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NASA NTRS2016

Internship Abstract and Final Reflection

The primary objective for this internship is the evaluation of an embedded natural language processor (NLP) as a way to introduce voice control into future space suits. An embedded natural language processor would provide an astronaut hands-free control for making adjustments to the environment of the space suit and checking status of consumables procedures and navigation. Additionally, the use of an embedded NLP could potentially reduce crew fatigue, increase the crewmember's situational awareness during extravehicular activity (EVA) and improve the ability to focus on mission critical details. The use of an embedded NLP may be valuable for other human spaceflight applications desiring hands-free control as well. An embedded NLP is unique because it is a small device that performs language tasks, including speech recognition, which normally require powerful processors. The dedicated device could perform speech recognition locally with a smaller form-factor and lower power consumption than traditional methods.

Sandor, Edward↗

NASA NTRSDate not supplied

Aerothermodynamic Measurements in Hypersonic Non-Equilibrium Flows

High enthalpy arc-jets are unique facilities particularly suited for simulating complex flows in the aerospace field, such as the aerothermodynamics of a re-entry vehicle. Arc-jets are often used to evaluate important design factors such as heat shield materials and vehicle design. Characterization of these facilities is important, as studies often match specific in-flight environments during experiments. Due to the complex environment produced by an arc-jet, with effects such as thermodynamic and chemical non-equilibrium occurring in the flow, characterization experiments are significantly more difficult than in traditional blow-down wind tunnels. The current work aims to characterize an arc-jet facility in terms of flow temperature, velocity and unsteadiness, in a spatially-resolved analysis. To achieve this goal, a non-intrusive imaging technique called “planar laser-induced fluorescence” was performed in the NASA Langley Hypersonic Materials Environ-mental Test System arc-jet facility. The experimental data was analyzed to produce the quantitative measurements in multiple regions of the flow around a blunt body sample. A quasi-1D low fidelity solver was created to numerically simulate the flow to investigate non-equilibrium effects occur-ring outside the imaging region in the arc-jet nozzle. Unsteadiness in the test section was minimized by analyzing a subset of data assessing the gas injection location. Radial velocity, rotational temperature and translational temperature measurements are provided that can be used to validate future high-fidelity computational studies. The temperature measurements revealed rotational non-equilibrium potentially occurring in the flow. This work provides a methodology for characterizing arc-jet facilities, identifying and correcting sources of systematic error, and estimating the uncertainty associated with the quantitative measurements.

laser induced fluorescence↗

NASA NTRS2022

Aerothermodynamic Measurements of Hypersonic Non-Equilibrium Flows

High enthalpy arc-jets are unique facilities particularly suited for producing complex flows in the aerospace field, such as the aerothermodynamics of a re-entry vehicle. Arc-jets are often used to evaluate important design factors that include heat shield materials and vehicle design. Characterization of these facilities is important, as studies often aim to match specific in-flight environments during experiments. Due to the complex environment produced by an arc-jet, with effects such as thermodynamic and chemical non-equilibrium occurring in the flow, characterization experiments are significantly more difficult than in conventional blow-down wind tunnels. The current work aims to characterize an arc-jet facility through spatially-resolved measurements of flow unsteadiness, temperature, and velocity. To achieve this goal, a non-intrusive imaging technique called “planar laser-induced fluorescence” was performed in the NASA Langley Hypersonic Materials Environmental Test System arc-jet facility. The experimental data was analysed to produce the quantitative measurements in multiple regions of the flow around a blunt body specimen. A three-temperature low fidelity numerical solver was created to simulate the flow in order to investigate thermal non-equilibrium effects occurring outside the imaging region in the arc-jet nozzle. Unsteadiness in the test section of the arc-jet was minimized by analyzing a subset of data assessing the gas injection configuration. Radial velocity, rotational temperature and translational temperature measurements are provided that can be used to validate future computational studies. The temperature measurements revealed rotational non-equilibrium occurring behind the bow-shock near the specimen surface. Computational results show the facility is capable of producing thermal non-equilibrium flow in the arc-jet nozzle. This work provides the first experimental and computational evidence of thermal trans-rotational non-equilibrium occurring in multiple regions of this arc-jet facility. Significant improvements to the methodology are also identified as recommendations for future arc-jet characterization studies.

Laser induced fluorescence↗

NASA NTRS1994

Integrating human factors knowledge into certification: The point of view of the Internatioanal Civil Aviation Organization (ICAO)

It is appropriate here to repeat the analogy described in the introduction to this paper which is that: The consideration of human factors requirements during the design stage of advanced, new technology systems may be seen as resting over a three-legged stool. The first leg, the equipment that a system will utilize to achieve its goals, has traditionally attracted ergonomic considerations associated with equipment design, usually centered around 'knobs and dials.' Lately, this view has expanded to include the so-called other important aspect of Human Factor's study which deals with the cognitive, behaviorial and social processes of the human operators. Study in this area must be furthered. The second leg of the stool, the procedures to operate the equipment, however, has been largely unaddressed. Procedures are not inherent to equipment, but must be developed. The importance of proper human factors consideration in the design of procedures can not be overstated. Lastly, the third leg of the stool, the certification of personnel who will operate the equipment, is very much underway, but far from being complete. The real quest now, however, is to integrate these three legs into an indivisible one. Finally, and most importantly, this workshop and its topic are extremely timely in that we are at the dawn of the most ambitious development ever undertaken in international civil aviation. This would allow us the rather unique opportunity to put theory into practice in the near future by ensuring that the concepts developed and furthered by this workshop and the follow-up are implemented in the design and certification of the ICAO future CNS/ATM systems described earlier in this paper. Now is the time to incorporate human factors requirements during the certification processes of these systems. This might act as a test to the feasibility of these ideas. Such endeavors represent a challenge for the research, engineering, training, operational and regulatory communities. But there is certainly more to be gained by attempting to meet the challenge rather than refraining from progress by decrying the difficulties involved.

Maurino, Daniel↗

NASA NTRS1995

The Role of Chemically Depleted Mantle in the Formation of Coronae on Venus

Without extensive plate subduction to act as a recycling mechanism, a thick layer of buoyant, depleted mantle material may accumulate beneath the thermal lithosphere on Venus due to the pressure-release melting that occurs during crustal formation. Such a layer could be the key factor that allows coronae to form on Venus but not on Earth. Coronae are roughly circular volcano-tectonic features that are interpreted as a manifestation of small-scale upwelling and are unique to Venus. The topographic expression of coronae is highly variable, ranging from domes to plateaus, with or without moats or single or multiple outer rises. In addition to why coronae from on Venus but not on Earth, two outstanding questions in the study of coronae are how the full range of topographic profiles are produced and the relationship between topography and the annulus of fractures that characterize coronae.

Coronae↗

NASA NTRSDate not supplied

Thermal Protection System Design of Aerocapture Systems for Uranus Orbiters

The National Academies Planetary Science and Astrobiology Decadal Survey recently identified Uranus and Neptune - called Ice Giants - as the priority destinations for science[1]. The survey assessed both a mission to Uranus through the Uranus Orbiter and Probe (UOP) concept, and Neptune through the Neptune-Triton Odyssey concept and determined that Uranus is the highest priority for a Flagship class mission. The UOP mission will deliver an in situ probe and conduct a multi-year orbital tour of the system to meet the science objectives. While the Uranus mission is currently viable with launch windows starting in 2031 using existing launch vehicles, the mission has a long cruise time to destination (between 12 and 15 years) and would require more than half of its weight in fuel propellant to achieve the change in velocity necessary for orbital insertion. Aerocapture is a method of orbital control that uses aerodynamic forces generated on a vehicle by the planet’s atmosphere to modulate a spacecraft’s trajectory, allowing mission designers to target the final orbital state. For the Uranus mission, using aerocapture for orbital insertion can decrease not only the cruise time to the destination by 2 - 3 years, but the propellant required to achieve orbital insertion (by more than 40%) which would, in turn, increase the available science payload and reduce the timeline for retrieving data vital to the mission’s science objectives[2]. Achieving orbital insertion via aerocapture requires novel algorithms for Guidance, Navigation and Control[3], and mass-efficient Thermal Protection Systems (TPS) performing in a new atmosphere. This paper will focus on the selection and tailoring of the Thermal Protection Systems for the forebody and aftbody heatshields of an aerocapture mission to Uranus. While preliminary results indicate that multiple systems in NASA’s repertoire are capable of performing in the predicted aerothermal environment there are unique aspects like the inert environment that affect ablation efficiency, and the heatload for aerocapture trajectories to the outer planets are among the highest of any mission to-date[4]. These two factors may impose operational requirements to heatshield separation in order to minimize thermal soak to the payload, and may demand TPS thickness and configurations that have not yet been demonstrated. This paper will discuss the updated maturity, manufacturing, and performance capabilities of candidate thermal protection systems, with specific areas of need highlighted to make thermal protection systems viable for use in the recommended Uranus Orbiter and Probe mission.

Uranus↗

NASA NTRS2011

Interpreting Methanol v(sub 2)-Band Emission in Comets Using Empirical Fluorescence g-Factors

For many years we have been developing the ability, through high-resolution spectroscopy targeting ro-vibrational emission in the approximately 3 - 5 micrometer region, to quantify a suite of (approximately 10) parent volatiles in comets using quantum mechanical fluorescence models. Our efforts are ongoing and our latest includes methanol (CH3OH). This is unique among traditionally targeted species in having lacked sufficiently robust models for its symmetric (v(sub 3) band) and asymmetric (v(sub 2) and v(sub 9) bands) C-H3 stretching modes, required to provide accurate predicted intensities for individual spectral lines and hence rotational temperatures and production rates. This has provided the driver for undertaking a detailed empirical study of line intensities, and has led to substantial progress regarding our ability to interpret CH3OH in comets. The present study concentrates on the spectral region from approximately 2970 - 3010 per centimeter (3.367 - 3.322 micrometer), which is dominated by emission in the (v(sub 7) band of C2H6 and the v(sub 2) band of CH3OH, with minor contributions from CH3OH (v(sub 9) band), CH4 (v(sub 3)), and OH prompt emissions (v(sub 1) and v(sub 2)- v(sub 1)). Based on laboratory jet-cooled spectra (at a rotational temperature near 20 K)[1], we incorporated approximately 100 lines of the CH3OH v(sub 2) band, having known frequencies and lower state rotational energies, into our model. Line intensities were determined through comparison with several comets we observed with NIRSPEC at Keck 2, after removal of continuum and additional molecular emissions and correcting for atmospheric extinction. In addition to the above spectral region, NIRSPEC allows simultaneous sampling of the CH3OH v(sub 3) band (centered at 2844 per centimeter, or 3.516 micrometers and several hot bands of H2O in the approximately 2.85 - 2.9 micrometer region, at a nominal spectral resolving power of approximately 25,000 [2]. Empirical g-factors for v(sub 2) lines were based on the production rate as determined from the v(sub 3) Q-branch intensity; application to comets spanning a range of rotational temperatures (approximately 50 - 90 K) will be reported. This work represents an extension of that presented for comet 21P/Giacobini-Zinner at the 2010 Division for Planetary Sciences meeting [3]. Our empirical study also allows for quantifying CH3OH in comets using IR spectrometers for which the v(sub 3) and v(sub 2) bands are not sampled simultaneously, for example CSHELL/NASA IRTF or CRIRES/VLT.

DiSanti, Michael↗

NASA NTRS1978

Study on utilization of advanced composites in commercial aircraft wing structures. Volume 1: Executive summary

The effort required by commercial transport manufacturers to accomplish the transition from current construction materials and practices to extensive use of composites in aircraft wings was investigated. The engineering and manufacturing disciplines which normally participate in the design, development, and production of an aircraft were employed to ensure that all of the factors that would enter a decision to commit to production of a composite wing structure were addressed. A conceptual design of an advanced technology reduced energy aircraft provided the framework for identifying and investigating unique design aspects. A plan development effort defined the essential technology needs and formulated approaches for effecting the required wing development. The wing development program plans, resource needs, and recommendations are summarized.

Sakata, I. F.↗

NASA NTRS1986

Global change in the geosphere-biosphere: Initial priorities for an IGBP

Some of the factors are outlined that leads one to endorse the concept of focused, international geosphere-biosphere program, whose goal is to understand the interactive physical, chemical, and biological processes that regulate the Earth's unique environment for life, the changes that are occurring in this system, and the manner in which they are influenced by human actions. There is a pressing need to assess the consequence of human activities in the context of natural global change and to provide the body of knowledge necessary to chart a wise course to the future. A number of specific objectives were developed which leads to the conclusion that the need for new programs of observation of the Earth as a planet, a better understanding of the interactive processes that governs its changes, the development of a new generation of coupled modes, and the design of suitable tests to guide the development of these models and the understanding of the processes involved. Some general recommendations are summarized.

Source record↗

NASA NTRS1986

On self-preserving, variable-density, turbulent free jets

Published experimental data on incompressible, compresible, free binary, and confined binary turbulent axisymmetric jet flows are compiled and characterized, and the effect of varying turbulent diffusivity across the mixing region of a free jet is investigated analytically, applying the similarity-solution approach of So and Hwang (1986) to the self-preserving region. It is shown that closed-form solutions, represented by Gaussian error functions and having the turbulent Reynolds number and a profile-shape factor as free parameters, can be obtained if the turbulent diffusivities of momentum, mass, or heat are assumed to be different and to vary in both the streamwise and radial directions. An entrainment function uniquely related to the turbulent Reynolds number is derived, and good agreement between theoretical predictions and experimental measurements is demonstrated in graphs.

So, R. M. C.↗

NASA NTRS1988

MECA Workshop on Atmospheric H2O Observations of Earth and Mars. Physical Processes, Measurements and Interpretations

The workshop was held to discuss a variety of questions related to the detection and cycling of atmospheric water. Among the questions addressed were: what factors govern the storage and exchange of water between planetary surfaces and atmospheres; what instruments are best suited for the measurement and mapping of atmospheric water; do regolith sources and sinks of water have uniquely identifiable column abundance signatures; what degree of time and spatial resolution in column abundance data is necessary to determine dynamic behavior. Of special importance is the question, does the understanding of how atmospheric water is cycled on Earth provide any insights for the interpretation of Mars atmospheric data.

Clifford, Stephen M.↗

NASA NTRS1992

Damage detection in elastic structures using vibratory residual forces and weighted sensitivity

A methodology is presented for detecting structural damage in elastic structures by nondestructive means. Measured modal test data along with a correlated analytical structural model are used to locate potentially damaged regions using residual modal force vectors and to conduct a weighted sensitivity analysis to assess the extent of mass and/or stiffness variations, where damage is characterized as a stiffness reduction. The current approach is unique among other approaches in that it accounts for (1) variations in system mass, system stiffness, and mass center (locations), (2) perturbations of both the natural frequencies and modal vectors, and (3) statistical confidence factors for the structural parameters and potential experimental instrumentation error. Moreover, this procedure can be used with either full or reduced models. A wide variety of numerical examples are presented that show that the current method provides a precise indication of both the location and the extent of structural damage.

Ricles, J. M.↗

NASA NTRS2001

The Standard Autonomous File Server, a Customized, Off-the-Shelf Success Story

The Standard Autonomous File Server (SAFS), which includes both off-the-shelf hardware and software, uses an improved automated file transfer process to provide a quicker, more reliable, prioritized file distribution for customers of near real-time data without interfering with the assets involved in the acquisition and processing of the data. It operates as a stand-alone solution, monitoring itself, and providing an automated fail-over process to enhance reliability. This paper will describe the unique problems and lessons learned both during the COTS selection and integration into SAFS, and the system's first year of operation in support of NASA's satellite ground network. COTS was the key factor in allowing the two-person development team to deploy systems in less than a year, meeting the required launch schedule. The SAFS system his been so successful, it is becoming a NASA standard resource, leading to its nomination for NASA's Software or the Year Award in 1999.

Semancik, Susan K.↗

NASA NTRS2012

Aqueously Dispersed Silver Nanoparticle-Decorated Boron Nitride Nanosheets for Reusable, Thermal Oxidation-Resistant Surface Enhanced Raman Spectroscopy (SERS) Devices

The impurity-free aqueous dispersions of boron nitride nanosheets (BNNS) allowed the facile preparation of silver (Ag) nanoparticle-decorated BNNS by chemical reduction of an Ag salt with hydrazine in the presence of BNNS. The resultant Ag-BNNS nanohybrids remained dispersed in water, allowing convenient subsequent solution processing. By using substrate transfer techniques, Ag-BNNS nanohybrid thin film coatings on quartz substrates were prepared and evaluated as reusable surface enhanced Raman spectroscopy (SERS) sensors that were robust against repeated solvent washing. In addition, because of the unique thermal oxidation-resistant properties of the BNNS, the sensor devices may be readily recycled by short-duration high temperature air oxidation to remove residual analyte molecules in repeated runs. The limiting factor associated with the thermal oxidation recycling process was the Ostwald ripening effect of Ag nanostructures.

Lin, Yi↗

NASA NTRS2024

Measurements of Silicosis Factors in Lunar and Martian Simulants

Simulants are geologically complex materials that are developed to represent the physical and/or compositional characteristics of a planetary surface (e.g., a naturally occurring soil or regolith). There are dozens of commercially available simulants that have been developed over the years; each simulant exhibits unique physical, chemical, and mineralogical characteristics. Simulants are derived from either natural or synthetic sources (i.e., “feedstocks”) of glass, minerals, and rocks. These feedstock components are processed by crushing, pulverizing, melting, etc., and then combined in the appropriate proportions to represent a particular site, surface, or region (e.g., Lunar Highlands Regolith). The process of creating simulants therefore requires the mechanical breakdown and reincorporation of feedstock components which may contain crystalline silica minerals such as quartz, cristobalite, and tridymite. Certain crystalline silica particles of the respirable fraction (<10 μm in diameter) are of great concern; chronic and acute exposure to these respirable crystalline silica (RCS) can lead to permanent damage and scarring of lung tissue, incurable lung diseases (i.e., silicosis), lung cancer, COPD (chronic obstructive pulmonary disease), and kidney disease. Planetary simulants are used extensively as test materials in the in scientific and engineering communities (e.g., testing of dust mitigation technologies, in-situ resource utilization, rover mobility, hardware, soft goods etc.). As such, this assessment was developed to serve as a guide for simulant users, local Safety and Occupational Health professionals, and Industrial Hygienists to evaluate the risk of silicosis across a wide variety of Lunar and Martian simulants. The goal of these works is to ensure that those working with simulant can do so safely and with an informed understanding of potential health risks.

Lunar↗

NASA NTRSDate not supplied

Measurements of Silicosis Factors in Lunar and Martian Simulants

Lunar↗

NASA NTRS2002

Factors in International Space Station Integration Feasibility Assessments

The International Space Station, ISS, is a growing vehicle. The ISS configuration changes internally and externally with each ISS flight. Each flight adds resources and capabilities such as docking/berthing ports, power, stowage volume, heat rejection, and data processing capability. The configuration, capabilities and performance characteristics of the vehicle will be in flux until assembly complete. At the same time the knowledge about what is required to support humans involved in long duration space flight is also being greatly expanded. In addition to the changes occurring on-orbit, the situation on the ground is also very dynamic. Proposals for new ISS elements, proposed deletions of elements, changes to the ISS requirements, and changes to the planned configuration are always under evaluation. Furthermore, budgetary issues have driven the need to explore alternative options for the ISS . This environment has made the role of the technical integrator in the ISS program unique in that the baseline against which proposals are evaluated is always changing. The nature of the International Space Station Program adds another dimension to the integrators task. ISS program activities are spread across several centers: KSC, MSFC, GRC, DFRC, ARC and JSc. There are six International Partners/participants each with their own unique organizations. The prime contractor is in Texas, California and Alabama. And, the Space Shuttle Program as the launch vehicle provider is another major interface. In spite of the fluidity of the technical baseline, projections and organizational complexity, in the course of evaluating proposals and producing feasibility assessments there are factors, which frequently emerge as significant. These factors tend to be the limiting conditions when they come into play. The finite resources, which tend to limit the options for ISS are: upmass, life support and crew rescue capability, crew time, utilities, exercise equipment, and docking/berthing ports. Upmass requirements need to be developed for each option proposed. Short term and long term impacts to upmass are the result of the implementation and long term operations. The upmass requirements need to be met by the existing launch vehicles and any change in flight rate will be a significant cost driver. In addition, when any item is brought to the ISS careful consideration must be given to the on-board stowage and crew time available to unpack, transfer, stow and use these items. If stowage is not available then something must be returned, use of non-standard stowage negotiated or the item in question stays on the ground. Additional crew time requirements will impact available utilization time or crew off-duty time. When the human element is affected, such as, by increasing the number of crew members or changing the duration of the crew stay (longer or shorter) there is an additional set of factors that come into play. The main considerations are: rescue capability, exercise requirements and availability of equipment, resupply, and life support capability.

Watson, Patricia M.↗

NASA NTRS1985

Design and construction of models for the National Transonic Facility, part 2

This lecture presents the results of fastener load and retention systems tests which were carried out as a part of the cryogenic models technology development program a the NASA Langley Research Center (LaRC). Various design concepts for the National Transonic Facility (NTF) developmental and production models are discussed. A number of NTF models are described with emphasis on materials used, uniqueness of design and design drivers. Design and fabrication experience is presented in terms of the primary thermal and mechanical considerations required for design as well as fabrication. Cost considerations are addressed in terms of factors influencing costs for NTF models and cost data comparisons which are taken from both NASA Langley and industry experience.

Young, C. P., Jr.↗