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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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NASA NTRS1978

Infrared Astronomical Satellite /IRAS/ and Shuttle Infrared Telescope Facility /SIRTF/ - Implications of scientific objectives on focal plane sensitivity requirements

The full potential of infrared astronomy can be realized only through observations made with space-based telescopes cooled to cryogenic temperatures. The paper outlines the scientific mission, system description, and focal plane requirements for two cryogenic telescopes: the Infrared Astronomical Satellite (IRAS) and the Shuttle Infrared Telescope Facility (SIRTF). IRAS, a 60-cm superfluid-helium-cooled telescope system, will perform a one-year 8-120-micron IR sky survey; it will provide results of high reliability and sensitivity, produce the first complete survey data for the 30-120-micron region, and fill in missing portions (spectrally and spatially) of previous surveys short of 30 microns; its focal plane assembly is being designed to approach background-limited performance with an array of 62 discrete detectors. The SIRTF design will allow detailed follow-up studies in the 1-1000-micron range with a 116-160-cm observatory-class instrument. The Shuttle sortie capability introduces the unique SIRTF concept of an easily refurbishable or replaceable focal plane instrument complement in an orbiting cryogenic telescope.

Mccreight, C. R.↗
NASA NTRS1994

Experiments with the Mesoscale Atmospheric Simulation System (MASS) using the synthetic relative humidity

This study is intended to examine the impact of the synthetic relative humidity on the model simulation of mesoscale convective storm environment. The synthetic relative humidity is derived from the National Weather Services surface observations, and non-conventional sources including aircraft, radar, and satellite observations. The latter sources provide the mesoscale data of very high spatial and temporal resolution. The synthetic humidity data is used to complement the National Weather Services rawinsonde observations. It is believed that a realistic representation of initial moisture field in a mesoscale model is critical for the model simulation of thunderstorm development, and the formation of non-convective clouds as well as their effects on the surface energy budget. The impact will be investigated based on a real-data case study using the mesoscale atmospheric simulation system developed by Mesoscale Environmental Simulations Operations, Inc. The mesoscale atmospheric simulation system consists of objective analysis and initialization codes, and the coarse-mesh and fine-mesh dynamic prediction models. Both models are a three dimensional, primitive equation model containing the essential moist physics for simulating and forecasting mesoscale convective processes in the atmosphere. The modeling system is currently implemented at the Applied Meteorology Unit, Kennedy Space Center. Two procedures involving the synthetic relative humidity to define the model initial moisture fields are considered. It is proposed to perform several short-range (approximately 6 hours) comparative coarse-mesh simulation experiments with and without the synthetic data. They are aimed at revealing the model sensitivities should allow us both to refine the specification of the observational requirements, and to develop more accurate and efficient objective analysis schemes. The goal is to advance the MASS (Mesoscal Atmospheric Simulation System) modeling expertise so that the model output can provide reliable guidance for thunderstorm forecasting.

Chang, Chia-Bo↗
NASA NTRS1980

Technologies Involved in Configuring an Advanced Earth-to-Orbit Transport for Low Structural Mass

The current space shuttle is expected to adequately meet Government and industry needs for the transport of cargo to and from orbit well into the 1990's. However, continual study of potential follow-on shuttle systems is necessary and desirable in order to complement ongoing research in materials, structures, propulsion, aerodynamics, and other related areas. By studying alternate systems well in advance, it will be possible to explore the various technologies and develop those for which there is the greatest apparent payoff. In this paper a single-stage Earth-to-orbit transport designed for delivery of approximately 29,500 kg (65,000 lb) payload will be described. The vehicle, which takes off vertically and lands horizontally, is 60 m (197 feet) long and weighs approximately 1.8 Gg (4 M lb) at liftoff. In the interest of weight reduction, a simple body of revolution is utilized for the main body shell. In this design the main propulsion tanks serve as a primary load-carrying structure. Further, in order to minimize structural mass, the cargo bay is located between two of the main propellant tanks. The cargo volume, at 396 cu m (14,000 cu feet), exceeds that provided by the shuttle; but the bay itself is nonconforming in shape - being approximately 10 m (32 feet) in diameter by 5 m (17 feet) long. Dual-fuel propulsion is employed, since a number of studies have shown that (though lowering performance) the operation of hydrocarbon (RP) engines in parallel with LOX/LH2 engines results in a net reduction in the vehicle's physical size and structural mass. Other weight-saving features entail the extensive use of honeycomb sandwiches, advanced materials, and advanced fabrication techniques. The vehicle presented is utilized only as a means to study and identify various technologies needed in order to develop a low mass Earth-to-orbit transportation system for the future. The conclusion of this study is that vehicle geometry and structural/materials technology are critical to the development of efficient single-stage Earth-to-orbit transports.

MacConochie, Ian O.↗
NASA NTRS1993

CFD Modeling of Turbulent Duct Flows for Coolant Channel Analysis

The design of modern liquid rocket engines requires the analysis of chamber coolant channels to maximize the heat transfer while minimizing the coolant flow. Coolant channels often do not remain at a constant cross section or at uniform curvature. New designs require higher aspect ratio coolant channels than previously used. To broaden the analysis capability and to complement standard analysis tools an investigation on the accuracy of CFD predictions for coolant channel flow has been initiated. Validation of CFD capabilities for coolant channel analysis will enhance the capabilities for optimizing design parameters without resorting to extensive experimental testing. The eventual goal is to use CFD to determine the flow fields of unique coolant channel designs and therefore determine critical heat transfer coefficients. In this presentation the accuracy of a particular CFD code is evaluated for turbulent flows. The first part of the presentation is a comparison of numerical results to existing cold flow data for square curved ducts (NASA CR-3367, 'Measurements of Laminar and Turbulent Flow in a Curved Duct with Thin Inlet Boundary Layers'). The results of this comparison show good agreement with the relatively coarse experimental data. The second part of the presentation compares two cases of higher aspect ratio channels (AR=2.5,10) to show changes in axial and secondary flow strength. These cases match experimental work presently in progress and will be used for future validation. The comparison shows increased secondary flow strength of the higher aspect ratio case due to the change in radius of curvature. The presentation includes a test case with a heated wall to demonstrate the program's capability. The presentation concludes with an outline of the procedure used to validate the CFD code for future design analysis.

Ungewitter, Ronald J.↗
NASA NTRS2006

Validation of Multi-Dimensional Stirling Engine Design Codes: Measurements in the 90-Degree Turn Test Section

The work to be presented herein was motivated largely by a desire to improve the understanding of oscillatory fluid mechanics inside a Stirling engine. To this end, a CFD project was undertaken at Cleveland State University with the goal of accurately predicting the fluid dynamics within an engine or engine component. Along with the CFD efforts, a code validation project was undertaken at the University of Minnesota. The material covered herein consists of four main parts. In section 1, an experimental investigation of a small aspect ratio impinging jet is discussed. Included in this discussion is a description of the test facilities and instrumentation. A presentation of the collected data is given and comments are made. Next, in section 2, a parallel experimental investigation is presented in which the same geometry as that of section 1 is used, but the flow conditions are changed from steady unidirectional flow to sinusoidally oscillating flow. In section Two, collected data are presented and comments are made. In section 3, a comparison is made between the results of sections 1 and 2, namely, sinusoidally oscillating flow results are compared to steady, unidirectional flow results from the same geometry. Finally, in section 4, a comparison is made between experimentally collected data (the main subject of this work) and CFD generated results. Furthermore, in appendix A, an introductory description of the primary measurement tool used in the experimental process the hot wire anemometer is given for the unfamiliar. The anemometer calibration procedure is described in appendix B. A portfolio of data reduction and data processing codes is provided in appendix C and lastly, a DVD and a roadmap of its contents is provided in an appendix D. 1.0 Unidirectional Flow Investigations 1.1 Introduction This unidirectional experimental program was undertaken to complement an oscillatory flow investigation conducted at the University of Minnesota. The oscillatory investigation is discussed thoroughly in section 2. We defer the description of the motivation behind these experiments until the introduction of section 2. The work that is discussed in this thesis began (chronologically) with oscillatory flow visualization experiments. It was decided that it would be valuable and important to investigate the flow under unidirectional conditions in the same geometry as that of the oscillatory experiments. The thought was that the unidirectional case would be less complicated to model with a CFD program (a moving boundary would be replaced with a steady state boundary condition). Thus, a series of unidirectional experiments were carried out to capture the important features of the flow within the test section. The purpose of these experiments was to provide a data set for comparison to CFD generated velocity fields. Hot-wire anemometry data were taken and flow visualization was conducted as a standard for code validation. The flow geometry was simple, such that it could be easily gridded in a CFD program. However, the geometry provided separation and transition zones, shear layers and recirculation zones. These characteristics made the flow complex and challenging for CFD computation. We comment that the order of experiments that produced this report is as follows: experimental flow visualization under oscillatory flow conditions was carried out; this was followed by unidirectional flow visualization and hot wire anemometry; finally, oscillatory hot wire anemometry was conducted. We present the results out of chronological order for the following reason: the unidirectional results are easier

Simon, Terrence W.↗
NASA NTRS1991

The 1991 International Conference on Aging Aircraft and Structural Airworthiness

Civil aviation serves a strategic interest to the United States. Thus, the need to maintain a high standard of aviation safety is axiomatic. While the industry has witnessed phenomenal growth in the past two decades, the proportion of aging aircraft in air carrier fleets has been ever increasing-a trend that is projected to continue. Certain events which occurred in 1988 and previous years and public concern about the safety of the high time aircraft led to an International Conference on Aging Aircraft in Washington, D.C., during which a number of aviation safety related issues applicable to aging aircraft were raised and discussed among the conference participants. Various groups that have a vital stake in commercial aviation made certain recommendations which led to the formation of a task force and a broad undertaking involving the Federal Aviation Administration (FAA), the National Aeronautics and Space Administration (NASA), industry and international organizations to insure continued airworthiness of aging airplanes. At the same time, significant research and development programs were initiated by the FAA and NASA to complement the broader effort. In view of the success of the 1988 conference, the FAA desired that conferences be held annually to disseminate information on the status of the task force's activities on aircraft certification and airline maintenance related issues and to offer a forum for participation by all interested parties. Thus, the 2nd International Conference was held in 1989 in Baltimore and the third in the series in 1990 in Bordeaux, France. Both of them, like the first conference, attracted rousing attendance and interest. Thus, the stage was set for organizing the 4th International Conference in 1991. By 1991, the FAA and NASA research programs were yielding significant results, a consideration that led to a larger segment of the 4th International Conference Program being devoted to presentations about the impact of the research on the other activities of the task group. Agreement had also been reached between the FAA and NASA to coordinate and integrate their respective program activities. Hence, NASA was co-opted as a sponsor of the conference. A group consisting of Mr. Stephen Erickson of the Air Transport Association of America, Mr. Jesse Lewis and Mr. Richard Johnson of the FAA, and Mr. Thomas Crooker of NASA was formed to organize the conference. The members of the group are owed special thanks for their efforts that ensured the success of the conference.

Aging Aircraft↗
NASA NTRSDate not supplied

RadLab and the Environmental Data Application Dashboard: Graphical and Programming Interfaces for Interrogation of Space Telemetry Data

Sensors on the International Space Station (ISS) and multiple spacecraft elsewhere in Earth orbit and in deep space continuously monitor and collect environmental data, transmitting this information back to Earth. These data include ionizing radiation and, on the ISS, CO2, relative humidity levels, and temperature, and are of great importance to space biology research. Ionizing radiation in particular has been established in ground-based experiments as being correlated with increased risk of carcinogenesis and cardiovascular and neurological effects. Looking ahead to future long duration crewed missions beyond low Earth orbit, the ability to study how factors including CO2 levels, light cycle, temperature modulate the response to ionizing radiation and microgravity is essential. To date, access to these data has been fragmented across space agencies, spacecraft, and databases. To address this issue, NASA’s Open Science Data Repository (osdr.nasa.gov) has developed two Web applications: the Environmental Data Application (EDA) and a radiation-specific RadLab. Each consists of an API (application programming interface) and an associated GUI (graphical user interface) that provide single points of access to the data. To date, OSDR has focused on the sensors from payloads and radiation detectors located on the ISS. The Web applications process telemetry information and associated data, such as spacecraft location and orientation, from multiple international databases. The applications’ request syntax enables users to interrogate these data by craft, sensor type, time range, radiation type (galactic cosmic rays, solar particle events, the contribution of the South Atlantic Anomaly), facilitating arbitrary comparisons of original source data at varying time resolutions. The applications provide programmatic access for use in computational pipelines and GUIs for data visualization and exploration, making these data FAIR (Findable, Accessible, Interoperable, and Reusable), complementing the biological data contained in OSDR, and providing the space science community with a valuable resource for scientific analyses.

radiation↗
NASA NTRS1997

Continuing Studies in Support of Ultraviolet Observations of Planetary Atmospheres

This program was a one-year extension of an earlier Planetary Atmospheres program grant, covering the period 1 August 1996 through 30 September 1997. The grant was for supporting work to complement an active program observing planetary atmospheres with Earth-orbital telescopes, principally the Hubble Space Telescope (HST). The recent concentration of this work has been on HST observations of Jupiter's upper atmosphere and aurora, but it has also included observations of Io, serendipitous observations of asteroids, and observations of the velocity structure in the interplanetary medium. The observations of Jupiter have been at vacuum ultraviolet wavelengths, including imaging and spectroscopy of the auroral and airglow emissions. The most recent HST observations have been at the same time as in situ measurements made by the Galileo orbiter instruments, as reflected in the meeting presentations listed below. Concentrated efforts have been applied in this year to the following projects: The analysis of HST WFPC 2 images of Jupiter's aurora, including the Io footprint emissions. We have performed a comparative analysis of the lo footprint locations with two magnetic field models, studied the statistical properties of the apparent dawn auroral storms on Jupiter, and found various other repeated patterns in Jupiter's aurora. Analysis and modeling of airglow and auroral Ly alpha emission line profiles from Jupiter. This has included modeling the aurora] line profiles, including the energy degradation of precipitating charged particles and radiative transfer of the emerging emissions. Jupiter's auroral emission line profile is self-absorbed, since it is produced by an internal source, and the resulting emission with a deep central absorption from the overlying atmosphere permits modeling of the depth of the emissions, plus the motion of the emitting layer with respect to the overlying atmospheric column from the observed Doppler shift of the central absorption. By contrast the airglow emission line, which is dominated by resonant scattering of solar emission, has no central absorption, but displays rapid time variations and broad wings, indicative of a superthermal component (or corona) in Jupiter's upper atmosphere. Modeling of the observed motions of the plumes produced after the impacts of the fragments of Comet S/L-9 with Jupiter in July 1994, from the HST WFPC 2 imaging series.

Clark, John↗
NASA NTRS2003

Nanophase Iron Globules in Lunar Soil

Micrometeoritic impacts on lunar soils produce melt and vapor. A patina of condensed vapor is deposited on lunar grains, the melt forms agglutinitic glass. In lunar soils, agglutinitic glass and rinds of grains host submicron-sized globules of pure Fe0 (Fe-rich globules larger than 1 micron usually contain other elements such as Ni, P, and S). Observation and measurement of such small size requires either back scattered electron (BSE) imaging with a high-resolution SEM or transmitted electron imaging with a TEM. The two techniques impose different limitations on the size-range of measurements. Resolution of BSE imaging of polished thin sections or grain mounts of lunar soils is at best around 4-5nm (JEOL 6340F field-emission (FE)-SEM at JSC). Therefore, Fe0 globules below 10nm in cross-sectional diameter are not truly measured. The upper limit of a millimeter or so is not a hindrance. In fact, it is an advantage because whole grains can be observed and mapped at varying magnifications. Angstrom-scale resolution of TEM images is more than sufficient to observe and measure the smallest of Fe0 globules that are about 1nm in cross-section. Microtoming edges of lunar grains; however, puts an upper size limitation of 50nm, at best, on the wafer, which more or less limits measuring Fe0 globules up to 30nm or so. Clearly, SEM and TEM techniques complement each other in obtaining the complete range of size distribution of Fe0 globules in lunar soils. Below we describe, in brief, our method of determining the size distribution of Fe0 globules in agglutinitic glass using BSE-SEM imaging and size measurement. Although our work is incomplete, we also include a table of results obtained so far, which understandably would be refined as we collect more data.

C. L. James↗
NASA NTRS1995

Robust integration schemes for generalized viscoplasticity with internal-state variables. Part 1: Theoretical developments and applications

This two-part report is concerned with the development of a general framework for the implicit time-stepping integrators for the flow and evolution equations in generalized viscoplastic models. The primary goal is to present a complete theoretical formulation, and to address in detail the algorithmic and numerical analysis aspects involved in its finite element implementation, as well as to critically assess the numerical performance of the developed schemes in a comprehensive set of test cases. On the theoretical side, the general framework is developed on the basis of the unconditionally-stable, backward-Euler difference scheme as a starting point. Its mathematical structure is of sufficient generality to allow a unified treatment of different classes of viscoplastic models with internal variables. In particular, two specific models of this type, which are representative of the present start-of-art in metal viscoplasticity, are considered in applications reported here; i.e., fully associative (GVIPS) and non-associative (NAV) models. The matrix forms developed for both these models are directly applicable for both initially isotropic and anisotropic materials, in general (three-dimensional) situations as well as subspace applications (i.e., plane stress/strain, axisymmetric, generalized plane stress in shells). On the computational side, issues related to efficiency and robustness are emphasized in developing the (local) interative algorithm. In particular, closed-form expressions for residual vectors and (consistent) material tangent stiffness arrays are given explicitly for both GVIPS and NAV models, with their maximum sizes 'optimized' to depend only on the number of independent stress components (but independent of the number of viscoplastic internal state parameters). Significant robustness of the local iterative solution is provided by complementing the basic Newton-Raphson scheme with a line-search strategy for convergence. In the present first part of the report, we focus on the theoretical developments, and discussions of the results of numerical-performance studies using the integration schemes for GVIPS and NAV models.

Saleeb, Atef F.↗
NASA NTRS1995

Robust integration schemes for generalized viscoplasticity with internal-state variables. Part 2: Algorithmic developments and implementation

This two-part report is concerned with the development of a general framework for the implicit time-stepping integrators for the flow and evolution equations in generalized viscoplastic models. The primary goal is to present a complete theoretical formulation, and to address in detail the algorithmic and numerical analysis aspects involved in its finite element implementation, as well as to critically assess the numerical performance of the developed schemes in a comprehensive set of test cases. On the theoretical side, the general framework is developed on the basis of the unconditionally-stable, backward-Euler difference scheme as a starting point. Its mathematical structure is of sufficient generality to allow a unified treatment of different classes of viscoplastic models with internal variables. In particular, two specific models of this type, which are representative of the present start-of-art in metal viscoplasticity, are considered in applications reported here; i.e., fully associative (GVIPS) and non-associative (NAV) models. The matrix forms developed for both these models are directly applicable for both initially isotropic and anisotropic materials, in general (three-dimensional) situations as well as subspace applications (i.e., plane stress/strain, axisymmetric, generalized plane stress in shells). On the computational side, issues related to efficiency and robustness are emphasized in developing the (local) interative algorithm. In particular, closed-form expressions for residual vectors and (consistent) material tangent stiffness arrays are given explicitly for both GVIPS and NAV models, with their maximum sizes 'optimized' to depend only on the number of independent stress components (but independent of the number of viscoplastic internal state parameters). Significant robustness of the local iterative solution is provided by complementing the basic Newton-Raphson scheme with a line-search strategy for convergence. In the present second part of the report, we focus on the specific details of the numerical schemes, and associated computer algorithms, for the finite-element implementation of GVIPS and NAV models.

Li, Wei↗
NASA NTRS1993

Investigation of Mars Rotational Dynamics Using Earth-based Radio Tracking of Mars Landers

The development of space geodetic techniques over the past two decades has made it possible to measure the rotational dynamics of the Earth at the milliarcsecond level, improving our geophysical models of the Earth 's interior and the interactions between the solid Earth and its atmosphere. We have found that the rotational dynamics of Mars can be determined to nearly the same level of accuracy by acquiring Earth-based two-way radio tracking observations of three or more landers globally distributed on the surface of Mars. Our results indicate that the precession and long-term obliquity changes of the Mars pole direction can be determined to an angular accuracy corresponding to about 15 cm/yr at the planet's surface. In addition, periodic nutations of the pole and seasonal variations in the spin rate of the planet can be determined to 10 cm or less. Measuring the rotation of Mars at this accuracy would greatly improve the determination of the planet' s moment of inertia and would resolve the size of a planetary fluid core, providing a valuable constraint on Mars interior models. Detecting seasonal variations in the spin rate of Mars would provide global constraints on atmospheric angular momentum changes due to sublimation of the Mars CO2 polar ice caps. Finally, observation of quasisecular changes in Mars obliquity would have significant implications for understanding long-term climatic change. The key to achieving these accuracies is a globally distributed network of Mars landers with stable, phase-coherent radio transponders. By simultaneously acquiring coherent two-way carrier phase observations between a single Earth tracking station and multiple Mars landers, Earth media errors are essentially eliminated, providing an extremely sensitive measure of changes in the differential path lengths between the Earth tracking station and the Mars landers due to Mars rotation. Time variability of the instrumental phase delay through the radio transponder may represent the limiting error source for this technique. Calibration of the transponder stability to about 0.1 ns or less, over a single tracking arc of up to 12 hr, is sufficient to provide the decimeter-level determination of Mars orientation parameters quoted above. We will provide a detailed description of the multilander tracking technique and the requirements it imposes on both the lander radio system and the Earth-based ground-tracking system. This concept is currently part of the strawman science plan for the Mars Environmental Survey (MESUR) mission and complements many of the other MESUR science goals.

Edwards, C. D., Jr.↗
NASA NTRS1999

Instrumentation Working Group Summary

The Instrumentation Working Group compiled a summary of measurement techniques applicable to gas turbine engine aerosol precursors and particulates. An assessment was made of the limits, accuracy, applicability, and technology readiness of the various techniques. Despite advances made in emissions characterization of aircraft engines, uncertainties still exist in the mechanisms by which aerosols and particulates are produced in the near-field engine exhaust. To adequately assess current understanding of the formation of sulfuric acid aerosols in the exhaust plumes of gas turbine engines, measurements are required to determine the degree and importance of sulfur oxidation in the turbine and at the engine exit. Ideally, concentrations of all sulfur species would be acquired, with emphasis on SO2 and SO3. Numerous options exist for extractive and non-extractive measurement of SO2 at the engine exit, most of which are well developed. SO2 measurements should be performed first to place an upper bound on the percentage of SO2 oxidation. If extractive and non-extractive techniques indicate that a large amount of the fuel sulfur is not detected as SO2, then efforts are needed to improve techniques for SO3 measurements. Additional work will be required to account for the fuel sulfur in the engine exhaust. Chemical Ionization Mass Spectrometry (CI-MS) measurements need to be pursued, although a careful assessment needs to be made of the sampling line impact on the extracted sample composition. Efforts should also be placed on implementing non-intrusive techniques and extending their capabilities by maximizing exhaust coverage for line-of-sight measurements, as well as development of 2-D techniques, where feasible. Recommendations were made to continue engine exit and combustor measurements of particulates. Particulate measurements should include particle size distribution, mass fraction, hydration properties, and volatile fraction. However, methods to ensure that unaltered samples are obtained need to be developed. Particulate speciation was also assigned a high priority for quantifying the fractions of carbon soot, PAH, refractory materials, metals, sulfates, and nitrates. High priority was also placed on performing a comparison of particle sizing instruments. Concern was expressed by the workshop attendees who routinely make particulate measurements about the variation in number density measured during in-flight tests by different instruments. In some cases, measurements performed by different groups of researchers during the same flight tests showed an order of magnitude variation. Second priority was assigned to measuring concentrations of odd hydrogen and oxidizing species. Since OH, HO2, H2O2, and O are extremely reactive, non-extractive measurements are recommended. A combination of absorption and fluorescence is anticipated to be effective for OH measurements in the combustor and at the engine exit. Extractive measurements of HO2 have been made in the stratosphere, where the ambient level of OH is relatively low. Use of techniques that convert HO2 to OH for combustor and engine exit measurements needs to be evaluated, since the ratio of HO2/OH may be 1% or less at both the combustor and engine exit. CI-MS might be a viable option for H2O2, subject to sampling line conversion issues. However, H2O2 is a low priority oxidizing species in the combustor and at the engine exit. Two candidates for atomic oxygen measurements are Resonance Enhanced Multi-Photon Ionization (REMPI) and Laser-Induced Fluorescence (LIF). Particulate measurement by simultaneous extractive and non-extractive techniques was given equal priority to the oxidizer measurements. Concern was expressed over the ability of typical ground test sampling lines to deliver an unaltered sample to a remotely located instrument. It was suggested that the sampling probe and line losses be checked out by attempting measurements using an optical or non-extractive technique immediately upstream of the sampling probe. This is a possible application for Laser Induced Incandescence (LII) as a check on the volume fraction of soot. Optical measurements of size distribution are not well developed for ultrafine particles less than about 20 nm in diameter, so a non-extractive technique for particulate size distribution cannot be recommended without further development. Carbon dioxide measurements need to be made to complement other extractive measurement techniques. CO2 measurements enable conversion of other species concentrations to emission indices. Carbon monoxide, which acts as a sink for oxidizing species, should be measured using non-extractive techniques. CO can be rapidly converted to CO2 in extractive probes, and a comparison between extractive and non-extractive measurements should be performed. Development of non-extractive techniques would help to assess the degree of CO conversion, and might be needed to improve the concentration measurement accuracy. Measurements of NO(x) will continue to be critical due to the role of NO and NO2 in atmospheric chemistry, and their influence on atmospheric ozone. Time-resolved measurements of temperature, velocity, and species concentrations were included on the list of desired measurement. Thermocouples are typically adequate for engine exit measurements. PIV and LDV are well established for obtaining velocity profiles. The techniques are listed in the accompanying table; are divided into extractive and non-extractive techniques. Efforts were made to include a measurement uncertainty for each technique. An assessment of the technology readiness was included.

Zaller, Michelle↗
NASA NTRS2014

Imagery Integration Team

The Human Exploration Science Office (KX) provides leadership for NASA's Imagery Integration (Integration 2) Team, an affiliation of experts in the use of engineering-class imagery intended to monitor the performance of launch vehicles and crewed spacecraft in flight. Typical engineering imagery assessments include studying and characterizing the liftoff and ascent debris environments; launch vehicle and propulsion element performance; in-flight activities; and entry, landing, and recovery operations. Integration 2 support has been provided not only for U.S. Government spaceflight (e.g., Space Shuttle, Ares I-X) but also for commercial launch providers, such as Space Exploration Technologies Corporation (SpaceX) and Orbital Sciences Corporation, servicing the International Space Station. The NASA Integration 2 Team is composed of imagery integration specialists from JSC, the Marshall Space Flight Center (MSFC), and the Kennedy Space Center (KSC), who have access to a vast pool of experience and capabilities related to program integration, deployment and management of imagery assets, imagery data management, and photogrammetric analysis. The Integration 2 team is currently providing integration services to commercial demonstration flights, Exploration Flight Test-1 (EFT-1), and the Space Launch System (SLS)-based Exploration Missions (EM)-1 and EM-2. EM-2 will be the first attempt to fly a piloted mission with the Orion spacecraft. The Integration 2 Team provides the customer (both commercial and Government) with access to a wide array of imagery options - ground-based, airborne, seaborne, or vehicle-based - that are available through the Government and commercial vendors. The team guides the customer in assembling the appropriate complement of imagery acquisition assets at the customer's facilities, minimizing costs associated with market research and the risk of purchasing inadequate assets. The NASA Integration 2 capability simplifies the process of securing one-of-a-kind imagery assets and skill sets, such as ground-based fixed and tracking cameras, crew-in the-loop imaging applications, and the integration of custom or commercial-off-the-shelf sensors onboard spacecraft. For spaceflight applications, the Integration 2 Team leverages modeling, analytical, and scientific resources along with decades of experience and lessons learned to assist the customer in optimizing engineering imagery acquisition and management schemes for any phase of flight - launch, ascent, on-orbit, descent, and landing. The Integration 2 Team guides the customer in using NASA's world-class imagery analysis teams, which specialize in overcoming inherent challenges associated with spaceflight imagery sets. Precision motion tracking, two-dimensional (2D) and three-dimensional (3D) photogrammetry, image stabilization, 3D modeling of imagery data, lighting assessment, and vehicle fiducial marking assessments are available. During a mission or test, the Integration 2 Team provides oversight of imagery operations to verify fulfillment of imagery requirements. The team oversees the collection, screening, and analysis of imagery to build a set of imagery findings. It integrates and corroborates the imagery findings with other mission data sets, generating executive summaries to support time-critical mission decisions.

Calhoun, Tracy↗
NASA NTRS2022

The Multiview Observatory for Solar Terrestrial Science (MOST)

Understanding the emergence of magnetic flux from the solar interior through the photosphere and its global impact on the inner heliosphere is a key scientific goal of the heliophysics community. This white paper outlines the concept of the Multiview Observatory for Solar Terrestrial Science (MOST) mission, which will make measurements of solar variability from the solar interior, atmosphere, and the interplanetary (IP) medium. MOST will be a 4- spacecraft mission with one each at L4 (MOST1) and L5 (MOST2) and the other two (MOST3 and MOST4) at variable locations along Earth orbit. MOST1 and MOST2 will each carry seven remote-sensing and 3 in-situ instruments. All four spacecraft will carry a novel radio package known as the Faraday Effect Tracker of Coronal and Heliospheric structures (FETCH) that will systematically probe the magnetic content of transient IP structures including coronal mass ejections (CMEs) and stream interaction regions (SIRs). The Faraday rotation measurements will provide magnetic content of these structures at various heliocentric distances from the outer corona to Earth’s vicinity. Photospheric and/or chromospheric magnetograms will cover >70% of the solar surface providing synchronic maps needed for accurately modeling the corona and solar wind. EUV, coronagraph, radio spectrograph, and heliospheric imager (HI) observations from multiple viewpoints provide 3-d information on CMEs/CME-driven shocks, SIRs, and other solar wind structures. Hard X-ray imagers will provide the flare aspects of solar eruptions to complement the CME aspects. MOST, a 10-year mission, is well aligned with NASA’s Heliophysics objectives and will provide an unprecedented opportunity to achieve these objectives with broad participation from the heliophysics community.

N. Gopalswamy↗
NASA NTRS2023

Mineralogical, Elemental, and Tomographic Reconnaissance Investigation for CLPS (METRIC)

METRIC is a robotic science laboratory that can determine the mineralogy, elemental chemistry, micromorphology, and thermophysical properties of planetary regolith. The METRIC suite comprises METRIC XRD/F, an X-ray diffraction/X-ray fluorescence instrument that can determine the mineralogy and elemental chemistry of regolith samples; METRIC XCT, a micro X-ray computed tomography instrument that can be used to evaluate grain/crystallite sizes and textures; METRIC IRS, an imaging spectrometer mounted on a rover that can determine mineralogy and thermophysical properties at the landing site; and a pneumatic sample collection, processing, distribution system developed by Honeybee Robotics. The payload elements could be deployed on a static lander or a rover. Data returned from the METRIC payload would inform origin, formation, and evolution of rocky planetary bodies. METRIC XRD/F draws on heritage from the CheMin instrument on the Mars Science Laboratory (MSL) Curiosity rover [1], with a few important improvements. Like CheMin, METRIC XRD/F operates in transmission geometry and uses piezoelectric actuators on sample cells in a tuning fork geometry to induce convective grain motion of the regolith to create a randomly oriented powder. MSL CheMin uses an energy-sensitive CCD to collect XRD patterns and XRF spectra simultaneously from the same sample cell, resulting in qualitative XRF data. METRIC XRD/F uses two different sample cells, one optimized for XRD and one optimized for XRF, and a silicon drift detector to detect fluoresced X-rays. This improvement to the XRF capabilities provides quantitative geochemical data of major elements down to Z = 11 and allows for the detection of minor and trace elements that are critical for evaluating geologic evolution of the Moon (e.g., P and Th). Modest improvements to the XRD geometry and hardware allow for better angular resolution and the ability to distinguish between members of the pyroxene group. METRIC XCT uses the same geometry and much of the same hardware as METRIC XRD/F, where a CCD would capture images of a regolith sample in a 3 mm diameter sample tube that is rotated 360° in steps <1°. Image brightness can be used to infer compositional data, where brighter materials indicate a higher Z, much like scanning electron microscopy. Data from METRIC XCT complement those from METRIC XRD/F. Particle size, shape, and texture can provide petrologic and provenance information, whereas vesicle size and morphology in volcanic or impact melt lithologies can inform cooling rates. METRIC IRS is a hyperspectral thermal imager that can be mounted to a lander or rover to provide mineralogical data from the broader landing site and help determine whether the samples analyzed by METRIC XRD/F and XCT are representative. The METRIC IRS spectral range (8–14 μm) and resolution (10.8 cm-1) allow for quantitative mineralogy from modelling Reststrahlen bands of major rock-forming minerals (e.g., silicates, phosphates). Radiance cubes can be processed and modelled with an onboard high-performance computer to determine mineral abundances of plagioclase, high-Ca pyroxene, pigeonite, orthopyroxene, olivine, and glass. Regolith samples can be acquired, processed, and delivered to the X-ray instruments via multiple sample handling systems, but the pneumatic sampling systems developed by Honeybee Robotics [e.g., 2] are best suited for relatively low-cost missions that are being competed for the Moon (e.g., NASA’s Payloads and Research Investigations for the Surface of the Moon program). There are pneumatic sampling systems that collect surface material and other systems that pneumatically drill up to ~1 m below the surface, providing material that has not been space weathered and has not been affected by the lander’s exhaust. [1] Blake, D. F., Vaniman, D., Achilles, C., Anderson, R., Bish, D., et al. (2012). Space Sci. Rev. 170, 341-478. https://doi.org/10.1007/s11214-012-9905-1. [2] Zacny, K., Betts, B., Hedlund, M., Long, P., Gramlich, M., Tura, K., Chu, P., Jacob, A., Garcia, A. (2014). IEEE Aerospace Conference, 3-7 March 2014, Big Sky, MT, U.S.A.

X-ray diffraction↗
NASA NTRS1993

The effect of an on-orbit near encounter on the number flux density of micron sized particles

Many materials and techniques have been developed by the authors to sample the flux of particles in Low Earth Orbit (LEO), and through regular insitu sampling of the flux in LEO, the materials and techniques have produced data which complement the data now being amassed by the Long Duration Exposure Facility (LDEF) research activities. Recent flight experiments on STS-32, STS-44, STS-46, and STS-52 have been conducted to develop an understanding of the spatial density as a function of size (mass) for particle sizes 1x10(exp -6) cm and larger. In addition to the enumeration of particle impacts, it was also the intent of these experiments that hypervelocity particles be captured and returned intact. Measurements were performed post-flight to determine the flux density, diameters, and subsequent effects on various optical, thermal control, and structural materials. During the course of the STS-44 mission, the Space Shuttle corrected its altitude by 26 km to evade a spent upper stage. The results of this near encounter suggests that a cloud of micron sized particles exist in the vicinity of the object. Data also suggest that the flux density is nearly two (2) orders of magnitude higher than background flux. A comparison of the number flux density along with microphotographs of the captured particles will be presented for the referenced shuttle flights.

Maag, Carl R.↗
NASA NTRS1992

Aerodynamic simulation on massively parallel systems

This paper briefly addresses the computational requirements for the analysis of complete configurations of aircraft and spacecraft currently under design to be used for advanced transportation in commercial applications as well as in space flight. The discussion clearly shows that massively parallel systems are the only alternative which is both cost effective and on the other hand can provide the necessary TeraFlops, needed to satisfy the narrow design margins of modern vehicles. It is assumed that the solution of the governing physical equations, i.e., the Navier-Stokes equations which may be complemented by chemistry and turbulence models, is done on multiblock grids. This technique is situated between the fully structured approach of classical boundary fitted grids and the fully unstructured tetrahedra grids. A fully structured grid best represents the flow physics, while the unstructured grid gives best geometrical flexibility. The multiblock grid employed is structured within a block, but completely unstructured on the block level. While a completely unstructured grid is not straightforward to parallelize, the above mentioned multiblock grid is inherently parallel, in particular for multiple instruction multiple datastream (MIMD) machines. In this paper guidelines are provided for setting up or modifying an existing sequential code so that a direct parallelization on a massively parallel system is possible. Results are presented for three parallel systems, namely the Intel hypercube, the Ncube hypercube, and the FPS 500 system. Some preliminary results for an 8K CM2 machine will also be mentioned. The code run is the two dimensional grid generation module of Grid, which is a general two dimensional and three dimensional grid generation code for complex geometries. A system of nonlinear Poisson equations is solved. This code is also a good testcase for complex fluid dynamics codes, since the same datastructures are used. All systems provided good speedups, but message passing MIMD systems seem to be best suited for large miltiblock applications.

Haeuser, Jochem↗