234,190 research outputs found

    Distributed archive and single access system for accelerometric event data : a NERIES initiative

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    We developed a common access facility to homogeneously formatted accelerometric event data and to the corresponding sheet of ground motion parameters. This paper is focused on the description of the technical development of the accelerometric data server and the link with the accelerometric data explorer. The server is the third node of the 3-tier architecture of the distributed archive system for accelerometric data. The server is the link between the data users and the accelero- metric data portal. The server follows three main steps: (1) Reading and analysis of the end-user request; (2) Processing and converting data; and (3) Archiving and updating the accelerometric data explorer. This paper presents the description of the data server and the data explorer for accessing data

    Small Explorer Data System MIL-STD-1773 fiber optic bus

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    The MIL-STD-1773 Fiber Optic Data Bus as implemented in the GSFC Small Explorer Data System (SEDS) for the Small Explorer Program is described. It provides an overview of the SEDS MIL-STD-1773 bus components system design considerations, reliability figures, acceptance and qualification testing requirements, radiation requirements and tests, error handling considerations, and component heritage. The first mission using the bus will be launched in June of 1992

    A multimission three-axis stabilized spacecraft flight dynamics ground support system

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    The Multimission Three-Axis Stabilized Spacecraft (MTASS) Flight Dynamics Support System (FDSS) has been developed in an effort to minimize the costs of ground support systems. Unlike single-purpose ground support systems, which attempt to reduce costs by reusing software specifically developed for previous missions, the multimission support system is an intermediate step in the progression to a fully generalized mission support system in which numerous missions may be served by one general system. The benefits of multimission attitude ground support systems extend not only to the software design and coding process, but to the entire system environment, from specification through testing, simulation, operations, and maintenance. This paper reports the application of an MTASS FDSS to multiple scientific satellite missions. The satellites are the Upper Atmosphere Research Satellite (UARS), the Extreme Ultraviolet Explorer (EUVE), and the Solar Anomalous Magnetospheric Particle Explorer (SAMPEX). Both UARS and EUVE use the multimission modular spacecraft (MMS) concept. SAMPEX is part of the Small Explorer (SMEX) series and uses a much simpler set of attitude sensors. This paper centers on algorithm and design concepts for a multimission system and discusses flight experience from UARS

    The On-Orbit Performance of the Galaxy Evolution Explorer

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    We report the first year on-orbit performance results for the Galaxy Evolution Explorer (GALEX), a NASA Small Explorer that is performing a survey of the sky in two ultraviolet bands. The instrument comprises a 50 cm diameter modified Ritchey-Chretien telescope with a 1.25 degree field of view, selectable imaging and objective grism spectroscopic modes, and an innovative optical system with a thin-film multilayer dichroic beam splitter that enables simultaneous imaging by a pair of photon counting, microchannel plate, delay line readout detectors. Initial measurements demonstrate that GALEX is performing well, meeting its requirements for resolution, efficiency, astrometry, bandpass definition and survey sensitivity.Comment: This paper will be published as part of the Galaxy Evolution Explorer (GALEX) Astrophysical Journal Letters Special Issu

    Exploring the Edge of Our Solar System: IBEX Mission (Poster)

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    This poster outlines the major mission highlights of the Interstellar Boundary Explorer (IBEX) mission, a Small Explorer Earth-orbiting spacecraft that is designed to map the distant boundary between the solar wind from our Sun and the interstellar medium. This poster supports a full-length planetarium show about the IBEX mission and the boundary of the Solar System. Each short activity/product helps to build awareness and engagement in the science and engineering aspects of the mission that are reinforced as visitors choose to participate in more activities, including viewing the show and mission website.

    Using Spec Explorer for Automatic Checking of Constraints in Software €Controlled Systems.

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    In software engineering, several formal models and tools are proposed for defining system requirements and constraints formally. Such formal definitions can help in the automatic checking and verification for them. It can also help in the automatic test case generation, execution and verification. In this paper, we will demonstrate and evaluate the usage of Spec Explorer from Microsoft for defining and checking examples of software controlled system such as cruise control. Such formal requirements can be eventually embedded in the developed system or can help in exposing important elements to test in the testing stage or through the usage of the applicationModel-Based Testing, Spec Explorer, FSM Models, Software Controlled Systems

    Preliminary Results from NEOWISE: An Enhancement to the Wide-field Infrared Survey Explorer for Solar System Science

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    The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and ~120 comets. The NEOWISE data set will enable a panoply of new scientific investigations

    International Ultraviolet Explorer (IUE) Post Launch Report 2

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    The International Ultraviolet Explorer (IUE), an Explorer class ultraviolet astronomy mission, is an international cooperative program between the United States, the United Kingdom (UK), and the European Space Agency (ESA) which provides for a single launch into geosynchronous orbit to conduct spectral distribution studies of celestial and solar system ultraviolet sources. The spacecraft and scientific instruments were designed and fabricated at the Goddard Space Flight Center. The spectrograph camera was provided by the UK; ESA provided the solar array as well as the European ground station. The IUE observatory system was designed to functionally resemble a ground-based optical observatory at which guest observers could execute observing programs in real time. Observatory performance substantially exceeded design and mission objectives. The secondary mission objectives were also met

    System Concepts for the Scout Explorer

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    NASA\u27s Explorer program is being expanded to include a series of Scout-class science missions. These small spacecraft will be supported by a Standard System, including a spacecraft bus and a transportable ground station. The system concept is being developed in anticipation of an experiment solicitation in 1988. The spacecraft will be a Sun, vertical and star pointer, momentum stabilized, with S-band communications direct to ground stations. The transportable ground stations allow Principal Investigators to assume complete control of the spacecraft. The Standard System is optional to each mission and may be used in part, in total, or not at all

    Varying the texture: a study of art, learning and multimedia

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    Art Explorer is an innovative multimedia system being designed and developed within the Institute of Educational Technology, at The Open University. Based on an analogy to dreams, Art Explorer is structured into several episodes. Each episode is designed to help beginning students of Art History foster personal constructs about paintings and develop a richer understanding of how their perceptions of paintings work. This discussion focuses on the pedagogic rationale motivating Art Explorer's development and is structured around two strands of a design story. First, it highlights the research behind the design. The reported research is about learners' problems - most specifically about the varying conceptual, perceptual and affective challenges learners face as they begin to study Art History. But, more broadly, it is about the problems faced by learners as they begin academic study and seek to engage with the knowledge and methods of discipline experts. Secondly, and it is argued, as a second pedagogic priority, the spotlight shifts to multimedia. The discussion tracks design decisions that aim both to exploit the potential of the medium and to match pre-identified learner needs. The ingredients of Art Explorer are described to illustrate some of the rich potential of the medium for negotiating understanding between teacher and learner
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