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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1992

On-line analysis capabilities developed to support the AFW wind-tunnel tests

A variety of on-line analysis tools were developed to support two active flexible wing (AFW) wind-tunnel tests. These tools were developed to verify control law execution, to satisfy analysis requirements of the control law designers, to provide measures of system stability in a real-time environment, and to provide project managers with a quantitative measure of controller performance. Descriptions and purposes of the developed capabilities are presented along with examples. Procedures for saving and transferring data for near real-time analysis, and descriptions of the corresponding data interface programs are also presented. The on-line analysis tools worked well before, during, and after the wind tunnel test and proved to be a vital and important part of the entire test effort.

Wieseman, Carol D.↗
NASA NTRS1992

Solar Probe thermal shield design and testing

This paper discusses the major thermal shield subsystem development activities in support of the Solar Probe study being conducted at JPL. The Solar Probe spacecraft will travel to within 4 solar radii of the sun's center to perform fundamental experiments in space physics. Exposure to 2900 earth suns at perihelion requires the spacecraft to be protected within the shadow envelope of a protective shield. In addition, the mass loss rate off of the shield at elevated temperature must comply with plasma instrument requirements and has become the driver of the shield design. This paper will focus on the analytical design work to size the shield and control the shield mass loss rate for the various spacecraft options under study, the application of carbon-carbon materials for shield components, development and preparation of carbon-carbon samples for materials testing, and a materials testing program for carbon-carbon and tungsten alloys to investigate thermal/optical properties, mass loss (carbon-carbon only), material integrity, and high velocity impact behavior.

Millard, Jerry M.↗
NASA NTRS1992

On-line analysis capabilities developed to support the AFW wind-tunnel tests

A variety of on-line analysis tools were developed to support two Active Flexible Wing wind-tunnel tests. These tools were developed to verify control law execution, to satisfy analysis requirements of the control law designers, to provide measures of system stability in a real-time environment, and to provide project managers with a quantitative measure of controller performance. Description and purposes of capabilities which were developed are presented in this paper along with examples. Procedures for saving and transferring data for near real-time analysis, and descriptions of the corresponding data interface programs are also presented. The on-line analysis tools worked well before, during, and after the wind-tunnel tests and proved to be a vital and important part of the entire test effort.

Wieseman, Carol D.↗
NASA NTRS1989

Payload processing study for ELV launches

A NASA-KSC study on payload ground processing activities in support of Expendable Launch Vehicle (ELV) launches at Cape Canaveral Air Force Station from January 1977 through February 1988, showed that nearly half of the payloads experienced schedule delays. While about 10 percent of the delays were weather-related, over 65 percent were caused by payload/launch vehicle problems. The planned processing time was exceeded by more than two weeks in most cases. Nearly 30 percent of the payloads required some storage time.

Terhune, Creighton A.↗
NASA NTRS1990

The NASA Space Life Sciences Training Program - Preparing the way

Attention is given to the goals and methods adopted in the NASA Space Life Sciences Training Program (SLSTP) for preparing scientists and engineers for space-related life-sciences research and operations. The SLSTP is based on six weeks of projects and lectures which give an overview of payload processing and experiment flow in the space environment. The topics addressed in the course of the program include descriptions of space vehicles, support hardware, equipment, and research directions. Specific lecture topics include the gravity responses of plants, mission integration of a flight experiment, and the cardiovascular deconditioning. The SLSTP is shown to be an important part of the process of recruiting and training qualified scientists and engineers to support space activities.

Biro, Ronald↗
NASA NTRS1991

The crisis in human capital

This overview discusses the current shortfalls in the U.S. national education system with attention to their effects on the aerospace industry and potential remedies. Student-achievement and literacy rates are examined to compare U.S. students to those of other countries, and the sociological and cultural phenomena are listed which can contribute to deficiencies in learning. Intervention programs for young children and for students in math and science are discussed, and corporate mechanisms are described which support scholarly activities. Also examined are teaching resources provided by government agencies that deal with science and technology. The general conclusion of the paper is that the efforts to date are insufficient because they do not address education levels across the country. It is suggested that corporations and communities rather than federal and state governments address the educational shortfalls.

Kersey, E. D. K.↗
NASA NTRS1991

The Space Station end-to-end data system - Linking architecture and operations

The paper describes tha data system designed for linking and integrating the Space Station Freedom (SSF) space and ground architecture and for providing instrument data to the user and discusses the operations of the system. Particular attention is given to the objectives, the organization, and the schedule of the SSF Program, the infrastructure elements of the end-to-end data system, the key active functional areas of the system, the types of data, the user scenario, and the SSF's space, space-to-ground, and ground infrastructures as they are active in support of the stipulated user scenario.

Fishkind, Stanley↗
NASA NTRS1988

Aircraft integrated design and analysis: A classroom experience

AAE 451 is the capstone course required of all senior undergraduates in the School of Aeronautics and Astronautics at Purdue University. During the past year the first steps of a long evolutionary process were taken to change the content and expectations of this course. These changes are the result of the availability of advanced computational capabilities and sophisticated electronic media availability at Purdue. This presentation will describe both the long range objectives and this year's experience using the High Speed Commercial Transport (HSCT) design, the AIAA Long Duration Aircraft design and a Remotely Piloted Vehicle (RPV) design proposal as project objectives. The central goal of these efforts was to provide a user-friendly, computer-software-based, environment to supplement traditional design course methodology. The Purdue University Computer Center (PUCC), the Engineering Computer Network (ECN), and stand-alone PC's were used for this development. This year's accomplishments centered primarily on aerodynamics software obtained from the NASA Langley Research Center and its integration into the classroom. Word processor capability for oral and written work and computer graphics were also blended into the course. A total of 10 HSCT designs were generated, ranging from twin-fuselage and forward-swept wing aircraft, to the more traditional delta and double-delta wing aircraft. Four Long Duration Aircraft designs were submitted, together with one RPV design tailored for photographic surveillance. Supporting these activities were three video satellite lectures beamed from NASA/Langley to Purdue. These lectures covered diverse areas such as an overview of HSCT design, supersonic-aircraft stability and control, and optimization of aircraft performance. Plans for next year's effort will be reviewed, including dedicated computer workstation utilization, remote satellite lectures, and university/industrial cooperative efforts.

Source record↗
NASA NTRS1993

Exploration planning in the context of human exploration and development of the Moon

It is widely believed that the next step beyond low Earth orbit in attaining the United States' stated goal of 'Expanding human presence beyond the Earth' should be to reestablish a lunar capability, building on the Apollo program, and preparing the way for eventual human missions to Mars. The Moon offers important questions in planetary and Earth science, can provide a unique platform for making astronomical observations of high resolution and sensitivity, and can be in the development path for unlocking resources of the inner solar system to support space activities and return benefits to Earth. NASA's Office of Exploration has undertaken the planning of future lunar exploration missions with the assistance of the Solar System Exploration Division in matters dealing with the quality of scientific data and the manner in which it will be made available to the scientific community. The initial elements of the proposed program include the Lunar Scout missions, which consist of two small identical spacecraft in polar orbit around the Moon, which can accomplish most of the objectives associated with previous proposals for Lunar Polar Orbiters. These missions would be followed by 'Artemis' landers, capable of emplacing up to 200 kg payloads anywhere on the Moon. In addition, the exploration program must incorporate data obtained from other missions, including the Galileo lunar flybys, the Clementine high orbital observations, and Japanese penetrator missions. In the past year, a rather detailed plan for a 'First Lunar Outpost (FLO)' which would place 4 astronauts on the lunar surface for 45 days has been developed as a possible initial step of a renewed human exploration program. In the coming year, the FLO concept will be reviewed and evolved to become more highly integrated with planning for the initial human exploration of Mars, which could come perhaps 5 years after the reestablishment of lunar capability. Both programs could benefit from the common development of systems and subsystems, where that is sensible from a performance perspective.

Duke, Michael B.↗
NASA NTRS1992

The effects of acid deposition on sulfate reduction and methane production in peatlands

Peatlands, as fens and bods, make up a large percentage of northern latitude terrestrial environments. They are organic rich and support an active community of anaerobic bacteria, such as methanogenic and sulfate-reducing bacteria. The end products of these microbial activities, methane and hydrogen sulfide, are important components in the global biogeochemical cycles of carbon and sulfur. Since these two bacterial groups compete for nutritional substrates, increases in sulfate deposition due to acid rain potentially can disrupt the balance between these processes leading to a decrease in methane production and emission. This is significant because methane is a potent greenhouse gas that effects the global heat balance. A section of Mire 239 in the Experimental Lakes Area, in Northwestern Ontario, was artificially acidified and rates of sulfate reduction and methane production were measured with depth. Preliminary results suggested that methane production was not affected immediately after acidification. However, concentrations of dissolved methane decreased and dissolved sulfide increased greatly after acidification and both took several days to recover. The exact mechanism for the decrease in methane was not determined. Analyses are under way which will be used to determine rates of sulfate reduction. These results will be available by Spring and will be discussed.

Murray, Georgia L.↗
NASA NTRS1993

Large eddy simulation and direct numerical simulation of high speed turbulent reacting flows

The objective of this research is to make use of Large Eddy Simulation (LES) and Direct Numerical Simulation (DNS) for the computational analyses of high speed reacting flows. Our efforts in the first phase of this research conducted within the past three years have been directed in several issues pertaining to intricate physics of turbulent reacting flows. In our previous 5 semi-annual reports submitted to NASA LaRC, as well as several technical papers in archival journals, the results of our investigations have been fully described. In this progress report which is different in format as compared to our previous documents, we focus only on the issue of LES. The reason for doing so is that LES is the primary issue of interest to our Technical Monitor and that our other findings were needed to support the activities conducted under this prime issue. The outcomes of our related investigations, nevertheless, are included in the appendices accompanying this report. The relevance of the materials in these appendices are, therefore, discussed only briefly within the body of the report. Here, results are presented of a priori and a posterior analyses for validity assessments of assumed Probability Density Function (PDF) methods as potential subgrid scale (SGS) closures for LES of turbulent reacting flows. Simple non-premixed reacting systems involving an isothermal reaction of the type A + B yields Products under both chemical equilibrium and non-equilibrium conditions are considered. A priori analyses are conducted of a homogeneous box flow, and a spatially developing planar mixing layer to investigate the performance of the Pearson Family of PDF's as SGS models. A posteriori analyses are conducted of the mixing layer using a hybrid one-equation Smagorinsky/PDF SGS closure. The Smagorinsky closure augmented by the solution of the subgrid turbulent kinetic energy (TKE) equation is employed to account for hydrodynamic fluctuations, and the PDF is employed for modeling the effects of scalar fluctuations. The implementation of the model requires the knowledge of the local values of the first two SGS moments. These are provided by additional modeled transport equations. In both a priori and a posteriori analyses, the predicted results are appraised by comparison with subgrid averaged results generated by DNS. Based on these results, the paths to be followed in future investigations are identified.

Adumitroaie, V.↗
NASA NTRS1993

Studies in remotely sensed geophysical parameter retrieval and analysis

This report describes Universities Space Research Association (USRA) activities in support of the Geophysical Parameter Retrieval and Analysis studies. Specifically it addresses personnel assigned to the effort, travel, consultant participants, technical progress, and contract spending.

Perkey, Donald J.↗
NASA NTRS1993

An OSI architecture for the deep space network

The flexibility and robustness of a monitor and control system are a direct result of the underlying inter-processor communications architecture. A new architecture for monitor & Control at the Deep Space Network Communications Complexes has been developed based on the Open System Interconnection (OSI) standards. The suitability of OSI standards for DSN M&C has been proven in the laboratory. The laboratory success has resulted in choosing an OSI-based architecture for DSS-13 M&C. DSS-13 is the DSN experimental station and is not part of the 'operational' DSN; it's role is to provide an environment to test new communications concepts can be tested and conduct unique science experiments. Therefore, DSS-13 must be robust enough to support operational activities, while also being flexible enough to enable experimentation. This paper describes the M&C architecture developed for DSS-13 and the results from system and operational testing.

Heuser, W. Randy↗
NASA NTRS1994

Third order LPF type compensator for flexible rotor suspension

The tuning job of the compensator for levitating flexible rotors supported by active magnetic bearings (AMB) concerns providing a good damping effect to the critical speed modes while avoiding the spillover problem on the instability of higher bending modes. In this paper, an idea for design of the control law of the compensator based on utilizing a third order low pass filter (LPF) is proposed to essentially enable elimination of the spillover instability. According to the proposed design method, good damping effects for the critical speeds are obtained by the usual phase lead/lag function. Stabilization for all of higher bending modes is completed by the additional function of the 3rd order LPF due to its phase lag approaching about -270 degrees in the high frequency domain. This idea is made clear by experiments and simulations.

Matsushita, Osami↗
NASA NTRS1993

KSC ground operations planning for Space Station

At the Kennedy Space Center (KSC) in Florida, processing facilities are being built and activated to support the processing, checkout, and launch of Space Station elements. The generic capability of these facilities will be utilized to support resupply missions for payloads, life support services, and propellants for the 30-year life of the program. Special Ground Support Equipment (GSE) is being designed for Space Station hardware special handling requirements, and a Test, Checkout, and Monitoring System (TCMS) is under development to verify that the flight elements are ready for launch. The facilities and equipment used at KSC, along with the testing required to accomplish the mission, are described in detail to provide an understanding of the complexity of operations at the launch site. Assessments of hardware processing flows through KSC are being conducted to minimize the processing flow times for each hardware element. Baseline operations plans and the changes made to improve operations and reduce costs are described, recognizing that efficient ground operations are a major key to success of the Space Station.

Lyon, J. R.↗
NASA NTRS1994

Increases in efficiency and enhancements to the Mars Observer non-stored commanding process

The Mars Observer team was, until the untimely loss of the spacecraft on August 21, 1993, performing flight operations with greater efficiency and speed than any previous JPL mission of its size. This level of through-put was made possible by a mission operations system which was composed of skilled personnel using sophisticated sequencing and commanding tools. During cruise flight operations, however, it was realized by the project that this commanding level was not going to be sufficient to support the activities planned for mapping operations. The project had committed to providing the science instrument principle investigators with a much higher level of commanding during mapping. Thus, the project began taking steps to enhance the capabilities of the flight team. One mechanism used by project management was a tool available from total quality management (TQM). This tool is known as a process action team (PAT). The Mars Observer PAT was tasked to increase the capacity of the flight team's nonstored commanding process by fifty percent with no increase in staffing and a minimal increase in risk. The outcome of this effort was, in fact, to increase the capacity by a factor of 2.5 rather than the desired fifty percent and actually reduce risk. The majority of these improvements came from the automation of the existing command process. These results required very few changes to the existing mission operations system. Rather, the PAT was able to take advantage of automation capabilities inherent in the existing system and make changes to the existing flight team procedures.

Brooks, Robert N., Jr.↗