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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 NTRS1992

Trends in aeropropulsion research and their impact on engineering education

This presentation is concerned with the trends in aeropropulsion both in the U.S. and abroad and the impact of these trends on the educational process in our universities. In this paper, we shall outline the new directions for research which may be of interest to educators in the aeropropulsion field. Awareness of new emphases, such as emission reductions, noise control, maneuverability, speed, etc., will have a great impact on engineering educators responsible for restructuring courses in propulsion. The information presented herein will also provide some background material for possible consideration in the future development of propulsion courses. In describing aeropropulsion, we are concerned primarily with air-breathing propulsion; however many observations apply equally as well to rocket engine systems. Aeropropulsion research needs are primarily motivated by technologies required for advanced vehicle systems and frequently driven by external requirements such as economic competitiveness, environmental concern and national security. In this presentation, vehicle based research is first described, followed by a discussion of discipline and multidiscipline research necessary to implement the vehicle-focused programs. The importance of collaboration in research and the training of future researchers concludes this presentation.

Povinelli, Louis A.↗
NASA NTRS1991

Space Station Freedom capabilities for users

Space Station Freedom's major objectives are to prepare for human space exploration by providing a long-duration, continuously habitable spacecraft in low earth orbit for physiology studies and for development of systems to support human presence in space and to enable laboratory and observational research in space. As a result of restructuring and the preliminary design review, designs of Space Station Freedom architecture and systems have progressed to the point where the accommodations for users can be well described. These capabilities are enumerated, covering such important resources as power and cooling, rack volume and external accommodations, crew time, data and command rates, and acceleration environment. Related items such as total energy, data management systems, and interfaces, station attitude, payload transportation, and on board and ground facilities are considered.

Taylor, William W. L.↗
NASA NTRS1991

Scientific use of Space Station Freedom

The overall strategic science planning of the Office of Space Science and Applications (OSSA) is presented. The science opportunities inherent to the restructured Space Station are discussed and a synopsis of the OSSA implementation plan for Space Station Freedom utilization is offered. Attention is given to the microgravity science and applications facilities, the advanced protein crystal growth facility, the biotechnology facility, the modular combustion facility, and the life sciences facility.

Rhome, Robert C.↗
NASA NTRS1992

Early use of Space Station Freedom for NASA's Microgravity Science and Applications Program

The paper describes microgravity science opportunities inherent to the restructured Space Station and presents a synopsis of the scientific utilization plan for the first two years of ground-tended operations. In the ground-tended utilization mode the Space Station is a large free-flyer providing a continuous microgravity environment unmatched by any other platform within any existing U.S. program. It is pointed out that the importance of this period of early Space Station mixed-mode utilization between crew-tended and ground-tended approaches is of such magnitude that Station-based microgravity science experiments many become benchmarks to the disciplines involved. The traffic model that is currently being pursued is designed to maximize this opportunity for the U.S. microgravity science community.

Rhome, Robert C.↗
NASA NTRS1992

Evolution design requirements and design strategy

Space Station Freedom (SSF) has undergone numerous design changes during the rephasing and restructuring activities occurring in 1989 and 1990/91, respectively. One direct result of these changes is that the Station has become more complex and compact which requires that future modifications to the Station be carefully planned and analyzed in conjunction with the baseline design process. This will ensure that the configuration has adequate design features and flexibility to accommodate the future capability and element upgrades. Six critical growth requirements (electrical power, thermal control, pressurized volume, structures, EVA equipment, and data management) have been identified and baselined in the Level I Program Requirements Document (PRD) and the Level II Program Definition and Requirements Document (PDRD). The approach to meeting the growth requirements will be to minimize the impact on the baseline design in the areas of weight, power, and development cost. The specifics of these requirements, with regard to scarring and implementation during the Follow-On and Evolution phases of SSF, are detailed in this paper.

Monell, D. W.↗
NASA NTRS1992

Intelligent data management for real-time spacecraft monitoring

Real-time AI systems have begun to address the challenge of restructuring problem solving to meet real-time constraints by making key trade-offs that pursue less than optimal strategies with minimal impact on system goals. Several approaches for adapting to dynamic changes in system operating conditions are known. However, simultaneously adapting system decision criteria in a principled way has been difficult. Towards this end, a general technique for dynamically making such trade-offs using a combination of decision theory and domain knowledge has been developed. Multi-attribute utility theory (MAUT), a decision theoretic approach for making one-time decisions is discussed and dynamic trade-off evaluation is described as a knowledge-based extension of MAUT that is suitable for highly dynamic real-time environments, and provides an example of dynamic trade-off evaluation applied to a specific data management trade-off in a real-world spacecraft monitoring application.

Schwuttke, Ursula M.↗
NASA NTRS1992

Introduction to Space Station Freedom

NASA field centers and contractors are organized to develop 'work packages' for Space Station Freedom. Marshall Space Flight Center and Boeing are building the U.S. laboratory and habitation modules, nodes, and environmental control and life support system; Johnson Space Center and McDonnell Douglas are responsible for truss structure, data management, propulsion systems, thermal control, and communications and guidance; Lewis Research Center and Rocketdyne are developing the power system. The Canadian Space Agency (CSA) is contributing a Mobile Servicing Center, Special Dextrous Manipulator, and Mobile Servicing Center Maintenance Depot. The National Space Development Agency of Japan (NASDA) is contributing a Japanese Experiment Module (JEM), which includes a pressurized module, logistics module, and exposed experiment facility. The European Space Agency (ESA) is contributing the Columbus laboratory module. NASA ground facilities, now in various stages of development to support Space Station Freedom, include: Marshall Space Flight Center's Payload Operations Integration Center and Payload Training Complex (Alabama), Johnson Space Center's Space Station Control Center and Space Station Training Facility (Texas), Lewis Research Center's Power System Facility (Ohio), and Kennedy Space Center's Space Station Processing Facility (Florida). Budget appropriations impact the development of the Space Station. In Fiscal Year 1988, Congress appropriated only half of the funds that NASA requested for the space station program ($393 million vs. $767 million). In FY 89, NASA sought $967 million for the program, and Congress appropriated $900 million. NASA's FY 90 request was $2.05 billion compared to an appropriation of $1.75 billion; the FY 91 request was $2.45 billion, and the appropriation was $1.9 billion. After NASA restructured the Space Station Freedom program in response to directions from Congress, the agency's full budget request of $2.029 billion for Space Station Freedom in FY 92 was appropriated. For FY 93, NASA is seeking $2.25 billion for the program; the planned budget for FY 94 is $2.5 billion. Further alterations to the hardware configuration for Freedom would be a serious setback; NASA intends 'to stick with the current baseline' and continue planning for utilization.

Kohrs, Richard↗
NASA NTRS1992

Earth observing system. Output data products and input requirements, version 2.0. Volume 2: Analysis of IDS input requirements

On 18 Jan. 1991, NASA confirmed 29 Inter-Disciplinary Science (IDS) teams, each involving a group of investigators, to conduct interdisciplinary research using data products from Earth Observing System (EOS) instruments. These studies are multi-disciplinary and require output data products from multiple EOS instruments, including both FI and PI instruments. The purpose of this volume is to provide information on output products expected from IDS investigators, required input data, and retrieval algorithms. Also included in this volume is the revised analysis of the 'best' and 'alternative' match data products for IDS input requirements. The original analysis presented in the August 1991 release of the SPSO Report was revised to incorporate the restructuring of the EOS platform. As a result of the reduced EOS payload, some of EOS instruments were deselected and their data products would not be available for IDS research. Information on these data products is also presented.

Lu, Yun-Chi↗
NASA NTRS1993

In search of meta-knowledge

Development of an Intelligent Information System (IIS) involves application of numerous artificial intelligence (AI) paradigms and advanced technologies. The National Aeronautics and Space Administration (NASA) is interested in an IIS that can automatically collect, classify, store and retrieve data, as well as develop, manipulate and restructure knowledge regarding the data and its application (Campbell et al., 1987, p.3). This interest stems in part from a NASA initiative in support of the interagency Global Change Research program. NASA's space data problems are so large and varied that scientific researchers will find it almost impossible to access the most suitable information from a software system if meta-information (metadata and meta-knowledge) is not embedded in that system. Even if more, faster, larger hardware is used, new innovative software systems will be required to organize, link, maintain, and properly archive the Earth Observing System (EOS) data that is to be stored and distributed by the EOS Data and Information System (EOSDIS) (Dozier, 1990). Although efforts are being made to specify the metadata that will be used in EOSDIS, meta-knowledge specification issues are not clear. With the expectation that EOSDIS might evolve into an IIS, this paper presents certain ideas on the concept of meta-knowledge and demonstrates how meta-knowledge might be represented in a pixel classification problem.

Lopez, Antonio M., Jr.↗
NASA NTRS1990

NASA supporting studies for microgravity research on eye movements

The purpose of the work on this project was to provide support for ground-based studies on the effects of gravity on eye movements. The effects of microgravity on the optokinetic eye movements of humans are investigated. OKN was induced by having subjects watch 3.3 deg stripes moving at 35 deg/s for 45 s in a binocular, head-fixed apparatus. The field (hor., 88 deg; vert., 72 deg), was rotated about axes that were upright or tilted 45 deg or 90 deg. The head was upright or tilted 45 deg on the body. Head-horizontal (yaw axis) and head-vertical (pitch axis) components of OKN were recorded with electro-oculography (EOG). Slow phase velocity vectors were determined relative to gravity. With the head upright, the axis of eye rotation during yaw axis OKN was coincident with the stimulus axis and the spatial vertical. With the head tilted 45 deg on the body, a persistent vertical component of eye velocity developed during yaw axis stimulation, and there was an average shift of the axis of eye rotation toward the spatial vertical of approximately 18 deg in six subjects. During oblique optokinetic stimulation with the head upright, the axis of eye rotation shifted 12 deg toward the spatial vertical. When the head was tilted, the axis of eye rotation rotated to the other side of the spatial vertical by 5.4 deg during the same oblique stimulation. This counter-rotation of the axis of eye rotation is similar to the 'Muller (E) effect', in which the perception of the upright counter-rotates to the opposite side of the spatial vertical when subjects are tilted in darkness. The data were simulated by a model of OKN. Despite the short OKAN time constants, strong horizontal to vertical cross-coupling was produced if the horizontal and vertical time constants were in proper ratio, and there was no suppression of nystagmus orthogonal to the stimulus direction. This shows that the spatial orientation of OKN can be due to a restructuring of the system matrix of velocity storage as a function of gravity. It is concluded that although human OKAN is weak, velocity storage orients the slow phase velocity of OKN towards the spatial vertical.

Cohen, Bernard↗
NASA NTRS1992

Mission modeling for the Manned Transportation System study

To determine the requirements and potential options for the next Manned Transportation System, a 'needs' analysis was performed. The analysis identified the number, mass, type, and destination of manned and unmanned payloads to space. The needs model is based on the NASA Mixed Fleet Manifest and a version of the FY90 Civil Needs Data Base with Space Station Restructure modifications and a 'strawman' DOD mission model.

Gaunce, Michael T.↗
NASA NTRS1993

Incorporation of a hierarchical grid component structure into GRIDGEN

The underlying framework of the GRIDGEN multiple block grid generation system has been refined so that grid components are now stored within a hierarchical data structure. This restructuring has enhanced the usability of the software by allowing grids to be generated on a more intuitive level. This new framework also provides a means by which the multiple block system can be edited at most any level in the grid generation process. Editing tools are currently being added to GRIDGEN so that a change to the grid can be propagated backward and forward in the data hierarchy. The new data structure, the editing tools, and other recent GRIDGEN improvements are described in this paper.

Steinbrenner, John P.↗
NASA NTRS1993

Design of deployable-truss masts for Space Station

This paper presents an overview of three deployable-truss designs that were considered for use on Space Station Freedom to deploy the solar array wings. The first design chosen early in the program was a nut-deployed coilable longeron mast which has the advantage of being lightweight and reliable, with considerable flight history. Subsequently, because of the restructure of Space Station, a second design was chosen: a lanyard-deployed FASTMast (Folding Articulated Square Truss Mast), which has improved strength and redundancy characteristics for a given stowed volume. After further definition of the load requirements during deployment, however, it became necessary to modify the deployment system, resulting in the third mast design for space station solar arrays: a nut-deployed FASTMast, which was ultimately selected to provide increased stiffness and strength during deployment. This paper presents a brief review of these mast designs and their associated deployment systems, emphasizing the trade-offs involved in selecting between them. In addition, some innovative features of the FASTMast design as it stands currently for Space Station are described, and a brief review of the test program that is underway to qualify this design for flight is included.

Bowden, Mary↗
NASA NTRS1993

Shaping of the magnetotail from the mantle - Global and local structuring

Kinetic modeling of the properties of magnetotail formation from a plasma mantle source are discussed, and a unified view of the structure of the central part of the magnetotail plasma sheet as well as the structure of its boundary layer is developed. The Tsyganenko magnetic field model for quiet periods of magnetospheric activity is used to trace trajectories of mantle protons in the presence of a uniform dawn-dusk electric field. The present model shows the evolution of the global structure of the tail with a clearly defined central plasma sheet and plasma sheet boundary layer developing from its beginnings as a plasma 'nucleus' in the distant tail current sheet. This large-scale restructuring is accompanied by the creation of small-scale features in the particle distribution functions. It is also shown that complementary ring distribution structures should also exist in the central plasma sheet. The ion distribution functions in the central plasma sheet should take a rather specific form in velocity space with loss regions oriented predominantly orthogonal to the magnetic field.

Ashour-Abdalla, Maha↗
NASA NTRS1992

Evaluation of the carbon dioxide removal assembly requirements for the Space Station Freedom in the Manned Tended Capability through Permanently Manned Capability configurations

Analyses have been conducted to assess the capability of the Atmosphere Revitalization Subsystem to control ambient CO2 levels of the Space Station Freedom (SSF). The adequacy of the Carbon Dioxide Removal Assembly (CDRA) performance to meet design requirements has been evaluated. Analyses considered transient effects of crew location and metabolic loading on SSF Restructure configurations. The analyses consisted of computer simulations of on-orbit conditions using both supplier-provided and adjusted CO2 removal performance approximations along with derived crew metabolic activities and locations. Results show that while the current performance of the CDRA will maintain CO2 levels within specifications for Man-Tended Operations, it cannot maintain the SSF atmosphere below specifications during Permanently Manned Operations. Potential design options are discussed and other relevant analyses are summarized.

Knox, J. C.↗
NASA NTRS1992

Viewing analyses for the assembly of Space Station Freedom (SSF)

Analyses are currently being conducted in the Man-Systems Division of the NASA Johnson Space Center, on the restructured Space Station Freedom configuration to determine viewing requirements for both robotic tasks and for extravehicular crew activities. The use of the PLAID software, a 3D modeling simulation tool, provides a simulation of the environment and the system hardware to identify potential problem areas needing further refinement in design development. This process enables human factor considerations and issues to be explored during the design process to identify and correct problems before hardware is actually constructed. Preliminary results have identified several potential viewing problem areas with the available lighting for both robotic and EVA tasks. To rectify the potential viewing problems identified through simulation, additional cameras and lighting enhancements are being proposed at various sites along the truss and on the Shuttle to provide more complete coverage of work task sites. Supplementing the existing cameras with color coded alignment aids will also help reduce the workload involved with robotic tasks.

Stealey, Sheryl↗
NASA NTRS1990

Evolution of land mammal diversity in North America during the Cenozoic

The North American continental patterns of generic richness, extinction, and origination have been reexamined and analyzed in the context of alpha and beta species diversity. The major models of diversity are discussed as well as primary concepts and theories based on studies of living organisms. The adequacy of the fossil record is considered and patterns of genetic richness and species level diversity are outlined. Major shifts in mammalian community structures are reviewed and hypotheses are presented on diversity origin, regulation, and maintenance for the North American record. Results demonstrate a complex relationship between continental alpha and beta diversity characterized by marked changes through time and differences in patterns at each level. It is clear that both biotic and abiotic factors have strongly influenced the evolution of North American species diversity and that major restructuring occurred in Cenozoic mammalian communities.

Stucky, Richard K.↗
NASA NTRS1993

Streamwise vortices in heated boundary layers

The nonlinear instability of the boundary layer on a heated flat plate placed in an oncoming flow is investigated. Such flows are unstable to stationary vortex instabilities and inviscid travelling wave disturbances governed by the Taylor-Goldstein equation. For small temperature differences the Taylor-Goldstein equation reduces to Rayleigh's equation. When the temperature difference between the wall and free stream is small the preferred mode of instability is a streamwise vortex. It is shown in this case that the vortex, assumed to be of small wavelength, restructures the underlying mean flow to produce a profile which can be massively unstable to inviscid travelling waves. The mean state is shown to be destabilized if the Prandtl number is less than unity.

Hall, Philip↗