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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 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Projection-operator methods for classical transport in magnetized plasmas. Part 2. Nonlinear response and the Burnett equations [Projection-operator methods for classical transport in magnetized plasmas. Part 1. Nonlinear response and the Burnett equations]

The time-independent projection-operator formalism for the derivation of Burnett equations is extended and considered in the context of multispecies and magnetized plasmas. The procedure provides specific formulas for transport coefficients in terms of two-time correlation functions involving both two and three phase-space points. It is shown how to calculate those correlation functions in the limit of weak coupling. The results are used to demonstrate, with the aid of a particular non-trivial example, that the Chapman–Enskog methodology employed by Catto & Simakov (CS) (Phys. Plasmas, vol. 11, 2004, pp. 90–102) to calculate the contributions to the parallel viscosity driven by temperature gradients is consistent with formulas previously derived from the two-time formalism by Brey (J. Chem. Phys., vol. 79, 1983, pp. 4585–4598). Here, the work serves to unify previous work on plasma kinetic theory with formalism usually applied to turbulence. Additional contributions include discussions of (i) Braginskii-order interspecies momentum exchange from the point of view of two-time correlations; and (ii) a simple stochastic model, unrelated to many-body theory, that exhibits Burnett effects. Insights from that model emphasize the role of non-Gaussian statistics in the evaluation of Burnett transport coefficients, including the effects calculated by CS that stem from the nonlinear collision operator. Together, Parts 1 and 2 of this series provide an introduction to projection-operator methods that should be broadly useful in theoretical plasma physics.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2017

Boundary dual of bulk local operators

We provide a procedure to determine if a given nonlocal operator in a large N holographic CFT is dual to a local bulk operator on the geometry associated with a particular code subspace of the CFT. This procedure does not presuppose knowledge of the bulk geometry. We are able to pick out local operators in a large region of the bulk, called the "localizable region,"' that can extend beyond event horizons in certain cases. The method relies heavily on the quantum-error correcting structure of AdS/CFT and, in particular, on entanglement wedge reconstruction. As a byproduct of this machinery, we are able to reconstruct the metric in the localizable region up to a conformal factor. This suggests a connection between our program and the recent light-cone cut approach to bulk reconstruction.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Porting the Kitten Lightweight Kernel Operating System to RISC-V

Hardware design in high-performance computing (HPC) is often highly experimental. Exploring new designs is difficult and time-consuming, requiring lengthy vendor cooperation. RISC-V is an open-source processor ISA that improves the accessibility of chip design, including the ability to do hardware/software co-design using open-source hardware and tools. Co-design allows design decisions to easily flow across the hardware/software boundary and influence future design ideas. However, new hardware designs require corresponding software to drive and test them. Conventional operating systems like Linux are massively complex and modification is time-prohibitive. In this paper, we describe our port of the Kitten lightweight kernel operating system to RISC-V in order to provide an alternative to Linux for conducting co-design research. Kitten's small code base and simple resource management policies are well matched for quickly exploring new hardware ideas that may require radical operating system modifications and restructuring. Our evaluation shows that Kitten on RISC-V is functional and provides similar performance to Linux for single-core benchmarks. This provides a solid foundation for using Kitten in future co-design research involving RISC-V.

Gordon, Nick↗
NASA NTRS1971

Apollo Operations Handbook Lunar Module (LM 11 and Subsequent) Vol. 2 Operational Procedures

The Apollo Operations Handbook (AOH) is the primary means of documenting LM descriptions and procedures. The AOH is published in two separately bound volumes. This information is useful in support of program management, engineering, test, flight simulation, and real time flight support efforts. This volume contains crew operational procedures: normal, backup, abort, malfunction, and emergency. These procedures define the sequence of actions necessary for safe and efficient subsystem operation.

Source record↗
NASA NTRS1972

Program operational summary: Operational 90 day manned test of a regenerative life support system

An operational 90-day manned test of a regenerative life support system was successfully completed. This test was performed with a crew of four carefully selected and trained men in a space station simulator (SSS) which had a two gas atmosphere maintained at a total pressure of 68.9, 10 psia, and composed of oxygen at a partial pressure of 3.05 psia with nitrogen as the diluent. The test was planned to provide data on regenerative life support subsystems and on integrated system operations in a closed ecology, similar to that of a space station. All crew equipment and expendables were stored onboard at the start of the mission to eliminate the need for pass-in operations. The significant accomplishments of the test, some of the pertinent test results, some of the problem areas, and conclusions are presented.

Jackson, J. K.↗
NASA NTRS1972

Guidance system operations plan for manned CM earth orbital missions using program SKYLARK 1. Section 4: Operational modes

The operational modes for the guidance system operations plan for Program SKYLARK 1 are presented. The procedures control the guidance and navigation system interfaces with the flight crew and the mission control center. The guidance operational concept is designed to comprise a set of manually initiated programs and functions which may be arranged by the flight crew to implement a large class of flight plans. This concept will permit both a late flight plan definition and a capability for real time flight plan changes.

Dunbar, J. C.↗
NASA NTRS1973

Mariner Mars 1971 project. Volume 3: Mission operations system implementation and standard mission flight operations

The Mariner Mars 1971 mission which was another step in the continuing program of planetary exploration in search of evidence of exobiological activity, information on the origin and evolution of the solar system, and basic science data related to the study of planetary physics, geology, planetology, and cosmology is reported. The mission plan was designed for two spacecraft, each performing a separate but complementary mission. However, a single mission plan was actually used for Mariner 9 because of failure of the launch vehicle for the first spacecraft. The implementation is described, of the Mission Operations System, including organization, training, and data processing development and operations, and Mariner 9 spacecraft cruise and orbital operations through completion of the standard mission from launch to solar occultation in April 1972 are discussed.

Source record↗
NASA NTRS1974

Towards an operational ERTS - requirements for implementing cartographic applications of an operational ERTS type satellite

After nearly 18 months of successful operation of the first Earth Resources Technology Satellite (ERTS-1), a careful look at the future in order. Judging from the results of ERTS-1 experiments, public sales of ERTS-1 products and overall worldwide response it is believed that ERTS-1 has demonstrated an earth sensing mode that should become operational. It is recognized that several studies leading to the definition of an operational ERTS have been made. However cartographic requirements are generally more basic and demanding than those of the earth science disciplines and are therefore treated separately in this report. One assumption made is that the configuration of ERTS, particularly with respect to the multispectral scanner and data transmission rates cannot be materially altered.

Colvocoresses, A. P.↗
NASA NTRS1978

Study to determine operational and performance criteria for STOL aircraft operating in low visibility conditions

The operational and performance criteria for civil CTOL passenger-carrying airplanes landing in low visibilities depend upon the characteristics of the airplane, the nature and use of the ground and airborne guidance and control systems, and the geometry and lighting of the landing field. Based upon these criteria, FAA advisory circulars, airplane and equipment design characteristics, and airline operational and maintenance procedures were formulated. The documents are selected, described, and discussed in relationship to the potential low weather minima operation of STOL aircraft. An attempt is made to identify fundamental differences between CTOL and STOL aircraft characteristics which could impact upon existing CTOL documentation. Further study and/or flight experiments are recommended.

Gorham, J. A.↗
NASA NTRS1982

Operations of the reconfigured Ground Communications Facility Central Communications Terminal and the Network Operations Control Center

The ground communications facility (GCF) central communications terminal and network operations control center (NOCC) hardware was rearranged, supplemented, and modified, and software programs changed to provide an improved GCF and NOCC operational environment and capability. Control center operations section activities required to make the changeover from the old to the new GCF and NOCC configuration are addressed.

Santana, J. C.↗
NASA NTRS1984

Shuttle operations era planning for flight operations

The Space Transportation System (STS) provides routine access to space for a wide range of customers in which cargos vary from single payloads on dedicated flights to multiple payloads that share Shuttle resources. This paper describes the flight operations planning process from payload introduction through flight assignment to execution of the payload objectives and the changes that have been introduced to improve that process. Particular attention is given to the factors that influence the amount of preflight preparation necessary to satisfy customer requirements. The partnership between the STS operations team and the customer is described in terms of their functions and responsibilities in the development of a flight plan. A description of the Mission Control Center (MCC) and payload support capabilities completes the overview of Shuttle flight operations.

Holt, J. D.↗
NASA NTRS1987

Space station operations task force. Panel 2 report: Ground operations and support systems

The Ground Operations Concept embodied in this report provides for safe multi-user utilization of the Space Station, eases user integration, and gives users autonomy and flexibility. It provides for meaningful multi-national participation while protecting U.S. interests. The concept also supports continued space operations technology development by maintaining NASA expertise and enabling technology evolution. Given attention here are pre/post flight operations, logistics, sustaining engineering/configuration management, transportation services/rescue, and information systems and communication.

Source record↗
NASA NTRS1990

The JPL telerobot operator control station: Operational experiences

The Operator Control Station of the JPL/NASA Telerobot Demonstration System provides an efficient man-machine interface for the performance of telerobot tasks. Its hardware and software have been designed with high flexibility. It provides a feedback-rich interactive environment in which the Operator performs teleoperation tasks, robotic tasks, and telerobotic tasks with ease. The to-date operational experiences of this system, particularly related to the Object Designate Process and the Voice Input/Output Process are discussed.

Kan, Edwin P.↗
NASA NTRS1991

Magellan spacecraft team remote mission operations - Experience and application to future operations systems

The Magellan Venus radar mapping mission was NASA's first planetary launch in 11 years, heralding a successful return to unmanned planetary exploration. This paper first describes the spacecraft, its mission, and its Mission Operations System, including the remotely located spacecraft team. It then discusses how the flight team achieved mission success, in spite of the obstacles imposed by challenges from the spacecraft and its environment, which had to be resolved with the spacecraft team nearly 1000 miles distant from the rest of the flight team. Benefits of remotely distributed spacecraft operations are summarized and suggestions offered, based on Magellan experience, for future mission operations systems considering the use of distributed elements.

Ledbetter, Kenneth W.↗
NASA NTRS1951

Preliminary Investigation of Molybdenum Disulfide-air-mist Lubrication for Roller Bearings Operating to DN Values of 1 x 10(exp 6) and Ball Bearings Operating to Temperatures of 1000 F

The effectiveness of molybdenum disulfide MoS2 as a bearing lubricant was determined at high temperature and at high speeds. A 1-inch-bore ball bearing operated at temperatures to 1000 F, a speed of 1725 rpm, and a thrust load of 20 pounds when lubricated only with MoS2-air mist. A 75-millimeter-bore cageless roller bearing, provided with a MoS2-syrup coating before operation, operated at DN values to 1 x 10(exp 6) with a load of 368 pounds.

BEARINGS, ANTI - FRICTION↗