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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 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2006

Lightweight Ablative and Ceramic Thermal Protection System Materials for NASA Exploration Systems Vehicles

As a collaborative effort among NASA Centers, the "Lightweight Nonmetallic Thermal Protection Materials Technology" Project was set up to assist mission/vehicle design trade studies, to support risk reduction in thermal protection system (TPS) material selections, to facilitate vehicle mass optimization, and to aid development of human-rated TPS qualification and certification plans. Missions performing aerocapture, aerobraking, or direct aeroentry rely on advanced heatshields that allow reductions in spacecraft mass by minimizing propellant requirements. Information will be presented on candidate materials for such reentry approaches and on screening tests conducted (material property and space environmental effects tests) to evaluate viable candidates. Seventeen materials, in three classes (ablatives, tiles, and ceramic matrix composites), were studied. In additional to physical, mechanical, and thermal property tests, high heat flux laser tests and simulated-reentry oxidation tests were performed. Space environmental effects testing, which included exposures to electrons, atomic oxygen, and hypervelocity impacts, was also conducted.

Valentine, Peter G.↗
NASA NTRS2018

Outer Solar System Material in Inner Solar System Regolith Breccias

There is excellent evidence that a dynamical instability in the early solar system led to gravitational interactions between the giant planets and trans-Neptunian objects (TNOs). Giant planetary migration triggered by the instability dispersed a disk of primordial TNOs and created a number of small body reservoirs (e.g. the Kuiper Belt, scattered disk, irregular satellites, and the Jupiter/Neptune Trojan populations). It also injected numerous bodies into the main asteroid belt, where modeling shows they can successfully reproduce the observed P and D-type asteroid populations. During the injection era and after implantation, some of these “main belt TNOs” would have collided with S-class asteroids. Some of this material may have survived as a component of asteroid regolith breccias. Thus, we have been searching for evidence of these impact events in the form of carbonaceous xenoliths in brecciated ordinary chondrites. These xenoliths would have experienced a wide range of impact velocities, and therefore we should expect to see everything between relatively unaltered material to completely shock-melted lithologies. This material might also be different from the carbonaceous chondrites that represent standard C-complex asteroids. A goal of this research is to define useful criteria for distinguishing between these two classes of materials, including O, Cr, N and C isotopes, petrographic characteristics, and chronology.

Zolensky, M.↗
NASA NTRS1980

Study of thermal control systems for orbiting power systems. Materials experiment carrier thermal control system study

Four possible arrangements of the materials experiment carrier (MEC) and power system (PS) thermal control loops were defined which would provide one kW of heat rejection for each kW of power to the MEC payload. These arrangements were compared to the baseline reference concept which provides only 16 kW heat rejection to show the cost of obtaining symmetry in terms of dollars, weight, complexity, growth potential, ease of integration, technology and total launch weight. The results of these comparisons was that the concept which splits the PS thermal control loop into two systems, one to reject PS waste heat and one payload waste heat, appeared favorable. The fluid selection study resulted in recommendation of FC72 as the MEC heat transport fluid based on the thermal and physical characteristics. The coatings reviewed indicated anodized and alodine treated aluminum surfaces or silver teflon are the best choices for the MEC vehicle where durability is an important factor. For high temperature radiators silver teflon or zinc orthotitanate are recommended choices.

Fleming, M. L.↗
NASA NTRS2019

Deployable Sheet Material Systems and Methods

Exemplary deployable sheet material systems may be configured to stow and deploy sheet material. The systems may include one or more masts, one or more extendable booms, and one or more guys wires configured to function in conjunction with each other to deploy the sheet material and then to maintain the sheet material in the deployed configuration.

Abrams, John L.↗
NASA NTRS2014

GCD TechPort Data Sheets Thermal Protection System Materials (TPSM) Project

The Thermal Protection System Materials (TPSM) Project consists of three distinct project elements: the 3-Dimensional Multifunctional Ablative Thermal Protection System (3D MAT) project element; the Conformal Ablative Thermal Protection System (CA-TPS) project element; and the Heatshield for Extreme Entry Environment Technology (HEEET) project element. 3D MAT seeks to design, develop and deliver a game changing material solution based on 3-dimensional weaving and resin infusion approach for manufacturing a material that can function as a robust structure as well as a thermal protection system. CA-TPS seeks to develop and deliver a conformal ablative material designed to be efficient and capable of withstanding peak heat flux up to 500 W/ sq cm, peak pressure up to 0.4 atm, and shear up to 500 Pa. HEEET is developing a new ablative TPS that takes advantage of state-of-the-art 3D weaving technologies and traditional manufacturing processes to infuse woven preforms with a resin, machine them to shape, and assemble them as a tiled solution on the entry vehicle substructure or heatshield.

HEEET↗
NASA NTRSDate not supplied

Multiscale Modeling of Woven Ablative Thermal Protection System Materials

The NASA Entry Systems Modeling project maintains a portfolio of computational model and tool development activities focused on reducing performance uncertainties in ablative Thermal Protection System (TPS) materials for NASA missions. The development activities span material scale and strive to allow microstructural characterization of material structure and properties, mesoscale analyses of damage, and macroscale evaluation of heatshield performance and recession in a given aerothermodynamic environment. This talk will detail the application of developed capabilities at all three scales to the woven TPS material that the Agency has selected as the heatshield for the Mars Sample Return Earth Entry System (MSR-EES) mission – 3D Mid-Density Carbon Phenolic (3MDCP). Each of the applications focuses on driving down uncertainties in material performance and thus risk for MSR-EES and other future missions that may leverage woven TPS. At the microscale, machine learning techniques are used to characterize images from destructive microscopy and inform structural variability. At the mesoscale, Lagrangian techniques are used to simulate ballistic impact and interpret damage modes noted in experiments. At the macroscale, coupled flow-material response techniques are validated by Arc Jet testing to enable heatshield design for missions with massive ablation.

Justin B Haskins↗
NASA NTRS1995

InGaAlAsPN: A Materials System for Silicon Based Optoelectronics and Heterostructure Device Technologies

A new material system is proposed for silicon based opto-electronic and heterostructure devices; the silicon lattice matched compositions of the (In,Ga,Al)-(As,P)N 3-5 compounds. In this nitride alloy material system, the bandgap is expected to be direct at the silicon lattice matched compositions with a bandgap range most likely to be in the infrared to visible. At lattice constants ranging between those of silicon carbide and silicon, a wider bandgap range is expected to be available and the high quality material obtained through lattice matching could enable applications such as monolithic color displays, high efficiency multi-junction solar cells, opto-electronic integrated circuits for fiber communications, and the transfer of existing 3-5 technology to silicon.

Broekaert, T. P. E.↗
NASA NTRS2010

Stable Chlorine Isotope Study: Application to Early Solar System Materials

A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the Cl-37/Cl-35 ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For example, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. A significantly large mass fractionation between two stable chlorine isotopes is expected during planetary processes In addition, in view of the isotopic heterogeneity of other light elements, the chlorine isotopes can potentially be used as a tracer for the origins and evolutionary processes of early solar system materials. Due to analytical difficulties, however, current chlorine isotope studies on planetary materials are quite controversial among IRMS (gas source mass spectrometry) and/or TIMS (Thermal Ionization Mass Spectrometry) groups [i.e. 1-3]. Although a cross-calibration of IRMS and TIMS indicates that both techniques are sufficiently consistent with each other [4], some authors have claimed that the 37Cl/35Cl ratio of geological samples obtained by TIMS technique are, in general, misleadingly too high and variable compared to those of IRMS [3]. For eample, almost no differences of Cl isotope composition were observed among mantle materials and carbonaceous meteorites by [3]. On the other hand, according to more recent IRMS work [2], significant Cl isotope variations are confirmed for mantle materials. Therefore, additional careful investigation of Cl isotope analyses are now required to confirm real chlorine isotope variations for planetary materials including carbonaceous chondrites [5]. In order to clarify the stable chlorine isotope features of early solar system materials, we have initiated development of the TIMS technique at NASA JSC applicable to analysis of small amounts of meteoritic and planetary materials. We report here the current status of chlorine isotope analysis at NASA JSC.

Mala,ira. M/↗
NASA NTRS1997

Development of Tailorable Electrically Conductive Thermal Control Material Systems

The optical characteristics of surfaces on spacecraft are fundamental parameters in controlling its temperature. Passive thermal control coatings with designed solar absorptance and infrared emittance properties have been developed and have been in use for some time. In this total space environment, the coating must be stable and maintain its desired optical properties as well as mechanical properties for the course of the mission lifetime. The mission lifetimes are increasing and in our quest to save weight, newer substrates are being integrated which limit electrical grounding schemes. All of this has added to already existing concerns about spacecraft charging and related spacecraft failures or operational failures. The concern is even greater for thermal control surfaces that are very large. One way of alleviating such concerns is to design new thermal control material systems (TCMS) that can help to mitigate charging via providing charge leakage paths. The objective of this program was to develop two types of passive electrically conductive TCMS. The first was a highly absorbing/emitting black surface and the second was a low (alpha(sub s)/epsilon(sub N)) type white surface. The surface resistance goals for the black absorber was 10(exp 4) to 10(exp 9) Omega/square, and for the white surfaces it was 10(exp 6) to 10(exp 10) Omega/square. Several material system concepts were suggested and evaluated for space environment stability and electrical performance characterization. Our efforts in designing and evaluating these material systems have resulted in several developments. New concepts, pigments and binders have been developed to provide new engineering quality TCMS. Some of these have already found application on space hardware, some are waiting to be recognized by thermal designers, and some require further detailed studies to become state-of-the-art for future space hardware and space structures. Our studies on baseline state-of-the-art materials and conductive concepts have resulted in several important findings that are of interest to all thermal designers and systems integrators.

Deshpande, M. S.↗
NASA NTRS2002

Ablative Laser Propulsion Using Multi-Layered Material Systems

Experimental investigations are ongoing to study the force imparted to materials when subjected to laser ablation. When a laser pulse of sufficient energy density impacts a material, a small amount of the material is ablated. A torsion balance is used to measure the momentum produced by the ablation process. The balance consists of a thin metal wire with a rotating pendulum suspended in the middle. The wire is fixed at both ends. Recently, multi-layered material systems were investigated. These multi-layered materials were composed of a transparent front surface and opaque sub surface. The laser pulse penetrates the transparent outer surface with minimum photon loss and vaporizes the underlying opaque layer.

Nehls, Mary↗
NASA NTRS2019

Additive Manufacturing of Multi-Material Systems for Aerospace Applications

Additive manufacturing methods for producing single materials are rapidly improving. The resulting material properties and microstructures are becoming more comparable to those of conventionally fabricated materials. However, the need for multi-functional and complex structures and components requires additional innovations in manufacturing such as multi-material and hybrid additive manufacturing approaches. Additive manufacturing machines with multiple print capabilities and combinations of AM, machining, and conventional processing methods will further open up design spaces and possibilities. In this presentation, several examples of the needs and methods for multi-material fabrication will be discussed with a focus on aerospace applications. Direct printing of silver coils in conjunction with fused deposition modeling, machined parts, and, binder jetting is being developed for innovative stator designs. Binder jetting of silicon-based materials with powder bed additions is being developed for heat exchanger applications. Additive manufacturing of bi-material systems is being pursued to fabricate lightweight, integrated, multifunctional structures.

multi-materials↗
NASA NTRSDate not supplied

Multiscale Thermal Conductivity Modeling of 3D Woven Composite Thermal Protection System Materials

Novel thermal protection systems (TPS) for re-entry and hypersonic vehicles utilize 3D woven composite materials with blended carbon filament tows (yarns) and a phenolic resin matrix. The presence of continuous carbon fibers provides superior stiffness and strength compared to legacy TPS, while the 3D weave pattern provides a great deal of design flexibility for both in-plane and through thickness thermomechanical behavior. However, modeling of 3D woven composites is notoriously complex and numerically intensive. The present investigation utilizes a unique ultra-efficient approach, known as Multiscale Recursive Micromechanics (MsRM), wherein recursive semi-analytical micromechanics methods are employed at various length scales within the composite. The MsRM approach has recently been extended to solve for the effective thermal conductivity as well as the local temperature and thermal flux fields throughout the composite. Presented model results focus on the impact of the microstructural geometry representation at each length scale on the material’s effective thermal conductivity, along with the local thermal flux and temperature fields induced in the microstructures, for a novel 3D woven TPS.

Composite↗
NASA NTRS2011

Terahertz Computed Tomography of NASA Thermal Protection System Materials

A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

Roth, D. J.↗
NASA NTRS2019

Micro-scale Artificial Weave Generation Capabilities for Thermal Protection System Material Modeling

Thermal Protection System (TPS) modeling requires accurate representation and prediction of the thermomechanical behavior of ablative materials. State-of-the-art TPS materials such as Phenolic Impregnated Carbon Ablator (PICA) have a proven flight record and demonstrate exceptional capabilities for handling extreme aerothermal heating conditions. The constant push for lightweight materials that are flexible in their design and performance, and hence allow for a wide range of mission profiles, has led NASA over the past years to develop its Heatshield for Extreme Entry Environment Technology (HEEET). HEEET is based primarily on a dual layer woven carbon fiber architecture and the technology has successfully been tested in arc-jet facilities. These recent developments have sparked interest in the accurate micro-scale modeling of composite weave architectures, to predict the structural response of macro-scale heatshields upon atmospheric entry. This effort can be extended to incorporate in-depth failure mechanics analyses as a result of local thermal gradients or high-velocity particle impact.

Visser, Sander J.↗
NASA NTRSDate not supplied

Multiscale Modeling of Fracture Strength in Fibrous Thermal Protection System Materials

This work presents a multiscale modeling approach to predict the fracture strength of fibrous Thermal Protection System (TPS) materials. The model assumes that system failure is initiated at the joints between individual fibers. We investigated three distinct TPS compositions: amorphous silica, alumina and aluminosilicate fibers. Molecular dynamics (MD) simulations were employed to determine the fracture strength values of these fiber joints for both material systems. These fracture strength values were then integrated into simulations of 3D randomly populated fiber structures, where tensile load transfer occurs through the fiber joints. These microscale properties are upscaled through a renormalization approach [1] to predict macroscale tensile strength of 3D random fiber networks, accounting for joint-dominated failure and effective load-bearing area. The study concludes by demonstrating the resulting strength variation as a function of material composition, fiber density, and morphology. We also show validation of results by comparing them against explicit fiber finite element (FE) modeling [2] where fiber joint fracture is represented by cohesive elements.

Jaehyun Cho↗
NASA NTRS1993

The implications of the LDEF results on Space Station Freedom power system materials

Results and implications of Long Duration Exposure Facility (LDEF) exposure of materials relevant to the Space Station Freedom (SSF) power system materials are presented. Atomic oxygen interactions with potential synergistic UV effects on silicone materials on LDEF were shown to result in the deposition of a dark contaminant film on adjoining surfaces. Silicones associated with solar array construction have the potential for causing reduced solar illumination of the solar cells if such silicone molecular fragments are found to be surface mobile. Results of LDEF atomic oxygen protective coatings on polyimide Kapton indicated acceptable durability to the synergistic effects of atomic oxygen, UV, thermal cycling, and micrometeoroid or debris impact. Results of combined atomic oxygen, UV radiation, thermal cycling, and micrometeoroid and debris impacts on LDEF high emittance radiator coatings indicate long term emittance and absorptance durability of Z 93 (zinc oxide pigment in a potassium silicate binder) coatings which have been selected for SSF radiator surfaces.

Banks, Bruce A.↗