea's low density, high albedo and relatively flat reflectance from 0.3 to 1.1 micron as well as the low infrared reflectances reported here are consistent with the presence of water ice on Rhea's surface.

Johnson, T. V.↗
NASA NTRS1977

Uranus rings - An optical search

The discovery of rings surrounding Uranus has prompted reexamination of telescopic observations made a year ago with a solid-state area detector called a charge-coupling device (CCD). The extreme narrowness of the rings apparently caused them to be hidden in glare from the planet, the reflectivity of which is very high in the blue and green regions of the spectrum. However, Uranus appears as a much darker image in the near-infrared spectral regions detected by the CCD. Although no direct evidence of the rings is obtainable from the CCD images, some simplifying assumptions permit the deduction from the CCD data that average reflectivity of individual particles composing the rings is at most a few percent, much closer to that of carbonaceous chondritic material than to that of the ice-coated particles in Saturn's rings.

Smith, B. A.↗
NASA NTRS1977

Phobos and Deimos

Ground-based and spacecraft observations of Phobos and Deimos are reviewed and the satellites' origin is discussed. The crater densities of both bodies are close to the saturation level. The largest impact events may have caused extensive fracturing of their surfaces. The surfaces are at least 1.5 billion years old and may date back to the early history of the solar system. The Martian satellites display large deviations from sphericity. As a result of tidal processes, they are in synchronous rotation. Several independent lines of evidence show that they have regoliths. Despite some provocative arguments, their internal strengths and the nature of their interior are poorly known at present. Photometric measurements suggest that they are made of either carbonaceous chondritic material or a basalt. Sinclair (1972), Born and Duxbury (1975) and Shor (1975) apparently have successfully determined Phobos' secular acceleration. Their value of approximately .001 deg/year/year implies that the interior of Mars has a low specific dissipation factor (about 100), may indicate that a portion of the Martian interior is experiencing partial melting. The low inclination of the satellites' orbits indicates that they were formed as part of the same process that resulted in Mars.

Pollack, J. B.↗
NASA NTRS1976

The sun since the Bronze Age

An investigation is conducted concerning the behavior of the sun during the last 7000 years. The C-14 content in carbonaceous fossil material can be used as an indicator regarding the level of solar activity at the time when the carbon was assimilated in the process of photosynthesis. Living trees, such as the bristlecone pine, provide a solar activity record to about 3000 B.C. The record can be extended with the aid of well-preserved dead wood to beyond 5000 B.C. The results of an analysis of solar activity levels as a function of time on the basis of C-14 contents are presented in a graph. Attention is given to the Maunder Minimum, a history of the sun in the last 5000 years, an interpretation of the major C-14 excursions, and the sun and climate history.

Eddy, J. A.↗
NASA NTRS1978

The origin and relative abundances of C, N and the noble gases on the terrestrial planets and in meteorites

Relative concentrations of noble gases and C and N are evaluated for the terrestrial planets. Comparisons between amounts of volatile materials in carbonaceous chondrites and on Earth and Mars are presented as support for the accretion model of planetary formation. However, attention is given to the large differences in the C/noble gas ratios on various bodies in the solar system, e.g. the Sun, Venus, Earth, Mars, stressing that the data are too incomplete to provide a reliable model for the sources of volatile and noble elements on the terrestrial planets.

Bogard, D. D.↗
NASA NTRS1978

Visual and radiometric photometry of 1580 Betulia

Broadband visual and 10.6-micron photometry of 1580 Betulia was obtained during its close approach to earth in May 1976. The photometry was analyzed by using the 'radiometric method' to derive the radius (2.10 + or - 0.40 km) and albedo (0.108 + or - 0.012) of Betulia. Radar and polarimetric results indicate a radius greater than 3.0 km and a geometric albedo of about 0.05. To be compatible with these results, Betulia was also modeled as having a surface with the thermal characteristics of bare rock rather than those of the 'lunar' regolith model used for previous analysis of radiometry of other asteroids. A 3.7-km radius and a geometric albedo of about 0.04 are compatible with all available observations. Betulia is the first Mars-crossing asteroid found to have such a low albedo, which may be indicative of carbonaceous surface material.

Lebofsky, L. A.↗
NASA NTRS1987

On the sputter alteration of regoliths of outer solar system bodies

Several processes that are expected to occur when the porous regoliths of outer solar system bodies (without atmospheres) are subjected to energetic ion bombardment are discussed. The conclusions reached in much of the literature addressing sputtering are quantitatively or qualitatively incorrect because effects of soil porosity have been neglected. It is shown theoretically and experimentally that porosity reduces the effective sputtering yield of a soil by more than an order of magnitude. Between 90 and 97% of the sputtered atoms are trapped within the regolith, where they are factionated by differential desorption. Experiments indicate that more volatile species have higher desorption probabilities. This process is the most important way in which alteration of chemical and optical properties occurs when a regolith is sputtered. When a basic silicate soil is irradiated these effects lead to sputter-deposited films enriched in metallic iron, while O, Na and K are preferentially lost. The Na and K are present in the atmosphere above the sputtered silicate in quantities much greater than their abundances in the regolith. Icy regoliths of SO2 should be enriched in elemental S and/or S2O. This prediction is supported by the probable identification of S2O and polysulfur oxide bands in the IR spectra of H-sputtered SO2 reported by Moore. When porous mixtures of water, ammonia and methane frosts are sputtered, the loss of H and surface reactions of C, N and O in the deposits should produce complex hydrocarbons and carbohydrates, some of which may be quite dark. Such reactions may have played a role in the formation of the matrix material of carbonaceous chondrites prior to agglomeration.

Hapke, Bruce↗
NASA NTRS1994

Origin of the hydrocarbon component of interplanetary dust particles

Using experiments as a basis, we have developed a scenario for the origin of the hydrocarbon material of carbonaceous chondrites. This scenario can also serve as an explanation for the origin of the hydrocarbon component of interplanetary dust particles (IDP's). The formation of polycyclic aromatic hydrocarbon (PAH) molecules in the atmospheres of C stars undergoing a late stage of stellar evolution is indicated by the observed unidentified infrared (UIR) emission bands. Those molecules are then transported through interstellar space where they become enriched with D through ion molecule reactions when passing through cold, dark clouds. Many of those PAH molecules are subsequently hydrogenated and cracked in a H-dominated plasma such as would have occurred in the solar nebula. The resulting mixture of alkanes and residual D-rich PAH molecules was then incorporated into the mineral fraction of the parent bodies of carbonaceous chondrites and IDP's.

Wdowiak, Thomas J.↗
NASA NTRS2005

Electron Beam Analysis of Micrometeoroids Captured in Aerogel as Stardust Analogues

In January 2004, NASA s Stardust spacecraft passed through the tail of Comet 81P/Wild-2. The on-board dust flux monitor instrument indicated that numerous micro- and nano-meter sized cometary dust particles were captured by the dedicated silica aerogel capture cell. The collected cometary particles will be returned to Earth in January 2006. Current Stardust analogues are: (i) Light-gas-gun accelerated individual mineral grains and carbonaceous meteoritic material in aerogels at the Stardust encounter velocity ca.approximately 6 kilometers per second. (ii) Aerogels exposed in low-Earth orbit (LEO) containing preserved cosmic dust grains. Studies of these impacts offer insight into the potential state of the captured cometary dust by Stardust and the suitability of various analytical techniques. A number of papers have discussed the application of sophisticated synchrotron analytical techniques to analyze Stardust particles. Yet much of the understanding gained on the composition and mineralogy of interplanetary dust particles (IDPs) has come from electron microscopy studies. Here we discuss the application of scanning electron microscopy (SEM) for Stardust during the preliminary phase of post-return investigations.

Graham, G. A.↗