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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS2007

White Dwarfs in the GALEX Survey

We have cross-correlated the 2dF QSO Redshift Survey (2QZ) white dwarf catalog with the GALEX 2nd Data Release and the Sloan Digital Sky Survey (SDSS) data release 5 to obtain ultraviolet photometry (FUV, NUV) for approximately 700 objects and optical photometry (ugriz) for approximately 800 objects. We have compared the optical-ultraviolet colors to synthetic white dwarf colors to obtain temperature estimates for approximately 250 of these objects. These white dwarfs have effective temperatures ranging from 10 000 K (cooling age of about 1Gyr) up to about 40000 K (cooling age of about 3 Myrs), with a few that have even higher temperatures. We found that to distinguish white dwarfs from other stellar luminosity classes both optical and ultraviolet colors are necessary, in particular for the hotter objects where there is contamination from B and 0 main-sequence stars. Using this sample we build a luminosity function for the DA white dwarfs with Mv < 12 mag.

Kawka, Adela↗
NASA NTRSDate not supplied

The Comet Astrobiology Exploration Sample Return (CAESAR) Mission

The Comet Astrobiology Exploration Sample Return (CAESAR) mission will acquire and return to Earth for laboratory analysis a minimum of 80 grams of surface material from the nucleus of comet 67P/Chur-yumov-Gerasimenko (67P). CAESAR will characterize the surface region sampled, preserve the collected sample in a pristine state, and return evolved volatiles by capturing them in a separate gas reservoir. NASA Goddard Space Flight Center provides project management, systems engineering, safety and mission assurance, contamination control, mission operations, and many other important functions. Northrop Grumman Space Systems will build the spacecraft, based on Dawn mission heritage, which like CAESAR, uses solar electric propulsion. CAESAR was selected by for Phase A study in the New Frontiers 4 Competition and will be proposed to New Frontiers 5.Collection of a sample from the surface of comet 67P is facilitated by a set of cameras that together provide images to support sample site selection, perform optical navigation, and document the sample before, during, and after col-lection. The sample is collected at the end of an arm during a 5-second touch-and-go (TAG) maneuver with the Sample Acquisition System (SAS)designed by Honeybee Robotics for the surface properties of comet 67P observed by the Rosetta mission. After sample collection, and while the sample is still cold (< -80°C), the TAG Arm inserts the sample container into the Sample Containment System (SCS) mounted inside the Sample Return Capsule (SRC). The SCS is sealed, preventing the sample from escaping into space. The sample is slowly warmed inside the SCS to enable sublimation of volatiles, which are collected in the Gas Containment System (GCS), a passively cooled gas reservoir. Separating the volatiles from the solid sample protects the solid sample from alteration. Once all sublimated H2O is transferred to the GCS, the GCS is sealed to capture the volatile sit contains, and the SCS is vented to space to maintain the solid sample under vacuum. The SCS vent is closed before Earth entry to prevent atmospheric contamination. Detailed laboratory analyses of the sample from 67P will trace the history of volatile reservoirs, delineate the chemical pathways that led from simple interstellar species to complex molecules, constrain the evolution of the comet, and evaluate the role of comets in delivering water and prebiotic organics to the early Earth. CAESAR will achieve these goals by carrying out coordinated sample analyses that will link macroscopic properties of the comet with microscale mineralogy, chemistry, and isotopic studies of volatiles and solids. Most of the sample (≥75%) will be set aside for analyses by generations of scientists using continually advancing tools and methods, yielding an enduring scientific treasure that only sample return can provide. This presentation will review development conducted during NF4 Phase A and discuss the NF5 mission concept.

A G Hayes↗
NASA NTRSDate not supplied

Thermoplastic Composite Lunar Tower Truss Structure: Design Development and Verification Plans

The National Aeronautics and Space Administration (NASA) Space Technology and Mission Directorate (STMD) is advancing thermoplastic composite (TPC) technologies for exploration missions. The Technology Development for Exploration Applications (TDEA) project goals are to develop and mature TPC materials, designs, analyses tools and techniques, and mature manufacturing processes. This includes development of manufacturing and joining approaches relevant to space environments. To these ends TDEA endeavors toward demonstrating a TPC truss structure for a lunar tower configuration. The design, predicated on robotic assembly, uses open section truss elements fused to a joint splice plate, without a structural adhesive. This presentation details the TDEA lunar truss structure design development approach including design heritage, the requirements established, the mechanical design and analyses, and thermal analyses demonstrating structural requirements conformance, as well as planned building block verification efforts either underway or planned. The mechanical analyses show the most severe environment is a moon-quake the truss dynamic responses. The thermal analyses show the extreme cold for on-orbit welding, the window for less severe on-orbit welding, as well as the large thermal gradients on the truss. The building block approach shown includes ultrasonic welding and lap shear coupon testing on various truss element thicknesses and layups. Knockdown factor determinations due to lunar dust contamination (simulated) and effects of welding in a vacuum are presented. The most highly loaded truss joint configuration sub-element verification test matrix is outlined. Lastly, plans to build, inspect, and test a 2-bay truss representative unit cell that is 1.5 meters by 1.5 meters by 3.0 meters tall are detailed.

Lunar Tower↗
NASA NTRS1980

NASCAP modelling computations on large optics spacecraft in geosynchronous substorm environments

The NASA Charging Analyzer Program (NASCAP) is used to evaluate qualitatively the possibility of such enhanced spacecraft contamination on a conceptual version of a large satellite. The evaluation is made by computing surface voltages on the satellite due to encounters with substorm environments and then computing charged particle trajectories in the electric fields around the satellite. Particular attention is paid to the possibility of contaminants reaching a mirror surface inside a dielectric tube because this mirror represents a shielded optical surface in the satellite model used. Deposition of low energy charged particles from other parts of the spacecraft onto the mirror was found to be possible in the assumed moderate substorm environment condition. In the assumed severe substorm environment condition, however, voltage build up on the inside and edges of the dielectric tube in which the mirror is located prevents contaminants from reaching the mirror surface.

Stevens, N. J.↗
NASA NTRS1980

NASCAP modelling computations on large optics spacecraft in geosynchronous substorm environments

Satellites in geosynchronous orbits have been found to be charged to significant negative voltages during encounters with geomagnetic substorms. When satellite surfaces are charged, there is a probability of enhanced contamination from charged particles attracted back to the satellite by electrostatic forces. This could be particularly disturbing to large satellites using sensitive optical systems. In this study the NASA Charging Analyzer Program (NASCAP) is used to evaluate qualitatively the possibility of such enhanced contamination on a conceptual version of a large satellite. The evaluation is made by computing surface voltages on the satellite due to encounters with substorm environments and then computing charged-particle trajectories in the electric fields around the satellite. Particular attention is paid to the possibility of contaminants reaching a mirror surface inside a dielectric tube because this mirror represents a shielded optical surface in the satellite model used. Deposition of low energy charged particles from other parts of the spacecraft onto the mirror was found to be possible in the assumed moderate substorm environment condition. In the assumed severe substorm environment condition, however, voltage build up on the inside and edges of the dielectric tube in which the mirror is located prevents contaminants from reaching the mirror surface.

Stevens, N. J.↗
NASA NTRS2023

PER- AND POLYFLUOROALKYL SUBSTANCES SITE ASSESSMENT PROGRESS REPORT FORMER FIRE STATION 2 AND VEHICLE ASSEMBLY BUILDING NORTH KENNEDY SPACE CENTER, FLORIDA

This Per- and Polyfluoroalkyl Substances (PFAS) Site Assessment Progress Report was prepared by AECOM Technical Services, Inc. (AECOM) for the National Aeronautics and Space Administration (NASA) under Indefinite Delivery Quantity Contract 80KSC019D0010, Task Order 80KSC019F0096. The purpose of this report is to document ongoing site assessment activities at Former Fire Station 2 (FS2) and the Vehicle Assembly Building North (VABN) Area. Former FS2 was identified as a potential source of PFAS contamination based on its previous use as a fire station; the VAB North Area has several areas that were identified as potential PFAS sources.

Megan E. Garcia↗
DOE OSTI2023

Lawrence Livermore National Laboratory Experimental Test Site 300 (S300): S300 Roadway Improvements - 817 Complex Soil Sampling and Analysis Plan, Addendum 1 (June 2023)

The purpose of this addendum is to amend and update the S300 Roadway Improvements – 817 Complex [project] Soil Sampling and Analysis Plan (SAP) dated May 2023. Field activities to implement the SAP were completed in May 2023 except for SB-17. SB-17 is therefore included in this addendum. In addition, this addendum amends the SAP by covering an expanded scope of work and project limits. The project limits have been expanded to include areas around Building 818. Sampling at the expanded project area is addressed in this addendum by two additional borings for geotechnical and environmental analyses. The project area consists of the access gate and existing access roads for the Process Area complex. Excavation depths are anticipated to be no deeper than 5 feet from current grade. None of the proposed disturbance areas are within known areas of contamination or mapped controlled excavation area (LLNL 2008). Therefore, this addendum proposes a sampling spacing in the vicinity of Building 818 of about 172 feet (Tier 2) in accordance with the Soil Screening and Management Plan (LLNL 2022). The information contained in this addendum supersedes the May 2023 SAP. However, this addendum only addresses elements of the May 2023 SAP that were modified. Elements of the May 2023 SAP that have not been modified are relevant and will remain in effect.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS2008

Sensing a Changing Chemical Mixture Using an Electronic Nose

A method of using an electronic nose to detect an airborne mixture of known chemical compounds and measure the temporally varying concentrations of the individual compounds is undergoing development. In a typical intended application, the method would be used to monitor the air in an inhabited space (e.g., the interior of a building) for the release of solvents, toxic fumes, and other compounds that are regarded as contaminants. At the present state of development, the method affords a capability for identifying and quantitating one or two compounds that are members of a set of some number (typically of the order of a dozen) known compounds. In principle, the method could be extended to enable monitoring of more than two compounds. An electronic nose consists of an array of sensors, typically made from polymer carbon composites, the electrical resistances of which change upon exposure to a variety of chemicals. By design, each sensor is unique in its responses to these chemicals: some or all of the sensitivities of a given sensor to the various vapors differ from the corresponding sensitivities of other sensors. In general, the responses of the sensors are nonlinear functions of the concentrations of the chemicals. Hence, mathematically, the monitoring problem is to solve the set of time-dependent nonlinear equations for the sensor responses to obtain the time dependent concentrations of individual compounds. In the present developmental method, successive approximations of the solution are generated by a learning algorithm based on independent-component analysis (ICA) an established information theoretic approach for transforming a vector of observed interdependent signals into a set of signals that are as nearly statistically independent as possible.

Duong, Tuan↗
NASA NTRS2003

A Tabletop Tool for Modeling Life Support Systems

This paper describes the development plan for a comprehensive research and diagnostic tool for aspects of advanced life support systems in space-based laboratories. Specifically it aims to build a high fidelity tabletop model that can be used for the purpose of risk mitigation, failure mode analysis, contamination tracking, and testing reliability. We envision a comprehensive approach involving experimental work coupled with numerical simulation to develop this diagnostic tool. It envisions a 10% scale transparent model of a space platform such as the International Space Station that operates with water or a specific matched index of refraction liquid as the working fluid. This allows the scaling of a 10 ft x 10 ft x 10 ft room with air flow to 1 ft x 1 ft x 1 ft tabletop model with water/liquid flow. Dynamic similitude for this length scale dictates model velocities to be 67% of full-scale and thereby the time scale of the model to represent 15% of the full- scale system; meaning identical processes in the model are completed in 15% of the full- scale time. The use of an index matching fluid (fluid that matches the refractive index of cast acrylic, the model material) allows making the entire model (with complex internal geometry) transparent and hence conducive to non-intrusive optical diagnostics. So using such a system one can test environment control parameters such as core flows (axial flows), cross flows (from registers and diffusers), potential problem areas such as flow short circuits, inadequate oxygen content, build up of other gases beyond desirable levels, test mixing processes within the system at local nodes or compartments and assess the overall system performance. The system allows quantitative measurements of contaminants introduced in the system and allows testing and optimizing the tracking process and removal of contaminants. The envisaged system will be modular and hence flexible for quick configuration change and subsequent testing. The data and inferences from the tests will allow for improvements in the development and design of next generation life support systems and configurations.

Ramachandran, N.↗
NASA NTRS2005

Space Laboratory on a Table Top: A Next Generative ECLSS design and diagnostic tool

This paper describes the development plan for a comprehensive research and diagnostic tool for aspects of advanced life support systems in space-based laboratories. Specifically it aims to build a high fidelity tabletop model that can be used for the purpose of risk mitigation, failure mode analysis, contamination tracking, and testing reliability. We envision a comprehensive approach involving experimental work coupled with numerical simulation to develop this diagnostic tool. It envisions a 10% scale transparent model of a space platform such as the International Space Station that operates with water or a specific matched index of refraction liquid as the working fluid. This allows the scaling of a 10 ft x 10 ft x 10 ft room with air flow to 1 ft x 1 ft x 1 ft tabletop model with water/liquid flow. Dynamic similitude for this length scale dictates model velocities to be 67% of full-scale and thereby the time scale of the model to represent 15% of the full- scale system; meaning identical processes in the model are completed in 15% of the full- scale-time. The use of an index matching fluid (fluid that matches the refractive index of cast acrylic, the model material) allows making the entire model (with complex internal geometry) transparent and hence conducive to non-intrusive optical diagnostics. So using such a system one can test environment control parameters such as core flows (axial flows), cross flows (from registers and diffusers), potential problem areas such as flow short circuits, inadequate oxygen content, build up of other gases beyond desirable levels, test mixing processes within the system at local nodes or compartments and assess the overall system performance. The system allows quantitative measurements of contaminants introduced in the system and allows testing and optimizing the tracking process and removal of contaminants. The envisaged system will be modular and hence flexible for quick configuration change and subsequent testing. The data and inferences from the tests will allow for improvements in the development and design of next generation life support systems and configurations. Preliminary experimental and modeling work in this area will be presented. This involves testing of a single inlet-exit model with detailed 3-D flow visualization and quantitative diagnostics and computational modeling of the system.

Ramachandran, N.↗
DOE OSTI2022

CO 2 supplementation eliminates sugar-rich media requirement for plant propagation using a simple inexpensive temporary immersion photobioreactor

In vitro plant propagation systems such as temporary immersion bioreactors (TIBs) are valuable tools that enable production of disease-free plants with improved traits. However, TIB systems can be expensive, difficult to implement, and prone to contamination due to sugar rich propagation media. Using rapidly growing chicory root cultures to expedite design-build-test cycles, we report here an improved, low-cost version of a previously reported Hydrostatically-driven TIB (Hy-TIB) that facilitates economical use of gas mixtures. Bioreactor improvements include decreased material costs, expanded modes of operation, and a horizontal orientation of a plastic film plant growth chambers that increase propagule light exposure. To take advantage of these improvements, we describe here experiments that evaluate the impacts of elevated CO 2 on propagation of cacao (Theobroma cacao) secondary embryos and nodal cultures of yam (Dioscorea spp.) during both phototrophic and photomixotrophic growth. Our experiments show that elevated CO 2 during plant propagation significantly improved both cacao and yam propagule development and eliminated the need for supplemental sugars in tissue culture growth media. Thus, our improved Hy-TIB shows potential as a simple, low-cost, and scalable propagation platform with cost-effective gas composition control and reduced risk of contamination overgrowth. We provide detailed instructions for assembly of this Hy-TIB design and discuss the implications of its adoption in food-insecure regions of the world.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

IER 555: Godiva Benchmark Update CED-2 (Final Design Report)

The International Criticality Safety Benchmark Evaluation Project (ICSBEP) evaluation of the Godiva IV critical assembly, HEU-MET-FAST-086: GODIVA-IV DELAYED-CRITICAL EXPERIMENTS (HMF-086), was completed by Russ Mosteller. Five critical experiment configurations performed at the Los Alamos National Laboratory (LANL) Technical Area (TA)-18 were evaluated as acceptable benchmark cases. The five cases consist of four delayed critical configurations which differ in control rod positions and one prompt critical configuration. All cases calculated a lower $k_{eff}$ than measured by experiment. This data is referred to as the TA-18 Godiva IV benchmark in this report. In 2005, Godiva IV was disassembled for relocation to the Nevada Test Site (NTS), now Nevada National Security Site (NNSS), at the National Criticality Experiments Research Center (NCERC). Following the disassembly and subsequent reassembly and startup of Godiva IV at NCERC, additional information about the Godiva IV components was obtained. An errata note was added to the HMF-086 evaluation in the ICSBEP handbook to provide this new information until a revision to the benchmark evaluation could be performed. In addition to those corrections, there are differences between the Godiva IV assembly at TA-18 and the Godiva IV assembly at NCERC. These differences include both assembly-specific differences (differences in the safety block gap, differences in the control rod positions, a new NCERC Top Hat and contamination shield) as well as environmental differences, such as the size and shape of the experimental building where the assembly is located. An additional model with similar cases, referred to as the NCERC Godiva IV benchmark in this report, will be added to the revised HMF-086 to capture these additional differences. This will provide the best benchmark model of Godiva for use by those performing experiments at NCERC. The IER 555 CED-2 report documents the information that will be updated in the HMF-086 revision, both the corrections to the TA-18 Godiva IV benchmark and the subsequent changes to create a NCERC Godiva IV benchmark. It describes the measurements that will be performed for cases similar to those performed at TA-18. It also describes measurements that will be included in the evaluation as additional data.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Modeling intrinsic galaxy alignment in the MICE simulation

The intrinsic alignment (IA) of galaxies is potentially a major limitation in deriving cosmological constraints from weak lensing surveys. In order to investigate this effect, we assign intrinsic shapes and orientations to galaxies in the light-cone output of the MICE simulation, spanning ~ 5000 deg 2 and reaching redshift Z = 1.4. This assignment is based on a semianalytic IA model that uses photometric properties of galaxies as well as the spin and shape of their host halos. Advancing on previous work, we include more realistic distributions of galaxy shapes and a luminosity-dependent galaxy-halo alignment. The IA model parameters are calibrated against COSMOS and BOSS LOWZ observations. The null detection of IA in observations of blue galaxies is accounted for by setting random orientations for these objects. We compare the two-point alignment statistics measured in the simulation against predictions from the analytical IA models NLA and TATT over a wide range of scales, redshifts, and luminosities for red and blue galaxies separately. We find that both models fit the measurements well at scales above 8h -1 Mpc, while TATT outperforms NLA at smaller scales. The IA parameters derived from our fits are in broad agreement with various observational constraints from red galaxies. Finally, we build a realistic source sample, mimicking DES Year 3 observations and use it to predict the IA contamination to the observed shear statistics. We find this prediction to be within the measurement uncertainty, which might be a consequence of the random alignment of blue galaxies in the simulation.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Methods—A Practical Approach to the Reversible Hydrogen Electrode Scale

Accurately quantifying applied potential is important to ensuring the comparability, accuracy, and precision of electrochemical studies. Reference electrodes (REs) enable knowledge/determination of the applied potential at electrodes in electrochemical systems. Ultimately, the choice of RE will depend on the particular requirements of a given electrochemical system, however, we note it is imperative to ensure the accuracy of the RE potential and its proper translation to a standardized scale. In this work, we highlight that while there are many commercially available REs, these must be experimentally calibrated to a reliable and practical standard potential scale, for instance the reversible hydrogen electrode (RHE) scale for aqueous systems. With representative data, we provide streamlined instructions on how to calibrate any RE to the RHE scale. We also provide guidance to mitigate and/or avoid possible electrolyte contamination issues arising from REs. Moreover, we offer a step-by-step guide on how to build a practical RHE RE, which may be a suitable and desirable option in certain applications. Our work emphasizes the need for the continuous adoption of standardized reference potential scales and demonstrates the versatility of the RHE scale, particularly in aqueous electrochemistry.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Phased Construction Completion Report for Decontamination Laundry Demolition at the Oak Ridge National Laboratory

This Phased Construction Completion Report (PCCR) documents completion of demolition, waste disposition, and slab stabilization activities of Building 2523 (Decontamination Laundry) for the Oak Ridge National Laboratory (ORNL). The Decontamination Laundry is located directly north of the intersection of White Oak Avenue and the 2519 Access Road. This demolition scope included the removal of the above-grade structures and facility components associated with Building 2523. This scope included the removal of Building 2523 (and all remaining contents inside), Trailer 2523A (and all remaining contents inside), an above-grade wastewater tank, and a wooden access porch connecting Buildings 2523 and Trailer 2523A. On the north side of Building 2523, above-grade portions of selected remaining foundations/stairs were removed from former Building 2517 to make room to stage waste containers. Building 2621 is west of the Laundry Building and Buildings 2547 and 2649 are to the east, while Building 2525 is to the north. Building 2523 is located within Bethel Valley Exposure Unit (EU) 3. The total area of the EU is approximately 39 acres. The area within EU 3 is bounded by First Street on the west, Central Avenue on the north, Third Street on the east and south. The slab of Building 2523 has been stabilized with a cap of flowable fill concrete and asphalt to contain residual radiological contamination and to provide surface suitable for vehicle parking. No below-grade demolition actions were performed during this task.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2024

Large-scale 2D heterostructures from hydrogen-bonded organic frameworks and graphene with distinct Dirac and flat bands

The current strategies for building 2D organic-inorganic heterojunctions involve mostly wet-chemistry processes or exfoliation and transfer, leading to interface contaminations, poor crystallizing, or limited size. Here we show a bottom-up procedure to fabricate 2D large-scale heterostructure with clean interface and highly-crystalline sheets. As a prototypical example, a well-ordered hydrogen-bonded organic framework is self-assembled on the highly-oriented-pyrolytic-graphite substrate. The organic framework adopts a honeycomb lattice with faulted/unfaulted halves in a unit cell, resemble to molecular “graphene”. Interestingly, the topmost layer of substrate is self-lifted by organic framework via strong interlayer coupling, to form effectively a floating organic framework/graphene heterostructure. The individual layer of heterostructure inherits its intrinsic property, exhibiting distinct Dirac bands of graphene and narrow bands of organic framework. Our results demonstrate a promising approach to fabricate 2D organic-inorganic heterostructure with large-scale uniformity and highly-crystalline via the self-lifting effect, which is generally applicable to most of van der Waals materials.

36 MATERIALS SCIENCE↗
NASA NTRS2022

Clean Air Shower Curtain for Protection of Contamination Sensitive Telescopes on the Ariane 5 Launcher

The launch of the James Webb Space Telescope (JWST) was successfully performed by Ariane 5 from French Guiana on December 25th 2021. The unique nature of the JWST mission led to various adaptations of the Ariane 5 launch system to fulfill stringent cleanliness and hygrometry requirements all along the launch preparation. JWST integration and test activities in the Final Assembly Building (BAF) had to be performed in ISO Class 7 equivalent conditions under Volatile Organic Compounds (VOC) protection and monitoring. For this purpose, a dedicated air supply system equipped with Airborne Molecular Contamination (AMC) filters was installed in the umbilical mast. The fairing itself was specially sealed to protect the inner environment, and to, guarantee ISO Class 7, the BAF Composite Hall (BAF-HC) facilities were upgraded with a removable “Air Shower Curtain” (AShC) containment enclosure between the mobile platforms around JWST. The preparation of these Ariane 5 launch system adaptations started several years before the launch campaign with close cooperation and coordination between Arianespace, ArianeGroup, the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA). This paper describes their specificities and addresses the challenges experienced to achieve the successful mission preparation.

Contamination Control, James Webb Space Telescope,↗