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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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Temperature and concentration profiles calculated. Study expands on earlier work including more realistic, mathematically complicating physical effects and yet retains simple geometry and enough simplifying assumptions to make equations solvable. Leads to improved understanding of metal and glass production, material processing in low low gravity other important material processing problems.
A program is under way to develop a YAG laser based materials processing workstation to fly in the cargo bay of the Space Shuttle. The system will be capable of cutting and welding steel, aluminum, and Inconel alloys of the type planned for use on Space Station Freedom. As well as demonstrating the ability of a YAG laser to perform remote (fiber-optic delivered) repair and fabrication operations in space, fundamental data will be collected on these interactions for comparison with terrestrial data and models. The flight system, scheduled to fly in 1995, will be constructed as two modules to fit into the standard Get Away Special (GAS) canisters. The first can holds the laser and its power supply, to be constructed by our industrial partner, Lumonics Industrial Processing Division. The second canister has the materials processing workstation and the command and data acquisition subsystems. These components will be provided by groups at the University of Tennessee Space Institute (UTSI) and the University of Waterloo. The cans are linked by a fiber-optic cable which transmits the beam from the laser head to the workstation.
The single greatest threat to material availability over the last decade has been Compliance to New Environmental Regulations. Federal Regulations: a) Clean Air Acts Amendments - 1990 - Titles I, III and VI; b) NASA Interim Policy- 1995 end date; c) Montreal Protocol - 2000 and 2005 end dates; d) Industrial Toxics Project - HAP emissions by 1995; e) Florida DER - VOC limits by 1995 (CA); f) OSHA Health Related Regulations 1) Carcinogens 2) Mutagens 3). Material availability is complicated by local and state regulations and their own compliance schedules.
In January 2007, the NASA Administrator and Associate Administrator for the Exploration Systems Mission Directorate chartered the NASA Engineering and Safety Center (NESC) to design, build, and test a full-scale Composite Crew Module (CCM). The overall goal of the CCM project was to develop a team from the NASA family with hands-on experience in composite design, manufacturing, and testing in anticipation of future space exploration systems being made of composite materials. The CCM project was planned to run concurrently with the Orion project s baseline metallic design within the Constellation Program so that features could be compared and discussed without inducing risk to the overall Program. The materials and process activities were prioritized based on a rapid prototype approach. This approach focused developmental activities on design details with greater risk and uncertainty, such as out-of-autoclave joining, over some of the more traditional lamina and laminate building block levels. While process development and associated building block testing were performed, several anomalies were still observed at the full-scale level due to interactions between process robustness and manufacturing scale-up. This paper describes the process anomalies that were encountered during the CCM development and the subsequent root cause investigations that led to the final design solutions. These investigations highlight the importance of full-scale developmental work early in the schedule of a complex composite design/build project.
Space technology transfer is discussed as applied to the field of materials science. Advances made in processing include improved computer techniques, and structural analysis. Technology transfer is shown to have an important impact potential in the overall productivity of the United States.
A methodology to predict the coupled optical/thermal performance of a reflective cavity heating system was developed and a laboratory test to verify the method was carried out. The procedure was utilized to design a rapid thermal processing (RTP) furnace for the Robot-Operated Material Processing in Space (ROMPS) Program which is a planned STS HH-G canister experiment involving robotics and material processing in microgravity. The laboratory test employed a tungsten-halogen reflector/lamp to heat thin, p-type silicon wafers. Measurements instrumentation consisted of 5-mil Pt/Pt-Rh thermocouples and an optical pyrometer. The predicted results, utilizing an optical ray-tracing program and a lumped-capacitance thermal analyzer, showed good agreement with the measured data for temperatures exceeding 1300 C.
The paper surveys current information, describes some important unknowns about lunar materials, and discusses ways to gain more scientific and engineering knowledge concerning the industrial processes that could be used on the moon for the production of products useful in future enterprises in space. Lunar rocks and soils are rich in oxygen, but it is mostly chemically bound in silicates, so that chemical or thermal energy must be supplied to recover it. Iron and titanium are abundant and, in some of their known forms, readily recoverable; aluminum is plentiful but harder to extract. Methods for recovering lunar oxygen and metals fall into three classes: chemical, electrolytic, and dissociative, broadly characterized by their respective process temperatures. Examples of these methods are briefly discussed.
Measurement of three-dimensional (3-D) three-component velocity fields is of great importance in both ground and space experiments for understanding materials processing and fluid physics. The experiments in these fields most likely inhibit the application of conventional planar probes for observing 3-D phenomena. Here, we present the investigation results of stereoscopic tracking velocimetry (STV) for measuring 3-D velocity fields, which include diagnostic technology development, experimental velocity measurement, and comparison with analytical and numerical computation. STV is advantageous in system simplicity for building compact hardware and in software efficiency for continual near-real-time monitoring. It has great freedom in illuminating and observing volumetric fields from arbitrary directions. STV is based on stereoscopic observation of particles-Seeded in a flow by CCD sensors. In the approach, part of the individual particle images that provide data points is likely to be lost or cause errors when their images overlap and crisscross each other especially under a high particle density. In order to maximize the valid recovery of data points, neural networks are implemented for these two important processes. For the step of particle overlap decomposition, the back propagation neural network is utilized because of its ability in pattern recognition with pertinent particle image feature parameters. For the step of particle tracking, the Hopfield neural network is employed to find appropriate particle tracks based on global optimization. Our investigation indicates that the neural networks are very efficient and useful for stereoscopically tracking particles. As an initial assessment of the diagnostic technology performance, laminar water jets with and without pulsation are measured. The jet tip velocity profiles are in good agreement with analytical predictions. Finally, for testing in material processing applications, a simple directional solidification apparatus is built for experimenting with a metal analog of succinonitrile. Its 3-D velocity field at the liquid phase is then measured to be compared with those from numerical computation. Our theoretical, numerical, and experimental investigations have proven STV to be a viable candidate for reliably measuring 3-D flow velocities. With current activities are focused on further improving the processing efficiency, overall accuracy, and automation, the eventual efforts of broad experimental applications and concurrent numerical modeling validation will be vital to many areas in fluid flow and materials processing.
A precise control of composite material processing would not only improve part quality, but it would also directly reduce the overall manufacturing cost. The development and incorporation of sensors will help to generate real-time information for material processing relationships and equipment characteristics. In the present work, the thermocouple, pressure transducer, and dielectrometer technologies were investigated. The monitoring sensors were integrated with the computerized control system in three non-autoclave fabrication techniques: hot-press, self contained tool (self heating and pressurizing), and pressure vessel). The sensors were implemented in the parts and tools.
The Robot Operated Materials Processing System (ROMPS) has been developed at Goddard Space Flight Center (GSFC) under a flight project to investigate commercially promising in-space material processes and to design reflyable robot automated systems to be used in the above processes for low-cost operations. The ROMPS is currently scheduled for flight in 1994 as a Hitchhiker payload in a Get Away Special (GAS) can. An important component of the ROMPS is a three degree-of-freedom (DOF) robot which will be responsible for carrying out the required tasks of in-space processing of selected materials. This report deals with testing of the mating capability of the ROMPS robot fingers with its various mechanical interfaces. In particular, the test plan will focus on studying the capability of a compliance mechanism mounted on the robot fingers in accommodating misalignments between the robot fingers and the interfaces during the mating. The report is organized as follows: Section 2 represents the main components of the ROMPS robot and briefly describes its operations. Section 3 presents the objectives of the test and outlines the test plan. The testbed comprising a Steward Platform-based high precision manipulator and associated data acquisition and control systems is described in Section 4. Section 5 presents results of numerous experiments conducted to study the mating capability of the robot fingers with its various interfaces under misalignments. The report is concluded with observations and recommendations based on the test results.
The Materials Science Research Rack (MSRR) is a research facility developed under a cooperative research agreement between NASA and ESA for materials science investigations on the International Space Station (ISS). MSRR was launched on STS-128 in August 2009, and is currently installed in the U.S. Destiny Laboratory Module. Since that time, MSRR has performed virtually flawlessly, logging more than 620 hours of operating time. The MSRR accommodates advanced investigations in the microgravity environment on the ISS for basic materials science research in areas such as solidification of metals and alloys. The purpose is to advance the scientific understanding of materials processing as affected by microgravity and to gain insight into the physical behavior of materials processing. MSRR allows for the study of a variety of materials including metals, ceramics, semiconductor crystals, and glasses. Materials science research benefits from the microgravity environment of space, where the researcher can better isolate chemical and thermal properties of materials from the effects of gravity. With this knowledge, reliable predictions can be made about the conditions required on Earth to achieve improved materials. MSRR is a highly automated facility with a modular design capable of supporting multiple types of investigations. Currently the NASA-provided Rack Support Subsystem provides services (power, thermal control, vacuum access, and command and data handling) to the ESA developed Materials Science Laboratory (MSL) which accommodates interchangeable Furnace Inserts (FI). Two ESA-developed FIs are presently available on the ISS: the Low Gradient Furnace (LGF) and the Solidification and Quenching Furnace (SQF). Sample-Cartridge Assemblies (SCAs), each containing one or more material samples, are installed in the FI by the crew and can be processed at temperatures up to 1400 C. Once an SCA is installed, the experiment can be run by automatic command or science conducted via telemetry commands from the ground. Initially, 12 SCAs were processed in the first furnace insert for a team of European and US investigators. After these samples were processed the Furnaces Inserts were exchanged and an additional single sample was processed. The processed samples have been returned to Earth for evaluation and comparison of their properties to samples similarly processed on the ground. A preliminary examination of the samples indicates that the majority of the desired science objectives have been successfully met leading to significant improvements in the understanding of alloy solidification processes. Six SCAs were launched on Space Shuttle Mission STS-135 in July 2011 for processing during the Fall of 2011. Additional batches are planned for future processing. This facility is available to support additional materials science investigations through programs such as the US National Laboratory, Technology Development, NASA Research Announcements, and others.
The tribology of brush seals is of considerable interest to turbine engine designers because bristle wear continues to limit long term seal performance and life. To provide better materials characterization and foster the development of improved seals, NASA Lewis has developed a brush seal tuft tester. In this test, a 'paintbrush' sample tuft is loaded under constant contact pressure against the outside diameter of a rotating journal. With this configuration, load and friction are directly measured and accurate wear measurements are possible. Previously reported research using this facility showed excellent data repeatability and wear morphology similar to published seal data and dynamic rig tests. This paper is an update of the ongoing research into the tribology of brush seals. The effects of wire materials processing on seal wear and the tribological results for three journal coatings are discussed. Included in the materials processing were two nickel-chrome superalloys each processed to two different yield strengths. The results suggest that seal wear is dependent more on material composition than processing conditions.
Observations with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope reveal a peculiar emission line region in the close vicinity to Eta Carinae. The lines of [SrII], [MnII], [CoII], [TiII], [NiII] and [FeI] are detected in the 6400-7000 Angstrom spectral interval at a blue-shifted velocity of approximately 95 km/sec and seem to be associated with a long, narrow filament with dimensions of less than 0.5 inches by 1.1 inches. The filament is notable as it is separate both in velocity and structure from the bright emission of the Integral Nebula. This filament is buried within the Homunculus and is not visible in direct images which are dominated by reflection nebulosities. In our literature searches we have found no evidence of strontium emission lines in nebulae. We are aware of permitted transitions of strontium seen in AGB stars. S-processed elements like strontium are not expected in the ejecta of a massive star like Eta Carinae. Detection of [SrII] and the fact that the [NiII], [MnII] and [CoII] lines are unusually strong compared to [FeI] are quite a surprise. It has long been known that nitrogen is overabundant in the ejecta of Eta Carinae. Is this processed material from the present star(s)? Has there been processed material ejected from a more evolved companion? The situation is decidedly mysterious. This research has been supported by NASA through STScI grants and the STIS GTO funding.
The Orbiting Astrophysical Spectrometer In Space (OASIS) is an Advanced Concept currently understudy at NASA as a mission for the next decade. The goal of the OASIS mission is to identify a local site or sites where galactic cosmic rays (GCR) originate and are accelerated. The mission will allow GCR data to be used to investigate how elements are made and distributed in the galaxy and to improve our understanding of supernovae and the nucleosynthesis of the heavy elements needed for life. OASIS consists of two instruments that provide complementary data on the location and nature of the source(s) through investigating the composition of ultraheavy nuclei and the energy spectrum of electrons. OASIS will measure the relative abundances in the actinide group to determine the age of the r-process material in GCRs. The presence of young r-process material would indicate that GCRs are a sample of the interstellar medium in OB associations. OASIS will follow the electron spectrum to its high-energy end. The energy where this spectrum ends will tell us the distance to the nearest GCR source(s). OASIS will look for spectral features and anisotropy in the high energy electron spectrum that are expected to appear when only a few of the nearest sources can contribute the electron flux. Possibly these measurements will lead to the identification of the nearest cosmic ray electron source.
Some of the primary purposes of this work are to study important technologies, particularly involving thin films, relevant to organic and polymeric materials for improving applicability to optical circuitry and devices and to assess the contribution of convection on film quality in unit and microgravity environments. Among the most important materials processing techniques of interest in this work are solution-based and by physical vapor transport, both having proven gravitational and acceleration dependence. In particular, PolyDiAcetylenes (PDA's) and PhthaloCyanines (Pc's) are excellent NonLinear Optical (NLO) materials with the promise of significantly improved NLO properties through order and film quality enhancements possible through microgravity processing. Our approach is to focus research on integrated optical circuits and optoelectronic devices relevant to solution-based and vapor processes of interest in the Space Sciences Laboratory at the Marshall Space Flight Center (MSFC). Modification of organic materials is an important aspect of achieving more highly ordered structures in conjunction with microgravity processing. Parallel activities include characterization of materials for particular NLO properties and determination of appropriation device designs consistent with selected applications. One result of this work is the determination, theoretically, that buoyancy-driven convection occurs at low pressures in an ideal gas in a thermalgradient from source to sink. Subsequent experiment supports the theory. We have also determined theoretically that buoyancy-driven convection occurs during photodeposition of PDA, an MSFC-patented process for fabricating complex circuits, which is also supported by experiment. Finally, the discovery of intrinsic optical bistability in metal-free Pc films enables the possibility of the development of logic gate technology on the basis of these materials.
Material processing techniques which can most fully utilize the advantages provided by space are related to containerless processing. An avoidance of physical contact between the melt and the walls of a container leads to an elimination of container-induced contamination and heterogeneous nucleation. Containerless processing facilities development by NASA will provide a basis for the performance of precursor experiments and processing technologies studies prior to Space Shuttle flights. Attention is given to acoustic containerless processing, electromagnetic containerless processing, electrostatic levitation technology, drop tubes, and the use of zero-G KC-135 aircraft flights for tests and training purposes.
The preliminary design proposed for the microelectronics materials processing equipment is presented. An overall mission profile, description of all processing steps, analysis methods and measurement techniques, data acquisition and storage, and a preview of the experimental hardware are included. The goal of the project is to investigate the viability of material processing of semiconductor microelectronics materials in a micro-gravity environment. The two key processes are examined: (1) Rapid Thermal Annealing (RTA) of semiconductor thin films and damaged solar cells, and (2) thin film deposition using a filament evaporator. The RTA process will be used to obtain higher quality crystalline properties from amorphous/poly-silicon films. RTA methods can also be used to repair radiation-damaged solar cells. On earth this technique is commonly used to anneal semiconductor films after ion-implantation. The damage to the crystal lattice is similar to the defects found in solar cells which have been exposed to high-energy particle bombardment.
The Materials Science Research Rack (MSRR) is a research facility developed under a cooperative research agreement between NASA and ESA for materials science investigations on the International Space Station (ISS). MSRR was launched on STS-128 in August 2009 and currently resides in the U.S. Destiny Laboratory Module. Since that time, MSRR has logged more than 1000 hours of operating time. The MSRR accommodates advanced investigations in the microgravity environment on the ISS for basic materials science research in areas such as solidification of metals and alloys. The purpose is to advance the scientific understanding of materials processing as affected by microgravity and to gain insight into the physical behavior of materials processing. MSRR allows for the study of a variety of materials, including metals, ceramics, semiconductor crystals, and glasses. Materials science research benefits from the microgravity environment of space, where the researcher can better isolate chemical and thermal properties of materials from the effects of gravity. With this knowledge, reliable predictions can be made about the conditions required on Earth to achieve improved materials. MSRR is a highly automated facility with a modular design capable of supporting multiple types of investigations. The NASA-provided Rack Support Subsystem provides services (power, thermal control, vacuum access, and command and data handling) to the ESA-developed Materials Science Laboratory (MSL) that accommodates interchangeable Furnace Inserts (FI). Two ESA-developed FIs are presently available on the ISS: the Low Gradient Furnace (LGF) and the Solidification and Quenching Furnace (SQF). Sample Cartridge Assemblies (SCAs), each containing one or more material samples, are installed in the FI by the crew and can be processed at temperatures up to 1400C. ESA continues to develop samples with 14 planned for launch and processing in the near future. Additionally NASA has begun developing SCAs to support US PIs and their partners. The first of these Flight SCAs are being developed for investigations to support research in the areas of crystal growth and liquid phase sintering. Subsequent investigations are in various stages of development. US investigations will include a ground test program in order to distinguish the particular effects of the absence of gravity.