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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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

The lateral-directional characteristics of a 74-degree Delta wing employing gothic planform vortex flaps

The low speed lateral/directional characteristics of a generic 74 degree delta wing body configuration employing the latest generation, gothic planform vortex flaps was determined. Longitudinal effects are also presented. The data are compared with theoretical estimates from VORSTAB, an extension of the Quasi vortex lattice Method of Lan which empirically accounts for vortex breakdown effects in the calculation of longitudinal and lateral/directional aerodynamic characteristics. It is indicated that leading edge deflections of 30 and 40 degrees reduce the magnitude of the wing effective dihedral relative to the baseline for a specified angle of attack or lift coefficient. For angles of attack greater than 15 degrees, these flap deflections reduce the configuration directional stability despite improved vertical tail effectiveness. It is shown that asymmetric leading edge deflections are inferior to conventional ailerons in generating rolling moments. VORSTAB calculations provide coarse lateral/directional estimates at low to moderate angles of attack. The theory does not account for vortex flow induced, vertical tail effects.

Grantz, A. C.↗
NASA NTRS1986

A Priority Protocol for Token-Ring Networks

New priority protocol controls access to token-ring local-area network (LAN) of digital-communication stations over widely ranging mix of low- and high-priority traffic. Protocol, called round-robin priority scheme (RRPS), introduces only small overhead and therefore degrades system performance only minimally. Key messages guaranteed access to local-area network during peak loads.

Liu, H. T.↗
NASA NTRS1985

Gateway design specification for fiber optic local area networks

This is a Design Specification for a gateway to interconnect fiber optic local area networks (LAN's). The internetworking protocols for a gateway device that will interconnect multiple local area networks are defined. This specification serves as input for preparation of detailed design specifications for the hardware and software of a gateway device. General characteristics to be incorporated in the gateway such as node address mapping, packet fragmentation, and gateway routing features are described.

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NASA NTRS1985

A color graphics environment in support of supercomputer systems

An initial step in the integration of an upgrade of a VPS-32 supercomputer to 16 million 64-bit words, to be closely followed by a further upgrade to 32 million words, was to develop a graphics language commonality with other computers at the Langley Center. The power of the upgraded supercomputer is to users at individual workstations, who will aid in defining the direction for future expansions in both graphics software and workstation requirements for the supercomputers. The LAN used is an ETHERNET configuration featuring both CYBER mainframe and PDP 11/34 image generator computers. The system includes a film recorder for image production in slide, CRT, 16 mm film, 35 mm film or polaroid film images. The workstations have screen resolutions of 1024 x 1024 with each pixel being one of 256 colors selected from a palette of 16 million colors. Each screen can have up to 8 windows open at a time, and is driven by a MC68000 microprocessor drawing on 4.5 Mb RAM, a 40 Mb hard disk and two floppy drives. Input is from a keyboard, digitizer pad, joystick or light pen. The system now allows researchers to view computed results in video time before printing out selected data.

Smith-Taylor, R.↗
NASA NTRS1985

Advanced local area network concepts

Development of a good model of the data traffic requirements for Local Area Networks (LANs) onboard the Space Station is the driving problem in this work. A parameterized workload model is under development. An analysis contract has been started specifically to capture the distributed processing requirements for the Space Station and then to develop a top level model to simulate how various processing scenarios can handle the workload and what data communication patterns result. A summary of the Local Area Network Extendsible Simulator 2 Requirements Specification and excerpts from a grant report on the topological design of fiber optic local area networks with application to Expressnet are given.

Grant, Terry↗
NASA NTRS1987

The evolution of the Mission Control Center

A discussion of the function and history of the Space Shuttle Mission Control Center describes the communications and data processing facilities, with an emphasis on display system changes. The current display system will be replaced by new technology as part of a project called the Mission Control Center Upgrade. That upgrade will implement a set of high-performance Local Area Networks (LANs) which transmit real-time and historical data to engineering workstations for processing and display. The benefits from such an architecture include a more flexible software development environment and a more modular system which will promote future upgrades. The proposed upgrade architecture is explored, and the engineering and project management challenges of that effort are described, emphasizing the local area networks task.

Kearney, Michael W., III↗
NASA NTRS1988

Space lab system analysis

An analysis of the Automated Booster Assembly Checkout System (ABACS) has been conducted. A computer simulation of the ETHERNET LAN has been written. The simulation allows one to investigate different structures of the ABACS system. The simulation code is in PASCAL and is VAX compatible.

Rives, T. B.↗
NASA NTRS1988

Performance evaluation of NASA/KSC CAD/CAE graphics local area network

This study had as an objective the performance evaluation of the existing CAD/CAE graphics network at NASA/KSC. This evaluation will also aid in projecting planned expansions, such as the Space Station project on the existing CAD/CAE network. The objectives were achieved by collecting packet traffic on the various integrated sub-networks. This included items, such as total number of packets on the various subnetworks, source/destination of packets, percent utilization of network capacity, peak traffic rates, and packet size distribution. The NASA/KSC LAN was stressed to determine the useable bandwidth of the Ethernet network and an average design station workload was used to project the increased traffic on the existing network and the planned T1 link. This performance evaluation of the network will aid the NASA/KSC network managers in planning for the integration of future workload requirements into the existing network.

Zobrist, George↗
NASA NTRS1988

Data Transport Subsystem - The SFOC glue

The design and operation of the Data Transport Subsystem (DTS) for the JPL Space Flight Operation Center (SFOC) are described. The SFOC is the ground data system under development to serve interplanetary space probes; in addition to the DTS, it comprises a ground interface facility, a telemetry-input subsystem, data monitor and display facilities, and a digital TV system. DTS links the other subsystems via an ISO OSI presentation layer and an LAN. Here, particular attention is given to the DTS services and service modes (virtual circuit, datagram, and broadcast), the DTS software architecture, the logical-name server, the role of the integrated AI library, and SFOC as a distributed system.

Parr, Stephen J.↗
NASA NTRS1990

Local-Area-Network Simulator

Local Area Network Extensible Simulator (LANES) computer program provides method for simulating performance of high-speed local-area-network (LAN) technology. Developed as design and analysis software tool for networking computers on board proposed Space Station. Load, network, link, and physical layers of layered network architecture all modeled. Mathematically models according to different lower-layer protocols: Fiber Distributed Data Interface (FDDI) and Star*Bus. Written in FORTRAN 77.

Gibson, Jim↗
NASA NTRS1990

The ISIS project: Fault-tolerance in large distributed systems

The semi-annual status report covers activities of the ISIS project during the second half of 1989. The project had several independent objectives: (1) At the level of the ISIS Toolkit, ISIS release V2.0 was completed, containing bypass communication protocols. Performance of the system is greatly enhanced by this change, but the initial software release is limited in some respects. (2) The Meta project focused on the definition of the Lomita programming language for specifying rules that monitor sensors for conditions of interest and triggering appropriate reactions. This design was completed, and implementation of Lomita is underway on the Meta 2.0 platform. (3) The Deceit file system effort completed a prototype. It is planned to make Deceit available for use in two hospital information systems. (4) A long-haul communication subsystem project was completed and can be used as part of ISIS. This effort resulted in tools for linking ISIS systems on different LANs together over long-haul communications lines. (5) Magic Lantern, a graphical tool for building application monitoring and control interfaces, is included as part of the general ISIS releases.

Birman, Kenneth P.↗
NASA NTRS1990

Intelligent manipulation technique for multi-branch robotic systems

New analytical development in kinematics planning is reported. The INtelligent KInematics Planner (INKIP) consists of the kinematics spline theory and the adaptive logic annealing process. Also, a novel framework of robot learning mechanism is introduced. The FUzzy LOgic Self Organized Neural Networks (FULOSONN) integrates fuzzy logic in commands, control, searching, and reasoning, the embedded expert system for nominal robotics knowledge implementation, and the self organized neural networks for the dynamic knowledge evolutionary process. Progress on the mechanical construction of SRA Advanced Robotic System (SRAARS) and the real time robot vision system is also reported. A decision was made to incorporate the Local Area Network (LAN) technology in the overall communication system.

Chen, Alexander Y. K.↗
NASA NTRS1989

Computer network environment planning and analysis

The GSFC Computer Network Environment provides a broadband RF cable between campus buildings and ethernet spines in buildings for the interlinking of Local Area Networks (LANs). This system provides terminal and computer linkage among host and user systems thereby providing E-mail services, file exchange capability, and certain distributed computing opportunities. The Environment is designed to be transparent and supports multiple protocols. Networking at Goddard has a short history and has been under coordinated control of a Network Steering Committee for slightly more than two years; network growth has been rapid with more than 1500 nodes currently addressed and greater expansion expected. A new RF cable system with a different topology is being installed during summer 1989; consideration of a fiber optics system for the future will begin soon. Summmer study was directed toward Network Steering Committee operation and planning plus consideration of Center Network Environment analysis and modeling. Biweekly Steering Committee meetings were attended to learn the background of the network and the concerns of those managing it. Suggestions for historical data gathering have been made to support future planning and modeling. Data Systems Dynamic Simulator, a simulation package developed at NASA and maintained at GSFC was studied as a possible modeling tool for the network environment. A modeling concept based on a hierarchical model was hypothesized for further development. Such a model would allow input of newly updated parameters and would provide an estimation of the behavior of the network.

Dalphin, John F.↗
NASA NTRS1991

Space shuttle Mission Control Center upgrade

The Mission Control Center (MCC) is the facility that provides centralization of all mission operations in support of the shuttle from liftoff through landing. This facility serves as the focal point for real time flight control operations supporting the shuttle, spacelab, and selected payload systems. MCC upgrade accomplishments are as follows: replaced 5 mainframe computers and the associated input/output data interfaces; developed and installed a distributed data system with 81 workstations, 5 LANs, data drivers, and a fiber optic distribution subsystem; developed over 1.5 million lines of code to support new distributed system; developed new digital voice system which provides the MCC capacity to handle th Shuttle programs demands and growth potential to handle Space Station; replaced failing digital TV equipment with digital generation equipment; replaced obsolete center screen projector; and provided the platform for the multiprogram control center.

Duffin, Pat↗
NASA NTRS1991

Networking standards

The enterprise network is currently a multivendor environment consisting of many defacto and proprietary standards. During the 1990s, these networks will evolve towards networks which are based on international standards in both Local Area Network (LAN) and Wide Area Network (WAN) space. Also, you can expect to see the higher level functions and applications begin the same transition. Additional information is given in viewgraph form.

Davies, Mark↗
NASA NTRS1991

Cooperative processing data bases

Cooperative processing for the 1990's using client-server technology is addressed. The main theme is concepts of downsizing from mainframes and minicomputers to workstations on a local area network (LAN). This document is presented in view graph form.

Hasta, Juzar↗
NASA NTRS1992

Functional requirements document for NASA/MSFC Earth Science and Applications Division: Data and information system (ESAD-DIS). Interoperability, 1992

These Earth Science and Applications Division-Data and Information System (ESAD-DIS) interoperability requirements are designed to quantify the Earth Science and Application Division's hardware and software requirements in terms of communications between personal and visualization workstation, and mainframe computers. The electronic mail requirements and local area network (LAN) requirements are addressed. These interoperability requirements are top-level requirements framed around defining the existing ESAD-DIS interoperability and projecting known near-term requirements for both operational support and for management planning. Detailed requirements will be submitted on a case-by-case basis. This document is also intended as an overview of ESAD-DIs interoperability for new-comers and management not familiar with these activities. It is intended as background documentation to support requests for resources and support requirements.

Stephens, J. Briscoe↗
NASA NTRS1992

Semiannual status report

The work performed in the previous six months can be divided into three main cases: (1) transmission of images over local area networks (LAN's); (2) coding of color mapped (pseudo-color) images; and (3) low rate video coding. A brief overview of the work done in the first two areas is presented. The third item is reported in somewhat more detail.

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