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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 1,117 records · Page 62
All sourcesNASA NTRSDOE OSTI
NASA NTRS1980

Implementation of NASTRAN on the IBM/370 CMS operating system

The NASA Structural Analysis (NASTRAN) computer program is operational on the IBM 360/370 series computers. While execution of NASTRAN has been described and implemented under the virtual storage operating systems of the IBM 370 models, the IBM 370/168 computer can also operate in a time-sharing mode under the virtual machine operating system using the Conversational Monitor System (CMS) subset. The changes required to make NASTRAN operational under the CMS operating system are described.

Britten, S. S.↗
NASA NTRS1979

Spacelab flight operations

The paper covers the primary activities involved in Spacelab flight operations. These operations are characterized by a partnership between the operators of the Space Transportation System (STS) and the mission management organization which involves the activities of flight control personnel and the flight crew, and must exist as an integrated team to complete a Spacelab flight. An overview of this partnership is presented from the initial planning phase through the actual flight operation, noting the responsibilities and functions of the flight crew members and the makeup of the flight control team. A typical flight scenario describing the basic operation of the Spacelab and a description of the Mission Control Center and Payload Operations Control Center are given.

Harlan, C. S.↗
NASA NTRS1981

Performance of computer-designed small-sized four-stage depressed collector for operation of dual-mode traveling wave tube

A computer-designed axisymmetric 2.4-cm-diameter four-stage depressed collectors was evaluated in conjunction with an octave bandwidth, dual-mode traveling wave tube (TWT). The TWT was operated over a wide range of conditions to simulate different applications. The collector performance was optimized (within the constraint of fixed collector geometry which was designed for operation of the TWT at saturation) over the range of TWT operating conditons covered. For operation of the dual-mode TWT at saturation, average collector efficiencies of 81 1/2 and 82 percent for the high and low modes, respectively, were obtained across an octave bandwidth, leading to a three-fold increase in the TWT overall efficiency. For operation of the TWT in the linear, low distortion range, collector efficiencies of 87 to 92 percent were obtained, leading to TWT overall efficiencies as high as 35 percent. For operation of the dual-mode TWT over a 10 to 1 range in output power, overall efficiencies of 14 to 41 percent were obtained.

Ramins, P.↗
NASA NTRS1982

The elements of a space operations system

The Space Shuttle has completed its flight test program and is entering operational service with its fifth flight in November 1982. With the completion of Shuttle development, its entry to operational service, and delivery of additional units into field service, it is timely to initiate development of the next elements of the system. The elements of a Space Operations System are the Shuttle, a Station in low earth orbit, and upper stages for low and high energy orbit delivery. To design these elements properly will require a substantial operations analysis effort to characterize the most effective performance tradeoffs among the discrete elements. The Shuttle establishes a new context for the design and execution of operations in space. The components of the Shuttle, Space Station, and upper stages will need to share technology and components to minimize the cost and complexity of the logistics of ownership and operation.

Loftus, J. P., Jr.↗
NASA NTRS1983

The IRAS project organisation and mission operations

The project organisation of IRAS is described, showing the tasks assigned to each project group during post-launch operations. The satellite is described, emphasizing the detectors. In the task division, the role of the U.S. is to construct the telescope and survey instrument, launch the satellite, process final science data for the survey instrument, and provide certain standard satellite items. The Netherlands construct the spacecraft and three additional instruments, integrates and tests the overall satellite, and designs and participates in the development of the operational system. The U.K. provides the operational control center and primary tracking station, generates a system for preliminary science analysis of the survey data, provides housekeeping analysis software and science data distribution software, and staffs the control center operations. The teams involved in mission planning and operations, and their roles, are identified, and a block diagram of the operations organisation is presented.

Van Holtz, R. C.↗
NASA NTRS1983

Designing for a new era of launch vehicle operational efficiency

It is pointed out that early recognition of operational requirements and assessment of their effects provides the best chance of designing an economically viable future space transportation system (FSTS). Operational factors which may influence configuration design include fleet size, operation mode, refurbishment, and the resource requirements. FTST has a simplified operational role compared to the Space Shuttle, which, in addition to transportation, must perform experiments, support payloads, and stay long on orbit. In the future a space station will perform many of these tasks. The FSTS comprises a two-stage fully reusable launch vehicle designed to carry 150,000 lb to a space station, off-load, and return. It would always be launched fully loaded, and its cargo would be processed and redistributed at the space station. Attention is given to ground servicing, flight operations, rendezvous-compatible orbits, launch windows, standard trajectories, entry windows, operational costs, the mission model, and resource requirements.

Talay, T. A.↗
NASA NTRS1984

Proximity operations for space stations and platforms

The present study is concerned with concepts, techniques, and system requirements which would permit 'automated' proximity operations utilizing an unmanned vehicle such as the proposed Orbital Maneuvering Vehicle (OMV). Attention is given to proximity operations mission phases, tethered operations, operational control zones, operation control zone objectives, operational control zone definition, aspects of monitoring and tracking, the departure zone, the rendezvous zone, and coorbiting satellite zones.

Lineberry, E. C., Jr.↗
NASA NTRS1985

Mod-2 wind turbine field operations experiment

The three-machine, 7.5 MW Goodnoe Hills located near Goldendale, Washington and is now in a research/experimental operations phase that offers a unique opportunity to study the effects of single and multiple wind turbines interacting with each other, the power grid; and the environment. Following a brief description of the turbine and project history, this paper addresses major problem areas and research and development test results. Field operations, both routine and nonroutine, are discussed. Routine operation to date has produced over 13,379,000 KWh of electrical energy during 11,064 hr of rotation. Nonroutine operation includes suspended activities caused by a crack in the low speed shaft that necessitated a redesign and reinstallation of this assembly on all three turbines. With the world's largest cluster back in full operation, two of the turbines will be operated over the next years to determine their value as energy producer. The third unit will be used primarily for conducting research tests requiring configuration changes to better understand the wind turbine technology. Technical areas summarized pertain to system performance and enhancements. Specific research tests relating to acoustics, TV interference, and wake effects conclude the paper.

Gordon, L. H.↗
NASA NTRS1985

Space Station operations

An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

Gray, R. H.↗
NASA NTRS1986

Real-time simulator for helicopter rotor wind-tunnel operations

This paper describes the elements and operation of a simulator that is being used to train operators of the Rotor Test Apparatus (RTA) in the large-scale 40- by 80-Foot Wind Tunnel at Ames Research Center. The simulator, named TUTOR (for Tunnel Utilization Trainer with Operating Rotor) duplicates the controls of the rotor and its dynamic behavior, as well as the wind-tunnel controls. The simulation software uses a preexisting blade-element model of a four-bladed rotor with flapping and lead-lag degrees of freedom. Equations were developed for all hardware and controls of the RTA and of the wind tunnel that are normally required to perform a wind-tunnel test of a helicopter rotor. The simulator hardware consists of consoles designed to have the same appearance and functions as those in the control room of the 40- by 80-Foot Wind Tunnel, allowing input from three operators who normally establish the required operating conditions during a test run. Normal operating procedures can be practiced, as well as simulated emergencies such as rotor power failure.

Talbot, P. D.↗
NASA NTRS1986

Operations and support for the next-generation space transportation system

The role of operations and support in the design of future space transportation systems (STSs) is studied. There is a need to reduce launch and operation costs for future space systems. Methods for reducing the cost of ground operations and supports for a STS are described. Technological advances such as expert systems, robotics, and sensors, and reduction in management of operations are discussed. Changes in the management of flight operations and control, from a manpower intensive monitoring to a strong vehicle autonomy, are examined. The development of equipment and procedures to improve space operations and reduce costs is analyzed. The use of a clean sheet approach for building a STS is proposed.

Sawaya, G. J.↗
NASA NTRS1987

Measuring Computer-Operator Workload

Subjective and objective measurements found to correlate and complement each other. Two ways of measuring workload of operator in large interactive computer system have shown meaningful and easy to use. One method based on operators' ratings of stress after subtasks in continuous task. Other method based on workload ratio, W, ratio of time required for operator to do subtask to time allowed for it. Both sensitive to workload level and individual subtasks in continuing interactive computer task. Pinpoints subtasks that press operator and use up too much available time, perhaps leading to operator errors and even failure of system. Gives clear indication when operator approaches allowed time and shows when risk of trouble becomes high.

Hird, E. E.↗
NASA NTRS1987

Operator function modeling: An approach to cognitive task analysis in supervisory control systems

In a study of models of operators in complex, automated space systems, an operator function model (OFM) methodology was extended to represent cognitive as well as manual operator activities. Development continued on a software tool called OFMdraw, which facilitates construction of an OFM by permitting construction of a heterarchic network of nodes and arcs. Emphasis was placed on development of OFMspert, an expert system designed both to model human operation and to assist real human operators. The system uses a blackboard method of problem solving to make an on-line representation of operator intentions, called ACTIN (actions interpreter).

Mitchell, Christine M.↗
NASA NTRS1987

EOS: A project to investigate the design and construction of real-time distributed Embedded Operating Systems

Project EOS is studying the problems of building adaptable real-time embedded operating systems for the scientific missions of NASA. Choices (A Class Hierarchical Open Interface for Custom Embedded Systems) is an operating system designed and built by Project EOS to address the following specific issues: the software architecture for adaptable embedded parallel operating systems, the achievement of high-performance and real-time operation, the simplification of interprocess communications, the isolation of operating system mechanisms from one another, and the separation of mechanisms from policy decisions. Choices is written in C++ and runs on a ten processor Encore Multimax. The system is intended for use in constructing specialized computer applications and research on advanced operating system features including fault tolerance and parallelism.

Campbell, R. H.↗
NASA NTRS1987

Space Station Program implications from the viewpoint of the Space Station Operations Task Force

An operational concept for the Space Station which has been developed by the Space Station Operations Task Force is described. The operations functions are described, and the relationships of these functions to the overall framework for operations are defined. Product flows for the recommended framework are discussed, and the roles and responsibilities for the proposed operations organization during both the development and the mature operations phases of the Space Station Program are examined.

Paules, Granville E.↗
NASA NTRS1988

MODIS information, data and control system (MIDACS) operations concepts

The MODIS Information, Data, and Control System (MIDACS) Operations Concepts Document provides a basis for the mutual understanding between the users and the designers of the MIDACS, including the requirements, operating environment, external interfaces, and development plan. In defining the concepts and scope of the system, how the MIDACS will operate as an element of the Earth Observing System (EOS) within the EosDIS environment is described. This version follows an earlier release of a preliminary draft version. The individual operations concepts for planning and scheduling, control and monitoring, data acquisition and processing, calibration and validation, data archive and distribution, and user access do not yet fully represent the requirements of the data system needed to achieve the scientific objectives of the MODIS instruments and science teams. The teams are not yet formed; however, it is possible to develop the operations concepts based on the present concept of EosDIS, the level 1 and level 2 Functional Requirements Documents, and through interviews and meetings with key members of the scientific community. The operations concepts were exercised through the application of representative scenarios.

Han, D.↗
NASA NTRS1989

Computer algebra and operators

The symbolic computation of operator expansions is discussed. Some of the capabilities that prove useful when performing computer algebra computations involving operators are considered. These capabilities may be broadly divided into three areas: the algebraic manipulation of expressions from the algebra generated by operators; the algebraic manipulation of the actions of the operators upon other mathematical objects; and the development of appropriate normal forms and simplification algorithms for operators and their actions. Brief descriptions are given of the computer algebra computations that arise when working with various operators and their actions.

Fateman, Richard↗
NASA NTRS1989

The evaluation of a metered mixer for RTV silicone for RSRM nozzle backfill operations

Metered mixing specifically for the RSRM backfill operation was investigated. Projected advantages were the elimination of waste RTV silicone produced in the operation and the elimination of entrapped air during the mix. Although metered mixing proved to be a viable method for mixing the Dow Corning DC 90-0006 rubber with its catalyst, applying the technology to the RSRM backfill operation has several disadvantages that are decisive. Use of a metered mixer would increase the amount of material that was being scraped for each backfill and increase the amount of time required to clean up the equipment after each operation. Therefore, use of metered static mixers is not recommended for use in the RSRM nozzle backfill operations. Because metered mixers proved to have significant disadvantages other methods of mixing and dispensing the RTV during the backfill operation are being investigated, and will be reported in a separate document.

Wardell, T. C.↗