SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
A compilation of the summary portions of each of the Research and Technology Operating Plans (RTOP) used for management review and control of research currently in progress throughout NASA is presented along with citations and abstracts of the RTOPs. Indexes include: subject; technical monitor; responsible NASA organization; and RTOP number.
The development and future requirements of life support systems are considered, and the choice of equipment for long-duration missions is examined. The need for programmatic flexibility, capability growth, and integration of life support systems is discussed. Water supply, CO2 control, oxygen supply, trace contaminant control, and waste management are surveyed, and evolution forecast is presented.
Complicated three-dimensional viscous transonic flows about bodies at high angles of attack are solved on the Illiac IV computer. It is shown that certain approximate forms of the compressible Reynolds-averaged Navier-Stokes equations can be computed about realistic three-dimensional geometries with relative ease on the Illiac IV. The ease and efficiency with which this can be done depend on the approximations made in the basic equations, the choice of the numerical algorithm used for the solution, and the data-base system that controls the data management and identifies and manipulates the vectors. A pencil data-base system is found to be particularly suitable for the approximations and numerical method chosen to produce the results presented. In addition, some comparisons are made of computer predictions with experimental results for various lows about hemisphere-cylinders in both subsonic and supersonic free streams. The same viscous model and numerical model are used, showing good qualitative agreement in the location of separation lines and pressure distributions.
A compilation of the summary portions of each of the Research and Technology Objectives and Plans (RTOPS) used for management review and control research currently in progress throughout NASA is presented. Indexes include: subject, technical monitor, responsible NASA organization, and RTOP number.
A compilation of the summary portions of each of the Research and Technology Objective Plans (RTOP) used for management review and control of research currently in progress throughout NASA is presented. Indexes include: subject, technical monitor, responsible NASA organization, and RTOP number.
The development of the Space Shuttle is traced. Aerodynamic loads and dynamic characteristics, structural design, ascent and entry heating profiles, and propulsion systems are discussed. Problems in the area of systems management and flight control during entry and in the design of an effective thermal control system are discussed in detail.
A compilation of summary portions of each of the Research and Technology Objectives and Plans (RTOPS) used for management review and control of research currently in progress throughout NASA is presented. Subject, technical monitors, responsible NASA organization, and RTOP number indexes are included.
To maximize performance in starved, multiplate cells, the cell design should rely on techniques which widen the volume tolerance characteristics. These involve engineering capillary pressure differences between the components of an electrochemical cell and using these forces to promote redistribution of electrolyte to the desired optimum values. This can be implemented in practice by prescribing pore size distributions for porous back-up plates, reservoirs, and electrodes. In addition, electrolyte volume management can be controlled by incorporating different pore size distributions into the separator. In a nickel/hydrogen cell, the separator must contain pores similar in size to the small pores of both the nickel and hydrogen electrodes in order to maintain an optimum conductive path for the electrolyte. The pore size distributions of all components should overlap in such a way as to prevent drying of the separator and/or flooding of the hydrogen electrode.
In searching for the optimum parameters that minimize the total life cycle cost of an energy conversion system, various combinations of components are examined and the resulting system performance and associated economics are studied. The systems performance and economics simulation computer program (SPECS) was developed to fill this need. The program simulates the fluid flow, thermal, and electrical characteristics of a system of components on a quasi-steady state basis for a variety of energy conversion systems. A unique approach is used in which the set of characteristic equations is solved by the Newton-Raphson technique. This approach eliminates the tedious iterative loops which are found in comparable programs such as TRNSYS or SOLTES-1. Several efficient features were also incorporated such as the centralized control and energy management scheme, and analogous treatment of energy flow in electrical and mechanical components, and the modeling of components of similar fundamental characteristics using generic subroutines. Initial tests indicate that this model can be used effectively with a relatively small number of time steps and low computer cost.
A compilation of summary portions of each of the Research and Technology Operating Plans (RTOPS) used for management review and control of research currently in progress throughout NASA is presented. Subject, technical monitor, responsible NASA organization, and RTOP number indexes are included.
The heart of NASA's STI system is a collection of scientific and technical information gathered from worldwide sources. Currently containing over 2.2 million items, the data base is growing at the rate of 140,000 items per year. In addition to announcement journals, information is disseminated through the NASA RECON on-line bibliographic search system. One part of RECON is NALNET which lists journals and books held by the NASA Centers. Another service now accessible by recon is a directory of numerical data bases (DND) which can be shared by NASA staff and contractors. The DND describes each data base and gives the name and phone number of a contact person. A NASA-wide integrated library system is being developed for the Center libraries which will include on-line catalog and subsystems for acquisition, circulation control, information retrieveal, management information, and an authority file. These subsystems can interact with on-line bibliographic, patron, and vendor files.
The four study areas addressed are: (1) attitude control, (2) data management, (3) long-life thermal management, and (4) automated housekeeping integration. The design concepts in each area were refined. The cost benefits, schedules, and life cycle costs for the options were evaluated. Technology advancement plans were prepared for each of the selected items, and documentation was prepared.
The program DGR03 Status of Langley Formal Reports was developed to aid the Research Information and Application Division (RIAD) in tracking the progress of NASA formal reports through the review cycle. This review cycle was established by Langley Management as a control for Langley's final product: its research reports. The cycle is divided into 5 main stages with substages in each. The cycle can be completed in 165 days. This program has been an aid to RIAD in eliminating manual calculation, providing visible data for everyone concerned with report processing, eliminating the need to telephone divisions when reports are delinquent. The program can also provide information on the number of reports in any stage of the system at any period.
Space station technology is considered along with a shuttle tethered satellite system development program, the development of advanced orbital maintenance/servicing techniques for EVA applications, human systems interfaces for space stations, materials and structures for space applications, progress in space nuclear reactor power systems technology development with the aid of the SP-100 Program, and the design of reliable power systems for communications satellites. Attention is given to problems and concepts of space station guidance and control, spacecraft data management hardware state-of-the-art, progressive autonomy, and automation in teleoperation from a man-machine interface viewpoint. A space exploration outlook is provided, and the space power systems of the early 21st century are discussed.
In an evaluation of the current technological basis for a space station, the Space Station Technology Steering Committee (SSTSC) came to the conclusion that a space station could certainly be made with existing technology. It was, however, found that state-of-the-art technology would not provide for the evolutionary growth aspects of a long life system. In the process of its reviews, the SSTSC identified 10 specific disciplines to categorize the technology which was found to be relevant or potentially applicable to a future space station design. Attention is given to the objectives for the advanced development program, systems and operations, data management, crew and life support, power, thermal management, human capability, auxiliary propulsion, fluid management systems, attitude control and stabilization, structures and mechanisms, and communications.
The Space Shuttle checkout is different from its Apollo predecessor. The complexity of the hardware, the shortened turnaround time, and the software that performs ground checkout are outlined. Generating new techniques and standards for software development and the management structure to control it are implemented. The utilization of computer systems for vehicle testing is high lighted.
A dual approach of mathematical modelling and laboratory experimentation aimed at examining the gas exchange characteristics of artificial animal/plant systems closed to the ambient atmosphere was initiated. The development of control techniques and management strategies for maintaining the atmospheric levels of carbon dioxide and oxygen at physiological levels is examined. A mathematical model simulating the atmospheric behavior in these systems was developed and an experimental gas closed system was constructed. These systems are described and preliminary results are presented.
The test design and results from assessment of the performance of the self-test program and the extent of fault latency in a redundant flight control system (FCS) are reported. Assembly language programming generated gate-level faults directed to every avionics component. Details of the fault-simulation software are described, noting the input needed to match the five control-surface parameters managed by the FCS. Most faults were immediately detected, and component-level faults, occurring at pins, were more easily noted than gate-level faults. The results indicated that a 200-word self-test program is sufficient to obtain a fault coverage of 85 percent. Minor hardware changes are required to reach levels over 90 percent.