44 research outputs found

    Annual report on nuclear physics activities. July 1, 1982 - June 30, 1983

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    Der vorliegende Bericht gibt einen Überblick über die Arbeiten an den drei Kernphysikalischen Instituten des Kernforschungszentrums Karlsruhe im Zeitraum vom 1. Juli 1982 bis zum 30. Juni 1983. Das Forschungsprogramm umfaßt die Gebiete Laserspektroskopie, Kernreaktionen mit leichten Ionen, Neutronenphysik, Neutrino-Physik, sowie Mittel- und Hochenergiephysik

    The Second Conference on Lunar Bases and Space Activities of the 21st Century, volume 1

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    These papers comprise a peer-review selection of presentations by authors from NASA, LPI industry, and academia at the Second Conference (April 1988) on Lunar Bases and Space Activities of the 21st Century, sponsored by the NASA Office of Exploration and the Lunar Planetary Institute. These papers go into more technical depth than did those published from the first NASA-sponsored symposium on the topic, held in 1984. Session topics covered by this volume include (1) design and operation of transportation systems to, in orbit around, and on the Moon, (2) lunar base site selection, (3) design, architecture, construction, and operation of lunar bases and human habitats, and (4) lunar-based scientific research and experimentation in astronomy, exobiology, and lunar geology

    Space communications responsive to events across missions (SCREAM): an investigation of network solutions for transient science space systems

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    2022 Spring.Includes bibliographical references.The National Academies have prioritized the pursuit of new scientific discoveries using diverse and temporally coordinated measurements from multiple ground and space-based observatories. Networked communications can enable such measurements by connecting individual observatories and allowing them to operate as a cohesive and purposefully designed system. Timely data flows across terrestrial and space communications networks are required to observe transient scientific events and processes. Currently, communications to space-based observatories experience large latencies due to manual service reservation and scheduling procedures, intermittent signal coverage, and network capacity constraints. If space communications network latencies could be reduced, new discoveries about dynamic scientific processes could be realized. However, science mission and network planners lack a systematic framework for defining, quantifying and evaluating timely space data flow implementation options for transient scientific observation scenarios involving multiple ground and space-based observatories. This dissertation presents a model-based systems engineering approach to investigate and develop network solutions to meet the needs of transient science space systems. First, a systematic investigation of the current transient science operations of the National Aeronautics and Space Administration's (NASA) Tracking and Data Relay Satellite (TDRS) space data network and the Neil Gehrels Swift Observatory resulted in a formal architectural model for transient science space systems. Two methods individual missions may use to achieve timely network services were defined, quantitatively modeled, and experimentally compared. Next, the architectural model was extended to describe two alternative ways to achieve timely and autonomous space data flows to multiple space-based observatories within the context of a purposefully designed transient science observation scenario. A quantitative multipoint space data flow modeling method based in queueing theory was defined. General system suitability metrics for timeliness, throughput, and capacity were specified to support the evaluation of alternative network data flow implementations. A hypothetical design study was performed to demonstrate the multipoint data flow modeling method and to evaluate alternative data flow implementations using TDRS. The merits of a proposed future TDRS broadcast service to implement multipoint data flows were quantified and compared to expected outcomes using the as-built TDRS network. Then, the architectural model was extended to incorporate commercial network service providers. Quantitative models for Globalstar and Iridium short messaging data services were developed based on publicly available sources. Financial cost was added to the set of system suitability metrics. The hypothetical design study was extended to compare the relative suitability of the as-built TDRS network with the commercial Globalstar and Iridium networks. Finally, results from this research are being applied by NASA missions and network planners. In 2020, Swift implemented the first automated command pipeline, increasing its expected gravitational wave follow-up detection rate by greater than 400%. Current NASA technology initiatives informed by this research will enable future space-based observatories to become interoperable sensing devices connected by a diverse ecosystem of network service providers

    1999 LDRD Laboratory Directed Research and Development

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    Design concepts for the Cherenkov Telescope Array CTA: An advanced facility for ground-based high-energy gamma-ray astronomy

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    Ground-based gamma-ray astronomy has had a major breakthrough with the impressive results obtained using systems of imaging atmospheric Cherenkov telescopes. Ground-based gamma-ray astronomy has a huge potential in astrophysics, particle physics and cosmology. CTA is an international initiative to build the next generation instrument, with a factor of 5-10 improvement in sensitivity in the 100 GeV-10 TeV range and the extension to energies well below 100 GeV and above 100 TeV. CTA will consist of two arrays (one in the north, one in the south) for full sky coverage and will be operated as open observatory. The design of CTA is based on currently available technology. This document reports on the status and presents the major design concepts of CTA.La lista completa de autores que integran el documento puede consultarse en el archivo.Departamento de AeronáuticaFacultad de IngenieríaInstituto Argentino de RadioastronomíaFacultad de Ciencias Astronómicas y Geofísica

    Earth orbital experiment program and requirements study, volume 1, sections 1 - 6

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    A reference manual for planners of manned earth-orbital research activity is presented. The manual serves as a systems approach to experiment and mission planning based on an integrated consideration of candidate research programs and the appropriate vehicle, mission, and technology development requirements. Long range goals and objectives for NASA activities during the 1970 to 1980 time period are analyzed. The useful and proper roles of manned and automated spacecraft for implementing NASA experiments are described. An integrated consideration of NASA long range goals and objectives, the system and mission requirements, and the alternative implementation plans are developed. Specific areas of investigation are: (1) manned space flight requirements, (2) space biology, (3) spaceborne astronomy, (4) space communications and navigation, (5) earth observation, (6) supporting technology development requirements, (7) data management system matrices, (8) instrumentation matrices, and (9) biotechnology laboratory experiments

    Model-based specification and design of large-scale embedded signal processing systems

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    In the digital part of large-scale phase array radio telescopes, the dominant streaming signal processing part is configured at run-time through a reactive and decentralized control and monitoring part. Interfacing and synchronizing these two parts without altering the behavior and performance of the dominant signal processing part is an issue when they are first considered in isolation. To address this issue before going to implementation, we propose to raise the level of abstraction, by expressing system-level specifications (in terms of application, architecture, and mapping) based on models. In the application model, the model of the control part and the model of the signal processing part are synchronized based on a notion of time that is known only to the control part. In the architecture model, the control model has a tree-like structure, whose leave nodes are interfaced with the computational nodes in the signal processing part. The mapping is based on iterative and interactive transformations that lead to an implementation-level specification, from where we consider that different implementation tools can take over to implement different parts of the system.UBL - phd migration 201

    Laboratory Directed Research and Development FY 1998 Progress Report

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