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Sample records for australian square-kilometre-array pathfinder

  1. Science with the Australian Square Kilometre Array Pathfinder (ASKAP)

    NASA Astrophysics Data System (ADS)

    Johnston, S.; Feain, I. J.; Gupta, N.

    2009-09-01

    The future of cm and m-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries that will be 50 times more sensitive than any existing radio facility. Most of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from a few hundred MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is a technology demonstrator aimed in the mid-frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phased-array feed systems on parabolic reflectors. The large field-of-view makes ASKAP an unprecedented synoptic telescope that will make substantial advances in SKA key science. ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of two sites selected by the international community as a potential location for the SKA. In this paper, we outline the ASKAP project and summarise its headline science goals as defined by the community at large.

  2. Science with ASKAP. The Australian square-kilometre-array pathfinder

    NASA Astrophysics Data System (ADS)

    Johnston, S.; Taylor, R.; Bailes, M.; Bartel, N.; Baugh, C.; Bietenholz, M.; Blake, C.; Braun, R.; Brown, J.; Chatterjee, S.; Darling, J.; Deller, A.; Dodson, R.; Edwards, P.; Ekers, R.; Ellingsen, S.; Feain, I.; Gaensler, B.; Haverkorn, M.; Hobbs, G.; Hopkins, A.; Jackson, C.; James, C.; Joncas, G.; Kaspi, V.; Kilborn, V.; Koribalski, B.; Kothes, R.; Landecker, T.; Lenc, E.; Lovell, J.; Macquart, J.-P.; Manchester, R.; Matthews, D.; McClure-Griffiths, N.; Norris, R.; Pen, U.-L.; Phillips, C.; Power, C.; Protheroe, R.; Sadler, E.; Schmidt, B.; Stairs, I.; Staveley-Smith, L.; Stil, J.; Tingay, S.; Tzioumis, A.; Walker, M.; Wall, J.; Wolleben, M.

    2008-12-01

    The future of cm and m-wave astronomy lies with the Square Kilometre Array (SKA), a telescope under development by a consortium of 17 countries. The SKA will be 50 times more sensitive than any existing radio facility. A majority of the key science for the SKA will be addressed through large-area imaging of the Universe at frequencies from 300 MHz to a few GHz. The Australian SKA Pathfinder (ASKAP) is aimed squarely in this frequency range, and achieves instantaneous wide-area imaging through the development and deployment of phase-array feed systems on parabolic reflectors. This large field-of-view makes ASKAP an unprecedented synoptic telescope poised to achieve substantial advances in SKA key science. The central core of ASKAP will be located at the Murchison Radio Observatory in inland Western Australia, one of the most radio-quiet locations on the Earth and one of the sites selected by the international community as a potential location for the SKA. Following an introductory description of ASKAP, this document contains 7 chapters describing specific science programmes for ASKAP. In summary, the goals of these programmes are as follows: The detection of a million galaxies in atomic hydrogen emission across 75% of the sky out to a redshift of 0.2 to understand galaxy formation and gas evolution in the nearby Universe.

  3. Source-Finding for the Australian Square Kilometre Array Pathfinder

    NASA Astrophysics Data System (ADS)

    Whiting, M.; Humphreys, B.

    2012-08-01

    The Australian Square Kilometre Array Pathfinder (ASKAP) presents a number of challenges in the area of source finding and cataloguing. The data rates and image sizes are very large, and require automated processing in a high-performance computing environment. This requires development of new tools, that are able to operate in such an environment and can reliably handle large datasets. These tools must also be able to accommodate the different types of observations ASKAP will make: continuum imaging, spectral-line imaging, transient imaging. The ASKAP project has developed a source-finder known as selavy, built upon the duchamp source-finder. selavy incorporates a number of new features, which we describe here. Since distributed processing of large images and cubes will be essential, we describe the algorithms used to distribute the data, find an appropriate threshold and search to that threshold and form the final source catalogue. We describe the algorithm used to define a varying threshold that responds to the local, rather than global, noise conditions, and provide examples of its use. And we discuss the approach used to apply two-dimensional fits to detected sources, enabling more accurate parameterisation. These new features are compared for timing performance, where we show that their impact on the pipeline processing will be small, providing room for enhanced algorithms. We also discuss the development process for ASKAP source finding software. By the time of ASKAP operations, the ASKAP science community, through the Survey Science Projects, will have contributed important elements of the source finding pipeline, and the mechanisms in which this will be done are presented.

  4. The Australian Square Kilometre Array Pathfinder: Performance of the Boolardy Engineering Test Array

    NASA Astrophysics Data System (ADS)

    McConnell, D.; Allison, J. R.; Bannister, K.; Bell, M. E.; Bignall, H. E.; Chippendale, A. P.; Edwards, P. G.; Harvey-Smith, L.; Hegarty, S.; Heywood, I.; Hotan, A. W.; Indermuehle, B. T.; Lenc, E.; Marvil, J.; Popping, A.; Raja, W.; Reynolds, J. E.; Sault, R. J.; Serra, P.; Voronkov, M. A.; Whiting, M.; Amy, S. W.; Axtens, P.; Ball, L.; Bateman, T. J.; Bock, D. C.-J.; Bolton, R.; Brodrick, D.; Brothers, M.; Brown, A. J.; Bunton, J. D.; Cheng, W.; Cornwell, T.; DeBoer, D.; Feain, I.; Gough, R.; Gupta, N.; Guzman, J. C.; Hampson, G. A.; Hay, S.; Hayman, D. B.; Hoyle, S.; Humphreys, B.; Jacka, C.; Jackson, C. A.; Jackson, S.; Jeganathan, K.; Joseph, J.; Koribalski, B. S.; Leach, M.; Lensson, E. S.; MacLeod, A.; Mackay, S.; Marquarding, M.; McClure-Griffiths, N. M.; Mirtschin, P.; Mitchell, D.; Neuhold, S.; Ng, A.; Norris, R.; Pearce, S.; Qiao, R. Y.; Schinckel, A. E. T.; Shields, M.; Shimwell, T. W.; Storey, M.; Troup, E.; Turner, B.; Tuthill, J.; Tzioumis, A.; Wark, R. M.; Westmeier, T.; Wilson, C.; Wilson, T.

    2016-09-01

    We describe the performance of the Boolardy Engineering Test Array, the prototype for the Australian Square Kilometre Array Pathfinder telescope. Boolardy Engineering Test Array is the first aperture synthesis radio telescope to use phased array feed technology, giving it the ability to electronically form up to nine dual-polarisation beams. We report the methods developed for forming and measuring the beams, and the adaptations that have been made to the traditional calibration and imaging procedures in order to allow BETA to function as a multi-beam aperture synthesis telescope. We describe the commissioning of the instrument and present details of Boolardy Engineering Test Array's performance: sensitivity, beam characteristics, polarimetric properties, and image quality. We summarise the astronomical science that it has produced and draw lessons from operating Boolardy Engineering Test Array that will be relevant to the commissioning and operation of the final Australian Square Kilometre Array Path telescope.

  5. Discovery of H I gas in a young radio galaxy at z = 0.44 using the Australian Square Kilometre Array Pathfinder

    NASA Astrophysics Data System (ADS)

    Allison, J. R.; Sadler, E. M.; Moss, V. A.; Whiting, M. T.; Hunstead, R. W.; Pracy, M. B.; Curran, S. J.; Croom, S. M.; Glowacki, M.; Morganti, R.; Shabala, S. S.; Zwaan, M. A.; Allen, G.; Amy, S. W.; Axtens, P.; Ball, L.; Bannister, K. W.; Barker, S.; Bell, M. E.; Bock, D. C.-J.; Bolton, R.; Bowen, M.; Boyle, B.; Braun, R.; Broadhurst, S.; Brodrick, D.; Brothers, M.; Brown, A.; Bunton, J. D.; Cantrall, C.; Chapman, J.; Cheng, W.; Chippendale, A. P.; Chung, Y.; Cooray, F.; Cornwell, T.; DeBoer, D.; Diamond, P.; Edwards, P. G.; Ekers, R.; Feain, I.; Ferris, R. H.; Forsyth, R.; Gough, R.; Grancea, A.; Gupta, N.; Guzman, J. C.; Hampson, G.; Harvey-Smith, L.; Haskins, C.; Hay, S.; Hayman, D. B.; Heywood, I.; Hotan, A. W.; Hoyle, S.; Humphreys, B.; Indermuehle, B. T.; Jacka, C.; Jackson, C.; Jackson, S.; Jeganathan, K.; Johnston, S.; Joseph, J.; Kendall, R.; Kesteven, M.; Kiraly, D.; Koribalski, B. S.; Leach, M.; Lenc, E.; Lensson, E.; Mackay, S.; Macleod, A.; Marquarding, M.; Marvil, J.; McClure-Griffiths, N.; McConnell, D.; Mirtschin, P.; Norris, R. P.; Neuhold, S.; Ng, A.; O'Sullivan, J.; Pathikulangara, J.; Pearce, S.; Phillips, C.; Popping, A.; Qiao, R. Y.; Reynolds, J. E.; Roberts, P.; Sault, R. J.; Schinckel, A.; Serra, P.; Shaw, R.; Shields, M.; Shimwell, T.; Storey, M.; Sweetnam, T.; Troup, E.; Turner, B.; Tuthill, J.; Tzioumis, A.; Voronkov, M. A.; Westmeier, T.; Wilson, C. D.

    2015-10-01

    We report the discovery of a new 21-cm H I absorption system using commissioning data from the Boolardy Engineering Test Array of the Australian Square Kilometre Array Pathfinder (ASKAP). Using the 711.5-1015.5 MHz band of ASKAP we were able to conduct a blind search for the 21-cm line in a continuous redshift range between z = 0.4 and 1.0, which has, until now, remained largely unexplored. The absorption line is detected at z = 0.44 towards the GHz-peaked spectrum radio source PKS B1740-517 and demonstrates ASKAP's excellent capability for performing a future wide-field survey for H I absorption at these redshifts. Optical spectroscopy and imaging using the Gemini-South telescope indicates that the H I gas is intrinsic to the host galaxy of the radio source. The narrow [O III] emission lines show clear double-peaked structure, indicating either large-scale outflow or rotation of the ionized gas. Archival data from the XMM-Newton satellite exhibit an absorbed X-ray spectrum that is consistent with a high column density obscuring medium around the active galactic nucleus. The H I absorption profile is complex, with four distinct components ranging in width from 5 to 300 km s-1 and fractional depths from 0.2 to 20 per cent. In addition to systemic H I gas, in a circumnuclear disc or ring structure aligned with the radio jet, we find evidence for a possible broad outflow of neutral gas moving at a radial velocity of v ˜ 300 km s-1. We infer that the expanding young radio source (tage ≈ 2500 yr) is cocooned within a dense medium and may be driving circumnuclear neutral gas in an outflow of ˜1 M⊙ yr-1.

  6. Cosmic magnetism with the Square Kilometre Array and its pathfinders

    NASA Astrophysics Data System (ADS)

    Gaensler, Bryan M.

    2009-04-01

    One of the five key science projects for the Square Kilometre Array (SKA) is “The Origin and Evolution of Cosmic Magnetism”, in which radio polarimetry will be used to reveal what cosmic magnets look like and what role they have played in the evolving Universe. Many of the SKA prototypes now being built are also targeting magnetic fields and polarimetry as key science areas. Here I review the prospects for innovative new polarimetry and Faraday rotation experiments with forthcoming facilities such as ASKAP, LOFAR, the ATA, the EVLA, and ultimately the SKA. Sensitive wide-field polarisation surveys with these telescopes will provide a dramatic new view of magnetic fields in the Milky Way, in nearby galaxies and clusters, and in the high-redshift Universe.

  7. Radio Continuum Surveys with Square Kilometre Array Pathfinders

    NASA Astrophysics Data System (ADS)

    Norris, Ray P.; Afonso, J.; Bacon, D.; Beck, Rainer; Bell, Martin; Beswick, R. J.; Best, Philip; Bhatnagar, Sanjay; Bonafede, Annalisa; Brunetti, Gianfranco; Budavári, Tamás; Cassano, Rossella; Condon, J. J.; Cress, Catherine; Dabbech, Arwa; Feain, I.; Fender, Rob; Ferrari, Chiara; Gaensler, B. M.; Giovannini, G.; Haverkorn, Marijke; Heald, George; Van der Heyden, Kurt; Hopkins, A. M.; Jarvis, M.; Johnston-Hollitt, Melanie; Kothes, Roland; Van Langevelde, Huib; Lazio, Joseph; Mao, Minnie Y.; Martínez-Sansigre, Alejo; Mary, David; Mcalpine, Kim; Middelberg, E.; Murphy, Eric; Padovani, P.; Paragi, Zsolt; Prandoni, I.; Raccanelli, A.; Rigby, Emma; Roseboom, I. G.; Röttgering, H.; Sabater, Jose; Salvato, Mara; Scaife, Anna M. M.; Schilizzi, Richard; Seymour, N.; Smith, Dan J. B.; Umana, Grazia; Zhao, G.-B.; Zinn, Peter-Christian

    2013-03-01

    In the lead-up to the Square Kilometre Array (SKA) project, several next-generation radio telescopes and upgrades are already being built around the world. These include APERTIF (The Netherlands), ASKAP (Australia), e-MERLIN (UK), VLA (USA), e-EVN (based in Europe), LOFAR (The Netherlands), MeerKAT (South Africa), and the Murchison Widefield Array. Each of these new instruments has different strengths, and coordination of surveys between them can help maximise the science from each of them. A radio continuum survey is being planned on each of them with the primary science objective of understanding the formation and evolution of galaxies over cosmic time, and the cosmological parameters and large-scale structures which drive it. In pursuit of this objective, the different teams are developing a variety of new techniques, and refining existing ones. To achieve these exciting scientific goals, many technical challenges must be addressed by the survey instruments. Given the limited resources of the global radio-astronomical community, it is essential that we pool our skills and knowledge. We do not have sufficient resources to enjoy the luxury of re-inventing wheels. We face significant challenges in calibration, imaging, source extraction and measurement, classification and cross-identification, redshift determination, stacking, and data-intensive research. As these instruments extend the observational parameters, we will face further unexpected challenges in calibration, imaging, and interpretation. If we are to realise the full scientific potential of these expensive instruments, it is essential that we devote enough resources and careful study to understanding the instrumental effects and how they will affect the data. We have established an SKA Radio Continuum Survey working group, whose prime role is to maximise science from these instruments by ensuring we share resources and expertise across the projects. Here we describe these projects, their science goals

  8. An Overview of the Square Kilometre Array

    NASA Technical Reports Server (NTRS)

    Huynh, Minh T.; Lazio, Joseph

    2013-01-01

    The Square Kilometre Array (SKA) will be the premier instrument to study radiation at centimetre and metre wavelengths from the cosmos, and in particular hydrogen, the most abundant element in the universe. The SKA will probe the dawn of galaxy formation as well as allow advances in many other areas of astronomy, such as fundamental physics, astrobiology and cosmology. Phase 1, which will be about 10% of the full SKA collecting area, will be built in Australia and South Africa. This paper describes the key science drivers of the SKA, provides an update on recent SKA Organisation activities and summarises the baseline design for Phase 1.

  9. Operations concept for the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Davis, Gary R.; Bock, Douglas C.; Chrysostomou, Antonio; Taljaard, Cornelius

    2016-07-01

    The Square Kilometre Array (SKA) is an ambitious project to build the world's largest radio telescope, eventually reaching one square kilometre in collecting area. The first phase of the project, SKA1, will consist of two telescopes: SKA1-LOW, comprising 131,000 dipole antennas at the Murchison Radio Observatory in Western Australia covering the range 50-350 MHz, and SKA1-MID, comprising 200 x 15-m dishes in the Karoo desert in South Africa covering the range 0.35-13.8 GHz. SKA1 is scheduled to commence operations in 2023 and, in order to appropriately influence the design of the system, operational planning has commenced. This paper presents an overview of the operational concept for SKA1.

  10. Science with the Square Kilometre Array

    NASA Technical Reports Server (NTRS)

    Lazio, Joseph; Huynh, Minh

    2010-01-01

    The Square Kilometre Array (SKA) is the centimeter- and meter-wavelength telescope for the 21st Century. Its Key Science Projects are (a) The end of the Dark Ages, involving searches for an H i signature and the first metalrich systems; (b) Testing theories of gravitation using an array of pulsars to search for gravitational waves and relativistic binaries to probe the strong-field regime; (c) Observations of H i to a redshift z 2 from which to study the evolution of galaxies and dark energy. (d) Astrobiology including planetary formation within protoplanetary disks; and (c) The origin and evolution of cosmic magnetism, both within the Galaxy and in intergalactic space. The SKA will operate over the wavelength range of at least 1.2 cm to 4 m (70 MHz to 25 GHz), providing milliarcsecond resolution at the shortest wavelengths.

  11. Square Kilometre Array Science Data Processing

    NASA Astrophysics Data System (ADS)

    Nikolic, Bojan; SDP Consortium, SKA

    2014-04-01

    The Square Kilometre Array (SKA) is planned to be, by a large factor, the largest and most sensitive radio telescope ever constructed. The first phase of the telescope (SKA1), now in the design phase, will in itself represent a major leap in capabilities compared to current facilities. These advances are to a large extent being made possible by advances in available computer processing power so that that larger numbers of smaller, simpler and cheaper receptors can be used. As a result of greater reliance and demands on computing, ICT is becoming an ever more integral part of the telescope. The Science Data Processor is the part of the SKA system responsible for imaging, calibration, pulsar timing, confirmation of pulsar candidates, derivation of some further derived data products, archiving and providing the data to the users. It will accept visibilities at data rates at several TB/s and require processing power for imaging in range 100 petaFLOPS -- ~1 ExaFLOPS, putting SKA1 into the regime of exascale radio astronomy. In my talk I will present the overall SKA system requirements and how they drive these high data throughput and processing requirements. Some of the key challenges for the design of SDP are: - Identifying sufficient parallelism to utilise very large numbers of separate compute cores that will be required to provide exascale computing throughput - Managing efficiently the high internal data flow rates - A conceptual architecture and software engineering approach that will allow adaptation of the algorithms as we learn about the telescope and the atmosphere during the commissioning and operational phases - System management that will deal gracefully with (inevitably frequent) failures of individual units of the processing system In my talk I will present possible initial architectures for the SDP system that attempt to address these and other challenges.

  12. From Nearby Low Luminosity AGN to High Redshift Radio Galaxies: Science Interests with Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Kharb, P.; Lal, D. V.; Singh, V.; Bagchi, J.; Ishwara Chandra, C. H.; Hota, A.; Konar, C.; Wadadekar, Y.; Shastri, P.; Das, M.; Baliyan, K.; Nath, B. B.; Pandey-Pommier, M.

    2016-12-01

    We present detailed science cases that a large fraction of the Indian AGN community is interested in pursuing with the upcoming Square Kilometre Array (SKA). These interests range from understanding low luminosity active galactic nuclei in the nearby Universe to powerful radio galaxies at high redshifts. Important unresolved science questions in AGN physics are discussed. Ongoing low-frequency surveys with the SKA pathfinder telescope GMRT, are highlighted.

  13. The renaissance of radio astronomy: towards the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Ferrari, C.

    2016-09-01

    In this paper, I will give a brief overview of the largest radio telescope in the world, the Square Kilometre Array (SKA). The history of this instrument, its development as a huge international project, as well as its main scientific goals, will be summarised. I will then focus on a particular science case by presenting how the first phase of the SKA (SKA1), whose observations are expected to start in the early 2020's, will change our radio view of the largest gravitationally bound structures of the Universe: galaxy clusters.

  14. The square kilometre array and the transient universe.

    PubMed

    Stappers, B W

    2013-06-13

    The square kilometre array (SKA) is a next generation radio telescope that will be built in southern Africa and Australasia. It will be built in two phases and will use a range of detectors, from aperture arrays to dishes, to span the frequency range from a few tens of megahertz to a few gigahertz. The combination of great sensitivity, wide field of view and unprecedented computing power mean that the SKA will be an excellent instrument for studying the transient radio universe. Transient radio emission is generated in extremes of: gravitational and magnetic fields, velocity, temperature, pressure and density. While we know about plenty of source classes for this type of short duration radio emission, there is still a large range of transient parameter space that has not yet been sampled owing to the limitations of current generation radio telescopes.

  15. Cosmology with the Square Kilometre Array by SKA-Japan

    NASA Astrophysics Data System (ADS)

    Yamauchi, Daisuke; Ichiki, Kiyotomo; Kohri, Kazunori; Namikawa, Toshiya; Oyama, Yoshihiko; Sekiguchi, Toyokazu; Shimabukuro, Hayato; Takahashi, Keitaro; Takahashi, Tomo; Yokoyama, Shuichiro; Yoshikawa, Kohji

    2016-12-01

    In the past several decades, the standard cosmological model has been established and its parameters have been measured to a high precision, while there are still many fundamental questions in cosmology; such as the physics in the very early universe, the origin of the cosmic acceleration, and the nature of dark matter. The forthcoming radio telescope, the Square Kilometre Array (SKA), which will be the world's largest, will be able to open a new frontier in cosmology and will be one of the most powerful tools for cosmology in the coming decade. The cosmological surveys conducted by the SKA would have the potential not only to answer these fundamental questions but also deliver precision cosmology. In this article we briefly review the role of the SKA from the viewpoint of modern cosmology. The cosmological science led by the SKA-Japan Consortium (SKA-JP) Cosmology Science Working Group is also discussed.

  16. Scalable Data Mining and Archiving for the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Jones, D. L.; Mattmann, C. A.; Hart, A. F.; Lazio, J.; Bennett, T.; Wagstaff, K. L.; Thompson, D. R.; Preston, R.

    2011-12-01

    As the technologies for remote observation improve, the rapid increase in the frequency and fidelity of those observations translates into an avalanche of data that is already beginning to eclipse the resources, both human and technical, of the institutions and facilities charged with managing the information. Common data management tasks like cataloging both data itself and contextual meta-data, creating and maintaining scalable permanent archive, and making data available on-demand for research present significant software engineering challenges when considered at the scales of modern multi-national scientific enterprises such as the upcoming Square Kilometre Array project. The NASA Jet Propulsion Laboratory (JPL), leveraging internal research and technology development funding, has begun to explore ways to address the data archiving and distribution challenges with a number of parallel activities involving collaborations with the EVLA and ALMA teams at the National Radio Astronomy Observatory (NRAO), and members of the Square Kilometre Array South Africa team. To date, we have leveraged the Apache OODT Process Control System framework and its catalog and archive service components that provide file management, workflow management, resource management as core web services. A client crawler framework ingests upstream data (e.g., EVLA raw directory output), identifies its MIME type and automatically extracts relevant metadata including temporal bounds, and job-relevant/processing information. A remote content acquisition (pushpull) service is responsible for staging remote content and handing it off to the crawler framework. A science algorithm wrapper (called CAS-PGE) wraps underlying code including CASApy programs for the EVLA, such as Continuum Imaging and Spectral Line Cube generation, executes the algorithm, and ingests its output (along with relevant extracted metadata). In addition to processing, the Process Control System has been leveraged to provide data

  17. Observation management challenges of the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Bridger, Alan; Williams, Stewart J.; Nicol, Mark; Klaassen, Pamela; Thompson, Roger S.; Knapic, Cristina; Jerse, Giovanna; Orlati, Andrea; Messina, Marco; Valame, Snehal

    2016-07-01

    The Square Kilometre Array (SKA) will be the world's most advanced radio telescope, designed to explore some of the biggest questions in astronomy today, such as the epoch of re-ionization, the nature of gravity and the origins of cosmic magnetism. SKA1, the first phase of SKA construction, is currently being designed by a large team of experts world-wide. SKA1 comprises two telescopes: a 200-element dish interferometer in South Africa and a 130000-element dipole antenna aperture array in Australia. To enable the ground-breaking science of the SKA an advanced Observation Management system is required to support both the needs of the astronomical community users and the SKA Observatory staff. This system will ensure that the SKA realises its scientiffc aims and achieves optimal scientific throughput. This paper provides an overview of the design of the system that will accept proposals from SKA users, and result in the execution of the scripts that will obtain science data, taking in the stages of detailed preparation, planning and scheduling of the observations and onwards tracking. It describes the unique challenges of the differing requirements of two telescopes, one of which is very much a software telescope, including the need to schedule the data processing as well as the acquisition, and to react to both internally and externally discovered transient events. The scheduling of multiple parallel sub-array use is covered, along with the need to handle commensal observing - using the same data stream to satisfy the science goals of more than one project simultaneously. An international team from academia and industry, drawing on expertise and experience from previous telescope projects, the virtual observatory and comparable problems in industry, has been assembled to design the solution to this challenging but exciting problem.

  18. Probing Magnetic Fields with Square Kilometre Array and its Precursors

    NASA Astrophysics Data System (ADS)

    Roy, Subhashis; Sur, Sharanya; Subramanian, Kandaswamy; Mangalam, Arun; Seshadri, T. R.; Chand, Hum

    2016-12-01

    Origin of magnetic fields, its structure and effects on dynamical processes in stars to galaxies are not well understood. Lack of a direct probe has remained a problem for its study. The first phase of Square Kilometre Array (SKA-I), will have almost an order of magnitude higher sensitivity than the best existing radio telescope at GHz frequencies. In this contribution, we discuss specific science cases that are of interest to the Indian community concerned with astrophysical turbulence and magnetic fields. The SKA-I will allow observations of a large number of background sources with detectable polarization and measure their Faraday depths (FDs) through the Milky Way, other galaxies and their circum-galactic mediums. This will probe line-of-sight magnetic fields in these objects well and provide field configurations. Detailed comparison of observational data (e.g., pitch angles in spirals) with models which consider various processes giving rise to field amplification and maintenance (e.g., various types of dynamo models) will then be possible. Such observations will also provide the coherence scale of the fields and its random component through RM structure function. Measuring the random component is important to characterize turbulence in the medium. Observations of FDs with redshift will provide important information on magnetic field evolution as a function of redshift. The background sources could also be used to probe magnetic fields and its coherent scale in galaxy clusters and in bridges formed between interacting galaxies. Other than FDs, sensitive observations of synchrotron emission from galaxies will provide complimentary information on their magnetic field strengths in the sky plane. The core shift measurements of AGNs can provide more precise measurements of magnetic field in the sub parsec region near the black hole and its evolution. The low band of SKA-I will also be useful to study circularly polarized emission from Sun and comparing various

  19. Searching for Extraterrestrial Intelligence with the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Siemion, A.; Benford, J.; Cheng-Jin, J.; Chennamangalam, J.; Cordes, J. M.; Falcke, H. D. E.; Garrington, S. T.; Garrett, M. A.; Gurvits, L.; Hoare, M.; Korpela, E.; Lazio, J.; Messerschmitt, D.; Morrison, I.; O'Brien, T.; Paragi, Z.; Penny, A.; Spitler, L.; Tarter, J.; Werthimer, D.

    2015-04-01

    The vast collecting area of the Square Kilometre Array (SKA), harnessed by sensitive receivers, flexible digital electronics and increased computational capacity, could permit the most sensitive and exhaustive search for technologically-produced radio emission from advanced extraterrestrial intelligence (SETI) ever performed. For example, SKA1-MID will be capable of detecting a source roughly analogous to terrestrial high-power radars (e.g. air route surveillance or ballistic missile warning radars, EIRP (EIRP = equivalent isotropic radiated power, ~10^17 erg sec^-1) at 10 pc in less than 15 minutes, and with a modest four beam SETI observing system could, in one minute, search every star in the primary beam out to ~100 pc for radio emission comparable to that emitted by the Arecibo Planetary Radar (EIRP ~2 x 10^20 erg sec^-1). The flexibility of the signal detection systems used for SETI searches with the SKA will allow new algorithms to be employed that will provide sensitivity to a much wider variety of signal types than previously searched for. Here we discuss the astrobiological and astrophysical motivations for radio SETI and describe how the technical capabilities of the SKA will explore the radio SETI parameter space. We detail several conceivable SETI experimental programs on all components of SKA1, including commensal, primary-user, targeted and survey programs and project the enhancements to them possible with SKA2. We also discuss target selection criteria for these programs, and in the case of commensal observing, how the varied use cases of other primary observers can be used to full advantage for SETI.

  20. The Australian SKA Pathfinder: project update and initial operations

    NASA Astrophysics Data System (ADS)

    Schinckel, Antony E. T.; Bock, Douglas C.-J.

    2016-08-01

    The Australian Square Kilometre Array Pathfinder (ASKAP) will be the fastest dedicated cm-wave survey telescope, and will consist of 36 12-meter 3-axis antennas, each with a large chequerboard phased array feed (PAF) receiver operating between 0.7 and 1.8 GHz, and digital beamforming prior to correlation. The large raw data rates involved ( 100 Tb/sec), and the need to do pipeline processing, has led to the antenna incorporating a third axis to fix the parallactic angle with respect to the entire optical system (blockages and phased array feed). It also results in innovative technical solutions to the data transport and processing issues. ASKAP is located at the Murchison Radio-astronomy Observatory (MRO), a new observatory developed for the Square Kilometre Array (SKA), 315 kilometres north-east of Geraldton, Western Australia. The MRO also hosts the SKA low frequency pathfinder instrument, the Murchison Widefield Array and will host the initial low frequency instrument of the SKA, SKA1-Low. Commissioning of ASKAP using six antennas equipped with first-generation PAFs is now complete and installation of second-generation PAFs and digital systems is underway. In this paper we review technical progress and commissioning to date, and refer the reader to relevant technical and scientific publications.

  1. The likelihood ratio as a tool for radio continuum surveys with Square Kilometre Array precursor telescopes

    NASA Astrophysics Data System (ADS)

    McAlpine, K.; Smith, D. J. B.; Jarvis, M. J.; Bonfield, D. G.; Fleuren, S.

    2012-06-01

    In this paper we investigate the performance of the likelihood ratio method as a tool for identifying optical and infrared counterparts to proposed radio continuum surveys with Square Kilometre Array (SKA) precursor and pathfinder telescopes. We present a comparison of the infrared counterparts identified by the likelihood ratio in the VISTA Deep Extragalactic Observations (VIDEO) survey to radio observations with 6, 10 and 15 arcsec resolution. We cross-match a deep radio catalogue consisting of radio sources with peak flux density >60 ?Jy with deep near-infrared data limited to Ks≲ 22.6. Comparing the infrared counterparts from this procedure to those obtained when cross-matching a set of simulated lower resolution radio catalogues indicates that degrading the resolution from 6 arcsec to 10 and 15 arcsec decreases the completeness of the cross-matched catalogue by approximately 3 and 7 per cent respectively. When matching against shallower infrared data, comparable to that achieved by the VISTA Hemisphere Survey, the fraction of radio sources with reliably identified counterparts drops from ˜89 per cent, at Ks≲ 22.6, to 47 per cent with Ks≲ 20.0. Decreasing the resolution at this shallower infrared limit does not result in any further decrease in the completeness produced by the likelihood ratio matching procedure. However, we note that radio continuum surveys with the MeerKAT and eventually the SKA, will require long baselines in order to ensure that the resulting maps are not limited by instrumental confusion noise.

  2. Neutron Star Physics in the Square Kilometre Array Era: An Indian Perspective

    NASA Astrophysics Data System (ADS)

    Konar, Sushan; Bagchi, Manjari; Bandyopadhyay, Debades; Banik, Sarmistha; Bhattacharya, Dipankar; Bhattacharyya, Sudip; Gangadhara, R. T.; Gopakumar, A.; Gupta, Yashwant; Joshi, B. C.; Maan, Yogesh; Maitra, Chandreyee; Mukherjee, Dipanjan; Pai, Archana; Paul, Biswajit; Ray, Alak K.; Sutaria, Firoza K.

    2016-12-01

    It is an exceptionally opportune time for astrophysics when a number of next-generation mega-instruments are poised to observe the Universe across the entire electromagnetic spectrum with unprecedented data quality. The Square Kilometre Array (SKA) is undoubtedly one of the major components of this scenario. In particular, the SKA is expected to discover tens of thousands of new neutron stars giving a major fillip to a wide range of scientific investigations. India has a sizeable community of scientists working on different aspects of neutron star physics with immediate access to both the uGMRT (an SKA pathfinder) and the recently launched X-ray observatory Astrosat. The current interests of the community largely centre around studies of (a) the generation of neutron stars and the SNe connection, (b) the neutron star population and evolutionary pathways, (c) the evolution of neutron stars in binaries and the magnetic fields, (d) the neutron star equation of state, (e) the radio pulsar emission mechanism, and (f) the radio pulsars as probes of gravitational physics. Most of these studies are the main goals of the SKA first phase, which is likely to be operational in the next four years. This article summarizes the science goals of the Indian neutron star community in the SKA era, with significant focus on coordinated efforts among the SKA and other existing/upcoming instruments.

  3. The Australian SKA Pathfinder: operations management and user engagement

    NASA Astrophysics Data System (ADS)

    Harvey-Smith, Lisa

    2016-07-01

    This paper describes the science operations model for the Australian Square Kilometre Array Pathfinder (ASKAP) telescope. ASKAP is a radio interferometer currently being commissioned in Western Australia. It will be operated by a dedicated team of observatory staff with the support of telescope monitoring, control and scheduling software. These tools, as well as the proposal tools and data archive will enable the telescope to operate with little direct input from the astronomy user. The paper also discusses how close engagement with the telescope user community has been maintained throughout the ASKAP construction and commissioning phase, leading to positive outcomes including early input into the design of telescope systems and a vibrant early science program.

  4. The Australian SKA Pathfinder: First Science Results

    NASA Astrophysics Data System (ADS)

    Harvey-Smith, Lisa

    2015-08-01

    The Australian SKA Pathfinder (ASKAP) is a precursor and technology demonstrator for the Square Kilometre Array.A specialist wide-field survey instrument, ASKAP compises 36 x 12m dish antennas with a maximum separation of 6km. The array operates in the frequency range 700 - 1800 MHz and has an instantaneous bandwidth of 300 MHz. Each dish is mounted with a 'phased array feed', a radio receiver that dramatically enhances the telescope's field-of-view from 1 to 30 square degrees. ASKAP is located at the Murchison Radio-astronomy Observatory, Australia's core site for the SKA.Ten Science Survey Projects have been established by teams of more than 600 astronomers from around the world. Astronomical research topics tackled by these teams include galaxy evolution, cosmic magnetism, the history of gas in galaxies and cosmology. A program of ASKAP Early Science will commence in late 2015. The 6-antenna Boolardy Engineering Test Array (BETA) is currently being used by the commissioning team and at the time of writing has produced its first scientific discovery paper.In this talk, hear the ASKAP Project Scientist report some of the exciting new capabilities demonstrated by ASKAP and learn about the first scientific discoveries made by the commissioning and early science team.

  5. Interstellar Medium and Star Formation Studies with the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Manoj, P.; Vig, S.; Maheswar, G.; Kamath, U. S.; Tej, A.

    2016-12-01

    Stars and planetary systems are formed out of molecular clouds in the interstellar medium. Although the sequence of steps involved in star formation are generally known, a comprehensive theory which describes the details of the processes that drive formation of stars is still missing. The Square Kilometre Array (SKA), with its unprecedented sensitivity and angular resolution, will play a major role in filling these gaps in our understanding. In this article, we present a few science cases that the Indian star formation community is interested in pursuing with SKA, which include investigation of AU-sized structures in the neutral ISM, the origin of thermal and non-thermal radio jets from protostars and the accretion history of protostars, and formation of massive stars and their effect on the surrounding medium.

  6. The Square Kilometre Array Science Data Processor. Preliminary compute platform design

    NASA Astrophysics Data System (ADS)

    Broekema, P. C.; van Nieuwpoort, R. V.; Bal, H. E.

    2015-07-01

    The Square Kilometre Array is a next-generation radio-telescope, to be built in South Africa and Western Australia. It is currently in its detailed design phase, with procurement and construction scheduled to start in 2017. The SKA Science Data Processor is the high-performance computing element of the instrument, responsible for producing science-ready data. This is a major IT project, with the Science Data Processor expected to challenge the computing state-of-the art even in 2020. In this paper we introduce the preliminary Science Data Processor design and the principles that guide the design process, as well as the constraints to the design. We introduce a highly scalable and flexible system architecture capable of handling the SDP workload.

  7. Fast Transients with the Square Kilometre Array and its Pathfinders: An Indian Perspective

    NASA Astrophysics Data System (ADS)

    Gupta, Yashwant; Chandra, Poonam; Bagchi, Manjari; Ramanujam, Niruj M.; Maan, Yogesh; Deshpande, Avinash A.; Bhattacharyya, Siddhartha

    2016-12-01

    In the rapidly developing field of study of the transient sky, fast radio transients are perhaps the most exciting objects of scrutiny at present. The SKA, with its wide field-of-view and significant improvement in sensitivity over existing facilities, is expected to detect a plethora of fast transients which, in addition to help resolve the mysteries surrounding their nature and origin, will also lead to other interesting applications in astrophysics. We explore some of these possibilities here, and also emphasize the current status and future plans of the Indian community working in this area, in the context of ongoing work and extension of this to the SKA.

  8. Probing Statistical Isotropy of Cosmological Radio Sources using Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Ghosh, Shamik; Jain, Pankaj; Kashyap, Gopal; Kothari, Rahul; Nadkarni-Ghosh, Sharvari; Tiwari, Prabhakar

    2016-12-01

    There currently exist many observations which are not consistent with the cosmological principle. We review these observations with a particular emphasis on those relevant for the Square Kilometre Array (SKA). In particular, several different data sets indicate a preferred direction pointing approximately towards the Virgo cluster. We also observe a hemispherical anisotropy in the Cosmic Microwave Background radiation (CMB) temperature fluctuations. Although these inconsistencies may be attributed to systematic effects, there remains the possibility that they indicate new physics and various theories have been proposed to explain them. One possibility, which we discuss in this review, is the generation of perturbation modes during the early pre-inflationary epoch, when the Universe may not obey the cosmological principle. Better measurements will provide better constraints on these theories. In particular, we propose measurement of the dipole in number counts, sky brightness, polarized flux and polarization orientations of radio sources. We also suggest test of alignment of linear polarizations of sources as a function of their relative separation. Finally we propose measurement of hemispherical anisotropy or equivalently dipole modulation in radio sources.

  9. Square Kilometre Array Telescope--Precision Reference Frequency Synchronisation via 1f-2f Dissemination.

    PubMed

    Wang, B; Zhu, X; Gao, C; Bai, Y; Dong, J W; Wang, L J

    2015-09-09

    The Square Kilometre Array (SKA) project is an international effort to build the world's largest radio telescope, with a one-square-kilometre collecting area. In addition to its ambitious scientific objectives, such as probing cosmic dawn and the cradle of life, the SKA demands several revolutionary technological breakthroughs, such as ultra-high precision synchronisation of the frequency references for thousands of antennas. In this report, with the purpose of application to the SKA, we demonstrate a frequency reference dissemination and synchronisation scheme in which the phase-noise compensation function is applied at the client site. Hence, one central hub can be linked to a large number of client sites, thus forming a star-shaped topology. As a performance test, a 100-MHz reference frequency signal from a hydrogen maser (H-maser) clock is disseminated and recovered at two remote sites. The phase-noise characteristics of the recovered reference frequency signal coincide with those of the H-maser source and satisfy the SKA requirements.

  10. A user interface framework for the Square Kilometre Array: concepts and responsibilities

    NASA Astrophysics Data System (ADS)

    Marassi, Alessandro; Brajnik, Giorgio; Nicol, Mark; Alberti, Valentina; Le Roux, Gerhard

    2016-07-01

    The Square Kilometre Array (SKA) project is responsible for developing the SKA Observatory, the world's largest radio telescope, with eventually over a square kilometre of collecting area and including a general headquarters as well as two radio telescopes: SKA1-Mid in South Africa and SKA1-Low in Australia. The SKA project consists of a number of subsystems (elements) among which the Telescope Manager (TM) is the one involved in controlling and monitoring the SKA telescopes. The TM element has three primary responsibilities: management of astronomical observations, management of telescope hardware and software subsystems, management of data to support system operations and all stakeholders (operators, maintainers, engineers and science users) in achieving operational, maintenance and engineering goals. Operators, maintainers, engineers and science users will interact with TM via appropriate user interfaces (UI). The TM UI framework envisaged is a complete set of general technical solutions (components, technologies and design information) for implementing a generic computing system (UI platform). Such a system will enable UI components to be instantiated to allow for human interaction via screens, keyboards, mouse and to implement the necessary logic for acquiring or deriving the information needed for interaction. It will provide libraries and specific Application Programming Interfaces (APIs) to implement operator and engineer interactive interfaces. This paper will provide a status update of the TM UI framework, UI platform and UI components design effort, including the technology choices, and discuss key challenges in the TM UI architecture, as well as our approaches to addressing them.

  11. Square Kilometre Array Telescope—Precision Reference Frequency Synchronisation via 1f-2f Dissemination

    NASA Astrophysics Data System (ADS)

    Wang, B.; Zhu, X.; Gao, C.; Bai, Y.; Dong, J. W.; Wang, L. J.

    2015-09-01

    The Square Kilometre Array (SKA) project is an international effort to build the world’s largest radio telescope, with a one-square-kilometre collecting area. In addition to its ambitious scientific objectives, such as probing cosmic dawn and the cradle of life, the SKA demands several revolutionary technological breakthroughs, such as ultra-high precision synchronisation of the frequency references for thousands of antennas. In this report, with the purpose of application to the SKA, we demonstrate a frequency reference dissemination and synchronisation scheme in which the phase-noise compensation function is applied at the client site. Hence, one central hub can be linked to a large number of client sites, thus forming a star-shaped topology. As a performance test, a 100-MHz reference frequency signal from a hydrogen maser (H-maser) clock is disseminated and recovered at two remote sites. The phase-noise characteristics of the recovered reference frequency signal coincide with those of the H-maser source and satisfy the SKA requirements.

  12. Scalable, efficient ASICS for the square kilometre array: From A/D conversion to central correlation

    NASA Astrophysics Data System (ADS)

    Schmatz, M. L.; Jongerius, R.; Dittmann, G.; Anghel, A.; Engbersen, T.; van Lunteren, J.; Buchmann, P.

    2014-05-01

    The Square Kilometre Array (SKA) is a future radio telescope, currently being designed by the worldwide radio-astronomy community. During the first of two construction phases, more than 250,000 antennas will be deployed, clustered in aperture-array stations. The antennas will generate 2.5 Pb/s of data, which needs to be processed in real time. For the processing stages from A/D conversion to central correlation, we propose an ASIC solution using only three chip architectures. The architecture is scalable - additional chips support additional antennas or beams - and versatile - it can relocate its receiver band within a range of a few MHz up to 4GHz. This flexibility makes it applicable to both SKA phases 1 and 2. The proposed chips implement an antenna and station processor for 289 antennas with a power consumption on the order of 600W and a correlator, including corner turn, for 911 stations on the order of 90 kW.

  13. An innovative, highly sensitive receiver system for the Square Kilometre Array Mid Radio Telescope

    NASA Astrophysics Data System (ADS)

    Tan, Gie Han; Lehmensiek, Robert; Billade, Bhushan; Caputa, Krzysztof; Gauffre, Stéphane; Theron, Isak P.; Pantaleev, Miroslav; Ljusic, Zoran; Quertier, Benjamin; Peens-Hough, Adriaan

    2016-07-01

    The Square Kilometre Array (SKA) Project is a global science and engineering project realizing the next-generation radio telescopes operating in the metre and centimetre wavelengths regions. This paper addresses design concepts of the broadband, exceptionally sensitive receivers and reflector antennas deployed in the SKA1-Mid radio telescope to be located in South Africa. SKA1-Mid (350 MHz - 13.8 GHz with an option for an upper limit of 24 GHz) will consist of 133 reflector antennas using an unblocked aperture, offset Gregorian configuration with an effective diameter of 15 m. Details on the unblocked aperture Gregorian antennas, low noise front ends and advanced direct digitization receivers, are provided from a system design perspective. The unblocked aperture results in increased aperture efficiency and lower side-lobe levels compared to a traditional on-axis configuration. The low side-lobe level reduces the noise contribution due to ground pick-up but also makes the antenna less susceptible to ground-based RFI sources. The addition of extra shielding on the sub-reflector provides a further reduction of ground pick-up. The optical design of the SKA1-Mid reflector antenna has been tweaked using advanced EM simulation tools in combination with sophisticated models for sky, atmospheric and ground noise contributions. This optimal antenna design in combination with very low noise, partially cryogenic, receivers and wide instantaneous bandwidth provide excellent receiving sensitivity in combination with instrumental flexibility to accommodate a wide range of astronomical observation modes.

  14. From Antikythera to the Square Kilometre Array: Lessons from the Ancients

    NASA Astrophysics Data System (ADS)

    More than a hundred years ago an extraordinary mechanism was found by sponge divers at the bottom of the sea near the island of Antikythera in Greece. This Antikythera mechanism is an ancient computer from about 100BC, which uses bronze gears to make astronomical calculations based on cycles of the Solar System. Now, more than 2000 years after the device was lost at sea, scientists have used the latest techniques in X-ray computed tomography and reflectance imaging to understand its intricate workings. In June 2012 we plan to hold a workshop linking modern and ancient astronomical technology through the Antikythera theme. We will explore the evolution of astrometry and computing from ancient Greece to the present, we will compare the technologies used to unravel the secrets of the Antikythera mechanism with the imaging tools of modern astronomy, and most importantly, as we pursue our vision of an exciting scientific future with telescopes such as the Square Kilometre Array we can reflect on why the Antikythera technology was lost for more than a thousand years and whether this can happen again.

  15. Neutron Stars in the Light of Square Kilometre Array: Data, Statistics and Science

    NASA Astrophysics Data System (ADS)

    Arjunwadkar, Mihir; Kashikar, Akanksha; Bagchi, Manjari

    2016-12-01

    The Square Kilometre Array (SKA), when it becomes functional, is expected to enrich Neutron Star (NS) catalogues by at least an order of magnitude over their current state. This includes the discovery of new NS objects leading to better sampling of under-represented NS categories, precision measurements of intrinsic properties such as spin period and magnetic field, as also data on related phenomena such as microstructure, nulling, glitching, etc. This will present a unique opportunity to seek answers to interesting and fundamental questions about the extreme physics underlying these exotic objects in the Universe. In this paper, we first present a meta-analysis (from a methodological viewpoint) of statistical analyses performed using existing NS data, with a two-fold goal. First, this should bring out how statistical models and methods are shaped and dictated by the science problem being addressed. Second, it is hoped that these analyses will provide useful starting points for deeper analyses involving richer data from SKA whenever it becomes available. We also describe a few other areas of NS science which we believe will benefit from SKA which are of interest to the Indian NS community.

  16. Possible gamma-ray burst radio detections by the Square Kilometre Array. New perspectives

    NASA Astrophysics Data System (ADS)

    Ruggeri, Alan Cosimo; Capozziello, Salvatore

    2016-09-01

    The next generation interferometric radio telescope, the Square Kilometre Array (SKA), which will be the most sensitive and largest radio telescope ever constructed, could greatly contribute to the detection, survey and characterization of Gamma Ray Bursts (GRBs). By the SKA, it will be possible to perform the follow up of GRBs even for several months. This approach would be extremely useful to extend the Spectrum Energetic Distribution (SED) from the gamma to the to radio band and would increase the number of radio detectable GRBs. In principle, the SKA could help to understand the physics of GRBs by setting constraints on theoretical models. This goal could be achieved by taking into account multiple observations at different wavelengths in order to obtain a deeper insight of the sources. Here, we present an estimation of GRB radio detections, showing that the GRBs can really be observed by the SKA. The approach that we present consists in determining blind detection rates derived by a very large sample consisting of merging several GRB catalogues observed by current missions as Swift, Fermi, Agile and INTEGRAL and by previous missions as BeppoSAX, CGRO, GRANAT, HETE-2, Ulysses and Wind. The final catalogue counts 7516 distinct sources. We compute the fraction of GRBs that could be observed by the SKA at high and low frequencies, above its observable sky. Considering the planned SKA sensitivity and through an extrapolation based on previous works and observations, we deduce the minimum fluence in the range 15-150 keV. This is the energy interval where a GRB should emit to be detectable in the radio band by the SKA. Results seem consistent with observational capabilities.

  17. Explosive and Radio-Selected Transients: Transient Astronomy with Square Kilometre Array and its Precursors

    NASA Astrophysics Data System (ADS)

    Chandra, Poonam; Anupama, G. C.; Arun, K. G.; Iyyani, Shabnam; Misra, Kuntal; Narasimha, D.; Ray, Alak; Resmi, L.; Roy, Subhashis; Sutaria, Firoza

    2016-12-01

    With the high sensitivity and wide-field coverage of the Square Kilometre Array (SKA), large samples of explosive transients are expected to be discovered. Radio wavelengths, especially in commensal survey mode, are particularly well-suited for uncovering the complex transient phenomena. This is because observations at radio wavelengths may suffer less obscuration than in other bands (e.g. optical/IR or X-rays) due to dust absorption. At the same time, multiwaveband information often provides critical source classification rapidly than possible with only radio band data. Therefore, multiwaveband observational efforts with wide fields of view will be the key to progress of transients astronomy from the middle 2020s offering unprecedented deep images and high spatial and spectral resolutions. Radio observations of Gamma Ray Bursts (GRBs) with SKA will uncover not only much fainter bursts and verifying claims of sensitivity-limited population versus intrinsically dim GRBs, they will also unravel the enigmatic population of orphan afterglows. The supernova rate problem caused by dust extinction in optical bands is expected to be lifted in the SKA era. In addition, the debate of single degenerate scenario versus double degenerate scenario will be put to rest for the progenitors of thermonuclear supernovae, since highly sensitive measurements will lead to very accurate mass loss estimation in these supernovae. One also expects to detect gravitationally lensed supernovae in far away Universe in the SKA bands. Radio counterparts of the gravitational waves are likely to become a reality once SKA comes online. In addition, SKA is likely to discover various new kinds of transients.

  18. Baryonic acoustic oscillations from 21 cm intensity mapping: the Square Kilometre Array case

    NASA Astrophysics Data System (ADS)

    Villaescusa-Navarro, Francisco; Alonso, David; Viel, Matteo

    2017-04-01

    We quantitatively investigate the possibility of detecting baryonic acoustic oscillations (BAO) using single-dish 21 cm intensity mapping observations in the post-reionization era. We show that the telescope beam smears out the isotropic BAO signature and, in the case of the Square Kilometre Array (SKA) instrument, makes it undetectable at redshifts z ≳ 1. We however demonstrate that the BAO peak can still be detected in the radial 21 cm power spectrum and describe a method to make this type of measurements. By means of numerical simulations, containing the 21 cm cosmological signal as well as the most relevant Galactic and extra-Galactic foregrounds and basic instrumental effect, we quantify the precision with which the radial BAO scale can be measured in the 21 cm power spectrum. We systematically investigate the signal to noise and the precision of the recovered BAO signal as a function of cosmic variance, instrumental noise, angular resolution and foreground contamination. We find that the expected noise levels of SKA would degrade the final BAO errors by ∼5 per cent with respect to the cosmic-variance limited case at low redshifts, but that the effect grows up to ∼65 per cent at z ∼ 2-3. Furthermore, we find that the radial BAO signature is robust against foreground systematics, and that the main effect is an increase of ∼20 per cent in the final uncertainty on the standard ruler caused by the contribution of foreground residuals as well as the reduction in sky area needed to avoid high-foreground regions. We also find that it should be possible to detect the radial BAO signature with high significance in the full redshift range. We conclude that a 21 cm experiment carried out by the SKA should be able to make direct measurements of the expansion rate H(z) with measure the expansion with competitive per cent level precision on redshifts z ≲ 2.5.

  19. Clusters of Galaxies and the Cosmic Web with Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Kale, Ruta; Dwarakanath, K. S.; Vir Lal, Dharam; Bagchi, Joydeep; Paul, Surajit; Malu, Siddharth; Datta, Abhirup; Parekh, Viral; Sharma, Prateek; Pandey-Pommier, Mamta

    2016-12-01

    The intra-cluster and inter-galactic media that pervade the large scale structure of the Universe are known to be magnetized at sub-micro Gauss to micro Gauss levels and to contain cosmic rays. The acceleration of cosmic rays and their evolution along with that of magnetic fields in these media is still not well understood. Diffuse radio sources of synchrotron origin associated with the Intra-Cluster Medium (ICM) such as radio halos, relics and mini-halos are direct probes of the underlying mechanisms of cosmic ray acceleration. Observations with radio telescopes such as the Giant Metrewave Radio Telescope, the Very Large Array and the Westerbork Synthesis Radio Telescope have led to the discoveries of about 80 such sources and allowed detailed studies in the frequency range 0.15-1.4 GHz of a few. These studies have revealed scaling relations between the thermal and non-thermal properties of clusters and favour the role of shocks in the formation of radio relics and of turbulent re-acceleration in the formation of radio halos and mini-halos. The radio halos are known to occur in merging clusters and mini-halos are detected in about half of the cool-core clusters. Due to the limitations of current radio telescopes, low mass galaxy clusters and galaxy groups remain unexplored as they are expected to contain much weaker radio sources. Distinguishing between the primary and the secondary models of cosmic ray acceleration mechanisms requires spectral measurements over a wide range of radio frequencies and with high sensitivity. Simulations have also predicted weak diffuse radio sources associated with filaments connecting galaxy clusters. The Square Kilometre Array (SKA) is a next generation radio telescope that will operate in the frequency range of 0.05-20 GHz with unprecedented sensitivities and resolutions. The expected detection limits of SKA will reveal a few hundred to thousand new radio halos, relics and mini-halos providing the first large and comprehensive

  20. A failure of serendipity: the Square Kilometre Array will struggle to eavesdrop on human-like extraterrestrial intelligence

    NASA Astrophysics Data System (ADS)

    Forgan, D. H.; Nichol, R. C.

    2011-04-01

    The Square Kilometre Array (SKA) will operate in frequency ranges often used by military radar and other communications technology. It has been shown that if extraterrestrial intelligences (ETIs) communicate using similar technology, then the SKA should be able to detect such transmissions up to distances of ~100 pc (~300 light years) from Earth. However, Mankind has greatly improved its communications technology over the last century, dramatically reducing signal leakage and making the Earth ‘radio quiet’. If ETIs follow the same pattern as the human race, will we be able to detect their signal leakage before they become radio quiet? We investigate this question using Monte Carlo realization techniques to simulate the growth and evolution of intelligent life in the Galaxy. We show that if civilizations are ‘human’ in nature (i.e. they are only ‘radio loud’ for ~100 years, and can only detect each other with an SKA-like instrument out to 100 pc, within a maximum communication time of 100 years), then the probability for such civilizations accidentally detecting each other is low (~10-7), much lower than if other, dedicated communication techniques are permissible (e.g. optical SETI or neutrino communication).

  1. Scatter broadening of compact radio sources by the ionized intergalactic medium: prospects for detection with Space VLBI and the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Koay, J. Y.; Macquart, J.-P.

    2015-01-01

    We investigate the feasibility of detecting and probing various components of the ionized intergalactic medium (IGM) and their turbulent properties at radio frequencies through observations of scatter broadening of compact sources. There is a strong case for conducting targeted observations to resolve scatter broadening (where the angular size scales as ˜ν-2) of compact background sources intersected by foreground galaxy haloes and rich clusters of galaxies to probe the turbulence of the ionized gas in these objects, particularly using Space very long baseline interferometry (VLBI) with baselines of 350 000 km at frequencies below 800 MHz. The sensitivity of the Square Kilometre Array (SKA) allows multifrequency surveys of interstellar scintillation (ISS) of ˜ 100 μJy sources to detect or place very strong constraints on IGM scatter broadening down to ˜ 1 μas scales at 5 GHz. Scatter broadening in the warm-hot component of the IGM with typical overdensities of ˜30 cannot be detected, even with Space VLBI or ISS, and even if the outer scales of turbulence have an unlikely low value of ˜1 kpc. None the less, intergalactic scatter broadening can be of the order of ˜ 100 μas at 1 GHz and ˜ 3 μas at 5 GHz for outer scales ˜1 kpc, assuming a sufficiently high-source redshift that most sight-lines intersect within a virial radius of at least one galaxy halo (z ≳ 0.5 and 1.4 for 1010 and 1011 M⊙ systems, following McQuinn 2014). Both Space VLBI and multiwavelength ISS observations with the SKA can easily test such a scenario, or place strong constraints on the outer scale of the turbulence in such regions.

  2. H I observations of galaxies in the southern filament of the Virgo Cluster with the Square Kilometre Array Pathfinder KAT-7 and the Westerbork Synthesis Radio Telescope

    NASA Astrophysics Data System (ADS)

    Sorgho, A.; Hess, K.; Carignan, C.; Oosterloo, T. A.

    2017-01-01

    We map the H I distribution of galaxies in a ˜1.5 × 2.5° region located at the virial radius south of the Virgo Cluster using the KAT-7 and the Westerbork Synthesis Radio Telescope interferometers. Because of the different beam sizes of the two telescopes, a similar column density sensitivity of NH I ˜ 1 × 1018 atoms cm- 2 was reached with the two observations over 16.5 km s-1. We pioneer a new approach to combine the observations and take advantage of their sensitivity to both the large- and small-scale structures. Out to an unprecedented extent, we detect an H I tail of ˜60 kpc being stripped off NGC 4424, a peculiar spiral galaxy. The properties of the galaxy, together with the shape of the tail, suggest that NGC 4424 is a post-merger galaxy undergoing ram pressure stripping as it falls towards the centre of the Virgo Cluster. We detect a total of 14 galaxies and three H I clouds lacking optical counterparts. One of the clouds is a new detection with an H I mass of 7 × 107 M⊙ and a strong H I profile with W50 = 73 km s-1. We find that 10 out of the 14 galaxies present H I deficiencies not higher than those of the cluster's late spirals, suggesting that the environmental effects are not more pronounced in the region than elsewhere in the cluster.

  3. African Astronomy and the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    MacLeod, Gordon

    2010-02-01

    We highlight the growth of astronomy across Africa and the effect of hosting the Square Kilometer Array (SKA) will have on this growth. From the construction of a new 25m radio telescope in Nigeria, to new university astronomy programmes in Kenya, the HESS in Namibia and the Mauritian Radio Telescope, to the world class projects being developed in South Africa (Southern African Large Telescope and Karoo Array Telescope) astronomy is re-emerging across the continent. The SKA will represent the pinnacle of technological advancement in astronomy when constructed; requiring ultra high speed data transmission lines over 3000 km baselines and the World's fastest computer for correlation purposes. The investment alone to build the SKA on African soil will be of great economic benefit to its people, but the required network connectivity will significantly drive commercial expansion far beyond the initial value of the SKA investment. The most important consequence of hosting the SKA in Africa would be the impact on Human Capital Development (HCD) on the continent. Major HCD projects already underway producing excellent results will be presented. )

  4. Measured aperture-array noise temperature of the Mark II phased array feed for ASKAP

    NASA Astrophysics Data System (ADS)

    Chippendale, A. P.; Brown, A. J.; Beresford, R. J.; Hampson, G. A.; Shaw, R. D.; Hayman, D. B.; Macleod, A.; Forsyth, A. R.; Hay, S. G.; Leach, M.; Cantrall, C.; Brothers, M. L.; Hotan, A. W.

    2015-11-01

    We have measured the aperture-array noise temperature of the first Mk. II phased array feed that CSIRO has built for the Australian Square Kilometre Array Pathfinder telescope. As an aperture array, the Mk. II phased array feed achieves a beam equivalent noise temperature less than 40 K from 0.78 GHz to 1.7 GHz and less than 50 K from 0.7 GHz to 1.8 GHz for a boresight beam directed at the zenith. We believe these are the lowest reported noise temperatures over these frequency ranges for ambient-temperature phased arrays. The measured noise temperature includes receiver electronics noise, ohmic losses in the array, and stray radiation from sidelobes illuminating the sky and ground away from the desired field of view. This phased array feed was designed for the Australian Square Kilometre Array Pathfinder to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array.

  5. Australian SKA Pathfinder: A High-Dynamic Range Wide-Field of View Survey Telescope

    NASA Astrophysics Data System (ADS)

    DeBoer, D. R.; Gough, R. G.; Bunton, J. D.; Cornwell, T. J.; Beresford, R. J.; Johnston, S.; Feain, I. J.; Schinckel, A. E.; Jackson, C. A.; Kesteven, M. J.; Chippendale, A.; Hampson, G. A.; O'Sullivan, J. D.; Hay, S. G.; Jacka, C. E.; Sweetnam, T. W.; Storey, M. C.; Ball, L.; Boyle, B. J.

    2009-08-01

    The Australia SKA Pathfinder (ASKAP) is a new telescope under development as a world-class high-dynamic-range wide-field-of-view survey instrument. It will utilize focal plane phased array feeds on the 36 12-m antennas that will compose the array. The large amounts of data present a huge computing challenge, and ASKAP will store data products in an archive after near real-time pipeline processing. This powerful instrument will be deployed at a new radio-quiet observatory, the Murchison Radio-astronomy Observatory in the midwest region of Western Australia, to enable sensitive surveys of the entire sky to address some of the big questions in contemporary physics. As a pathfinder for the SKA, ASKAP will demonstrate field of view enhancement and computing/processing technology as well as the operation of a large-scale radio array in a remote and radio-quiet region of Australia.

  6. The Square Kilometre Array: a challenge for 2020 to which Spain can contribute in 2012

    NASA Astrophysics Data System (ADS)

    Verdes-Montenegro, L.; Dios Santander-Vela, J. D.

    2013-05-01

    The SKA, composed of several hundreds of three different types of antennas with separations up to 3.000 km, and up to 200 square degrees field of view, will be the largest, most sensitive radio telescope ever built. It will be able to provide fundamental answers in areas such as the dark era, when gas in galaxies was first turned into stars and the first black holes formed, star formation in nearby galaxies from stellar birth to death, faint extragalactic emission, magnetism in galaxies, extrasolar planets, or confrontation of Einstein predictions with pulsars and black hole observations. The technological challenges involved offer an unprecedented opportunity to collaborate in the development of hardware and software technologies. The energy requirements of the SKA provide an opportunity to accelerate technology development in scalable renewable energy generation, distribution, storage and demand monitoring and reduction. Data transport will reach over a hundred times the current global internet traffic data rates, delivering as much data as the full World Wide Web. Processing this data torrent in real time will require high-performance distributed computing as well as data storage and innovative retrieval technologies in the exascale. This way to do science, based on data-intensive interdisciplinary cooperation, is the base of the concept of e-Science, which necessarily includes outreach as an indissoluble part of the knowledge-based human progress. The scientific and technological challenges and opportunities that SKA can bring to the Spanish community will be described in this talk.

  7. Probing Individual Sources during Reionization and Cosmic Dawn using Square Kilometre Array HI 21-cm Observations

    NASA Astrophysics Data System (ADS)

    Datta, Kanan K.; Ghara, Raghunath; Majumdar, Suman; Choudhury, T. Roy; Bharadwaj, Somnath; Roy, Himadri; Datta, Abhirup

    2016-12-01

    Detection of individual luminous sources during the reionization epoch and cosmic dawn through their signatures in the HI 21-cm signal is one of the direct approaches to probe the epoch. Here, we summarize our previous works on this and present preliminary results on the prospects of detecting such sources using the SKA1-low experiment. We first discuss the expected HI 21-cm signal around luminous sources at different stages of reionization and cosmic dawn. We then introduce two visibility based estimators for detecting such signals: one based on the matched filtering technique and the other relies on simply combing the visibility signal from different baselines and frequency channels. We find that the SKA1-low should be able to detect ionized bubbles of radius Rb ≳ 10 Mpc with ˜100 h of observations at redshift z˜8 provided that the mean outside neutral hydrogen fraction x_{ {HI}} ≳ 0.5. We also investigate the possibility of detecting HII regions around known bright QSOs such as around ULASJ1120+0641 discovered by Mortlock et al. ( Nature 474, 7353 (2011)). We find that a 5 σ detection is possible with 600 h of SKA1-low observations if the QSO age and the outside xHI are at least ˜2×107 Myr and ˜0.2 respectively. Finally, we investigate the possibility of detecting the very first X-ray and Ly- α sources during the cosmic dawn. We consider mini-QSOs like sources which emits in X-ray frequency band. We find that with a total ˜ 1000 h of observations, SKA1-low should be able to detect those sources individually with a ˜ 9 σ significance at redshift z=15. We summarize how the SNR changes with various parameters related to the source properties.

  8. Measured Sensitivity of the First Mark II Phased Array Feed on an ASKAP Antenna

    NASA Astrophysics Data System (ADS)

    Chippendale, A. P.; Brown, A. J.; Beresford, R. J.; Hampson, G. A.; Macleod, A.; Shaw, R. D.; Brothers, M. L.; Cantrall, C.; Forsyth, A. R.; Hay, S. G.; Leach, M.

    2015-09-01

    This paper presents the measured sensitivity of CSIRO's first Mk. II phased array feed (PAF) on an ASKAP antenna. The Mk. II achieves a minimum system-temperature-over-efficiency T_{sys}/η of 78 K at 1.23 GHz and is 95 K or better from 835 MHz to 1.8 GHz. This PAF was designed for the Australian SKA Pathfinder telescope to demonstrate fast astronomical surveys with a wide field of view for the Square Kilometre Array (SKA).

  9. LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Stebbins, Robin

    2008-01-01

    USA Pathfinder is a space mission dedicated to demonstrating technology for the Laser Interferometer Space Antenna (LISA). LISA is a joint ESA/NASA mission to detect low-frequency gravitational waves on the 0.0001 to 0.1 Hz frequency band. LISA is expected to observe 100's of merging massive black hole binaries out z-15, tens of thousands of close compact binary systems in the Milky Way, merging intermediate-mass black hole binaries, tens of stellar-mass black holes falling into supermassive black holes in galactic centers, and possibly other exotic sources. Several critical LISA technologies have not been demonstrated at the requisite level of performance. In spaceflight, and some fight hardware cannot be tested in a 1-g environment. Hence, the LISA Pathfinder mission is being implemented to demonstrate these critical LISA technologies in a relevant flight environment. LISA Pathfinder mimics one arm of the LISA constellation by shrinking the 5-million-kilometer armlength down to a few tens of centimeters. The experimental concept is to measure the relative separation between two test masses nominally following their own geodesics, and thereby determine the relative residual acceleration between them near 1 mHz, about a decade above the lowest frequency required by LISA. To implement such a concept, disturbances on the test masses must be kept very small by many design features, but chiefly by "drag-free" flight. A drag-free spacecraft follows a free-falling test mass which it encloses, but has no mechanical connection to. The spacecraft senses it's orientation and separation with respect to the proof mass, and its propulsion system is commanded to keep the spacecraft centered about the test mass. Thus, the spacecraft shields the test mass from most external influences, and minimizes the effect of force gradients arising from the spacecraft, and acting on the test mass. LISA Pathfinder will compare the geodesic of one test mass against that of the other. Only a

  10. H I observations of two new dwarf galaxies: Pisces A and B with the SKA Pathfinder KAT-7

    NASA Astrophysics Data System (ADS)

    Carignan, C.; Libert, Y.; Lucero, D. M.; Randriamampandry, T. H.; Jarrett, T. H.; Oosterloo, T. A.; Tollerud, E. J.

    2016-03-01

    Context. Pisces A and Pisces B are the only two galaxies found via optical imaging and spectroscopy out of 22 Hi clouds identified in the GALFAHI survey as dwarf galaxy candidates. Aims: We derive the Hi content and kinematics of Pisces A and B. Methods: Our aperture synthesis Hi observations used the seven-dish Karoo Array Telescope (KAT-7), which is a pathfinder instrument for MeerKAT, the South African precursor to the mid-frequency Square Kilometre Array (SKA-MID). Results: The low rotation velocities of ~5 km s-1 and ~10 km s-1 in Pisces A and B, respectively, and their Hi content show that they are really dwarf irregular galaxies (dIrr). Despite that small rotation component, it is more the random motions ~9-11 km s-1 that provide most of the gravitational support, especially in the outer parts. The study of their kinematics, especially the strong gradients of random motions, suggest that those two dwarf galaxies are not yet in equilibrium. Conclusions: These Hi- rich galaxies may be indicative of a large population of dwarfs at the limit of detectability. However, such gas-rich dwarf galaxies will most likely never be within the virial radius of MW-type galaxies and become subhalo candidates. Systems such as Pisces A and B are more likely to be found at a few Mpc s from MW-type galaxies. The final FITS cube is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/L3

  11. Automated detection of extended sources in radio maps: progress from the SCORPIO survey

    NASA Astrophysics Data System (ADS)

    Riggi, S.; Ingallinera, A.; Leto, P.; Cavallaro, F.; Bufano, F.; Schillirò, F.; Trigilio, C.; Umana, G.; Buemi, C. S.; Norris, R. P.

    2016-08-01

    Automated source extraction and parametrization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper, we present a new algorithm, called CAESAR (Compact And Extended Source Automated Recognition), to detect and parametrize extended sources in radio interferometric maps. It is based on a pre-filtering stage, allowing image denoising, compact source suppression and enhancement of diffuse emission, followed by an adaptive superpixel clustering stage for final source segmentation. A parametrization stage provides source flux information and a wide range of morphology estimators for post-processing analysis. We developed CAESAR in a modular software library, also including different methods for local background estimation and image filtering, along with alternative algorithms for both compact and diffuse source extraction. The method was applied to real radio continuum data collected at the Australian Telescope Compact Array (ATCA) within the SCORPIO project, a pathfinder of the Evolutionary Map of the Universe (EMU) survey at the Australian Square Kilometre Array Pathfinder (ASKAP). The source reconstruction capabilities were studied over different test fields in the presence of compact sources, imaging artefacts and diffuse emission from the Galactic plane and compared with existing algorithms. When compared to a human-driven analysis, the designed algorithm was found capable of detecting known target sources and regions of diffuse emission, outperforming alternative approaches over the considered fields.

  12. LUNASKA experiments using the Australia Telescope Compact Array to search for ultrahigh energy neutrinos and develop technology for the lunar Cherenkov technique

    SciTech Connect

    James, C. W.; Protheroe, R. J.; Ekers, R. D.; Phillips, C. J.; Roberts, P.; Alvarez-Muniz, J.; Bray, J. D.; McFadden, R. A.

    2010-02-15

    We describe the design, performance, sensitivity and results of our recent experiments using the Australia Telescope Compact Array (ATCA) for lunar Cherenkov observations with a very wide (600 MHz) bandwidth and nanosecond timing, including a limit on an isotropic neutrino flux. We also make a first estimate of the effects of small-scale surface roughness on the effective experimental aperture, finding that contrary to expectations, such roughness will act to increase the detectability of near-surface events over the neutrino energy-range at which our experiment is most sensitive (though distortions to the time-domain pulse profile may make identification more difficult). The aim of our 'Lunar UHE Neutrino Astrophysics using the Square Kilometre Array' (LUNASKA) project is to develop the lunar Cherenkov technique of using terrestrial radio telescope arrays for ultrahigh energy (UHE) cosmic ray (CR) and neutrino detection, and, in particular, to prepare for using the Square Kilometre Array (SKA) and its path-finders such as the Australian SKA Pathfinder (ASKAP) and the Low Frequency Array (LOFAR) for lunar Cherenkov experiments.

  13. Pathfinder Rear Ramp

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder's rear rover ramp can be seen successfully unfurled in this image, taken at the end of Sol 2 by the Imager for Mars Pathfinder (IMP). This ramp was later used for the deployment of the microrover Sojourner, which occurred at the end of Sol 2. Areas of a lander petal and deflated airbag are visible at left. The image helped Pathfinder scientists determine that the rear ramp was the one to use for rover deployment. At upper right is the rock dubbed 'Barnacle Bill,' which Sojourner will later study.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C.

  14. Pathfinder aircraft flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder research aircraft's wing structure is clearly defined as it soars under a clear blue sky during a test flight from Dryden Flight Research Center, Edwards, California, in November of 1996. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

  15. The LISA Pathfinder mission

    NASA Astrophysics Data System (ADS)

    Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Brandt, N.; Caleno, M.; Cañizares, P.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Ferrone, V.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marin, A.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gilbert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hernández, V.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Monsky, A.; Nicolini, D.; Nicolodi, D.; Nofrarias, M.; Pedersen, F.; Perreur-Lloyd, M.; Plagnol, E.; Prat, P.; Racca, G. D.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schleicher, A.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Steier, F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tu, H.-B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Ziegler, T.; Zweifel, P.

    2012-06-01

    In this paper, we describe the current status of the LISA Pathfinder mission, a precursor mission aimed at demonstrating key technologies for future space-based gravitational wave detectors, like LISA. Since much of the flight hardware has already been constructed and tested, we will show that performance measurements and analysis of these flight components lead to an expected performance of the LISA Pathfinder which is a significant improvement over the mission requirements, and which actually reaches the LISA requirements over the entire LISA Pathfinder measurement band.

  16. MESUR Pathfinder Science Investigations

    NASA Technical Reports Server (NTRS)

    Golombek, M.

    1993-01-01

    The MESUR (Mars Environmental Survey) Pathfinder mission is the first Discovery mission planned for launch in 1996. MESUR Pathfinder is designed as an engineering demonstration of the entry, descent and landing approach to be employed by the follow-on MESUR Network mission, which will land of order 10 small stations on the surface of Mars to investigate interior, atmospheric and surface properties. Pathfinder is a small Mars lander, equipped with a microrover to deploy instruments and explore the local landing site. Instruments selected for Pathfinder include a surface imager on a 1 m pop-up mast (stereo with spectral filters), an atmospheric structure instrument/surface meteorology package, and an alpha proton x-ray spectrometer. The microrover will carry the alpha proton x-ray spectrometer to a number of different rocks and surface materials and provide close-up imaging...

  17. Pathfinder: Humans in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1988-01-01

    Viewgraphs are presented on the Pathfinder program. Information is given on human exploration of the solar system, technical requirements interfaces, program objectives, space suits, human performance, man-machine systems, space habitats, life support systems, and artificial gravity

  18. Pathfinder Innovation Projects

    EPA Pesticide Factsheets

    The Pathfinder program supports high-risk, high-reward research ideas with funding and staff time. The goal is to feed a culture of innovation in the Agency and integrate innovative ideas in EPA research programs.

  19. LISA and its pathfinder

    NASA Astrophysics Data System (ADS)

    The LISA Pathfinder Team

    2015-08-01

    On astronomical scales, gravity is the engine of the Universe. The launch of LISA Pathfinder this year to prepare the technology to detect gravitational waves will help us 'listen' to the whole Universe.

  20. Pathfinder aircraft in flight

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The Pathfinder is shown flying low over Rogers Dry Lakebed at Edwards Air Force Base. Its wing is very flexible, while its upper surface is covered with solar cells. While at high altitude, the vehicle was controlled by a remote pilot on the ground, but when the concept is fully developed, a vehicle larger than but similar to Pathfinder may be able to stay aloft for months at a time, without landing and with only sunlight as its 'fuel.'

  1. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L. I.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    LISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter. The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper

  2. JWST Pathfinder Telescope Integration

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Kennard, Scott H.; Broccolo, Ronald T.; Ellis, James M.; Daly, Elizabeth A.; Hahn, Walter G.; Amon, John N.; Mt. Pleasant, Stephen M.; Texter, Scott; Atkinson, Charles B.; McKay, Andrew; Levi, Joshua; Keski-Kuha, Ritva; Feinberg, Lee

    2015-01-01

    The James Webb Space Telescope (JWST) is a 6.5m, segmented, IR telescope that will explore the first light of the universe after the big bang. In 2014, a major risk reduction effort related to the Alignment, Integration, and Test (AI&T) of the segmented telescope was completed. The Pathfinder telescope includes two Primary Mirror Segment Assemblies (PMSA's) and the Secondary Mirror Assembly (SMA) onto a flight-like composite telescope backplane. This pathfinder allowed the JWST team to assess the alignment process and to better understand the various error sources that need to be accommodated in the flight build. The successful completion of the Pathfinder Telescope provides a final integration roadmap for the flight operations that will start in August 2015.

  3. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    McNamara, Paul

    2015-04-01

    LISA Pathfinder is the second of the European Space Agency's Small Missions for Advanced Research and Technology (SMART). The goal of LISA Pathfinder (LPF) is to demonstrate the technologies required for future laser interferometric spaceborne gravitational wave detectors. The development of the LPF hardware is now over, and final integration and testing of the spacecraft and payload is underway. The delivery of the opto-mechanical heart of the payload is scheduled for Q2 2015, following which the final system tests will be performed. Launch is scheduled for September 2015. First results will be available approximately 3 months after launch. In this presentation I will describe the LISA Pathfinder mission, and provide the current status of the mission and remaining activities to launch and operations.

  4. Pathfinder: A Retrospective

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Mars is one of the most interesting planets in the solar system, featuring enormous canyons, giant volcanoes, and indications that, early in its history, it might have had rivers and perhaps even oceans. Five years ago, in July of 1997, the Pathfinder mission landed on Mars, bringing with it the microwave-oven sized Sojourner rover to wander around on the surface and analyse rocks. Among the experiments on the mission was one designed to analyse dust deposition. Pathfinder is only the first of an armada of spacecraft which will examine Mars from the pole to the equator in the next decade, culminating with a mission to bring humans to Mars.

  5. Martian terrain near Pathfinder

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Large boulders are visible in this enlargement of pictures taken by the Mars Pathfinder lander camera on July 4, 1997. The landing site is in the dry flood channel named Ares Valles. The boulders probably represent deposits from one of the catastrophic floods that carved the ancient channel. Between the rocks is brownish windblown soil. The gray-tan sky results from dust particles in the atmosphere.

    Pathfinder, a low-cost Discovery mission, is the first of a new fleet of spacecraft that are planned to explore Mars over the next ten years. Mars Global Surveyor, already en route, arrives at Mars on September 11 to begin a two year orbital reconnaissance of the planet's composition, topography, and climate. Additional orbiters and landers will follow every 26 months.

    Mars Pathfinder was developed and managed by the Jet Propulsion Laboratory for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  6. The LISA Pathfinder mission

    NASA Astrophysics Data System (ADS)

    McNamara, Paul

    2012-07-01

    LISA Pathfinder, the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology demonstrator for future spaceborne gravitational wave observatories, for example the proposed ESA mission, NGO. The technologies required for NGO are many and extremely challenging. This coupled with the fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise, led to the implementation of the LISA Pathfinder mission to test the critical NGO technologies in a flight environment. LISA Pathfinder essentially mimics one arm of the NGO constellation by shrinking the 1 million kilometre armlength down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology: the distance between the two test masses is measured using a laser interferometric technique similar to one aspect of the NGO interferometry system. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. Here I will present an overview of the mission, focusing on scientific and technical goals, followed by the current status of the project.

  7. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    McNamara, Paul

    2013-04-01

    LISA Pathfinder, the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future interferometric spaceborne gravitational wave observatories, for example the proposed eLISA mission. The technologies required for eLISA are many and extremely challenging. This coupled with the fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise, led to the implementation of the LISA Pathfinder mission to test the critical eLISA technologies in a flight environment. LISA Pathfinder essentially mimics one arm of the eLISA constellation by shrinking the 1 million kilometre armlength down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology: the distance between the two test masses is measured using a laser interferometric technique similar to one aspect of the eLISA interferometry system. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. Here I will present an overview of the mission, focusing on scientific and technical goals, followed by the current status of the project.

  8. The Pathfinder Microrover

    NASA Technical Reports Server (NTRS)

    Matijevic, J. R.; Bickler, D. B.; Braun, D. F.; Eisen, H. J.; Matthies, L. H.; Mishkin, A. H.; Stone, H. W.; van Nieuwstadt, L. M.; Wen, L. C.; Wilcox, B. H.; Ferguson, D.; Landis, G. A.; Oberle, L.

    1996-01-01

    An exciting scientific component of the Pathfinder mission is the rover, which will act as a mini-field geologist by providing us with access to samples for chemical analyses and close-up images of the Martian surface, performing active experiments to modify the surface and study the results, and exploring the landing site area.

  9. The LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Thorpe, james; McNamara, P. W.

    2011-01-01

    LISA Pathfinder is a dedicated technology demonstration space mission for the Laser Interferometer Space Antenna (LISA), a NASA/ESA collaboration to operate a space-based observatory for gravitational waves in the milli-Hertz band. Although the formal partnership between the agencies was dissolved in the Spring of 2011, both agencies are actively pursuing concepts for LISA-like gravitational wave observatories. These concepts take advantage of the significant technology development efforts that have already been made, especially those of the LISA Pathfinder mission. LISA Pathfinder, which is in the late stages of implementation, will place two test masses in drag-free flight and measure the relative acceleration between them. This measurement will validate a number of technologies that are critical to LISA-like gravitational wave instruments including sensing and control of the test masses, drag-free control laws, microNewton thrusters, and picometer-level laser metrology. We will present the current status of the LISA Pathfinder mission and associated activities.

  10. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    McNamara, Paul W.

    2013-01-01

    Laser Interferometer Space Antenna (LISA) Pathfinder (formerly known as SMART-2) is a European Space Agency mission designed to pave the way for the joint ESA/NASA LISA mission by testing in flight the critical technologies required for space borne gravitational wave detection; it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra precise micro-Newton propulsion system. LISA Pathfinder (LPF) essentially mimics one arm of space-borne gravitational wave detectors by shrinking the million kilometer scale armlengths down to a few tens of centimeters, giving up the sensitivity to gravitational waves, but keeping the measurement technology. The scientific objective of the LPF mission consists then of the first in-flight test of low frequency gravitational wave detection metrology.

  11. The LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Stebbins, Robin

    2009-01-01

    LISA Pathfinder (formerly known as SMART-2) is a European Space Agency (ESA) mission designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for spaceborne gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. LISA Pathfinder is currently in the integration and test phase of the development, and is due to be launched on a dedicated launch vehicle in late 2011, with first results on the performance of the system being available approx 6 months later. This poster will describe the mission in detail, give the current status of the spacecraft development, and highlight the future milestones in the integration and test campaign.

  12. The LISA Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    McNamara, P.; Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Bogenstahl, J.; Bortoluzzi, D.; Brandt, N.; Caleno, M.; Cavalleri, A.; Congedo, G.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixton, G.; Dolesi, R.; Dumbar, N.; Fauste, J.; Ferraioli, L.; Ferroni, V.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Huesler, J.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Korsakova, N.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Mateos, I.; Mendes, J.; Mitchell, E.; Nicolodi, D.; Nofrarias, M.; Perreur-Lloyd, M.; Plagnol, E.; Prat, P.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Schleicher, A.; Shaul, D.; Sopuerta, C. F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Ziegler, T.; Zweifel, P.

    2013-01-01

    LISA Pathfinder (formerly known as SMART-2) is an European Space Agency mission designed to pave the way for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission by testing in flight the critical technologies required for space-borne gravitational wave detection; it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control, and an ultra precise micro-Newton propulsion system. LISA Pathfinder (LPF) essentially mimics one arm of spaceborne gravitational wave detectors by shrinking the million kilometre scale armlengths down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. In this paper I will give a brief overview of the mission, focusing on scientific and technical goals.

  13. A Southern Sky Survey with Fermi LAT and ASKAP

    SciTech Connect

    Cameron, Robert A.; /SLAC /KIPAC, Menlo Park

    2010-04-29

    We present the prospects for a future joint gamma-ray and radio survey of southern hemisphere sources using the Fermi Large Area Telescope (LAT) and the upcoming Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope. ASKAP is a next generation radio telescope designed to perform surveys at GHz frequencies at a much higher survey speed than previous radio telescopes, and is scheduled to start engineering observations in 2011. The survey capabilities of both Fermi LAT and ASKAP are described, and the planned science surveys for ASKAP are summarized. We give some expected details of the Variable and Slow Transient (VAST) survey using ASKAP, which will search for transients on timescales from 5 seconds to years. Some observational properties of faint and transient sources seen at gamma-ray and radio wavelengths are summarized, and prospects and strategies for using ASKAP survey data for LAT source counterpart identification are summarized.

  14. Mars Pathfinder Status at Launch

    NASA Technical Reports Server (NTRS)

    Spear, A. J.; Freeman, Delma C., Jr.; Braun, Robert D.

    1996-01-01

    The Mars Pathfinder Flight System is in final test, assembly and launch preparations at the Kennedy Space Center in Florida. Launch is scheduled for 2 Dec. 1996. The Flight System development, in particular the Entry, Descent, and Landing (EDL) system, was a major team effort involving JPL, other NASA centers and industry. This paper provides a summary Mars Pathfinder description and status at launch. In addition, a section by NASA's Langley Research Center, a key EDL contributor, is provided on their support to Mars Pathfinder. This section is included as an example of the work performed by Pathfinder team members outside JPL.

  15. The Mars Pathfinder Mission

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.

    1996-09-01

    The Mars Pathfinder mission is a Discovery class mission that will place a small lander and rover on the surface of Mars on July 4, 1997. The Pathfinder flight system is a single small lander, packaged within an aeroshell and back cover with a back-pack-style cruise stage. The vehicle will be launched, fly independently to Mars, and enter the atmosphere directly on approach behind the aeroshell. The vehicle is slowed by a parachute and 3 small solid rockets before landing on inflated airbags. Petals of a small tetrahedron shaped lander open up, to right the vehicle. The lander is solar powered with batteries and will operate on the surface for up to a year, downlinking data on a high-gain antenna. Pathfinder will be the first mission to use a rover, with 3 imagers and an alpha proton X-ray spectrometer, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which will provide a calibration point or "ground truth" for orbital remote sensing observations. The rover (includes a series of technology experiments), the instruments (including a stereo multispectral surface imager on a pop up mast and an atmospheric structure instrument-surface meteorology package) and the telemetry system will allow investigations of: the surface morphology and geology at meter scale, the petrology and geochemistry of rocks and soils, the magnetic properties of dust, soil mechanics and properties, a variety of atmospheric investigations and the rotational and orbital dynamics of Mars. Landing downstream from the mouth of a giant catastrophic outflow channel, Ares Vallis, offers the potential of identifying and analyzing a wide variety of crustal materials, from the ancient heavily cratered terrain, intermediate-aged ridged plains and reworked channel deposits, thus allowing first-order scientific investigations of the early differentiation and evolution of the crust, the development of weathering products and early environments and conditions on Mars.

  16. Science with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Sumner, T. J.

    2013-01-01

    LISA Pathfinder will offer a unique opportunity to use an extremely sensitive calibrated pair of accelerometers on a drag-free spacecraft platform to perform weak force experiments in an environment not available on Earth. The Science Team has identified a number of interesting tests which could be done after the main technology demonstration mission is completed. Potential tests include a measurement of G in space to a comparable accuracy to existing ground-based measurements, a long-range 1/r2 test and a Sun-Earth saddle point crossing to search for signatures of modified Newtonian dynamics.

  17. Delta II Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Final preparations for lift off of the DELTA II Mars Pathfinder Rocket are shown. Activities include loading the liquid oxygen, completing the construction of the Rover, and placing the Rover into the Lander. After the countdown, important visual events include the launch of the Delta Rocket, burnout and separation of the three Solid Rocket Boosters, and the main engine cutoff. The cutoff of the main engine marks the beginning of the second stage engine. After the completion of the second stage, the third stage engine ignites and then cuts off. Once the third stage engine cuts off spacecraft separation occurs.

  18. Pathfinder Rover Atop Mermaid Dune

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars Pathfinder Lander camera image of Sojourner Rover atop the Mermaid 'dune' on Sol 30. Note the dark material excavated by the rover wheels. These, and other excavations brought materials to the surface for examination and allowed estimates of mechanical properties of the deposits.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  19. LISA Pathfinder ground testing

    NASA Astrophysics Data System (ADS)

    Guzman, Felipe; LISA Pathfinder Team

    2010-01-01

    The space-based gravitational wave observatory LISA is a joint NASA-ESA mission that requires challenging technology to ensure pure geodetic trajectories of test masses and the interferometric measurement of distance variations between them. The LISA Pathfinder mission is an ESA-launched technology demonstrator of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of pre-flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems is currently ongoing. Studies have been carried out on very sensitive torsion pendulums that effectively reproduce a free-fall condition for the test mass within a horizontal plane in the lab, down to frequencies < 0.1 mHz. Thermal gradient induced effects, impact of gas molecules, noisy charging, surface charge patches, and other effects have been investigated and their physical models consolidated. A final upper limit on non-modeled disturbances has also been obtained within one order of magnitude of LISA requirements at 1 mHz. The interferometry system has also been extensively studied to identify noise sources and develop approaches to mitigate them. Engineering models of the optical bench, laser head and laser modulators have been interconnected and tested for functionality and noise level in closed-loop operation, demonstrating the required optical metrology sensitivity to test mass displacement. This poster presents the current status in the development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts.

  20. Launch Abort System Pathfinder Arrival

    NASA Video Gallery

    The Orion Launch Abort System, or LAS, pathfinder returned home to NASA Langley on Oct. 18 on its way to NASA's Kennedy Space Center. The hardware was built at Langley and was used in preparation f...

  1. Pathfinder Innovation Projects: Awardees 2014

    EPA Pesticide Factsheets

    The Pathfinder program supports high-risk, high-reward research ideas with funding and staff time. The goal is to feed a culture of innovation in the Agency and integrate innovative ideas in EPA research programs.

  2. LISA Pathfinder: mission and status

    NASA Astrophysics Data System (ADS)

    Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marin, A.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gilbert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Monsky, A.; Nicolini, D.; Nicolodi, D.; Nofrarias, M.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schleicher, A.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Steier, F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

    2011-05-01

    LISA Pathfinder, the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology demonstrator for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission. The technologies required for LISA are many and extremely challenging. This coupled with the fact that some flight hardware cannot be fully tested on ground due to Earth-induced noise led to the implementation of the LISA Pathfinder mission to test the critical LISA technologies in a flight environment. LISA Pathfinder essentially mimics one arm of the LISA constellation by shrinking the 5 million kilometre armlength down to a few tens of centimetres, giving up the sensitivity to gravitational waves, but keeping the measurement technology: the distance between the two test masses is measured using a laser interferometric technique similar to one aspect of the LISA interferometry system. The scientific objective of the LISA Pathfinder mission consists then of the first in-flight test of low frequency gravitational wave detection metrology. LISA Pathfinder is due to be launched in 2013 on-board a dedicated small launch vehicle (VEGA). After a series of apogee raising manoeuvres using an expendable propulsion module, LISA Pathfinder will enter a transfer orbit towards the first Sun-Earth Lagrange point (L1). After separation from the propulsion module, the LPF spacecraft will be stabilized using the micro-Newton thrusters, entering a 500 000 km by 800 000 km Lissajous orbit around L1. Science results will be available approximately 2 months after launch.

  3. LISA Pathfinder data analysis

    NASA Astrophysics Data System (ADS)

    Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marin, A.; García Marirrodriga, C.; Gesa, L.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Monsky, A.; Nicolini, D.; Nicolodi, D.; Nofrarias, M.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Steier, F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

    2011-05-01

    As the launch of LISA Pathfinder (LPF) draws near, more and more effort is being put in to the preparation of the data analysis activities that will be carried out during the mission operations. The operations phase of the mission will be composed of a series of experiments that will be carried out on the satellite. These experiments will be directed and analysed by the data analysis team, which is part of the operations team. The operations phase will last about 90 days, during which time the data analysis team aims to fully characterize the LPF, and in particular, its core instrument the LISA Technology Package. By analysing the various couplings present in the system, the different noise sources that will disturb the system, and through the identification of the key physical parameters of the system, a detailed noise budget of the instrument will be constructed that will allow the performance of the different subsystems to be assessed and projected towards LISA. This paper describes the various aspects of the full data analysis chain that are needed to successfully characterize the LPF and build up the noise budget during mission operations.

  4. Mars Pathfinder Landing Site Workshop

    NASA Technical Reports Server (NTRS)

    Golombek, Matthew (Editor)

    1994-01-01

    The Mars Pathfinder Project is an approved Discovery-class mission that will place a lander and rover on the surface of the Red Planet in July 1997. The Mars Pathfinder Landing Site Workshop was designed to allow the Mars scientific community to provide input as to where to land Pathfinder on Mars. The workshop was attended by over 60 people from around the United States and from Europe. Over 20 landing sites were proposed at the workshop, and the scientific questions and problems concerning each were addressed. The workshop and the discussion that occured during and afterward have significantly improved the ability to select a scientifically exciting but safe landing site on Mars.

  5. The LISA Pathfinder Radiation Monitor

    NASA Astrophysics Data System (ADS)

    Wass, P. J.; Araújo, H.; Boatella, C.; Chmeissani, M.; Hajdas, W.; Lobo, A.; Puigdengoles, C.; Sumner, T.

    2006-11-01

    We present the concept, design and testing of the radiation monitor for LISA Pathfinder. Galactic cosmic rays (GCRs) and solar energetic particles (SEPs) will cause charging of the LISA Pathfinder test masses producing unwanted disturbances which could be significant during a large solar eruption. A radiation monitor on board LISA Pathfinder, using silicon PIN diodes as particle detectors, will measure the particle flux responsible for charging. It will also be able to record spectral information to identify solar energetic particle events. The design of the monitor was supported by Monte Carlo simulations which allow detailed predictions of the radiation monitor performance. We present these predictions as well as the results of high-energy proton tests carried out at the Paul Scherrer Institute, Switzerland. The tests show good agreement with our simulations and confirm the capability of the radiation monitor to perform well in the space environment, meeting all science requirements.

  6. Using 21 cm absorption surveys to measure the average H I spin temperature in distant galaxies

    NASA Astrophysics Data System (ADS)

    Allison, J. R.; Zwaan, M. A.; Duchesne, S. W.; Curran, S. J.

    2016-10-01

    We present a statistical method for measuring the average H I spin temperature in distant galaxies using the expected detection yields from future wide-field 21 cm absorption surveys. As a demonstrative case study, we consider an all-southern-sky simulated survey of 2-h per pointing with the Australian Square Kilometre Array Pathfinder for intervening H I absorbers at intermediate cosmological redshifts between z = 0.4 and 1. For example, if such a survey yielded 1000 absorbers, we would infer a harmonic-mean spin temperature of overline{T}_spin ˜ 100 K for the population of damped Lyman α absorbers (DLAs) at these redshifts, indicating that more than 50 per cent of the neutral gas in these systems is in a cold neutral medium (CNM). Conversely, a lower yield of only 100 detections would imply overline{T}_spin ˜ 1000 K and a CNM fraction less than 10 per cent. We propose that this method can be used to provide independent verification of the spin temperature evolution reported in recent 21 cm surveys of known DLAs at high redshift and for measuring the spin temperature at intermediate redshifts below z ≈ 1.7, where the Lyman α line is inaccessible using ground-based observatories. Increasingly more sensitive and larger surveys with the Square Kilometre Array should provide stronger statistical constraints on the average spin temperature. However, these will ultimately be limited by the accuracy to which we can determine the H I column density frequency distribution, the covering factor and the redshift distribution of the background radio source population.

  7. Tracing the neutral gas environments of young radio AGN with ASKAP

    NASA Astrophysics Data System (ADS)

    Allison, J. R.; Sadler, E. M.; Moss, V. A.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B. T.; McConnell, D.; Sault, R. J.; Whiting, M. T.

    2016-02-01

    At present neutral atomic hydrogen (H I) gas in galaxies at redshifts above {z ˜ 0.3} (the extent of 21 cm emission surveys in individual galaxies) and below {z ˜ 1.7} (where the Lyman-\\alpha line is not observable with ground-based telescopes) has remained largely unexplored. The advent of precursor telescopes to the Square Kilometre Array will allow us to conduct the first systematic radio-selected 21 cm absorption surveys for H I over these redshifts. While H I absorption is a tracer of the reservoir of cold neutral gas in galaxies available for star formation, it can also be used to reveal the extreme kinematics associated with jet-driven neutral outflows in radio-loud active galactic nuclei. Using the six-antenna Boolardy Engineering Test Array of the Australian Square Kilometre Array Pathfinder, we have demonstrated that in a single frequency tuning we can detect H I absorption over a broad range of redshifts between z = 0.4 and 1.0. As part of our early science and commissioning program, we are now carrying out a search for absorption towards a sample of the brightest GPS and CSS sources in the southern sky. These intrinsically compact sources present us with an opportunity to study the circumnuclear region of recently re-started radio galaxies, in some cases showing direct evidence of mechanical feedback through jet-driven outflows. With the sensitivity of the full ASKAP array we will be able to study the kinematics of atomic gas in a few thousand radio galaxies, testing models of radio jet feedback well beyond the nearby Universe.

  8. Pathfinder Teaching and Learning Units.

    ERIC Educational Resources Information Center

    Hawaii Univ., Honolulu. Sea Grant Program.

    This collection of teaching units were selected from materials developed during the Operation Pathfinder Institutes (OPI) which took place in the Pacific region between 1994 and 1999. The institutes were intended to provide upper elementary and middle school science teachers with an opportunity to develop a deeper understanding of the marine…

  9. The Sonic Pathfinder: An Evaluation.

    ERIC Educational Resources Information Center

    Dodds, Allan G.; And Others

    1984-01-01

    An objective evaluation of the Sonic Pathfinder, a new ultrasonic mobility aid, showed that use of the aid changes mobility in many ways. Reduced perception of environmental sounds was not reflected in performance. The majority of users traveled slowly and exhibited less than optimal strategies. (Author/CL)

  10. Spacetime Metrology with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Congedo, Giuseppe

    2012-04-01

    LISA is the proposed ESA-NASA gravitational wave detector in the 0.1 mHz - 0.1 Hz band. LISA Pathfinder is the down-scaled version of a single LISA arm. The arm - named Doppler link - can be treated as a differential accelerometer, measuring the relative acceleration between test masses. LISA Pathfinder - the in-flight test of the LISA instrumentation - is currently in the final implementation and planned to be launched in 2014. It will set stringent constraints on the ability to put test masses in geodesic motion to within the required differential acceleration of 3times10^{-14} m s^{-2} Hz^{-1/2} and track their relative motion to within the required differential displacement measurement noise of 9times10^{-12} m Hz^{-1/2}, around 1 mHz. Given the scientific objectives, it will carry out - for the first time with such high accuracy required for gravitational wave detection - the science of spacetime metrology, in which the Doppler link between two free-falling test masses measures the curvature. This thesis contains a novel approach to the calculation of the Doppler response to gravitational waves. It shows that the parallel transport of 4-vectors records the history of gravitational wave signals. In practice, the Doppler link is implemented with 4 bodies in LISA and 3 bodies in LISA Pathfinder. To compensate for noise sources a control logic is implemented during the measurement. The closed-loop dynamics of LISA Pathfinder can be condensed into operators acting on the motion coordinates, handling the couplings, as well as the cross-talks. The scope of system identification is the optimal calibration of the instrument. This thesis describes some data analysis procedures applied to synthetic experiments and shows the relevance of system identification for the success of LISA Pathfinder in demonstrating the principles of spacetime metrology for all future space-based missions.

  11. LISA Pathfinder: A Mission Status

    NASA Astrophysics Data System (ADS)

    Hewitson, Martin; LISA Pathfinder Team Team

    2016-03-01

    On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

  12. Multispectral Imaging from Mars PATHFINDER

    NASA Technical Reports Server (NTRS)

    Ferrand, William H.; Bell, James F., III; Johnson, Jeffrey R.; Bishop, Janice L.; Morris, Richard V.

    2007-01-01

    The Imager for Mars Pathfinder (IMP) was a mast-mounted instrument on the Mars Pathfinder lander which landed on Mars Ares Vallis floodplain on July 4, 1997. During the 83 sols of Mars Pathfinders landed operations, the IMP collected over 16,600 images. Multispectral images were collected using twelve narrowband filters at wavelengths between 400 and 1000 nm in the visible and near infrared (VNIR) range. The IMP provided VNIR spectra of the materials surrounding the lander including rocks, bright soils, dark soils, and atmospheric observations. During the primary mission, only a single primary rock spectral class, Gray Rock, was recognized; since then, Black Rock, has been identified. The Black Rock spectra have a stronger absorption at longer wavelengths than do Gray Rock spectra. A number of coated rocks have also been described, the Red and Maroon Rock classes, and perhaps indurated soils in the form of the Pink Rock class. A number of different soil types were also recognized with the primary ones being Bright Red Drift, Dark Soil, Brown Soil, and Disturbed Soil. Examination of spectral parameter plots indicated two trends which were interpreted as representing alteration products formed in at least two different environmental epochs of the Ares Vallis area. Subsequent analysis of the data and comparison with terrestrial analogs have supported the interpretation that the rock coatings provide evidence of earlier martian environments. However, the presence of relatively uncoated examples of the Gray and Black rock classes indicate that relatively unweathered materials can persist on the martian surface.

  13. Pathfinder-Plus on flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days

  14. Pathfinder-Plus on flight over Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on flight over Hawaii. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days above 50

  15. Pathfinder-Plus on flight over Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus flying over the Hawaiian Islands in 1998 with Ni'ihau Island in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100

  16. Research Pathfinders: Offline Access to Online Searching.

    ERIC Educational Resources Information Center

    Graves, Judith K.

    1998-01-01

    A pathfinder diskette contains a customized Web page that links the student immediately to content-rich Web sites, eliminating the false starts and dead ends inherent in preliminary Web searches. Suggestions are provided for creating pathfinders that meet multiple information needs within the school. (AEF)

  17. Software Aids Visualization Of Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Weidner, Richard J.

    1996-01-01

    Report describes Simulator for Imager for Mars Pathfinder (SIMP) computer program. SIMP generates "virtual reality" display of view through video camera on Mars lander spacecraft of Mars Pathfinder mission, along with display of pertinent textual and graphical data, for use by scientific investigators in planning sequences of activities for mission.

  18. MARS PATHFINDER CAMERA TEST IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), workers from the Jet Propulsion Laboratory (JPL) are conducting a systems test of the imager for the Mars Pathfinder. Mounted on the Pathfinder lander, the imager (the white cylindrical element the worker is touching) is a specially designed camera featuring a stereo-imaging system with color capability provided by a set of selectable filters. It is mounted on an extendable mast that will pop up after the lander touches down on the Martian surface. The imager will transmit images of the terrain, allowing engineers back on Earth to survey the landing site before the Pathfinder rover is deployed to explore the area. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2. JPL manages the Pathfinder project for NASA.

  19. Mars Pathfinder mission operations concepts

    NASA Technical Reports Server (NTRS)

    Sturms, Francis M., Jr.; Dias, William C.; Nakata, Albert Y.; Tai, Wallace S.

    1994-01-01

    The Mars Pathfinder Project plans a December 1996 launch of a single spacecraft. After jettisoning a cruise stage, an entry body containing a lander and microrover will directly enter the Mars atmosphere and parachute to a hard landing near the sub-solar latitude of 15 degrees North in July 1997. Primary surface operations last for 30 days. Cost estimates for Pathfinder ground systems development and operations are not only lower in absolute dollars, but also are a lower percentage of total project costs than in past planetary missions. Operations teams will be smaller and fewer than typical flight projects. Operations scenarios have been developed early in the project and are being used to guide operations implementation and flight system design. Recovery of key engineering data from entry, descent, and landing is a top mission priority. These data will be recorded for playback after landing. Real-time tracking of a modified carrier signal through this phase can provide important insight into the spacecraft performance during entry, descent, and landing in the event recorded data is never recovered. Surface scenarios are dominated by microrover activity and lander imaging during 7 hours of the Mars day from 0700 to 1400 local solar time. Efficient uplink and downlink processes have been designed to command the lander and microrover each Mars day.

  20. Northeast View From Pathfinder Lander

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This panorama of the region to the northeast of the lander was constructed to support the Sojourner Rover Team's plans to conduct an 'autonomous traverse' to explore the terrain away from the lander after science objectives in the lander vicinity had been met. The large, relatively bright surface in the foreground, about 10 meters (33 feet) from the spacecraft, in this scene is 'Baker's Bench.' The large, elongated rock left of center in the middle distance is 'Zaphod.'

    This view was produced by combining 8 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator.

  1. "Library as Laboratory": Online Pathfinders and the Humanities Graduate Student

    ERIC Educational Resources Information Center

    Harrington, Sara

    2007-01-01

    This article explores how online pathfinders can best meet the information needs of graduate students and foster advanced research. The article reviews the literature on pathfinders, including the historic characteristics of print pathfinders, and the recommendations that have emerged for online pathfinder content. The article explores the…

  2. Dust devils as observed by Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Ferri, Francesca; Smith, Peter H.; Lemmon, Mark; Rennó, Nilton O.

    2003-12-01

    Dust devils are localized meteorological phenomena frequently observed in terrestrial dry lands and desert landscapes as well as on Mars. They are low-pressure, warm core vortices that form at the bottom of convective plumes and loft dust from the surface. They move with the speed of the ambient wind and are tilted by wind shears. The Mars Pathfinder detected dust devils as dust plumes in the Imager for Mars Pathfinder images and as low-pressure convective vortices in the meteorological Mars Pathfinder Atmospheric Structure Investigation/Meteorology (ASI/MET) experiment data. The Pathfinder data have been analyzed in terms of dust devil size, spatial distribution, and frequency of occurrence. The results show that the Pathfinder imaging and MET observations are consistent with each other and with the observations made by the Viking 1 Orbiter and Mars Global Surveyor. The dust devil's ability to loft dust into the atmosphere has been investigated and a thermodynamic theory for dust devils has been used to calculate their physical parameters relevant to dust transport. The dust devils observed in an active day provide a pumping rate larger than the dust-settling rate derived from the optical obscuration of the Pathfinder rover solar panels. Therefore dust devils are a major factor in transporting dust from the surface to the atmosphere at the Pathfinder site.

  3. The Pathfinder Chemical Transfer Propulsion Program

    NASA Technical Reports Server (NTRS)

    Hannum, Ned P.; Berkopec, Frank D.; Zurawski, Robert L.

    1989-01-01

    Pathfinder is a research and technology initiative by the National Aeronautics and Space Administration (NASA) intended to strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in FY-89. One of the four major thrusts is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which are expected to be operated and maintained in space. These advanced engines will enhance or enable a variety of future space exploration missions. The goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder are described.

  4. Pathfinder aircraft returning from a flight

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Pathfinder solar-powered research aircraft settles in for landing on the bed of Rogers Dry Lake at the Dryden Flight Research Center, Edwards, California, after a successful test flight Nov. 19, 1996. The ultra-light craft flew a racetrack pattern at low altitudes over the flight test area for two hours while project engineers checked out various systems and sensors on the uninhabited aircraft. The Pathfinder was controlled by two pilots, one in a mobile control unit which followed the craft, the other in a stationary control station. Pathfinder, developed by AeroVironment, Inc., is one of several designs being evaluated under NASA's Environmental Research Aircraft and Sensor Technology (ERAST) program. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71

  5. Navigation Flight Operations for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Vaughan, Robin M.; Kallemeyn, Pieter H., Jr.; Spencer, David A.; Braun, Robert D.

    2004-01-01

    On July 4, 1997, Mars Pathfinder became the first spacecraft to land on the surface of Mars in 21 years. Pathfinder was launched on December 4, 1996 and spent seven months en route to the red planet. This report discusses the navigation flight experience for the Mars Pathfinder interplanetary cruise. In particular, orbit determination and maneuver design and execution results are presented. Special emphasis is given to the navigation role in the days and hours leading up to and including the Entry, Descent, and Landing (EDL) phase.

  6. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  7. Gravitational science with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Trenkel, C.; Kemble, S.

    2009-03-01

    We investigate the potential of conducting interesting gravitational science experiments with LISA Pathfinder, by executing well defined de-orbiting manoeuvres following the nominal mission. Preliminary work suggests that the residual control authority of the micropropulsion system is sufficient to follow trajectories that cross the region surrounding the Sun-Earth saddle point, and also include one or multiple Earth flybys. Crossing the saddle point region may allow tests of Modified Newtonian Dynamics (MOND), while the flybys may potentially shed some light on the so-called flyby anomaly. We present some sample trajectories and discuss the limitations of the current model. Finally, we discuss the work required to take these ideas from the proof of principle presented here, to a concrete proposal for an extended mission.

  8. Mars pathfinder lander deployment mechanisms

    NASA Technical Reports Server (NTRS)

    Gillis-Smith, Greg R.

    1996-01-01

    The Mars Pathfinder Lander employs numerous mechanisms, as well as autonomous mechanical functions, during its Entry, Descent and Landing (EDL) Sequence. This is the first US lander of its kind, since it is unguided and airbag-protected for hard landing using airbags, instead of retro rockets, to soft land. The arrival condition, location, and orientation of the Lander will only be known by the computer on the Lander. The Lander will then autonomously perform the appropriate sequence to retract the airbags, right itself, and open, such that the Lander is nearly level with no airbag material covering the solar cells. This function uses two different types of mechanisms - the Airbag Retraction Actuators and the Lander Petal Actuators - which are designed for the high torque, low temperature, dirty environment and for limited life application. The development of these actuators involved investigating low temperature lubrication, Electrical Discharge Machining (EDM) to cut gears, and gear design for limited life use.

  9. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical and functional tests of its pyrotechic petal deployer system by Jet Propulsion Laboratory (JPL) engineers and technicians in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). In the background is the Pathfinder cruise stage, which the lander will be mated to once its functional tests are complete. The lander will remain attached to this stage during its six-to-seven-month journey to Mars. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the Sojourner autonomous rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  10. Pathfinder-Plus flight in Hawaii

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Pathfinder-Plus flight in Hawaii June 2002 AeroVironment's Pathfinder-Plus solar-powered flying wing recently flew a three-flight demonstration of its ability to relay third-generation cell phone and video signals as well as provide Internet linkage. The two pods underneath the center section of the wing carried the advanced two-way telecom package, developed by Japanese telecommunications interests.

  11. MARS PATHFINDER LAUNCH AT LC-17B

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder begins the journey to Mars with liftoff atop a Delta II expendable launch vehicle at 1:58 a.m. EST, Dec. 4, 1996, from Launch Complex 17B on Cape Canaveral Air Station. The Mars Pathfinder will travel on a direct trajectory to the Red Planet, arriving there in July 1997. Mars Pathfinder will send a lander and small robotic rover, Sojourner, to the surface of Mars. The primary objective of the mission is to demonstrate a low-cost way of delivering a science package to the surface of the Red Planet using a direct entry, descent and landing with the aid of small rocket engines, a parachute, airbags and other techniques. In addition, landers and rovers of the future will share the heritage of Mars Pathfinder designs and technologies first tested in this mission. Pathfinder also will collect invaluable data about the Martian surface. The Jet Propulsion Laboratory manages the Mars Pathfinder mission for NASA's Office of Space Science. McDonnell Douglas Aerospace builds the Delta II launch vehicle.

  12. LISA Pathfinder instrument data analysis

    NASA Astrophysics Data System (ADS)

    Guzman, Felipe

    LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtrac-tion techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology Subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of pre-flight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

  13. LISA Pathfinder Instrument Data Analysis

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    LISA Pathfinder (LPF) is an ESA-launched demonstration mission of key technologies required for the joint NASA-ESA gravitational wave observatory in space, LISA. As part of the LPF interferometry investigations, analytic models of noise sources and corresponding noise subtraction techniques have been developed to correct for effects like the coupling of test mass jitter into displacement readout, and fluctuations of the laser frequency or optical pathlength difference. Ground testing of pre-flight hardware of the Optical Metrology subsystem is currently ongoing at the Albert Einstein Institute Hannover. In collaboration with NASA Goddard Space Flight Center, the LPF mission data analysis tool LTPDA is being used to analyze the data product of these tests. Furthermore, the noise subtraction techniques and in-flight experiment runs for noise characterization are being defined as part of the mission experiment master plan. We will present the data analysis outcome of preflight hardware ground tests and possible noise subtraction strategies for in-flight instrument operations.

  14. The EUSO-Balloon pathfinder

    NASA Astrophysics Data System (ADS)

    Adams, J. H.; Ahmad, S.; Albert, J.-N.; Allard, D.; Anchordoqui, L.; Andreev, V.; Anzalone, A.; Arai, Y.; Asano, K.; Ave Pernas, M.; Baragatti, P.; Barrillon, P.; Batsch, T.; Bayer, J.; Bechini, R.; Belenguer, T.; Bellotti, R.; Belov, K.; Berlind, A. A.; Bertaina, M.; Biermann, P. L.; Biktemerova, S.; Blaksley, C.; Blanc, N.; Błȩcki, J.; Blin-Bondil, S.; Blümer, J.; Bobik, P.; Bogomilov, M.; Bonamente, M.; Briggs, M. S.; Briz, S.; Bruno, A.; Cafagna, F.; Campana, D.; Capdevielle, J.-N.; Caruso, R.; Casolino, M.; Cassardo, C.; Castellinic, G.; Catalano, C.; Catalano, G.; Cellino, A.; Chikawa, M.; Christl, M. J.; Cline, D.; Connaughton, V.; Conti, L.; Cordero, G.; Crawford, H. J.; Cremonini, R.; Csorna, S.; Dagoret-Campagne, S.; de Castro, A. J.; De Donato, C.; de la Taille, C.; De Santis, C.; del Peral, L.; Dell'Oro, A.; De Simone, N.; Di Martino, M.; Distratis, G.; Dulucq, F.; Dupieux, M.; Ebersoldt, A.; Ebisuzaki, T.; Engel, R.; Falk, S.; Fang, K.; Fenu, F.; Fernández-Gómez, I.; Ferrarese, S.; Finco, D.; Flamini, M.; Fornaro, C.; Franceschi, A.; Fujimoto, J.; Fukushima, M.; Galeotti, P.; Garipov, G.; Geary, J.; Gelmini, G.; Giraudo, G.; Gonchar, M.; González Alvarado, C.; Gorodetzky, P.; Guarino, F.; Guzmán, A.; Hachisu, Y.; Harlov, B.; Haungs, A.; Hernández Carretero, J.; Higashide, K.; Ikeda, D.; Ikeda, H.; Inoue, N.; Inoue, S.; Insolia, A.; Isgrò, F.; Itow, Y.; Joven, E.; Judd, E. G.; Jung, A.; Kajino, F.; Kajino, T.; Kaneko, I.; Karadzhov, Y.; Karczmarczyk, J.; Karus, M.; Katahira, K.; Kawai, K.; Kawasaki, Y.; Keilhauer, B.; Khrenov, B. A.; Kim, J.-S.; Kim, S.-W.; Kim, S.-W.; Kleifges, M.; Klimov, P. A.; Kolev, D.; Kreykenbohm, I.; Kudela, K.; Kurihara, Y.; Kusenko, A.; Kuznetsov, E.; Lacombe, M.; Lachaud, C.; Lee, J.; Licandro, J.; Lim, H.; López, F.; Maccarone, M. C.; Mannheim, K.; Maravilla, D.; Marcelli, L.; Marini, A.; Martinez, O.; Masciantonio, G.; Mase, K.; Matev, R.; Medina-Tanco, G.; Mernik, T.; Miyamoto, H.; Miyazaki, Y.; Mizumoto, Y.; Modestino, G.; Monaco, A.; Monnier-Ragaigne, D.; Morales de los Ríos, J. A.; Moretto, C.; Morozenko, V. S.; Mot, B.; Murakami, T.; Murakami, M. Nagano; Nagata, M.; Nagataki, S.; Nakamura, T.; Napolitano, T.; Naumov, D.; Nava, R.; Neronov, A.; Nomoto, K.; Nonaka, T.; Ogawa, T.; Ogio, S.; Ohmori, H.; Olinto, A. V.; Orleański, P.; Osteria, G.; Panasyuk, M. I.; Parizot, E.; Park, I. H.; Park, H. W.; Pastircak, B.; Patzak, T.; Paul, T.; Pennypacker, C.; Perez Cano, S.; Peter, T.; Picozza, P.; Pierog, T.; Piotrowski, L. W.; Piraino, S.; Plebaniak, Z.; Pollini, A.; Prat, P.; Prévôt, G.; Prieto, H.; Putis, M.; Reardon, P.; Reyes, M.; Ricci, M.; Rodríguez, I.; Rodríguez Frías, M. D.; Ronga, F.; Roth, M.; Rothkaehl, H.; Roudil, G.; Rusinov, I.; Rybczyński, M.; Sabau, M. D.; Sáez-Cano, G.; Sagawa, H.; Saito, A.; Sakaki, N.; Sakata, M.; Salazar, H.; Sánchez, S.; Santangelo, A.; Santiago Crúz, L.; Sanz Palomino, M.; Saprykin, O.; Sarazin, F.; Sato, H.; Sato, M.; Schanz, T.; Schieler, H.; Scotti, V.; Segreto, A.; Selmane, S.; Semikoz, D.; Serra, M.; Sharakin, S.; Shibata, T.; Shimizu, H. M.; Shinozaki, K.; Shirahama, T.; Siemieniec-Oziȩbło, G.; Silva López, H. H.; Sledd, J.; Słomińska, K.; Sobey, A.; Sugiyama, T.; Supanitsky, D.; Suzuki, M.; Szabelska, B.; Szabelski, J.; Tajima, F.; Tajima, N.; Tajima, T.; Takahashi, Y.; Takami, H.; Takeda, M.; Takizawa, Y.; Tenzer, C.; Tibolla, O.; Tkachev, L.; Tokuno, H.; Tomida, T.; Tone, N.; Toscano, S.; Trillaud, F.; Tsenov, R.; Tsunesada, Y.; Tsuno, K.; Tymieniecka, T.; Uchihori, Y.; Unger, M.; Vaduvescu, O.; Valdés-Galicia, J. F.; Vallania, P.; Valore, L.; Vankova, G.; Vigorito, C.; Villaseñor, L.; von Ballmoos, P.; Wada, S.; Watanabe, J.; Watanabe, S.; Watts, J.; Weber, M.; Weiler, T. J.; Wibig, T.; Wiencke, L.; Wille, M.; Wilms, J.; Włodarczyk, Z.; Yamamoto, T.; Yamamoto, Y.; Yang, J.; Yano, H.; Yashin, I. V.; Yonetoku, D.; Yoshida, K.; Yoshida, S.; Young, R.; Zotov, M. Yu.; Zuccaro Marchi, A.

    2015-11-01

    EUSO-Balloon is a pathfinder for JEM-EUSO, the Extreme Universe Space Observatory which is to be hosted on-board the International Space Station. As JEM-EUSO is designed to observe Ultra-High Energy Cosmic Rays (UHECR)-induced Extensive Air Showers (EAS) by detecting their ultraviolet light tracks "from above", EUSO-Balloon is a nadir-pointing UV telescope too. With its Fresnel Optics and Photo-Detector Module, the instrument monitors a 50 km2 ground surface area in a wavelength band of 290-430 nm, collecting series of images at a rate of 400,000 frames/sec. The objectives of the balloon demonstrator are threefold: a) perform a full end-to-end test of a JEM-EUSO prototype consisting of all the main subsystems of the space experiment, b) measure the effective terrestrial UV background, with a spatial and temporal resolution relevant for JEM-EUSO. c) detect tracks of ultraviolet light from near space for the first time. The latter is a milestone in the development of UHECR science, paving the way for any future space-based UHECR observatory. On August 25, 2014, EUSO-Balloon was launched from Timmins Stratospheric Balloon Base (Ontario, Canada) by the balloon division of the French Space Agency CNES. From a float altitude of 38 km, the instrument operated during the entire astronomical night, observing UV-light from a variety of ground-covers and from hundreds of simulated EASs, produced by flashers and a laser during a two-hour helicopter under-flight.

  15. Battery study for the Mars Environmental Survey (MESUR) Pathfinder

    NASA Technical Reports Server (NTRS)

    Dawson, Stephen F.; Otzinger, B.; Perrone, D.; Distefano, Sal; Halpert, Gerald

    1994-01-01

    Viewgraphs on the battery study for the Mars Environmental Survey (MESUR) Pathfinder are presented. Topics covered include: MESUR pathfinder introduction; power subsystem concept; battery technology selection; mission battery performance; cell/battery baseline design; charge methodology; and proposed testing.

  16. Overhead view of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image, prepared by Pathfinder scientists at NASA/ Ames Research Center, is a view of the landing site from above. Seen in the lower right is Mermaid dune, with its long axis oriented northwest-southeast and its steeper side, the presumed slipface, toward the southwest. Dunes like Mermaid, the depositional tails and erosional moats associated with rocks in the area, and the fluted and polished surfaces on several boulders at the landing site all indicate an effective wind that blows from the northeast to the southwest.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  17. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineer Jerry Gutierrez in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  18. MARS PATHFINDER PYRO SYSTEMS SWITCHING ACTIVITY

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder lander is subjected to a electrical test of its pyrotechnic system by Jet Propulsion Laboratory (JPL) engineers Lorraine Garcia (foreground) and Linda Robeck in KSC's Spacecraft Assembly and Encapsulation Facility (SAEF-2). A wheel of the Sojourner autonomous rover, which is attached to one of the lander's petals, can be seen behind the lander. When the lander touches down on the surface of Mars next year, the pyrotechnic system will deploy its three petals open like a flower and allow the rover to explore the Martian surface. The Mars Pathfinder is scheduled for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. JPL is managing the Mars Pathfinder project for NASA.

  19. Dynamic Pathfinders: Leveraging Your OPAC to Create Resource Guides

    ERIC Educational Resources Information Center

    Hunter, Ben

    2008-01-01

    Library pathfinders are a time-tested method of leading library users to important resources. However, paper-based pathfinders suffer from space limitations, and both paper-based and Web-based pathfinders require frequent updates to keep up with new library acquisitions. This article details a step-by-step method to create an online dynamic…

  20. System modelling for LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Diaz-Aguiló, Marc; Grynagier, Adrien; Rais, Boutheina

    LISA Pathfinder is the technology demonstrator for LISA, a space-borne gravitational waves observatory. The goal of the mission is to characterise the dynamics of the LISA Technology Package (LTP) to prove that on-board experimental conditions are compatible with the de-tection of gravitational waves. The LTP is a drag-free dynamics experiment which includes a control loop with sensors (interferometric and capacitive), actuators (capacitive actuators and thrusters), controlled disturbances (magnetic coils, heaters) and which is subject to various endogenous or exogenous noise sources such as infrared pressure or solar wind. The LTP experiment features new hardware which was never flown in space. The mission has a tight operation timeline as it is constrained to about 100 days. It is therefore vital to have efficient and precise means of investigation and diagnostics to be used during the on-orbit operations. These will be conducted using the LTP Data Analysis toolbox (LTPDA) which allows for simulation, parameter identification and various analyses (covariance analysis, state estimation) given an experimental model. The LTPDA toolbox therefore contains a series of models which are state-space representations of each component in the LTP. The State-Space Models (SSM) are objects of a state-space class within the LTPDA toolbox especially designed to address all the requirements of this tool. The user has access to a set of linear models which represent every satellite subsystem; the models are available in different forms representing 1D, 2D and 3D systems, each with settable symbolic and numeric parameters. To limit the possible errors, the models can be automatically linked to produce composite systems and closed-loops of the LTP. Finally, for the sake of completeness, accuracy and maintainability of the tool, the models contain all the physical information they mimic (i.e. variable units, description of parameters, description of inputs/outputs, etc). Models

  1. Pathfinder Landing Site in Color

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site]

    Released 14 May 2004 This image of the Mars Pathfinder Landing site was acquired July 17, 2002, during northern spring.

    The THEMIS VIS camera is capable of capturing color images of the martian surface using its five different color filters. In this mode of operation, the spatial resolution and coverage of the image must be reduced to accommodate the additional data volume produced from the use of multiple filters. To make a color image, three of the five filter images (each in grayscale) are selected. Each is contrast enhanced and then converted to a red, green, or blue intensity image. These three images are then combined to produce a full color, single image. Because the THEMIS color filters don't span the full range of colors seen by the human eye, a color THEMIS image does not represent true color. Also, because each single-filter image is contrast enhanced before inclusion in the three-color image, the apparent color variation of the scene is exaggerated. Nevertheless, the color variation that does appear is representative of some change in color, however subtle, in the actual scene. Note that the long edges of THEMIS color images typically contain color artifacts that do not represent surface variation.

    Image information: VIS instrument. Latitude 19.4, Longitude 326.8 East (33.2 West). 38 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science

  2. Mars Pathfinder Landing Site and Surroundings

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Pathfinder landed on Mars on July 4, 1997, and continued operating until Sept. 27 of that year. The landing site is on an ancient flood plain of the Ares and Tiu outflow channels. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took an image on Dec. 21, 2006, that provides unprecedented detail of the geology of the region and hardware on the surface.

    [figure removed for brevity, see original site] HiRISE Image This is the entire image. The crater at center bottom was unofficially named 'Big Crater' by the Pathfinder team. Its wall was visible from Pathfinder, located 3 kilometers (2 miles) to the north. The two bright features to the upper left of Big Crater are the 'Twin Peaks,' also observed by Pathfinder. The bright mound to the upper right of the Twin Peaks is 'North Knob,' seen in Pathfinder images as peaking over the horizon.

    At this scale there is no obvious geologic evidence of an ancient flood. Rather, impact craters dominate the scene, attesting to an old surface. The age is probably on the order of 1.8 billion to 3.5 billion years, when the Ares and Tiu floods are estimated to have occurred. Wind-formed linear ripples and dunes are seen throughout and are concentrated within craters. Sets of polygonal ridges of enigmatic origin are seen east of the Pathfinder lander. Rocks are visible over the entire image, with heavy concentrations near fresh-looking craters. Most of them are probably blocks tossed outward by crater-forming impacts.

    The complete image is centered at 19.1 degrees north latitude, 326.8 degrees east longitude. The range to the target site was 284.7 kilometers (177.9 miles). At this distance the image scale is 28.5 centimeters (11 inches) per pixel, so objects about 85 centimeters (33 inches) across are resolved. The image shown here has been map-projected to 25 centimeters (10 inches) per pixel. North is up. The image was taken at a local Mars time

  3. NASA's Chemical Transfer Propulsion Program for Pathfinder

    NASA Technical Reports Server (NTRS)

    Hannum, Ned P.; Berkopec, Frank D.; Zurawski, Robert L.

    1989-01-01

    Pathfinder is a research and technology project, with specific deliverables, initiated by the National Aeronautics and Space Administration (NASA) which will strengthen the technology base of the United States civil space program in preparation for future space exploration missions. Pathfinder begins in Fiscal Year 1989, and is to advance a collection of critical technologies for these missions and ensure technology readiness for future national decisions regarding exploration of the solar system. The four major thrusts of Pathfinder are: surface exploration, in-space operations, humans-in-space, and space transfer. The space transfer thrust will provide the critical technologies needed for transportation to, and return from, the Moon, Mars, and other planets in the solar system, as well as for reliable and cost-effective Earth-orbit operations. A key element of this thrust is the Chemical Transfer Propulsion program which will provide the propulsion technology for high performance, liquid oxygen/liquid hydrogen expander cycle engines which may be operated and maintained in space. Described here are the program overview including the goals and objectives, management, technical plan, and technology transfer for the Chemical Transfer Propulsion element of Pathfinder.

  4. Mechanical design of the Mars Pathfinder mission

    NASA Technical Reports Server (NTRS)

    Eisen, Howard Jay; Buck, Carl W.; Gillis-Smith, Greg R.; Umland, Jeffrey W.

    1997-01-01

    The Mars Pathfinder mission and the Sojourner rover is reported on, with emphasis on the various mission steps and the performance of the technologies involved. The mechanical design of mission hardware was critical to the success of the entry sequence and the landing operations. The various mechanisms employed are considered.

  5. Strategy for selecting Mars Pathfinder landing sites

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kuzmin, Ruslin O.

    1994-01-01

    A strategy for Pathfinder site selection must be developed that is fundamentally different from most previous considerations. At least two approaches can be identified. In one approach, the objective is to select a site representing a key geologic unit on Mars, i.e., a unit that is widespread, easily recognized, and used frequently as a datum in various investigations. The second approach is to select a site that potentially affords access to a wide variety of rock types. Because rover range is limited, rocks from a variety of sources must be assembled in a small area for sampling. Regardless of the approach taken in site selection, the Pathfinder site should include eolian deposits and provisions should be made to obtain measurements on soils. A recommended approach for selecting the Mars Pathfinder landing site is to identify a deltaic deposit, composed of sediments derived from sources of various ages and geologic units that shows evidence of eolian activity. The site should be located as close as possible to the part of the outwash where rapid deposition occurred because the likelihood of 'sorting' by size and composition increases with distance, decreasing the probability of heterogeneity. In addition, it is recommended that field operation tests be conducted to gain experience and insight into conducting science with Pathfinder.

  6. Pathfinders on Black Dance in America.

    ERIC Educational Resources Information Center

    Roy, Loriene, Ed.

    This is a compilation of 18 pathfinders (i.e., a bibliographic instruction aid) on black dance in America, prepared by graduate students in the "Information Resources in the Humanities" and the "Information Resources in the Social Sciences" classes in the Graduate School of Library and Information Science at the University of…

  7. Free-Flight Experiments in LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Thorpe, J. I.; Cutler, C. J.; Hewitson, M.; Jennrich, O.; Maghami, P.; Paczkowski, S.; Russano, G.; Vitale, S.; Weber, W. J.

    2014-01-01

    The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this 'suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.

  8. Free-flight experiments in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Cutler, C.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, LI; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Maghami, P.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this ‘suspension noise’. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.

  9. Ventifacts at the Pathfinder landing site

    USGS Publications Warehouse

    Bridges, N.T.; Greeley, R.; Haldemann, A.F.C.; Herkenhoff, K. E.; Kraft, M.; Parker, T.J.; Ward, A.W.

    1999-01-01

    About half of the rocks at the Mars Pathfinder Ares Vallis landing site appear to be ventifacts, rocks abraded by windborne particles. Comparable resolution images taken by the Imager for Mars Pathfinder (IMP) camera and the Viking landers show that ventifacts are more abundant at the Pathfinder site. The ventifacts occur in several forms, including rocks with faceted edges, finger-like projections, elongated pits, flutes, grooves, and possible rills. The trends of elongated pits, flutes, grooves, and rills cluster at ???280-330?? clockwise from north and generally dip 10-30?? away from their trend direction. These orientations are indicative of southeast to northwest winds and differ from the trend of wind tails at the landing site, the direction of local wind streaks, and predictions of the Global Circulation Model, all of which indicate northeast to southwest winds. The disparity between these data sets strongly suggests that local circulation patterns have changed since the abrasion of the ventifacted rocks. The greater number of ventifacts at the Pathfinder site compared to either of the Viking sites is most easily explained as being due to a larger supply of abrading particles, composed of either sand-sized grains or indurated dust aggregates, and higher surface roughness, which should increase the momentum of saltating grains. The Pathfinder ventifacts may have formed shortly after the deposition of outflow channel sediments nearly 2 Gry ago, when a large local supply of abrading particles should have been abundant and atmospheric conditions may have been more conducive to rock abrasion from saltating grains. Based on how ventifacts form on Earth, the several ventifact forms seen at the Pathfinder site and their presence on some rocks but not on others are probably due to local airflow conditions, original rock shape, exposure duration, rock movement, and to a lesser extent, rock lithology. The abundance of ventifacts at the Pathfinder site, together with

  10. Galaxy And Mass Assembly: the 1.4 GHz SFR indicator, SFR-M* relation and predictions for ASKAP-GAMA

    NASA Astrophysics Data System (ADS)

    Davies, L. J. M.; Huynh, M. T.; Hopkins, A. M.; Seymour, N.; Driver, S. P.; Robotham, A. G. R.; Baldry, I. K.; Bland-Hawthorn, J.; Bourne, N.; Bremer, M. N.; Brown, M. J. I.; Brough, S.; Cluver, M.; Grootes, M. W.; Jarvis, M.; Loveday, J.; Moffet, A.; Owers, M.; Phillipps, S.; Sadler, E.; Wang, L.; Wilkins, S.; Wright, A.

    2017-04-01

    We present a robust calibration of the 1.4 GHz radio continuum star formation rate (SFR) using a combination of the Galaxy And Mass Assembly (GAMA) survey and the Faint Images of the Radio Sky at Twenty-cm (FIRST) survey. We identify individually detected 1.4 GHz GAMA-FIRST sources and use a late-type, non-active galactic nucleus, volume-limited sample from GAMA to produce stellar mass-selected samples. The latter are then combined to produce FIRST-stacked images. This extends the robust parametrization of the 1.4 GHz-SFR relation to faint luminosities. For both the individually detected galaxies and our stacked samples, we compare 1.4 GHz luminosity to SFRs derived from GAMA to determine a new 1.4 GHz luminosity-to-SFR relation with well-constrained slope and normalization. For the first time, we produce the radio SFR-M* relation over 2 decades in stellar mass, and find that our new calibration is robust, and produces a SFR-M* relation which is consistent with all other GAMA SFR methods. Finally, using our new 1.4 GHz luminosity-to-SFR calibration we make predictions for the number of star-forming GAMA sources which are likely to be detected in the upcoming Australian Square Kilometre Array Pathfinder surveys, Evolutionary Map of the Universe and Deep Investigation of Neutral Gas Origins.

  11. Wide-field broad-band radio imaging with phased array feeds: a pilot multi-epoch continuum survey with ASKAP-BETA

    NASA Astrophysics Data System (ADS)

    Heywood, I.; Bannister, K. W.; Marvil, J.; Allison, J. R.; Ball, L.; Bell, M. E.; Bock, D. C.-J.; Brothers, M.; Bunton, J. D.; Chippendale, A. P.; Cooray, F.; Cornwell, T. J.; De Boer, D.; Edwards, P.; Gough, R.; Gupta, N.; Harvey-Smith, L.; Hay, S.; Hotan, A. W.; Indermuehle, B.; Jacka, C.; Jackson, C. A.; Johnston, S.; Kimball, A. E.; Koribalski, B. S.; Lenc, E.; Macleod, A.; McClure-Griffiths, N.; McConnell, D.; Mirtschin, P.; Murphy, T.; Neuhold, S.; Norris, R. P.; Pearce, S.; Popping, A.; Qiao, R. Y.; Reynolds, J. E.; Sadler, E. M.; Sault, R. J.; Schinckel, A. E. T.; Serra, P.; Shimwell, T. W.; Stevens, J.; Tuthill, J.; Tzioumis, A.; Voronkov, M. A.; Westmeier, T.; Whiting, M. T.

    2016-04-01

    The Boolardy Engineering Test Array is a 6 × 12 m dish interferometer and the prototype of the Australian Square Kilometre Array Pathfinder (ASKAP), equipped with the first generation of ASKAP's phased array feed (PAF) receivers. These facilitate rapid wide-area imaging via the deployment of simultaneous multiple beams within an ˜30 deg2 field of view. By cycling the array through 12 interleaved pointing positions and using nine digitally formed beams, we effectively mimic a traditional 1 h × 108 pointing survey, covering ˜150 deg2 over 711-1015 MHz in 12 h of observing time. Three such observations were executed over the course of a week. We verify the full bandwidth continuum imaging performance and stability of the system via self-consistency checks and comparisons to existing radio data. The combined three epoch image has arcminute resolution and a 1σ thermal noise level of 375 μJy beam-1, although the effective noise is a factor of ˜3 higher due to residual sidelobe confusion. From this we derive a catalogue of 3722 discrete radio components, using the 35 per cent fractional bandwidth to measure in-band spectral indices for 1037 of them. A search for transient events reveals one significantly variable source within the survey area. The survey covers approximately two-thirds of the Spitzer South Pole Telescope Deep Field. This pilot project demonstrates the viability and potential of using PAFs to rapidly and accurately survey the sky at radio wavelengths.

  12. The ASKAP/EMU Source Finding Data Challenge

    NASA Astrophysics Data System (ADS)

    Hopkins, A. M.; Whiting, M. T.; Seymour, N.; Chow, K. E.; Norris, R. P.; Bonavera, L.; Breton, R.; Carbone, D.; Ferrari, C.; Franzen, T. M. O.; Garsden, H.; González-Nuevo, J.; Hales, C. A.; Hancock, P. J.; Heald, G.; Herranz, D.; Huynh, M.; Jurek, R. J.; López-Caniego, M.; Massardi, M.; Mohan, N.; Molinari, S.; Orrù, E.; Paladino, R.; Pestalozzi, M.; Pizzo, R.; Rafferty, D.; Röttgering, H. J. A.; Rudnick, L.; Schisano, E.; Shulevski, A.; Swinbank, J.; Taylor, R.; van der Horst, A. J.

    2015-10-01

    The Evolutionary Map of the Universe (EMU) is a proposed radio continuum survey of the Southern Hemisphere up to declination + 30°, with the Australian Square Kilometre Array Pathfinder (ASKAP). EMU will use an automated source identification and measurement approach that is demonstrably optimal, to maximise the reliability and robustness of the resulting radio source catalogues. As a step toward this goal we conducted a "Data Challenge" to test a variety of source finders on simulated images. The aim is to quantify the accuracy and limitations of existing automated source finding and measurement approaches. The Challenge initiators also tested the current ASKAPsoft source-finding tool to establish how it could benefit from incorporating successful features of the other tools. As expected, most finders show completeness around 100% at ≈ 10σ dropping to about 10% by ≈ 5σ. Reliability is typically close to 100% at ≈ 10σ, with performance to lower sensitivities varying between finders. All finders show the expected trade-off, where a high completeness at low signal-to-noise gives a corresponding reduction in reliability, and vice versa. We conclude with a series of recommendations for improving the performance of the ASKAPsoft source-finding tool.

  13. Measuring Noise Temperatures of Phased-Array Antennas for Astronomy at CSIRO

    NASA Astrophysics Data System (ADS)

    Chippendale, A. P.; Hayman, D. B.; Hay, S. G.

    We describe the development of a noise-temperature testing capability for phased-array antennas operating in receive mode from 0.7 GHz to 1.8 GHz. Sampled voltages from each array port were recorded digitally as the zenith-pointing array under test was presented with three scenes: (1) a large microwave absorber at ambient temperature, (2) the unobstructed radio sky, and (3) broadband noise transmitted from a reference antenna centred over and pointed at the array under test. The recorded voltages were processed in software to calculate the beam equivalent noise temperature for a maximum signal-to-noise ratio beam steered at the zenith. We introduced the reference-antenna measurement to make noise measurements with reproducible, well-defined beams directed at the zenith and thereby at the centre of the absorber target. We applied a detailed model of cosmic and atmospheric contributions to the radio sky emission that we used as a noise-temperature reference. We also present a comprehensive analysis of measurement uncertainty including random and systematic effects. The key systematic effect was due to uncertainty in the beamformed antenna pattern and how efficiently it illuminates the absorber load. We achieved a combined uncertainty as low as 4 K for a 40 K measurement of beam equivalent noise temperature. The measurement and analysis techniques described in this paper were pursued to support noise-performance verification of prototype phased-array feeds for the Australian Square Kilometre Array Pathfinder telescope.

  14. Data Triage of Astronomical Transients: A Machine Learning Approach

    NASA Astrophysics Data System (ADS)

    Rebbapragada, U.

    This talk presents real-time machine learning systems for triage of big data streams generated by photometric and image-differencing pipelines. Our first system is a transient event detection system in development for the Palomar Transient Factory (PTF), a fully-automated synoptic sky survey that has demonstrated real-time discovery of optical transient events. The system is tasked with discriminating between real astronomical objects and bogus objects, which are usually artifacts of the image differencing pipeline. We performed a machine learning forensics investigation on PTF’s initial system that led to training data improvements that decreased both false positive and negative rates. The second machine learning system is a real-time classification engine of transients and variables in development for the Australian Square Kilometre Array Pathfinder (ASKAP), an upcoming wide-field radio survey with unprecedented ability to investigate the radio transient sky. The goal of our system is to classify light curves into known classes with as few observations as possible in order to trigger follow-up on costlier assets. We discuss the violation of standard machine learning assumptions incurred by this task, and propose the use of ensemble and hierarchical machine learning classifiers that make predictions most robustly.

  15. Mars Pathfinder Landing Site and Surroundings

    NASA Technical Reports Server (NTRS)

    2007-01-01

    NASA's Mars Pathfinder landed on Mars on July 4, 1997, and continued operating until Sept. 27 of that year. The landing site is on an ancient flood plain of the Ares and Tiu outflow channels. The High Resolution Imaging Science Experiment (HiRISE) camera on NASA's Mars Reconnaissance Orbiter took an image on Dec. 21, 2006, that provides unprecedented detail of the geology of the region and hardware on the surface.

    [figure removed for brevity, see original site] HiRISE Image This is the entire image. The crater at center bottom was unofficially named 'Big Crater' by the Pathfinder team. Its wall was visible from Pathfinder, located 3 kilometers (2 miles) to the north. The two bright features to the upper left of Big Crater are the 'Twin Peaks,' also observed by Pathfinder. The bright mound to the upper right of the Twin Peaks is 'North Knob,' seen in Pathfinder images as peaking over the horizon.

    At this scale there is no obvious geologic evidence of an ancient flood. Rather, impact craters dominate the scene, attesting to an old surface. The age is probably on the order of 1.8 billion to 3.5 billion years, when the Ares and Tiu floods are estimated to have occurred. Wind-formed linear ripples and dunes are seen throughout and are concentrated within craters. Sets of polygonal ridges of enigmatic origin are seen east of the Pathfinder lander. Rocks are visible over the entire image, with heavy concentrations near fresh-looking craters. Most of them are probably blocks tossed outward by crater-forming impacts.

    The complete image is centered at 19.1 degrees north latitude, 326.8 degrees east longitude. The range to the target site was 284.7 kilometers (177.9 miles). At this distance the image scale is 28.5 centimeters (11 inches) per pixel, so objects about 85 centimeters (33 inches) across are resolved. The image shown here has been map-projected to 25 centimeters (10 inches) per pixel. North is up. The image was taken at a local Mars time

  16. Assessment of Mars Pathfinder landing site predictions

    USGS Publications Warehouse

    Golombek, M.P.; Moore, H.J.; Haldemann, A.F.C.; Parker, T.J.; Schofield, J.T.

    1999-01-01

    Remote sensing data at scales of kilometers and an Earth analog were used to accurately predict the characteristics of the Mars Pathfinder landing site at a scale of meters. The surface surrounding the Mars Pathfinder lander in Ares Vallis appears consistent with orbital interpretations, namely, that it would be a rocky plain composed of materials deposited by catastrophic floods. The surface and observed maximum clast size appears similar to predictions based on an analogous surface of the Ephrata Fan in the Channeled Scabland of Washington state. The elevation of the site measured by relatively small footprint delay-Doppler radar is within 100 m of that determined by two-way ranging and Doppler tracking of the spacecraft. The nearly equal elevations of the Mars Pathfinder and Viking Lander 1 sites allowed a prediction of the atmospheric conditions with altitude (pressure, temperature, and winds) that were well within the entry, descent, and landing design margins. High-resolution (~38 m/pixel) Viking Orbiter 1 images showed a sparsely cratered surface with small knobs with relatively low slopes, consistent with observations of these features from the lander. Measured rock abundance is within 10% of that expected from Viking orbiter thermal observations and models. The fractional area covered by large, potentially hazardous rocks observed is similar to that estimated from model rock distributions based on data from the Viking landing sites, Earth analog sites, and total rock abundance. The bulk and fine-component thermal inertias measured from orbit are similar to those calculated from the observed rock size-frequency distribution. A simple radar echo model based on the reflectivity of the soil (estimated from its bulk density), and the measured fraction of area covered by rocks was used to approximate the quasi-specular and diffuse components of the Earth-based radar echos. Color and albedo orbiter data were used to predict the relatively dust free or unweathered

  17. Australian Defense.

    DTIC Science & Technology

    1979-12-01

    Australia in World Affairs 1966-1970, (Melbourne: Cheshire Publishing Pty Ltd , 1974), p. 258. 6Department of Defence, Australian Defence Review...Pvt, Ltd .: 1977), p. 69. 74 17Desmond Ball, "American Bases: Implications for Australian Securi- ty" The Strategic and Defence Studies Centre...million with aircraft, or 3) a " Woolworth " carrier costing $300-400 million with aircraft.33 Defence planners are now faced with determin- ing which

  18. Potential landing sites for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Kuzmin, Ruslan O.; Landheim, R.; Greeley, Ronald

    1994-01-01

    In addition to a better understanding of the geological evolution of Mars, new techniques for processing available data have emerged, new data have been acquired, and the engineering approaches for placing spacecraft on the surface have evolved. Selection of the Mars Pathfinder landing site must take these issues into account, along with mission constraints. An advantage of Mars Pathfinder is the rover for sampling surface materials over a range of tens of meters. However, engineering constraints and the limited scientific payload of this mission require new approaches for landing site selection. One approach is to select sites exhibiting a wide variety of rocks near the lander. An alternative approach is to select sites in which the regional geology consists of a single rock type representing a key datum for the geological study of Mars, and is uniformly distributed within the landing ellipse.

  19. APECS - The Atacama Pathfinder Experiment Control System

    NASA Astrophysics Data System (ADS)

    Muders, D.; Hafok, H.; Wyrowski, F.; Polehampton, E.; Belloche, A.; König, C.; Schaaf, R.

    2006-07-01

    APECS is the CORBA based, distributed control system for the new Atacama Pathfinder EXperiment (APEX) Telescope located at the Llano de Chajnantor at an altitude of 5100m in the Atacama desert in northern Chile. The telescope has been operational since August 2005 and APECS is now being used for regular science observations. APECS employs a modern, object-oriented design. Generic interfaces facilitate adding new instruments. The IPython based observer command language allows using macros and creating more complex observing modes.

  20. Overhead View of Area Surrounding Pathfinder

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Overhead view of the area surrounding the Pathfinder lander illustrating the Sojourner traverse. Red rectangles are rover positions at the end of sols 1-30. Locations of soil mechanics experiments, wheel abrasion experiments, and APXS measurements are shown. The A numbers refer to APXS measurements as discussed in the paper by Rieder et al. (p. 1770, Science Magazine, see image note). Coordinates are given in the LL frame.

    The photorealistic, interactive, three-dimensional virtual reality (VR) terrain models were created from IMP images using a software package developed for Pathfinder by C. Stoker et al. as a participating science project. By matching features in the left and right camera, an automated machine vision algorithm produced dense range maps of the nearfield, which were projected into a three-dimensional model as a connected polygonal mesh. Distance and angle measurements can be made on features viewed in the model using a mouse-driven three-dimensional cursor and a point-and-click interface. The VR model also incorporates graphical representations of the lander and rover and the sequence and spatial locations at which rover data were taken. As the rover moved, graphical models of the rover were added for each position that could be uniquely determined using stereo images of the rover taken by the IMP. Images taken by the rover were projected into the model as two-dimensional 'billboards' to show the proper perspective of these images.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  1. Mars Pathfinder Project: Planetary Constants and Models

    NASA Technical Reports Server (NTRS)

    Vaughan, Robin

    1995-01-01

    This document provides a common set of astrodynamic constants and planetary models for use by the Mars Pathfinder Project. It attempts to collect in a single reference all the quantities and models in use across the project during development and for mission operations. These models are central to the navigation and mission design functions, but they are also used in other aspects of the project such as science observation planning and data reduction.

  2. Pathfinder-Plus aircraft in flight

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The Pathfinder-Plus solar-powered aircraft is shown taking off from a runway, then flying at low altitude over the ocean. The vehicle, which looks like a flying ruler, operates at low airspeed. Among the missions proposed for a solar-powered aircraft are communications relay, atmospheric studies, pipeline monitoring and gas leak detection, environmental monitoring using thermal and radar images, and disaster relief and monitoring.

  3. Canadian Hydrogen Intensity Mapping Experiment (CHIME) pathfinder

    NASA Astrophysics Data System (ADS)

    Bandura, Kevin; Addison, Graeme E.; Amiri, Mandana; Bond, J. Richard; Campbell-Wilson, Duncan; Connor, Liam; Cliche, Jean-François; Davis, Greg; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gibbs, Kenneth; Gilbert, Adam; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Klages, Peter; Landecker, Tom L.; Masui, Kiyoshi; Mena Parra, Juan; Newburgh, Laura B.; Pen, Ue-li; Peterson, Jeffrey B.; Recnik, Andre; Shaw, J. Richard; Sigurdson, Kris; Sitwell, Mike; Smecher, Graeme; Smegal, Rick; Vanderlinde, Keith; Wiebe, Don

    2014-07-01

    A pathfinder version of CHIME (the Canadian Hydrogen Intensity Mapping Experiment) is currently being commissioned at the Dominion Radio Astrophysical Observatory (DRAO) in Penticton, BC. The instrument is a hybrid cylindrical interferometer designed to measure the large scale neutral hydrogen power spectrum across the redshift range 0.8 to 2.5. The power spectrum will be used to measure the baryon acoustic oscillation (BAO) scale across this poorly probed redshift range where dark energy becomes a significant contributor to the evolution of the Universe. The instrument revives the cylinder design in radio astronomy with a wide field survey as a primary goal. Modern low-noise amplifiers and digital processing remove the necessity for the analog beam forming that characterized previous designs. The Pathfinder consists of two cylinders 37m long by 20m wide oriented north-south for a total collecting area of 1,500 square meters. The cylinders are stationary with no moving parts, and form a transit instrument with an instantaneous field of view of ~100 degrees by 1-2 degrees. Each CHIME Pathfinder cylinder has a feedline with 64 dual polarization feeds placed every ~30 cm which Nyquist sample the north-south sky over much of the frequency band. The signals from each dual-polarization feed are independently amplified, filtered to 400-800 MHz, and directly sampled at 800 MSps using 8 bits. The correlator is an FX design, where the Fourier transform channelization is performed in FPGAs, which are interfaced to a set of GPUs that compute the correlation matrix. The CHIME Pathfinder is a 1/10th scale prototype version of CHIME and is designed to detect the BAO feature and constrain the distance-redshift relation. The lessons learned from its implementation will be used to inform and improve the final CHIME design.

  4. MARS PATHFINDER CAMERA TEST IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Jet Propulsion Laboratory (JPL) workers conduct a systems test of the Mars Pathfinder imager, installed atop the Pathfinder lander (with JPL insignia). The imager is the white cyclindrical structure close to the worker's gloved hand. At left is the small rover that will be deployed from the lander to explore the Martian surface. The rover is mounted on one of three petals that will be attached to the lander. The two-pronged mast extending upward from the lander is for the low-gain antenna. The imager is mounted on a mast that will be extended after the lander touches down on Mars, affording a better view of the area. The imager is a camera that will transmit images of the Martian surface as well as the trail left by the rover, helping researchers to better understand the composition of the soil. It also is equipped with selectable filters for gathering data about the atmosphere of the Red Planet. JPL manages the Mars Pathfinder project for NASA. The journey to Mars is scheduled to begin with liftoff Dec. 2 aboard a Delta II expendable launch vehicle.

  5. Pathfinder: Visual Analysis of Paths in Graphs

    PubMed Central

    Partl, C.; Gratzl, S.; Streit, M.; Wassermann, A. M.; Pfister, H.; Schmalstieg, D.; Lex, A.

    2016-01-01

    The analysis of paths in graphs is highly relevant in many domains. Typically, path-related tasks are performed in node-link layouts. Unfortunately, graph layouts often do not scale to the size of many real world networks. Also, many networks are multivariate, i.e., contain rich attribute sets associated with the nodes and edges. These attributes are often critical in judging paths, but directly visualizing attributes in a graph layout exacerbates the scalability problem. In this paper, we present visual analysis solutions dedicated to path-related tasks in large and highly multivariate graphs. We show that by focusing on paths, we can address the scalability problem of multivariate graph visualization, equipping analysts with a powerful tool to explore large graphs. We introduce Pathfinder (Figure 1), a technique that provides visual methods to query paths, while considering various constraints. The resulting set of paths is visualized in both a ranked list and as a node-link diagram. For the paths in the list, we display rich attribute data associated with nodes and edges, and the node-link diagram provides topological context. The paths can be ranked based on topological properties, such as path length or average node degree, and scores derived from attribute data. Pathfinder is designed to scale to graphs with tens of thousands of nodes and edges by employing strategies such as incremental query results. We demonstrate Pathfinder's fitness for use in scenarios with data from a coauthor network and biological pathways. PMID:27942090

  6. Pathfinder-Plus takes off on flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight over Hawaii in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4 days

  7. Pathfinder-Plus on flight over Hawaiian Islands

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on flight over Hawaiian Islands in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least 4

  8. Pathfinder-Plus on a flight in Hawaii

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight in 1998 over Hawaiian waters. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non-stop for at least

  9. Mars pathfinder Rover egress deployable ramp assembly

    NASA Technical Reports Server (NTRS)

    Spence, Brian R.; Sword, Lee F.

    1996-01-01

    The Mars Pathfinder Program is a NASA Discovery Mission, led by the Jet Propulsion Laboratory, to launch and place a small planetary Rover for exploration on the Martian surface. To enable safe and successful egress of the Rover vehicle from the spacecraft, a pair of flight-qualified, deployable ramp assemblies have been developed. This paper focuses on the unique, lightweight deployable ramp assemblies. A brief mission overview and key design requirements are discussed. Design and development activities leading to qualification and flight systems are presented.

  10. Mars Pathfinder Wheel Abrasion Experiment Ground Test

    NASA Technical Reports Server (NTRS)

    Keith, Theo G., Jr.; Siebert, Mark W.

    1998-01-01

    The National Aeronautics and Space Administration (NASA) sent a mission to the martian surface, called Mars Pathfinder. The mission payload consisted of a lander and a rover. The primary purpose of the mission was demonstrating a novel entry, descent, and landing method that included a heat shield, a parachute, rockets, and a cocoon of giant air bags. Once on the surface, the spacecraft returned temperature measurements near the Martian surface, atmosphere pressure, wind speed measurements, and images from the lander and rover. The rover obtained 16 elemental measurements of rocks and soils, performed soil-mechanics, atmospheric sedimentation measurements, and soil abrasiveness measurements.

  11. The LISA Pathfinder DMU and Radiation Monitor

    NASA Astrophysics Data System (ADS)

    Canizares, P.; Chmeissani, M.; Conchillo, A.; Diaz–Aguiló, M.; García-Berro, E.; Gesa, L.; Gibert, F.; Grimani, C.; Lloro, I.; Lobo, A.; Mateos, I.; Nofrarias, M.; Ramos-Castro, J.; Sanjuán, J.; Sopuerta, Carlos F.; Araújo, H. M.; Wass, P.

    2011-05-01

    The LISA Pathfinder DMU (Data Management Unit) flight model was formally accepted by ESA and ASD on 11 February 2010, after all hardware and software tests had been successfully completed. The diagnostics items are scheduled to be delivered by the end of 2010. In this paper, we review the requirements and performance of this instrumentation, specially focusing on the Radiation Monitor and the DMU, as well as the status of their programmed use during mission operations, on which work is ongoing at the time of writing.

  12. Scientific results of the Mars Pathfinder mission.

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.

    1999-02-01

    The author, project scientist of the Mars Pathfinder mision, presents a summary of the most important scientific results from the space probe, which descended to the Martian surface on July 4, 1997. These results include the strong evidence for catastrophic water floods in the history of the planet; close-up studies of the morphology and mineralogy of Martian rocks; the characteristics, chemistry, and origin of the magnetic dust particles deposited on the Martian surface; and meteorological measurements of temperature fluctuations, pressure variations, and wind velocities.

  13. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO)

    NASA Technical Reports Server (NTRS)

    McCormick, M. Patrick; Winker, David M.

    1998-01-01

    This paper will describe the planned 3-year Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission, its instrumentation and implementation. It will use LITE and other data, plus analyses, to show the feasibility of such a mission. PICASSO is being proposed for NASA's Earth System Science Pathfinder (ESSP) program with launch predicted in 2003.

  14. Pathfinders for Finding Information on Native Americans with Disabilities.

    ERIC Educational Resources Information Center

    Roy, Loriene, Comp.

    This bibliography offers strategies for locating information on selected topics of concern to those working with Native Americans with disabilities. The strategies are arranged in a format called a pathfinder. Each pathfinder follows a similar format, beginning with a brief overview of the topic, followed with an annotated bibliography, and…

  15. Australian Extinctions

    ERIC Educational Resources Information Center

    Science Teacher, 2005

    2005-01-01

    Massive extinctions of animals and the arrival of the first humans in ancient Australia--which occurred 45,000 to 55,000 years ago--may be linked. Researchers at the Carnegie Institution, University of Colorado, Australian National University, and Bates College believe that massive fires set by the first humans may have altered the ecosystem of…

  16. LISA Pathfinder Science Operations Concept and Development

    NASA Astrophysics Data System (ADS)

    Fauste, Jorge; McNamara, Paul; Armano, Michele; Texier, Damien; Freschi, Marco

    LISA Pathfinder is the second of the ESA Small Missions for Advanced Research in Technology, is a dedicated technology demonstrator for the joint ESA/NASA Laser Interferometer Space Antenna (LISA) mission. LISA Pathfinder carries two payloads, the European provided LISA Technology Package (LTP) and the NASA provided Disturbance Reduction System (DRS). The ground segment for LPF in the operational configuration will consist of one ground track-ing station, Cebreros (Spain), the Mission Operations Centre (MOC) at ESOC (Darmstadt, Germany), the Science Technology Operations Centre (STOC) located at ESOC and ESAC (Madrid, Spain) and LTP and DRS teams. The Science Technology Operations Centre although initially a small entity compatible with the operational requirements for an ESA SMART, has evolved in complexity in the last few years containing most of the systems and interfaces included as part of a normal ESA Science Operations Centre. In order to maintain a reasonable cost approach for its development and operations, a general reuse philosophy from systems already tested in previous ESA missions and/or from industry has been applied for the design and operation concept of the LPF STOC. The present paper describes the current LPF STOC design and it foreseen operational concept, highlighting the general reuse and customization process carried out for each of their individual subsystems.

  17. Detection of Micrometeoroids with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Thorpe, Ira; Littenberg, Tyson; Janchez, Diego; Baker, John; The LISA Pathfinder Team Team

    2017-01-01

    The LISA Pathfinder mission (LPF), a joint ESA/NASA technology demonstration mission currently operating at the Sun-Earth L1 point, contains the most precise accelerometry system ever flown. Analysis suggests that LPF should have sufficient sensitivity to detect impacts of small micrometeoroids and dust through their transfer of momentum to the spacecraft. Moreover, LPF's ability to fully resolve both the linear and angular momentum transfer in three dimensions allows a magnitude, direction, and location to be estimated for each impact. We present preliminary results from a systematic search of the LISA Pathfinder data for such impacts and discuss the prospects for using these and future results to inform models of the formation and evolution of dust populations in the inner solar system. These models have wide applicability to both pure and applied space science, ranging from the physics of planet formation and dynamics of minor Solar System bodies to estimates of the micrometeorite hazard for future spacecraft. 2017 NASA Science Innovation Fund.

  18. Overhead View of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Planimetric (overhead view) map of the landing site, to a distance of 20 meters from the spacecraft. North is at the top in this and Plates 3-5. To produce this map, images were geometrically projected onto an assumed mean surface representing the ground. Features above the ground plane (primarily rocks) therefore appear displaced radially outward; the amount of distortion increases systematically with distance. The upper surfaces of the lander and rover also appear enlarged and displaced because of their height. Primary grid (white) is based on the Landing Site Cartographic (LSC) coordinate system, defined with X eastward, Y north, and Z up, and origin located at the mean ground surface immediately beneath the deployed position of the IMP camera gimbal center. Secondary ticks (cyan) are based on the Mars local level (LL) frame, which has X north, Y east, Z down, with origin in the center of the lander baseplate. Rover positions (including APXS measurements) are commonly reported in the LL frame. Yellow grid shows polar coordinates based on the LSC system. Cartographic image processing by U.S. Geological Survey.

    NOTE: original caption as published in Science Magazine

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  19. In-flight Diagnostics in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Lobo, A.; Nofrarias, M.; Ramos-Castro, J.; Sanjuan, J.; Conchillo, A.; Ortega, J. A.; Xirgu, X.; Araujo, H.; Boatella, C.; Chmeissani, M.; Grimani, C.; Puigdengoles, C.; Wass, P.; García-Berro, E.; García, S.; Martínez, L. M.; Montero, G.

    2006-11-01

    LISA PathFinder (LPF) will be flown with the objective to test in space key technologies for LISA. However its sensitivity goals are, for good reason, one order of magnitude less than those which LISA will have to meet, both in drag-free and optical metrology requirements, and in the observation frequency band. While the expected success of LPF will of course be of itself a major step forward to LISA, one might not forget that a further improvement by an order of magnitude in performance will still be needed. Clues for the last leap are to be derived from proper disentanglement of the various sources of noise which contribute to the total noise, as measured in flight during the PathFinder mission. This paper describes the principles, workings and requirements of one of the key tools to serve the above objective: the diagnostics subsystem. This consists in sets of temperature, magnetic field, and particle counter sensors, together with generators of controlled thermal and magnetic perturbations. At least during the commissioning phase, the latter will be used to identify feed-through coefficients between diagnostics sensor readings and associated actual noise contributions. A brief progress report of the current state of development of the diagnostics subsystem will be given as well.

  20. Mars Pathfinder flight system integration and test.

    NASA Astrophysics Data System (ADS)

    Muirhead, B. K.

    This paper describes the system integration and test experiences, problems and lessons learned during the assembly, test and launch operations (ATLO) phase of the Mars Pathfinder flight system scheduled to land on the surface of Mars on July 4, 1997. The Mars Pathfinder spacecraft consists of three spacecraft systems: cruise stage, entry vehicle and lander. The cruise stage carries the entry and lander vehicles to Mars and is jettisoned prior to entry. The entry vehicle, including aeroshell, parachute and deceleration rockets, protects the lander during the direct entry and reduces its velocity from 7.6 to 0 km/s in stages during the 5 min entry sequence. The lander's touchdown is softened by airbags which are retracted once stopped on the surface. The lander then uprights itself, opens up fully and begins surface operations including deploying its camera and rover. This paper overviews the system design and the results of the system integration and test activities, including the entry, descent and landing subsystem elements. System test experiences including science instruments, the microrover, Sojourner, and software are discussed. The final qualification of the entry, descent and landing subsystems during this period is also discussed.

  1. Pathfinder landing sites at candidate SNC impact ejection sites

    NASA Technical Reports Server (NTRS)

    Golombek, Matthew P.

    1994-01-01

    If Mars Pathfinder were able to land at a site on Mars from which the SNC meteorites were ejected by impact, the Pathfinder mission would essentially represent a very inexpensive sample return mission. Geologic units that contain four potential impact craters from which SNC meteorites could have been ejected from Mars are accessible to the Mars Pathfinder lander. Determining that SNC meteorites came from a particular spot on Mars raises the intriguing possibility of using Pathfinder as a sample return mission and providing a radiometric age for the considerably uncertain martian crater-age timescale. Pathfinder instruments are capable of determining if the rock type at the landing site is similar to that of one or more of the SNC meteorites, which would strengthen the hypothesis that the SNC meteorites did, in fact, come from Mars. Unfortunately, instrument observations from Pathfinder are probably not capable of determining if the geologic unit sampled by the lander is definitively the unit from which a SNC meteorite came from as opposed to Mars in general or perhaps a particular region on Mars. This abstract evaluates the possibility of landing at potential SNC ejection sites and the ability of Pathfinder to identify the landing site as the place from which an SNC meteorite came.

  2. Big Crater as Viewed by Pathfinder Lander

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona. Superimposed on the rim of Big Crater (the central part of the rim as seen here) is a smaller crater nicknamed 'Rimshot Crater.' The distance to this smaller crater, and the nearest portion of the rim of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater, south from the spacecraft, almost lost in the atmospheric dust 'haze,' is the large streamlined mountain nicknamed 'Far Knob.' This mountain is over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles) from the spacecraft. Another, smaller and closer knob, nicknamed 'Southeast Knob' can be seen as a triangular peak to the left of the flanks of the Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the spacecraft.

    The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed 'Otter', is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.

    This view of Big Crater was produced by combining 6 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

    Mars Pathfinder is the second in NASA

  3. JWST pathfinder telescope risk reduction cryo test program

    NASA Astrophysics Data System (ADS)

    Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noël, Darin M.; Havey, Keith A.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon; Hadaway, James B.; Keski-Kuha, Ritva; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Marsh, James M.

    2015-08-01

    In 2014, the Optical Ground Support Equipment was integrated into the large cryo vacuum chamber at Johnson Space Center (JSC) and an initial Chamber Commissioning Test was completed. This insured that the support equipment was ready for the three Pathfinder telescope cryo tests. The Pathfinder telescope which consists of two primary mirror segment assemblies and the secondary mirror was delivered to JSC in February 2015 in support of this critical risk reduction test program prior to the flight hardware. This paper will detail the Chamber Commissioning and first optical test of the JWST Pathfinder telescope.

  4. JWST Pathfinder Telescope Risk Reduction Cryo Test Program

    NASA Technical Reports Server (NTRS)

    Matthews, Gary W.; Scorse, Thomas R.; Spina, John A.; Noel, Darin M.; Havey, Keith A., Jr.; Huguet, Jesse A.; Whitman, Tony L.; Wells, Conrad; Walker, Chanda B.; Lunt, Sharon; Hadaway, James B.; Keski-Kuha, Ritva; Feinberg, Lee D.; Voyton, Mark F.; Lander, Juli A.; Marsh, James M.

    2015-01-01

    In 2014, the Optical Ground Support Equipment was integrated into the large cryo vacuum chamber at Johnson Space Center (JSC) and an initial Chamber Commissioning Test was completed. This insured that the support equipment was ready for the three Pathfinder telescope cryo tests. The Pathfinder telescope which consists of two primary mirror segment assemblies and the secondary mirror was delivered to JSC in February 2015 in support of this critical risk reduction test program prior to the flight hardware. This paper will detail the Chamber Commissioning and first optical test of the JWST Pathfinder telescope.

  5. APECS - the Atacama pathfinder experiment control system

    NASA Astrophysics Data System (ADS)

    Muders, D.; Hafok, H.; Wyrowski, F.; Polehampton, E.; Belloche, A.; König, C.; Schaaf, R.; Schuller, F.; Hatchell, J.; van der Tak, F.

    2006-08-01

    APECS is the distributed control system of the new Atacama Pathfinder EXperiment (APEX) telescope located on the Llano de Chajnantor at an altitude of 5107 m in the Atacama desert in northern Chile. APECS is based on Atacama Large Millimeter Array (ALMA) software and employs a modern, object-oriented design using the Common Object Request Broker Architecture (CORBA) as the middleware. New generic device interfaces simplify adding instruments to the control system. The Python based observer command scripting language allows using many existing software libraries and facilitates creating more complex observing modes. A new self-descriptive raw data format (Multi-Beam FITS or MBFITS) has been defined to store the multi-beam, multi-frequency data. APECS provides an online pipeline for initial calibration, observer feedback and a quick-look display. APECS is being used for regular science observations in local and remote mode since August 2005.

  6. Mars Pathfinder airbag impact attenuation system

    SciTech Connect

    Waye, D.E.; Cole, J.K.; Rivellini, T.P.

    1995-04-01

    The Mars Pathfinder spacecraft, scheduled for launch in November 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia`s High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  7. Imager for Mars Pathfinder (IMP) image calibration

    USGS Publications Warehouse

    Reid, R.J.; Smith, P.H.; Lemmon, M.; Tanner, R.; Burkland, M.; Wegryn, E.; Weinberg, J.; Marcialis, R.; Britt, D.T.; Thomas, N.; Kramm, R.; Dummel, A.; Crowe, D.; Bos, B.J.; Bell, J.F.; Rueffer, P.; Gliem, F.; Johnson, J. R.; Maki, J.N.; Herkenhoff, K. E.; Singer, Robert B.

    1999-01-01

    The Imager for Mars Pathfinder returned over 16,000 high-quality images from the surface of Mars. The camera was well-calibrated in the laboratory, with <5% radiometric uncertainty. The photometric properties of two radiometric targets were also measured with 3% uncertainty. Several data sets acquired during the cruise and on Mars confirm that the system operated nominally throughout the course of the mission. Image calibration algorithms were developed for landed operations to correct instrumental sources of noise and to calibrate images relative to observations of the radiometric targets. The uncertainties associated with these algorithms as well as current improvements to image calibration are discussed. Copyright 1999 by the American Geophysical Union.

  8. Pathfinder autonomous rendezvous and docking project

    NASA Technical Reports Server (NTRS)

    Lamkin, Stephen (Editor); Mccandless, Wayne (Editor)

    1990-01-01

    Capabilities are being developed and demonstrated to support manned and unmanned vehicle operations in lunar and planetary orbits. In this initial phase, primary emphasis is placed on definition of the system requirements for candidate Pathfinder mission applications and correlation of these system-level requirements with specific requirements. The FY-89 activities detailed are best characterized as foundation building. The majority of the efforts were dedicated to assessing the current state of the art, identifying desired elaborations and expansions to this level of development and charting a course that will realize the desired objectives in the future. Efforts are detailed across all work packages in developing those requirements and tools needed to test, refine, and validate basic autonomous rendezvous and docking elements.

  9. The Imager for Mars Pathfinder Insurance Pan

    NASA Technical Reports Server (NTRS)

    Herkenhoff, K. E.; Johnson, J. R.; Weller, L. A.

    2003-01-01

    The Imager for Mars Pathfinder (IMP) obtained a full panorama of the Sagan Memorial Station landing site on Sol 2, before the IMP mast was deployed. The images in this panorama were taken in 4 filters (including stereo) and losslessly compressed to provide a high-quality multispectral survey of the landing site even if the IMP mast did not successfully deploy; this data set was therefore called the Insurance Pan. It was completed late in the afternoon of Sol 2, just before the IMP mast was (successfully) deployed. The data were stored in memory and returned to Earth after it became clear that downlink rates were higher than expected. The Insurance Pan horizontal (azimuth) coverage is nearly complete, with gaps caused by pointing errors and data packet losses. Stereo data were acquired in the blue (445 nm) filter, as well as right-eye green (531 nm), orange (600 nm), and near-infrared (752 nm) data.

  10. Statechart Analysis with Symbolic PathFinder

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.

    2012-01-01

    We report here on our on-going work that addresses the automated analysis and test case generation for software systems modeled using multiple Statechart formalisms. The work is motivated by large programs such as NASA Exploration, that involve multiple systems that interact via safety-critical protocols and are designed with different Statechart variants. To verify these safety-critical systems, we have developed Polyglot, a framework for modeling and analysis of model-based software written using different Statechart formalisms. Polyglot uses a common intermediate representation with customizable Statechart semantics and leverages the analysis and test generation capabilities of the Symbolic PathFinder tool. Polyglot is used as follows: First, the structure of the Statechart model (expressed in Matlab Stateflow or Rational Rhapsody) is translated into a common intermediate representation (IR). The IR is then translated into Java code that represents the structure of the model. The semantics are provided as "pluggable" modules.

  11. Modal analysis of PATHFINDER unmanned air vehicle

    SciTech Connect

    Woehrle, T.G.; Costerus, B.W.; Lee, C.L.

    1994-10-19

    An experimental modal analysis was performed on PATHFINDER, a 450-lb, 100-ft wing span, flying-wing-design aircraft powered by solar/electric motors. The aircraft was softly suspended and then excited using random input from a long-stroke shaker. Modal data was taken from 92 measurement locations on the aircraft using newly designed, lightweight, tri-axial accelerometers. A conventional PC-based data acquisition system provided data handling. Modal parameters were calculated, and animated mode shapes were produced using SMS STARStruct{trademark} Modal Analysis System software. The modal parameters will be used for validation of finite element models, optimum placement of onboard accelerometers during flight testing, and vibration isolation design of sensor platforms.

  12. 360 Degree Panorama Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This is the first contiguous, uniform 360-degree color panorama taken by the Imager for Mars Pathfinder (IMP) over the course of sols 8, 9, and 10 (Martian days). Different regions were imaged at different times over the three Martian days to acquire consistent lighting and shadow conditions for all areas of the panorama. At left is a lander petal and a metallic mast which is a portion of the low-gain antenna. On the horizon the double 'Twin Peaks' are visible, about 1-2 kilometers away. The rock 'Couch' is the dark, curved rock at right of Twin Peaks. Another lander petal is at left-center, showing the fully deployed forward ramp at far left, and rear ramp at right, which rover Sojourner used to descend to the surface of Mars on July 5. Immediately to the left of the rear ramp is the rock Barnacle Bill, which scientists found to be andesitic, possibly indicating that it is a volcanic rock (a true andesite) or a physical mixture of particles. Just beyond Barnacle Bill, rover tracks lead to Sojourner, shown using its Alpha Proton X-Ray Spectrometer (APXS) instrument to study the large rock Yogi. Yogi, low in quartz content, appears to be more primitive than Barnacle Bill, and appeared more like the common basalts found on Earth. The tracks and circular pattern in the soil leading up to Yogi were part of Sojourner's soil mechanics experiments, in which varying amounts of pressure were applied to the wheels in order to determine physical properties of the soil. During its traverse to Yogi the rover stirred the soil and exposed material from several centimeters in depth. During one of the turns to deploy Sojourner's Alpha Proton X-Ray Spectrometer, the wheels dug particularly deeply and exposed white material. Spectra of this white material show it is virtually identical to the rock Scooby Doo, and such white material may underlie much of the site. Deflated airbags are visible at the perimeter of all three lander petals. The IMP is a stereo imaging system with color

  13. Electrostatic Charging of the Pathfinder Rover

    NASA Technical Reports Server (NTRS)

    Siebert, Mark W.; Kolecki, Joseph C.

    1996-01-01

    The Mars Pathfinder mission will send a lander and a rover to the martian surface. Because of the extremely dry conditions on Mars, electrostatic charging of the rover is expected to occur as it moves about. Charge accumulation may result in high electrical potentials and discharge through the martian atmosphere. Such discharge could interfere with the operation of electrical elements on the rover. A strategy was sought to mitigate this charge accumulation as a precautionary measure. Ground tests were performed to demonstrate charging in laboratory conditions simulating the surface conditions expected at Mars. Tests showed that a rover wheel, driven at typical rover speeds, will accumulate electrical charge and develop significant electrical potentials (average observed, 110 volts). Measurements were made of wheel electrical potential, and wheel capacitance. From these quantities, the amount of absolute charge was estimated. An engineering solution was developed and recommended to mitigate charge accumulation. That solution has been implemented on the actual rover.

  14. Model Checking JAVA Programs Using Java Pathfinder

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Pressburger, Thomas

    2000-01-01

    This paper describes a translator called JAVA PATHFINDER from JAVA to PROMELA, the "programming language" of the SPIN model checker. The purpose is to establish a framework for verification and debugging of JAVA programs based on model checking. This work should be seen in a broader attempt to make formal methods applicable "in the loop" of programming within NASA's areas such as space, aviation, and robotics. Our main goal is to create automated formal methods such that programmers themselves can apply these in their daily work (in the loop) without the need for specialists to manually reformulate a program into a different notation in order to analyze the program. This work is a continuation of an effort to formally verify, using SPIN, a multi-threaded operating system programmed in Lisp for the Deep-Space 1 spacecraft, and of previous work in applying existing model checkers and theorem provers to real applications.

  15. International Planned Parenthood head visits Pathfinder.

    PubMed

    1996-01-01

    In January 1995, Dr. Ingar Brueggemann, the new Secretary General of International Planned Parenthood, and her Deputy Director attended a meeting sponsored by Pathfinder International in the US. Brueggemann discussed the impact of the 1994 International Conference on Population and Development (ICPD) and noted that, in order to implement the ICPD Programme of Action, family planning (FP) must become an accepted national objective in all countries. An integrated approach to FP services is also needed so that the programs can provide HIV/AIDS services and reach young people. Brueggemann noted that FP and reproductive health care must be viewed in a broad manner that highlights the positive aspects of the services rather than simply the negative ones (unwanted pregnancy, unsafe abortion, etc.).

  16. Java PathFinder User Guide

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus

    1999-01-01

    The JAVA PATHFINDER, JPF, is a translator from a subset of JAVA 1.0 to PROMELA, the programming language of the SPIN model checker. The purpose of JPF is to establish a framework for verification and debugging of JAVA programming based on model checking. The main goal is to automate program verification such that a programmer can apply it in the daily work without the need for a specialist to manually reformulate a program into a different notation in order to analyze the program. The system is especially suited for analyzing multi-threaded JAVA applications, where normal testing usually falls short. The system can find deadlocks and violations of boolean assertions stated by the programmer in a special assertion language. This document explains how to Use JPF.

  17. Mars Pathfinder Airbag Impact Attenuation System

    NASA Technical Reports Server (NTRS)

    Waye, Donald; Cole, J. Kenneth; Rivellini, Tommaso P.

    1995-01-01

    The Mars Pathfinder spacecraft, scheduled for launch in December 1996, is designed to validate a low cost Entry, Descent, and Landing system and to perform scientific surface operations. The Jet Propulsion Laboratory and Sandia National Laboratories teamed to design, fabricate, test and validate a prototype 0.38 scale model of an airbag impact attenuation system. A computer code was developed to predict the performance of the airbag system. A test program in Sandia's High Altitude Chamber was performed to validate the code and demonstrate the feasibility of the airbag concept and design. In addition, freefall tests were performed at representative velocities to demonstrate the structural integrity of the airbag system design. The feasibility program demonstrated that the airbag impact attenuation design will protect the lander upon impact with the Martian surface.

  18. Birdseye View of Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    This image is one frame of an animation that was created by using two mosaics: a color image of the Gallery Pan and an image which indicates the distance to the nearest object at each pixel location, referred to as a range image. The range data set is treated as a displacement map with respect to a sphere's surface, and the color image mosaic is draped onto the inside of the sphere. The position of the camera is fixed at the sphere's center, while its viewing direction is in this case looking at the south pole of the sphere. The mosaics were projected onto a continuous cylindrical/perspective coordinate system spanning 360 degrees of azimuth. The distortion visible near the edges of this image is due to the large field of view, as well as the limitation introduced by using cylindrically-projected images on the sphere - the effects of which are less apparent when smaller fields of view are used.

    The image has been rotated so that the main points of interest, which are the 'Rock Garden,' the rover Sojourner and the rock 'Yogi,' are easily seen arching across the upper hemisphere. In fixed Mars Surface coordinates, the top of the image looks out towards a point a few degrees north of West. Color has been enhanced to improve contrast in features, and is derived from IMP spectral filters 5, 9 and 0.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech).

  19. JANUS, A Proposed Pathfinder Mission to Mercury

    NASA Astrophysics Data System (ADS)

    Curtis, S. A.; Clark, P. E.; Giles, B.; Eyerman, C.; Marr, G.; Winterhalter, D.; Janus Mercury Pathfinder Mission Team

    1998-09-01

    Despite the Mariner 10 flybys and decades of ground-based observations, the planet Mercury remains the most poorly understood inner planet although it could potentially provide essential information on the evolution and origin of the solar system. JANUS, a mission proposed for the NASA Discovery Program, is an extremely fast, low cost, low risk, multiple flyby, four platform pathfinder to Mercury which would provide this essential data and complete the exploration of both hemispheres. JANUS studies Mercury and its environment as a system by simultaneously exploring its interior, surface, atmosphere, and magnetosphere. After a direct transfer orbit from Earth, the first dayside equatorial encounter with Mercury is 115 days post-launch, and includes the release of three Remote Experiment Packages (REPs) targeted for north and south poles and the magnetotail. This encounter provides the fist direct compositional measurements of Mercury and simultaneous multi-point modeling of its magnetic field. Perihelion engine burn following this encounter places the main spacecraft in a 264 day orbit allowing view of alternate sunlit faces of Mercury at each encounter. By the end of the second encounter (one year post-launch), the first photospectral map of the entire planet and a completed set of previously mission compositional constraints for inner solar system, core, and planetary formation is produced. The third encounter, less than two years post-launch, takes the spacecraft over the south pole in search of polar volatiles. JANUS features an experienced, integrated science team and a robust instrumentation package: imaging, X-ray, UV, and neutron spectrometers, energetic particle and electric field detectors, magnetometer, low energy plasma analyzer, and search coil on the main spacecraft, and duplicates of the last three instruments on each REP. JANUS is a true pathfinder, completing the primary exploration of Mercury and forging the path for future GSFC/JPL partnerships.

  20. Exobiology site priorities for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Farmer, Jack D.; Desmarais, David J.

    1994-01-01

    The fact that life developed on the Earth within the first billion years of its history makes it quite plausible that life may have also developed on Mars. If life did develop on Mars, it undoubtedly left behind a fossil record. Such a fossil record is likely to be more accessible than either subsurface environments that may harbor life, or scattered 'oases' that may be present at the surface. Consequently, the post-Viking approach of Mars exobiology has shifted focus to search for evidence of an ancient martian biosphere. This has led to the emergence of a new subdiscipline of paleontology, herein termed 'exopaleontology', which deals with the exploration for fossils on other planets and whose core concepts derive from Earth-based Precambrian paleontology, microbial ecology, and sedimentology. Potential targets on Mars for subaqueous spring deposits, sedimentary cements, and evaporites are ancient terminal lake basins where hydrological systems could have endured for some time under arid conditions. Potential targets for the Mars Pathfinder mission include channeled impact craters and areas of deranged drainage associated with outflows in northwest Arabia and Xanthe Terra, where water may have ponded temporarily to form lakes. The major uncertainty of such targets is their comparatively younger age and the potentially short duration of hydrological activity compared to older paleolake basins found in the southern hemisphere. However, it has been suggested that cycles of catastrophic flooding associated with Tharsis volcanism may have sustained a large body of water, Oceanus Borealis, in the northern plains area until quite late in martian history. Although problematic, the shoreline areas of the proposed northern ocean provide potential targets for a Mars Pathfinder mission aimed at exploring for carbonates or other potentially fossiliferous marine deposits. Carbonates and evaporites possess characteristic spectra signatures in the near-infrared and should be

  1. The CO Mapping Array Pathfinder (COMAP)

    NASA Astrophysics Data System (ADS)

    Cleary, Kieran; Bigot-Sazy, Marie-Anne; Chung, Dongwoo; Church, Sarah E.; Dickinson, Clive; Eriksen, Hans; gaier, todd; Goldsmith, Paul; Gundersen, Joshua O.; Harper, Stuart; Harris, Andrew I.; Lamb, James; Li, Tony; Munroe, Ryan; Pearson, Timothy J.; Readhead, Anthony C. S.; Wechsler, Risa H.; Kathrine Wehus, Ingunn; Woody, David

    2016-01-01

    The CO Mapping Array Pathfinder (COMAP) will open a new window on both the Epoch of Reionization (EoR) and the Epoch of Galaxy Assembly by using carbon monoxide (CO) lines to trace the distribution of star-forming galaxies in both epochs. Phase I of COMAP comprises a 10-m telescope, located at the Owens Valley Radio Observatory (OVRO), equipped with a 19-pixel spectrometer array that will map a total of 10 square degrees of sky in the frequency range 30-34 GHz, with spectral resolution R~800. This band will be sensitive to CO(1-0) in the redshift slice z=2.4-2.8 and to CO(2-1) in the redshift slice z = 5.8-6.7.Constraining the CO power spectrum from the EoR will ultimately require measurements at multiple frequencies and arrays with hundreds of elements. The aim of this pathfinder experiment is to i) demonstrate the feasibility and future potential of wide-field CO intensity mapping, and ii) provide a test-bed for the technology development and observational strategies. Phase I of COMAP will focus on constraining the CO power spectrum from the Epoch of Galaxy Assembly, at z=2.4-2.8. A wide range of predictions for the strength of this power spectrum have appeared in the literature; much of this range can either be confirmed or ruled out by COMAP.Cross-correlation with galaxy surveys in this redshift range will allow us to disentangle the impact of cosmological parameters, star formation rate (SFR) and the CO-SFR connection. Cross-correlation will also establish confidence that the observed signal is CO and allow inferences to be drawn about the unobserved, but CO-luminous galaxy population. The COMAP fields will therefore be chosen to overlap with galaxy surveys.COMAP Phase I observations are planned to start in late 2017, continuing until late 2019.

  2. Operations and Autonomy of the Mars Pathfinder Microrover

    NASA Technical Reports Server (NTRS)

    Mishkin, A. H.; Morrison, J. C.; Nguyen, T. T.; Stone, H. W.; Cooper, B. K.

    1998-01-01

    The Microrover Flight Experiment (MFEX) is a NSAS OACT (Office of Advanced Concepts and Technology) flight experiment which, integrated with the Mars Pathfinder (MPF) lander and spacecraft system, landed on Mars on July 4, 1997.

  3. Lithium-Thionyl Chloride Batteries for the Mars Pathfinder Microrover

    NASA Technical Reports Server (NTRS)

    Deligiannis, Frank; Frank, Harvey; Staniewicz, R. J.; Willson, John

    1996-01-01

    A discussion of the power requirements for the Mars Pathfinder Mission is given. Topics include: battery requirements; cell design; battery design; test descriptions and results. A summary of the results is also included.

  4. LISA Pathfinder paves way for gravitational-wave probe

    NASA Astrophysics Data System (ADS)

    Johnston, Hamish

    2016-07-01

    Researchers working on the LISA Pathfinder space mission have successfully managed to isolate from the environment two 2 kg test masses at a special “Lagrangian point” between the Earth and the Sun.

  5. The Mission and Operations of the Mars Pathfinder Microrover

    NASA Technical Reports Server (NTRS)

    Matijevic, J.; Shirley, D.

    1996-01-01

    The Microrover Flight Experiment (MFEX) is a NASA OACT flight experiment which is planned to be delivered and integrated with the Mars Pathfinder (MPF) lander and spacecraft system for landing on Mars on July 4, 1997.

  6. Pathfinder aircraft taking off from ground - side view

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This 27-second video clip shows the Pathfinder taking off from Rogers Dry Lakebed near the NASA Dryden Flight Research Center on Edwards Air Force Base. Shown from the lakebed side, the video shows Edwards and Dryden in the background.

  7. Vernon A. Walters: Pathfinder of the Intelligence Profession

    DTIC Science & Technology

    2004-06-03

    Intelligence College, for his proficient work in preliminary editing of these proceedings. Russell.Swenson@dia.mil, Editor and Director, Center for...Conference 2004 “LTG VERNON A. WALTERS: PATHFINDER OF THE INTELLIGENCE PROFESSION” Thursday, 3 June 2004 Defense Intelligence Analysis Center , Tighe...Analysis Center and on behalf of all the Joint Military Intelligence College to welcome you to this conference on “Vernon A. ‘Dick’ Walters: Pathfinder

  8. MARS PATHFINDER INSPECTED BY ENGINEER LINDA ROBECK IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the SAEF-2 spacecraft checkout facility, engineer Linda Robeck of the Jet Propulsion Laboratory inspects the Mars Pathfinder lander. The spacecraft arrived at Kennedy Space Center from Pasadena, CA on Aug. 13, 1996. The petals of the lander will be opened for checkout of the spacecraft and the installation of the small rover. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

  9. Australian Brain Alliance.

    PubMed

    2016-11-02

    A proposal for an Australian Brain Initiative (ABI) is under development by members of the Australian Brain Alliance. Here we discuss the goals of the ABI, its areas of research focus, its context in the Australian research setting, and its necessity for ensuring continued success for Australian brain research.

  10. The Mars Pathfinder Mission and Science Results

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.

    1999-01-01

    Mars Pathfinder, the first low-cost, quick Discovery class mission to be completed, successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments and 10 technology experiments. The mission operated on Mars for 3 months and returned 2.3 Gbits of new data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 million individual temperature, pressure and wind measurements. The rover traversed 100 m clockwise around the lander, exploring about 200 square meters of the surface. The mission captured the imagination of the public, and garnered front page headlines during the first week. A total of about 566 million internet "hits" were registered during the first month of the mission, with 47 million "hits" on July 8th alone, making the Pathfinder landing by far the largest internet event in history at the time. Pathfinder was the first mission to deploy a rover on Mars. It carried a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which provided a calibration point or "ground truth" for orbital remote sensing observations. The combination of spectral imaging of the landing area by the lander camera, chemical analyses aboard the rover, and close-up imaging of colors, textures and fabrics with the rover cameras offered the potential of identifying rocks (petrology and mineralogy). With this payload, a landing site in Ares Vallis was selected because it appeared acceptably safe and offered the prospect of analyzing a variety of rock types expected to be deposited by catastrophic floods, which enabled addressing first-order scientific questions such as differentiation of the crust, the development of weathering products, and the nature of the early Martian environment and its subsequent evolution. The 3 instruments and rover allowed seven areas of scientific investigation: the

  11. LISA Pathfinder as a micrometeorite instrument

    NASA Astrophysics Data System (ADS)

    Thorpe, James

    2016-03-01

    The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. We describe an approach for using the LISA Pathfinder [LPF] mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launched on Dec. 3rd, 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as 4 × 10-8 N . s. We then estimate the rate of such impulses resulting from impacts of micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses > 10-9 g during LPF's roughly six-month science operations phase.

  12. The Mars Pathfinder Mission and Science Results

    NASA Astrophysics Data System (ADS)

    Golombek, M. P.

    1999-01-01

    Mars Pathfinder, the first low-cost, quick Discovery class mission to be completed, successfully landed on the surface of Mars on July 4, 1997, deployed and navigated a small rover, and collected data from 3 science instruments and 10 technology experiments. The mission operated on Mars for 3 months and returned 2.3 Gbits of new data, including over 16,500 lander and 550 rover images, 16 chemical analyses of rocks and soil, and 8.5 million individual temperature, pressure and wind measurements. The rover traversed 100 m clockwise around the lander, exploring about 200 square meters of the surface. The mission captured the imagination of the public, and garnered front page headlines during the first week. A total of about 566 million internet "hits" were registered during the first month of the mission, with 47 million "hits" on July 8th alone, making the Pathfinder landing by far the largest internet event in history at the time. Pathfinder was the first mission to deploy a rover on Mars. It carried a chemical analysis instrument, to characterize the rocks and soils in a landing area over hundreds of square meters on Mars, which provided a calibration point or "ground truth" for orbital remote sensing observations. The combination of spectral imaging of the landing area by the lander camera, chemical analyses aboard the rover, and close-up imaging of colors, textures and fabrics with the rover cameras offered the potential of identifying rocks (petrology and mineralogy). With this payload, a landing site in Ares Vallis was selected because it appeared acceptably safe and offered the prospect of analyzing a variety of rock types expected to be deposited by catastrophic floods, which enabled addressing first-order scientific questions such as differentiation of the crust, the development of weathering products, and the nature of the early Martian environment and its subsequent evolution. The 3 instruments and rover allowed seven areas of scientific investigation: the

  13. Data Analysis for the LISA Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Thorpe, James Ira

    2009-01-01

    The LTP (LISA Technology Package) is the core part of the Laser Interferometer Space Antenna (LISA) Pathfinder mission. The main goal of the mission is to study the sources of any disturbances that perturb the motion of the freely-falling test masses from their geodesic trajectories as well as 10 test various technologies needed for LISA. The LTP experiment is designed as a sequence of experimental runs in which the performance of the instrument is studied and characterized under different operating conditions. In order to best optimize subsequent experimental runs, each run must be promptly analysed to ensure that the following ones make best use of the available knowledge of the instrument ' In order to do this, all analyses must be designed and tested in advance of the mission and have sufficient built-in flexibility to account for unexpected results or behaviour. To support this activity, a robust and flexible data analysis software package is also required. This poster presents two of the main components that make up the data analysis effort: the data analysis software and the mock-data challenges used to validate analysis procedures and experiment designs.

  14. Bayesian model selection for LISA pathfinder

    NASA Astrophysics Data System (ADS)

    Karnesis, Nikolaos; Nofrarias, Miquel; Sopuerta, Carlos F.; Gibert, Ferran; Armano, Michele; Audley, Heather; Congedo, Giuseppe; Diepholz, Ingo; Ferraioli, Luigi; Hewitson, Martin; Hueller, Mauro; Korsakova, Natalia; McNamara, Paul W.; Plagnol, Eric; Vitale, Stefano

    2014-03-01

    The main goal of the LISA Pathfinder (LPF) mission is to fully characterize the acceleration noise models and to test key technologies for future space-based gravitational-wave observatories similar to the eLISA concept. The data analysis team has developed complex three-dimensional models of the LISA Technology Package (LTP) experiment onboard the LPF. These models are used for simulations, but, more importantly, they will be used for parameter estimation purposes during flight operations. One of the tasks of the data analysis team is to identify the physical effects that contribute significantly to the properties of the instrument noise. A way of approaching this problem is to recover the essential parameters of a LTP model fitting the data. Thus, we want to define the simplest model that efficiently explains the observations. To do so, adopting a Bayesian framework, one has to estimate the so-called Bayes factor between two competing models. In our analysis, we use three main different methods to estimate it: the reversible jump Markov chain Monte Carlo method, the Schwarz criterion, and the Laplace approximation. They are applied to simulated LPF experiments in which the most probable LTP model that explains the observations is recovered. The same type of analysis presented in this paper is expected to be followed during flight operations. Moreover, the correlation of the output of the aforementioned methods with the design of the experiment is explored.

  15. Mars Pathfinder Microrover Flight Experiment - A New Paradigm for Very Low-Cost Spacecraft

    NASA Technical Reports Server (NTRS)

    Shirley, Donna L.

    1994-01-01

    The Mars Pathfinder Microrover Flight Experiment (MFEX) will be carried by the Mars Pathfinder mission to the surface of Mars, where it will perform technology, science and Mars mission engineeering experiments in July, 1997.

  16. From laboratory experiments to LISA Pathfinder: achieving LISA geodesic motion

    NASA Astrophysics Data System (ADS)

    Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Brandt, N.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marin, A.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Giardini, D.; Gibert, F.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Monsky, A.; Nicolini, D.; Nicolodi, D.; Nofrarias, M.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schleicher, A.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Steier, F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

    2011-05-01

    This paper presents a quantitative assessment of the performance of the upcoming LISA Pathfinder geodesic explorer mission. The findings are based on the results of extensive ground testing and simulation campaigns using flight hardware, flight control and operations algorithms. The results show that, for the central experiment of measuring the stray differential acceleration between the LISA test masses, LISA Pathfinder will be able to verify the overall acceleration noise to within a factor 2 of the LISA requirement at 1 mHz and within a factor 6 at 0.1 mHz. We also discuss the key elements of the physical model of disturbances, coming from LISA Pathfinder and ground measurement that will guarantee the LISA performance.

  17. Communication: Are Australians Different?

    ERIC Educational Resources Information Center

    Hansford, B. C.

    1992-01-01

    Examines the question of the distinctive nature of communication in Australia. Discusses nonverbal messages, gender concerns, historical influences on communication, the Australian accent, communication with indigenous persons, communication apprehension, and classroom communication. Argues that Australians' communication is relatively similar to…

  18. Mars Pathfinder Rover-Lewis Research Center Technology Experiments Program

    NASA Technical Reports Server (NTRS)

    Stevenson, Steven M.

    1997-01-01

    An overview of NASA's Mars Pathfinder Program is given and the development and role of three technology experiments from NASA's Lewis Research Center and carried on the Mars Pathfinder rover is described. Two recent missions to Mars were developed and managed by the Jet Propulsion Laboratory, and launched late last year: Mars Global Surveyor in November 1996 and Mars Pathfinder in December 1996. Mars Global Surveyor is an orbiter which will survey the planet with a number of different instruments, and will arrive in September 1997, and Mars Pathfinder which consists of a lander and a small rover, landing on Mars July 4, 1997. These are the first two missions of the Mars Exploration Program consisting of a ten year series of small robotic martian probes to be launched every 26 months. The Pathfinder rover will perform a number of technology and operational experiments which will provide the engineering information necessary to design and operate more complex, scientifically oriented surface missions involving roving vehicles and other machinery operating in the martian environment. Because of its expertise in space power systems and technologies, space mechanisms and tribology, Lewis Research Center was asked by the Jet Propulsion Laboratory, which is heading the Mars Pathfinder Program, to contribute three experiments concerning the effects of the martian environment on surface solar power systems and the abrasive qualities of the Mars surface material. In addition, rover static charging was investigated and a static discharge system of several fine Tungsten points was developed and fixed to the rover. These experiments and current findings are described herein.

  19. Mars Pathfinder Rover-Lewis Research Center Technology Experiments Program

    NASA Astrophysics Data System (ADS)

    Stevenson, Steven M.

    1997-07-01

    An overview of NASA's Mars Pathfinder Program is given and the development and role of three technology experiments from NASA's Lewis Research Center and carried on the Mars Pathfinder rover is described. Two recent missions to Mars were developed and managed by the Jet Propulsion Laboratory, and launched late last year: Mars Global Surveyor in November 1996 and Mars Pathfinder in December 1996. Mars Global Surveyor is an orbiter which will survey the planet with a number of different instruments, and will arrive in September 1997, and Mars Pathfinder which consists of a lander and a small rover, landing on Mars July 4, 1997. These are the first two missions of the Mars Exploration Program consisting of a ten year series of small robotic martian probes to be launched every 26 months. The Pathfinder rover will perform a number of technology and operational experiments which will provide the engineering information necessary to design and operate more complex, scientifically oriented surface missions involving roving vehicles and other machinery operating in the martian environment. Because of its expertise in space power systems and technologies, space mechanisms and tribology, Lewis Research Center was asked by the Jet Propulsion Laboratory, which is heading the Mars Pathfinder Program, to contribute three experiments concerning the effects of the martian environment on surface solar power systems and the abrasive qualities of the Mars surface material. In addition, rover static charging was investigated and a static discharge system of several fine Tungsten points was developed and fixed to the rover. These experiments and current findings are described herein.

  20. MARS PATHFINDER LANDER REMOVED FROM SHIPPING CONTAINER IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the SAEF-2 spacecraft checkout facility at Kennedy Space Center, engineers and technicians from Jet Propulsion Laboratory remove the Mars Pathfinder lander from its shipping container, still covered in protective wrapping. Pictured from L-R, Linda Robeck, Jerry Gutierrez, Lorraine Garcia, Chuck Foehlinger of JPL. The arrival of the spacecraft at KSC from Pasadena, CA occurred on Aug. 13, 1996. Launch of Mars Pathfinder aboard a McDonnell Douglas Delta II rocket will occur from Pad B at Complex 17 on Dec. 2.

  1. Mars Pathfinder Microrover - Implementing a Low Cost Planetary Mission Experiment

    NASA Technical Reports Server (NTRS)

    Matijevic, J.

    1995-01-01

    The Mars Pathfinder Microrover Flight Experiment (MFEX) is a NASA OACT flight experiment which is planned to be delivered and integrated with the Mars Pathfinder (MFP) lander and spacecraft system for landing on Mars on July 4, 1997. After landing, the MFEX rover is deployed from the lander and begins a 7 sol (1 sol=1 Martian day) mission to conduct technology experiments, deploy an alpha proton x-ray spectrometer (APXS) on rocks and soil, and image the lander as part of the engineering assessment of the mission after landing.

  2. Mars Pathfinder Microrover- Implementing a Low Cost Planetary Mission Experiment

    NASA Technical Reports Server (NTRS)

    Matijevic, J.

    1996-01-01

    The Mars Pathfinder Microrover Flight Experiment (MFEX) is a NASA Office of Space Access and Technology (OSAT) flight experiment which has been delivered and integrated with the Mars Pathfinder (MPF) lander and spacecraft system. The total cost of the MFEX mission, including all subsystem design and development, test, integration with the MPF lander and operations on Mars has been capped at $25 M??is paper discusses the process and the implementation scheme which has resulted in the development of this first Mars rover.

  3. MOC's Highest Resolution View of Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    2000-01-01

    [figure removed for brevity, see original site] (A) Mars Pathfinder site, left: April 1998; right: January 2000.

    [figure removed for brevity, see original site] (B) top: April 1998; bottom: January 2000.

    Can Mars Global Surveyor's 1.5 meter (5 ft) per pixel camera be used to find any evidence as to the fate of the Mars Polar Lander that was lost on December 3, 1999? One way to find out is to look for one of the other Mars landers and determine what, if anything, can be seen. There have been three successful Mars lander missions: Viking 1 (July 1976), Viking 2 (September 1976), and Mars Pathfinder (July 1997). Of these, the location of Mars Pathfinder is known the best because there are several distinct landmarks visible in the lander's images that help in locating the spacecraft. The MGS MOC Operations Team at Malin Space Science Systems has been tasked since mid-December 1999 with looking for the lost Polar Lander. Part of this effort has been to test the capabilities of MOC by taking a picture of the landing site of Mars Pathfinder.

    An attempt to photograph the Pathfinder site was made once before, in April 1998, by turning the entire MGS spacecraft so that the camera could point at the known location of the Mars Pathfinder lander. Turning the MGS spacecraft like this is not a normal operation--it takes considerable planning, and disrupts the on-going, normal acquisition of science data. It took 3 attempts to succeed, but on April 22, 1998, MOC acquired the picture seen on the left side of Figure A, above. The three near-by major landmarks that were visible to the Pathfinder's cameras are labeled here (North Peak, Big Crater, Twin Peaks). It was known at the time that this image was not adequate to see the Pathfinder lander because the camera was not in focus and had a resolution of only 3.3 meters (11 ft) per pixel. In this and all other images shown here, north is up. All views of the 1998 MOC image are illuminated from the lower right, all views

  4. Holographic beam mapping of the CHIME pathfinder array

    NASA Astrophysics Data System (ADS)

    Berger, Philippe; Newburgh, Laura B.; Amiri, Mandana; Bandura, Kevin; Cliche, Jean-François; Connor, Liam; Deng, Meiling; Denman, Nolan; Dobbs, Matt; Fandino, Mateus; Gilbert, Adam J.; Good, Deborah; Halpern, Mark; Hanna, David; Hincks, Adam D.; Hinshaw, Gary; Höfer, Carolin; Johnson, Andre M.; Landecker, Tom L.; Masui, Kiyoshi W.; Mena Parra, Juan; Oppermann, Niels; Pen, Ue-Li; Peterson, Jeffrey B.; Recnik, Andre; Robishaw, Timothy; Shaw, J. Richard; Siegel, Seth; Sigurdson, Kris; Smith, Kendrick; Storer, Emilie; Tretyakov, Ian; Van Gassen, Kwinten; Vanderlinde, Keith; Wiebe, Donald

    2016-08-01

    The Canadian Hydrogen Intensity Mapping Experiment (CHIME) Pathfinder radio telescope is currently surveying the northern hemisphere between 400 and 800 MHz. By mapping the large scale structure of neutral hydrogen through its redshifted 21 cm line emission between z 0.8-2.5 CHIME will contribute to our understanding of Dark Energy. Bright astrophysical foregrounds must be separated from the neutral hydrogen signal, a task which requires precise characterization of the polarized telescope beams. Using the DRAO John A. Galt 26 m telescope, we have developed a holography instrument and technique for mapping the CHIME Pathfinder beams. We report the status of the instrument and initial results of this effort.

  5. LISA Pathfinder and eLISA news

    NASA Technical Reports Server (NTRS)

    Thorpe, James Ira; Mueller, Guido

    2014-01-01

    Two important gatherings of the space-based gravitational-wave detector community were held in Zurich, Switzerland this past March. The first was a meeting of the Science Working Team for LISA Pathfinder (LPF), a dedicated technology demonstrator mission for a future LISA-like gravitational wave observatory. LPF is entering an extremely exciting phase with launch less than 15 months away. All flight components for both the European science payload, known as the LISA Technology Package (LTP), and the NASA science payload, known as the Space Technology 7 Disturbance Reduction System (ST7-DRS), have been delivered and are undergoing integration. The final flight component for the spacecraft bus, a cold-gas thruster based on the successful GAIA design, will be delivered later this year. Current focus is on completing integration of the science payload (see Figures 1 and 2) and preparation for operations and data analysis. After a launch in Summer 2015, LPF will take approximately 90 days to reach its operational orbit around the Earth-Sun Lagrange point (L1), where it will begin science operations. After 90 days of LTP operations followed by 90 days of DRS operations, LPF will have completed its prime mission of paving the way for a space-based observatory of gravitational waves in the milliHertz band. Immediately following the meeting of the LPF team, the eLISA consortium held its third progress meeting. The consortium (www.elisascience.org) is the organizing body of the European space-based gravitational-wave community, and it was responsible for the "The Gravitational Universe" whitepaper that resulted in the November 2013 election of a gravitational-wave science theme for ESA's Cosmic Visions L3 opportunity. In preparation for an L3 mission concept call, which is expected later this decade, and for launch in the mid 2030s, the eLISA consortium members are coordinating technology development and mission study activities which will build on the LPF results. The final

  6. Modis, SeaWIFS, and Pathfinder funded activities

    NASA Technical Reports Server (NTRS)

    Evans, Robert H.

    1995-01-01

    MODIS (Moderate Resolution Imaging Spectrometer), SeaWIFS (Sea-viewing Wide Field Sensor), Pathfinder, and DSP (Digital Signal Processor) objectives are summarized. An overview of current progress is given for the automatic processing database, client/server status, matchup database, and DSP support.

  7. Sedimentary geomorphology of the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Rice, James W., Jr.; Parker, Timothy Jay

    1997-01-01

    The first landing on Mars in over 20 years will take place July 4, 1997, near te mouth of the Ares Vallis outflow channel located in southeastern Chryse Planitia. Mars Pathfinder, unlike Viking 1, is expected to land on a surface that has a distinct and unambiguous fluvial signature.

  8. Teacher Job Satisfaction: Lessons from the TSW Pathfinder Project

    ERIC Educational Resources Information Center

    Butt, Graham; Lance, Ann; Fielding, Antony; Gunter, Helen; Rayner, Steve; Thomas, Hywel

    2005-01-01

    Government policy assumes that modernization and remodelling will be effective as external intervention mechanisms to improve job satisfaction. Based on data collected as part of the evaluation of the "Transforming the School Workforce Pathfinder Project", an argument is presented here which suggests that internal management models may…

  9. Re-examination of Mars Pathfinder parachute drag coefficient estimate

    NASA Technical Reports Server (NTRS)

    Desai, P.; Schofield, T.; Lisano, M.

    2003-01-01

    The Mars Exploration Rover (MER) mission utilizes the Mars Pathfinder (MPF) parachute design. The MPF parachute drag coefficient is a driver for the MER entry, descent, and landing (EDL) design. As a result, a good estimate of the performance of the MPF parachute at Mars is required.

  10. LISA Pathfinder: the geodesy explorer testing alternative theories of gravity

    NASA Astrophysics Data System (ADS)

    Armano, Michele

    The LISA Pathfinder spacecraft by ESA is on schedule to fly by autumn 2015. Implementing a high precision free-fall in-flight system near a Lagrangian point, the mission relies on technologies never used before in space environments and crucial to gravitational waves observatories. The core instrument configuration makes LISA Pathfinder a gradiometer of unprecedented sensitivity. The designated orbit places it in position to further cruise through a volume of space where Newtonian pulls compensate and the Newtonian acceleration is close to zero. In the global picture that sees several dark matter/energy models and many theories at work to match observations, the free-fall specialist LISA Pathfinder can directly explore gravity at its alleged depart from the Newtonian regime, realizing a null dynamical test so far missing between astrophysical measurements and planetary tests. We will explicitly consider MOND theories as a test canvas and show that without further modifications the LISA Pathfinder instrument could sample several scales of the Newtonian-MONDian regime. We shall highlight the science case, the current experiment, the measurement design and the related data analysis.

  11. A Pathfinder for Animal Research and Animal Rights.

    ERIC Educational Resources Information Center

    Anderson, David C.

    1992-01-01

    This pathfinder was originally prepared for "Biomedical Research and Animal Rights," a session sponsored by the Veterinary Medical Libraries and Research Libraries Sections of the Medical Library Association. Current resources are described, from bibliographies to electronic bulletin boards, which relate to the issue of laboratory animal…

  12. Coordinate Map of Rocks at Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Mars-local-level (LL frame) coordinate map of rocks counted at the Mars Pathfinder landing site. Positions, apparent diameters (D), and heights (H) were measured to the nearest centimeter in the Mars map virtual reality environment constructed from the 'Monster Pan'

  13. Relating MBSE to Spacecraft Development: A NASA Pathfinder

    NASA Technical Reports Server (NTRS)

    Othon, Bill

    2016-01-01

    The NASA Engineering and Safety Center (NESC) has sponsored a Pathfinder Study to investigate how Model Based Systems Engineering (MBSE) and Model Based Engineering (MBE) techniques can be applied by NASA spacecraft development projects. The objectives of this Pathfinder Study included analyzing both the products of the modeling activity, as well as the process and tool chain through which the spacecraft design activities are executed. Several aspects of MBSE methodology and process were explored. Adoption and consistent use of the MBSE methodology within an existing development environment can be difficult. The Pathfinder Team evaluated the possibility that an "MBSE Template" could be developed as both a teaching tool as well as a baseline from which future NASA projects could leverage. Elements of this template include spacecraft system component libraries, data dictionaries and ontology specifications, as well as software services that do work on the models themselves. The Pathfinder Study also evaluated the tool chain aspects of development. Two chains were considered: 1. The Development tool chain, through which SysML model development was performed and controlled, and 2. The Analysis tool chain, through which both static and dynamic system analysis is performed. Of particular interest was the ability to exchange data between SysML and other engineering tools such as CAD and Dynamic Simulation tools. For this study, the team selected a Mars Lander vehicle as the element to be designed. The paper will discuss what system models were developed, how data was captured and exchanged, and what analyses were conducted.

  14. Pathfinder wing tip video at 50,000 feet

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In this clip, the Pathfinder's wing camera shows the view from 50,000 feet. Below is the reddish-brown desert, with the curvature of the Earth visible. Above this is a haze, which blends into the blue-black sky. The vehicle is more than 10,000 feet above an airliner's normal altitude.

  15. ASKAP H I imaging of the galaxy group IC 1459

    NASA Astrophysics Data System (ADS)

    Serra, P.; Koribalski, B.; Kilborn, V.; Allison, J. R.; Amy, S. W.; Ball, L.; Bannister, K.; Bell, M. E.; Bock, D. C.-J.; Bolton, R.; Bowen, M.; Boyle, B.; Broadhurst, S.; Brodrick, D.; Brothers, M.; Bunton, J. D.; Chapman, J.; Cheng, W.; Chippendale, A. P.; Chung, Y.; Cooray, F.; Cornwell, T.; DeBoer, D.; Diamond, P.; Forsyth, R.; Gough, R.; Gupta, N.; Hampson, G. A.; Harvey-Smith, L.; Hay, S.; Hayman, D. B.; Heywood, I.; Hotan, A. W.; Hoyle, S.; Humphreys, B.; Indermuehle, B.; Jacka, C.; Jackson, C. A.; Jackson, S.; Jeganathan, K.; Johnston, S.; Joseph, J.; Kamphuis, P.; Leach, M.; Lenc, E.; Lensson, E.; Mackay, S.; Marquarding, M.; Marvil, J.; McClure-Griffiths, N.; McConnell, D.; Meyer, M.; Mirtschin, P.; Neuhold, S.; Ng, A.; Norris, R. P.; O'Sullivan, J.; Pathikulangara, J.; Pearce, S.; Phillips, C.; Popping, A.; Qiao, R. Y.; Reynolds, J. E.; Roberts, P.; Sault, R. J.; Schinckel, A. E. T.; Shaw, R.; Shimwell, T. W.; Staveley-Smith, L.; Storey, M.; Sweetnam, A. W.; Troup, E.; Tzioumis, A.; Voronkov, M. A.; Westmeier, T.; Whiting, M.; Wilson, C.; Wong, O. I.; Wu, X.

    2015-09-01

    We present H I imaging of the galaxy group IC 1459 carried out with six antennas of the Australian Square Kilometre Array Pathfinder equipped with phased-array feeds. We detect and resolve H I in 11 galaxies down to a column density of ˜1020 cm-2 inside a ˜6 deg2 field and with a resolution of ˜1 arcmin on the sky and ˜8 km s-1 in velocity. We present H I images, velocity fields and integrated spectra of all detections, and highlight the discovery of three H I clouds - two in the proximity of the galaxy IC 5270 and one close to NGC 7418. Each cloud has an H I mass of ˜109 M⊙ and accounts for ˜15 per cent of the H I associated with its host galaxy. Available images at ultraviolet, optical and infrared wavelengths do not reveal any clear stellar counterpart of any of the clouds, suggesting that they are not gas-rich dwarf neighbours of IC 5270 and NGC 7418. Using Parkes data, we find evidence of additional extended, low-column-density H I emission around IC 5270, indicating that the clouds are the tip of the iceberg of a larger system of gas surrounding this galaxy. This result adds to the body of evidence on the presence of intragroup gas within the IC 1459 group. Altogether, the H I found outside galaxies in this group amounts to several times 109 M⊙, at least 10 per cent of the H I contained inside galaxies. This suggests a substantial flow of gas in and out of galaxies during the several billion years of the group's evolution.

  16. A pilot ASKAP survey of radio transient events in the region around the intermittent pulsar PSR J1107-5907

    NASA Astrophysics Data System (ADS)

    Hobbs, G.; Heywood, I.; Bell, M. E.; Kerr, M.; Rowlinson, A.; Johnston, S.; Shannon, R. M.; Voronkov, M. A.; Ward, C.; Banyer, J.; Hancock, P. J.; Murphy, Tara; Allison, J. R.; Amy, S. W.; Ball, L.; Bannister, K.; Bock, D. C.-J.; Brodrick, D.; Brothers, M.; Brown, A. J.; Bunton, J. D.; Chapman, J.; Chippendale, A. P.; Chung, Y.; DeBoer, D.; Diamond, P.; Edwards, P. G.; Ekers, R.; Ferris, R. H.; Forsyth, R.; Gough, R.; Grancea, A.; Gupta, N.; Harvey-Smith, L.; Hay, S.; Hayman, D. B.; Hotan, A. W.; Hoyle, S.; Humphreys, B.; Indermuehle, B.; Jacka, C. E.; Jackson, C. A.; Jackson, S.; Jeganathan, K.; Joseph, J.; Kendall, R.; Kiraly, D.; Koribalski, B.; Leach, M.; Lenc, E.; MacLeod, A.; Mader, S.; Marquarding, M.; Marvil, J.; McClure-Griffiths, N.; McConnell, D.; Mirtschin, P.; Neuhold, S.; Ng, A.; Norris, R. P.; O'Sullivan, J.; Pearce, S.; Phillips, C. J.; Popping, A.; Qiao, R. Y.; Reynolds, J. E.; Roberts, P.; Sault, R. J.; Schinckel, A. E. T.; Serra, P.; Shaw, R.; Shimwell, T. W.; Storey, M.; Sweetnam, A. W.; Tzioumis, A.; Westmeier, T.; Whiting, M.; Wilson, C. D.

    2016-03-01

    We use observations from the Boolardy Engineering Test Array (BETA) of the Australian Square Kilometre Array Pathfinder (ASKAP) telescope to search for transient radio sources in the field around the intermittent pulsar PSR J1107-5907. The pulsar is thought to switch between an `off' state in which no emission is detectable, a weak state and a strong state. We ran three independent transient detection pipelines on two-minute snapshot images from a 13 h BETA observation in order to (1) study the emission from the pulsar, (2) search for other transient emission from elsewhere in the image and (3) to compare the results from the different transient detection pipelines. The pulsar was easily detected as a transient source and, over the course of the observations, it switched into the strong state three times giving a typical time-scale between the strong emission states of 3.7 h. After the first switch it remained in the strong state for almost 40 min. The other strong states lasted less than 4 min. The second state change was confirmed using observations with the Parkes radio telescope. No other transient events were found and we place constraints on the surface density of such events on these time-scales. The high sensitivity Parkes observations enabled us to detect individual bright pulses during the weak state and to study the strong state over a wide observing band. We conclude by showing that future transient surveys with ASKAP will have the potential to probe the intermittent pulsar population.

  17. Illuminating the past 8 billion years of cold gas towards two gravitationally lensed quasars

    NASA Astrophysics Data System (ADS)

    Allison, J. R.; Moss, V. A.; Macquart, J.-P.; Curran, S. J.; Duchesne, S. W.; Mahony, E. K.; Sadler, E. M.; Whiting, M. T.; Bannister, K. W.; Chippendale, A. P.; Edwards, P. G.; Harvey-Smith, L.; Heywood, I.; Indermuehle, B. T.; Lenc, E.; Marvil, J.; McConnell, D.; Sault, R. J.

    2017-03-01

    Using the Boolardy Engineering Test Array of the Australian Square Kilometre Array Pathfinder (ASKAP BETA), we have carried out the first z = 0-1 survey for H I and OH absorption towards the gravitationally lensed quasars PKS B1830-211 and MG J0414+0534. Although we detected all previously reported intervening systems towards PKS B1830-211, in the case of MG J0414+0534, three systems were not found, indicating that the original identifications may have been confused with radio frequency interference. Given the sensitivity of our data, we find that our detection yield is consistent with the expected frequency of intervening H I systems estimated from previous surveys for 21-cm emission in nearby galaxies and z ∼ 3 damped Lyman α absorbers. We find spectral variability in the z = 0.886 face-on spiral galaxy towards PKS B1830-211 from observations undertaken with the Westerbork Synthesis Radio Telescope in 1997/1998 and ASKAP BETA in 2014/2015. The H I equivalent width varies by a few per cent over approximately yearly time-scales. This long-term spectral variability is correlated between the north-east and south-west images of the core, and with the total flux density of the source, implying that it is observationally coupled to intrinsic changes in the quasar. The absence of any detectable variability in the ratio of H I associated with the two core images is in stark contrast to the behaviour previously seen in the molecular lines. We therefore infer that coherent opaque H I structures in this galaxy are larger than the parsec-scale molecular clouds found at mm-wavelengths.

  18. High-velocity OH megamasers in IRAS 20100-4156: evidence for a supermassive black hole

    NASA Astrophysics Data System (ADS)

    Harvey-Smith, L.; Allison, J. R.; Green, J. A.; Bannister, K. W.; Chippendale, A.; Edwards, P. G.; Heywood, I.; Hotan, A. W.; Lenc, E.; Marvil, J.; McConnell, D.; Phillips, C. J.; Sault, R. J.; Serra, P.; Stevens, J.; Voronkov, M.; Whiting, M.

    2016-08-01

    We report the discovery of new, high-velocity narrow-line components of the OH megamaser in IRAS 20100-4156. Results from the Australian Square Kilometre Array Pathfinder (ASKAP)'s Boolardy Engineering Test Array (BETA) and the Australia Telescope Compact Array (ATCA) provide two independent measurements of the OH megamaser spectrum. We found evidence for OH megamaser clumps at -409 and -562 km s-1 (blue-shifted) from the systemic velocity of the galaxy, in addition to the lines previously known. The presence of such high velocities in the molecular emission from IRAS 20100-4156 could be explained by a ˜50 pc molecular ring enclosing a ˜3.8 billion solar mass black hole. We also discuss two alternatives, i.e. that the narrow-line masers are dynamically coupled to the wind driven by the active galactic nucleus or they are associated with two separate galactic nuclei. The comparison between the BETA and ATCA spectra provides another scientific verification of ASKAP's BETA. Our data, combined with previous measurements of the source enabled us to study the variability of the source over a 26 yr period. The flux density of the brightest OH maser components has reduced by more than a factor of 2 between 1988 and 2015, whereas a secondary narrow-line component has more than doubled in the same time. Plans for high-resolution very long baseline interferometry follow-up of this source are discussed, as are prospects for discovering new OH megamasers during the ASKAP early science programme.

  19. Results of the Imager for Mars Pathfinder windsock experiment

    USGS Publications Warehouse

    Sullivan, R.; Greeley, R.; Kraft, M.; Wilson, G.; Golombek, M.; Herkenhoff, K.; Murphy, J.; Smith, P.

    2000-01-01

    The Imager for Mars Pathfinder (IMP) windsock experiment measured wind speeds at three heights within 1.2 m of the Martian surface during Pathfinder landed operations. These wind data allowed direct measurement of near-surface wind profiles on Mars for the first time, including determination of aerodynamic roughness length and wind friction speeds. Winds were light during periods of windsock imaging, but data from the strongest breezes indicate aerodynamic roughness length of 3 cm at the landing site, with wind friction speeds reaching 1 m/s. Maximum wind friction speeds were about half of the threshold-of-motion friction speeds predicted for loose, fine-grained materials on smooth Martian terrain and about one third of the threshold-of-motion friction speeds predicted for the same size particles over terrain with aerodynamic roughness of 3 cm. Consistent with this, and suggesting that low wind speeds prevailed when the windsock array was not imaged and/or no particles were available for aeolian transport, no wind-related changes to the surface during mission operations have been recognized. The aerodynamic roughness length reported here implies that proposed deflation of fine particles around the landing site, or activation of duneforms seen by IMP and Sojourner, would require wind speeds >28 m/s at the Pathfinder top windsock height (or >31 m/s at the equivalent Viking wind sensor height of 1.6 m) and wind speeds >45 m/s above 10 m. These wind speeds would cause rock abrasion if a supply of durable particles were available for saltation. Previous analyses indicate that the Pathfinder landing site probably is rockier and rougher than many other plains units on Mars, so aerodynamic roughness length elsewhere probably is less than the 3-cm value reported for the Pathfinder site. Copyright 2000 by the American Geophysical Union.

  20. Dust devils as observed by the Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Ferri, F.; Smith, P. H.; Lemmon, M.; Rennó, N. O.

    1999-09-01

    Dust devils have been observed on Mars by the Viking Orbiters and Landers [Ryan and Lucich, 1983; Thomas and Gierash, 1985], by the Mars Pathfinder [Schofield et al., 1997; Metzger et al., 1999] and more recently by the Mars Global Surveyor. Dust devils are low-pressure, warm-core vortices that form at the bottom of convective plumes and loft dust from the surface; on Earth they are frequently observed in hot arid regions. They move with the speed of the ambient wind and slope in the wind shear direction. On Mars, they might play an important role in the maintenance of the atmospheric dust. In the Pathfinder data, dust devils have been detected as dust plumes in the IMP images and as convective vortices in the ASI/MET temperature, pressure and wind data. The size and location of the dust devils observed in the IMP images have been estimated based on assumptions about the ambient wind. The obtained results are in good agreement with the Pathfinder ASI/MET data and observations by the Viking 1 orbiter. A simple thermodynamic theory for dust devils [Rennó et al., 1998;1999] has been used to compute the intensity and some physical parameters of the Martian dust devils. Moreover, their capability of lofting dust high into the atmosphere has been investigated on the basis of Pathfinder's observations. It is concluded that Martian dust devils can provide a pumping rate comparable to the dust settling rate derived from the optical obscuration of the solar panels of the Pathfinder rover [Rover team, 1997]. Therefore, they might be responsible for the maintenance of the dust normally observed in the Martian atmosphere.

  1. Mars Pathfinder First Anniversary Special -- Refined Landing Site Location

    NASA Technical Reports Server (NTRS)

    1998-01-01

    It has been one year since NASA's Return to the Red Planet began with the spectacular landing of Mars Pathfinder and its microrover, Sojourner. The spacecraft bounced onto a flood-washed landscape on July 4, 1997.

    Mars Pathfinder was soon joined by the orbiting Mars Global Surveyor on September 11, 1997 (PDT). Mars Global Surveyor's high resolution camera, MOC, took a picture of the Mars Pathfinder landing site region during its 256th orbit on April 22, 1998. This picture--at about 5 meters (11 feet) per pixel--is the best available for the site. The previous best images were from the Viking 1 Orbiter in 1976, and had resolutions of about 38 meters (125 feet) per pixel.

    The MOC image has allowed scientists to determine the exact location of the Mars Pathfinder lander. Unfortunately, the image resolution is not good enough to actually see the lander--nor can any of the familiar boulders (e.g., 'Yogi') be seen at this resolution.

    Using the MOC image, the landing site location has been refined by Dr. Michael Malin, Principal Investigator for the Mars Global Surveyor MOC Team and a Participating Scientist on the Mars Pathfinder mission. The images above illustrate how the landing site was located by using the 'sight lines' published by T. Parker (Jet Propulsion Laboratory, Pasadena, CA) and topographic map provided by R. Kirk (U.S. Geological Survey, Flagstaff, AZ).

    Left image: MOC image 25603 subframe, shown at 15 meters (about 50 feet) per pixel resolution. Small, colored box is a topographic map of the Mars Pathfinder landing site produced by the U.S. Geological Survey (Flagstaff, AZ) from Mars Pathfinder stereographic images . Dark, heavy lines are 'sight lines' to various landmarks seen along the horizon in Mars Pathfinder camera images, measured by T. Parker and matched to features seen in Viking Orbiter images. These lines were published in Science, v. 278, p. 1746, December 5, 1997. The lighter, thinner sightlines are the same lines, adjusted to

  2. Interface Generation and Compositional Verification in JavaPathfinder

    NASA Technical Reports Server (NTRS)

    Giannakopoulou, Dimitra; Pasareanu, Corina

    2009-01-01

    We present a novel algorithm for interface generation of software components. Given a component, our algorithm uses learning techniques to compute a permissive interface representing legal usage of the component. Unlike our previous work, this algorithm does not require knowledge about the component s environment. Furthermore, in contrast to other related approaches, our algorithm computes permissive interfaces even in the presence of non-determinism in the component. Our algorithm is implemented in the JavaPathfinder model checking framework for UML statechart components. We have also added support for automated assume-guarantee style compositional verification in JavaPathfinder, using component interfaces. We report on the application of the presented approach to the generation of interfaces for flight software components.

  3. True Color of Mars - Pathfinder Sol 39 Sunrise

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Sunrise, sol 39. This true color, pre-sunrise image (approximately 0530LST) is composed of six images extending 30 o in azimuth and 45 o in elevation and shows the brownish gray predawn sky. A description of the techniques used to generate this color image from IMP data can be found in Maki et al., 1999. Note: a calibrated output device is required accurately reproduce the correct colors.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal investigator.

  4. Melas Chasma: A Mars Pathfinder view of Valles Marineris

    NASA Technical Reports Server (NTRS)

    Treiman, Allan H.; Murchie, Scott

    1994-01-01

    A Mars Pathfinder landing site in Melas Chasma (Valles Marineris) would yield significant science return, but is outside present mission constraints. In Melas Chasma, Mars Pathfinder could investigate minimally altered basaltic material, sedimentary deposits, chemical weathering, tectonic features, the highland crust, equatorial weather, and Valles mists. Critical issues include the following: (1) nature and the origin of the Valles interior layered deposits, important for understanding water as a sedimentary and chemical agent, and for the past existence of of environments favorable for life; (2) compositions of little-altered basaltic sands, important for understanding magma genesis and weathering on Mars, and the martian meteorites; and (3) structure and composition of the highland crust, important for understanding Mars' early history .

  5. First light of the LINC-NIRVANA Pathfinder experiment

    NASA Astrophysics Data System (ADS)

    Bergomi, M.; Viotto, V.; Arcidiacono, C.; Marafatto, L.; Farinato, J.; Baumeister, H.; Bertram, T.; Berwein, J.; Briegel, F.; Conrad, A.; Kittman, F.; Kopon, D.; Hofferbert, R.; Magrin, D.; Radhakrishnan Santhakumari, K. K.; Puglisi, A.; Xompero, M.; Briguglio, R.; Quiros-Pacheco, F.; Herbst, T. M.; Ragazzoni, R.

    2014-07-01

    The LINC-NIRVANA Pathfinder experiment is a test-bed to verify a very complex sub-system: the Ground-layer Wavefront Sensor, or GWS. Pathfinder will test the GWS in its final working environment and demonstrate on-sky the performance achievable with a multiple natural guide star, ground-layer adaptive optics system with a very wide FoV. The GWS uses up to 12 natural guide stars within a 2.8'-6' annular field of view and drives the LBT adaptive secondary mirror to correct the lower layers of atmospheric turbulence. This paper will trace the path of the instrument on its way to First Light on-sky in November 2013, from its installation on the telescope to the calibrations to its final operation, focusing in particular on opto-mechanical and software aspects and how they lead to the main achieved results.

  6. LISA Pathfinder: picometers and femtoNewtons in space

    NASA Astrophysics Data System (ADS)

    Hewitson, Martin; LISA Pathfinder Team Team

    2016-03-01

    On December 3rd at 04:04 UTC, The European Space Agency launched the LISA Pathfinder satellite on board a VEGA rocket from Kourou in French Guiana. After a series of orbit raising manoeuvres and a 2 month long transfer orbit, LISA Pathfinder arrived at L1. Following a period of commissioning, the science operations commenced at the start of March, beginning the demonstration of technologies and methodologies which pave the way for a future large-scale gravitational wave observatory in space. This talk will present the scientific goals of the mission, discuss the technologies being tested, elucidate the link to a future space-based observatory, such as LISA, and present preliminary results from the in-orbit operations and experiments.

  7. Java PathFinder: A Translator From Java to Promela

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus

    1999-01-01

    JAVA PATHFINDER, JPF, is a prototype translator from JAVA to PROMELA, the modeling language of the SPIN model checker. JPF is a product of a major effort by the Automated Software Engineering group at NASA Ames to make model checking technology part of the software process. Experience has shown that severe bugs can be found in final code using this technique, and that automated translation from a programming language to a modeling language like PROMELA can help reducing the effort required.

  8. Pathfinder. Volume 8, Number 6, November/December 2010

    DTIC Science & Technology

    2010-12-01

    NAME(S) AND ADDRESS(ES) National Geospatial-Intelligence Agency,Office of Corporate Communications,4600 Sangamore Road, Mail Stop D-54,Bethesda,MD...Agency Office of Corporate Communications 4600 Sangamore Road, Mail Stop D-54 Bethesda, MD 20816-5003 Telephone: (301) 227-9123 DSN 287-9123 E...mail: pathfinder@nga.mil Director Letitia A. Long Deputy Director Lloyd Rowland Office of Corporate Communications, Director Kimberly Thompson Public

  9. JPL Experience with the Mars Pathfinder, Mission Simulation Battery

    NASA Technical Reports Server (NTRS)

    Perrone, Dave; Ewell, Richard

    1997-01-01

    A summary of the Mars Pathfinder Battery is given. The battery survived 47 days at 25 deg. C; it survived a 7 month stand at 10 to -5 deg. C; it met and exceeded 40 ampere-hour capacity for EDL; it met the 30 cycle minimum for Mars surface operation; and the project power profile for MArs surface operation does not yield energy balance.

  10. 2005 PathfinderPlus Aero-Elastic Research Flight

    NASA Technical Reports Server (NTRS)

    Navarro, Robert

    2005-01-01

    This viewgraph presentation describes the 2005 Pathfinder along with an investigation of its aeroelastic responses. The contents include: 1) HALE Class of Vehicles; 2) Aero-elastic Research Flights Overall Objective; 3) General Arrangement; 4) Sensor Locations; 5) NASA Ramp Operations; 6) Lakebed Operations; 7) 1st Flight Data Set; 8) Tool development / data usage; 9) HALE Tool Development & Validation; 10) Building a HALE Foundation; 11) Compelling Needs Drive HALE Efforts; and 12) Team Photo

  11. ST7-DRS on LISA Pathfinder: Initial Status

    NASA Astrophysics Data System (ADS)

    Cutler, Curt; Ziemer, John; Barela, Phil; Demmons, Nathaniel; Dunn, Charles; Hruby, Vlad; Hsu, Oscar; Liepack, Otfrid; Maghami, Peiman; O'Donnell, James; Slutsky, Jacob; Thorpe, James; Romero-Wolfe, Andrew

    2016-03-01

    LISA Pathfinder (LPF), a European Space Agency Mission to demonstrate technologies for future space-based gravitational wave observatories, was launched from French Guiana on Dec 3, 2015. A payload on LPF is the NASA-provided ST7 Disturbance Reduction System (ST7-DRS). We will describe the current state of ST7-DRS, including results from the initial on-orbit commissioning and the experimental plan for the ST7-DRS operations in the summer of 2016.

  12. LISA and LISA Pathfinder: Gravitational Wave Observation in Space

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1 mHz--100 mHz. This observation band is inaccessible to ground-based detectors due to fluctuations in the Earth gravitational field. Gravitational wave sources for LISA include galactic binaries, mergers of supermassive black-hole binaries, extreme-mass-ratio inspirals, and cosmology backgrounds and bursts. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset of 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such as spacecraft control with micronewton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. A detailed description of the two missions and an overview of current investigations conducted by the community will be discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented.

  13. Latest Results from the Mars Pathfinder Atmospheric Structure Investigation

    NASA Technical Reports Server (NTRS)

    Magalhaes, J. A.

    1999-01-01

    The Mars Pathfinder Atmospheric Structure Investigation (ASI) obtained information on Martian atmospheric structure from three science accelerometers, which measured the deceleration of the probe at all levels in the atmosphere. Entry, descent, and landing occurred within 850 km of the Viking 1 landing site and somewhat later in northern summer. Pathfinder entered at 3 AME Local Mars Time (LMT), which provided the first opportunity to study Mars' nighttime atmospheric structure, and Viking 1 entered at 4:15 PME LMT. Magalhaes et al and Schofield et al have previously reported on the analysis of accelerometer measurements from the entry phase, which ended at about 8.5 km. The derived temperature profile extends from 140 km altitude down to 8.9 km, with a vertical resolution ranging from 250 meters to 50 meters, respectively. Here we report on a refined analysis of the Pathfinder entry phase ASIE data in which the effects of the small angular motions of the entry vehicle have been removed, thus enabling a search for small amplitude and small vertical wavelength structures. In addition, we will report on the atmospheric structure at altitudes below 8 km which is being derived from the accelerometer data acquired during the parachute descent phase. Additional information is contained in the original extended abstract.

  14. Characterization of the LISA Pathfinder Drag Reduction System

    NASA Astrophysics Data System (ADS)

    Slutsky, Jacob; LISA Pathfinder Team

    2015-04-01

    The LISA Pathfinder mission will be launched this year by ESA, and so it is urgent to simulate and characterize key experiments to optimize and validate the Gravitational Reference Sensor (GRS) performance. Success of this technology directly applies to any future LISA-like mission. Pathfinder is comprised of both European and NASA payloads, the LISA Technology Package (LTP) and Space Technology 7 (ST-7), respectively. ST-7 includes a Colloid Micro-Newton Thruster (CMNT) system, to maneuver the spacecraft with low noise, and a control system for spacecraft and test mass actuation. European partners have developed the LTP Data Analysis (LTPDA) Matlab suite, including state-space simulations of the full mission to create mock data, analysis pipelines constructed to reduce this and eventual actual data. We have adapted this infrastructure to reflect CMNT physics and control design where they differ from LTP. We analyze the residual GRS acceleration noise, paying particular attention to ST-7 specific CMNT noise characterization experiments and the performance differentials between using the inertial and interferometric sensing systems of Pathfinder in and out of loop. I will discuss our current results analyzing simulated ST-7 experimental runs and our future plans.

  15. LISA Pathfinder: First steps to observing gravitational waves from space

    NASA Astrophysics Data System (ADS)

    McNamara, Paul; LISA Pathfinder Collaboration

    2017-01-01

    With the first direct detection of gravitational waves a little over a year ago, the gravitational window to the Universe has been opened. The gravitational wave spectrum spans many orders of magnitude in frequency, with several of the most interesting astronomical sources emitting gravitational waves at frequencies only observable from space The European Space Agency (ESA) has been active in the field of space-borne gravitational wave detection for many years, and in 2013 selected the Gravitational Universe as the science theme for the third large class mission in the Cosmic Vision science programme. In addition, ESA took the step of developing the LISA Pathfinder mission to demonstrate the critical technologies required for a future mission. The goal of the LISA Pathfinder mission is to place a test body in free fall such that any external forces (acceleration) are reduced to levels lower than those expected from the passage of a gravitational wave LISA Pathfinder was launched on the 3rd December 2015 from the European Spaceport in Kourou, French Guiana. After a series of 6 apogee raising manoeuvres, the satellite left earth orbit, and travelled to its final science orbit around the first Sun-Earth Lagrange point (L1). Following a relatively short commissioning phase, science operations began on 1st March 2016. In the following 3 months over 100 experiments and over 1500hours of noise measurements have been performed, demonstrating that the observation of gravitational waves from space can be realised.

  16. Pathfinder-Plus on flight over Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non

  17. Pathfinder-Plus on flight near Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight with the Hawaiian island of N'ihau in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and

  18. Pathfinder-Plus on a flight over Hawaiian island N'ihau

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on a flight over the Hawaiian island of N'ihau in 1998. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet and flying non

  19. Periodontal status among adolescents in Georgia. A pathfinder study.

    PubMed

    Levin, Liran; Margvelashvili, Vladimer; Bilder, Leon; Kalandadze, Manana; Tsintsadze, Nino; Machtei, Eli E

    2013-01-01

    Objectives. The aim of the present pathfinder study was to screen and map the periodontal status of Georgian population in accordance with the guidelines of the World Health Organization for population based surveys. Methods. During 2012, a pathfinder study was conducted to collect this data. For the periodontal portion of the study, 15-year-old school children were examined in the capital city of Tbilisi as well as in two other large cities and 4 smaller villages. All participants were examined by a trained dental team in a classroom using a dental mirror and a periodontal probe. Periodontal examination included plaque scores, calculus scores, probing depth measurements and bleeding on probing. These measurements were recorded for the Ramfjord index teeth. Results. A total of 397 15-year-old participants were examined in this pathfinder study. There were 240 females (60.45%) and 157 males (39.55%). Of the total participants 196 (49.37%) were urban adolescents while 201 (50.63%) were from rural communities. Mean probing depth was 3.34 ± 0.57 mm with a range of 1 to 10 mm; a relatively high proportion (34.26%) of these subjects presented with at least one site with pockets of 5 mm or deeper. Males presented with greater plaque, calculus and probing depths than females. When urban and rural populations were compared, urban participants presented with more plaque, probing depths and bleeding on probing. Greater pocket depths were found to be related to the presence of plaque calculus and bleeding on probing. Conclusions. Overall, rather high incidences of periodontal pockets ≥ 5 mm were detected in this population. This data should serve to prepare further more detailed epidemiological studies that will serve to plan and implement prevent and treat strategies for periodontal diseases in Georgia and also help make manpower decisions.

  20. NASA Ocean Altimeter Pathfinder Project. Report 1; Data Processing Handbook

    NASA Technical Reports Server (NTRS)

    Koblinsky, C. J.; Beckley, Brian D.; Ray, Richard D.; Wang, Yan-Ming; Tsaoussi, Lucia; Brenner, Anita; Williamson, Ron

    1998-01-01

    The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-sedes data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. This report describes the processing schemes used to produce a consistent data set and two of the products derived f rom these data. Other reports have been produced that: a) describe the validation of these data sets against tide gauge measurements and b) evaluate the statistical properties of the data that are relevant to climate change. The use of satellite altimetry for earth observations was proposed in the early 1960s. The first successful space based radar altimeter experiment was flown on SkyLab in 1974. The first successful satellite radar altimeter was flown aboard the Geos-3 spacecraft between 1975 and 1978. While a useful data set was collected from this mission for geophysical studies, the noise in the radar measured and incomplete global coverage precluded ft from inclusion in the Ocean Altimeter Pathfinder program. This program initiated its analysis with the Seasat mission, which was the first satellite radar altimeter flown for oceanography.

  1. The Data Processor of the JEM-EUSO pathfinders

    NASA Astrophysics Data System (ADS)

    Scotti, V.; Osteria, G.

    2014-06-01

    JEM-EUSO is a wide-angle refractive UV telescope being proposed for attachment to the Japanese Experiment Module on ISS. The main goal of the mission is to study Extreme Energy Cosmic Rays. Two pathfinder mission are now in progress: EUSO-TA and EUSO-Balloon. The EUSO-TA project foresees the installation of a telescope prototype in the Telescope Array site. The aim of this project is to calibrate the telescope with the TA fluorescence detector. An initial run of one year starting from 2013 is foreseen. EUSO-Balloon is a pathfinder mission in which a prototype telescope will be mounted on a stratospheric balloon. The main aim of this mission is to perform a end-to-end test of all the key technologies and instrumentation of JEM-EUSO detectors and to prove the global detection chain. EUSO-Balloon will measure the UV background fundamental for the development of the simulations. EUSO-Balloon has the potential to detect Extensive Air Showers from above, paving the way for any future space-based EECR observatory. We will present the Data Processor of the pathfinders. The DP is the component of the Electronics System which performs data management and instrument control. The DP controls front-end electronics, performs 2nd level trigger filtering, tags events with arrival time and payload position through a GPS system, manages mass memory for data storage, measures live and dead time of the telescope, provides signals for time synchronization of the event, performs housekeeping monitor and handles interface to the telemetry system. We will describe the main components of the DP, the state-of-the-art and the results of the tests carried out.

  2. Neural pathfinding on uni- and multidirectional photopolymerized micropatterns.

    PubMed

    Tuft, Bradley W; Xu, Linjing; White, Scott P; Seline, Alison E; Erwood, Andrew M; Hansen, Marlan R; Guymon, C Allan

    2014-07-23

    Overcoming signal resolution barriers of neural prostheses, such as the commercially available cochlear impant (CI) or the developing retinal implant, will likely require spatial control of regenerative neural elements. To rationally design materials that direct nerve growth, it is first necessary to determine pathfinding behavior of de novo neurite growth from prosthesis-relevant cells such as spiral ganglion neurons (SGNs) in the inner ear. Accordingly, in this work, repeating 90° turns were fabricated as multidirectional micropatterns to determine SGN neurite turning capability and pathfinding. Unidirectional micropatterns and unpatterned substrates are used as comparisons. Spiral ganglion Schwann cell alignment (SGSC) is also examined on each surface type. Micropatterns are fabricated using the spatial reaction control inherent to photopolymerization with photomasks that have either parallel line spacing gratings for unidirectional patterns or repeating 90° angle steps for multidirectional patterns. Feature depth is controlled by modulating UV exposure time by shuttering the light source at given time increments. Substrate topography is characterized by white light interferometry and scanning electron microscopy (SEM). Both pattern types exhibit features that are 25 μm in width and 7.4 ± 0.7 μm in depth. SGN neurites orient randomly on unpatterned photopolymer controls, align and consistently track unidirectional patterns, and are substantially influenced by, but do not consistently track, multidirectional turning cues. Neurite lengths are 20% shorter on multidirectional substrates compared to unidirectional patterns while neurite branching and microfeature crossing events are significantly higher. For both pattern types, the majority of the neurite length is located in depressed surface features. Developing methods to understand neural pathfinding and to guide de novo neurite growth to specific stimulatory elements will enable design of innovative

  3. Laser Interferometry for Gravitational Wave Observation: LISA and LISA Pathfinder

    NASA Technical Reports Server (NTRS)

    Guzman, Felipe

    2010-01-01

    The Laser Interferometer Space Antenna (LISA) is a planned NASA-ESA gravitational wave observatory in the frequency range of 0.1mHz-100mHz. This observation band is inaccessible to ground-based detectors due to the large ground motions of the Earth. Gravitational wave sources for LISA include galactic binaries, mergers of supermasive black-hole binaries, extreme-mass-ratio inspirals, and possibly from as yet unimagined sources. LISA is a constellation of three spacecraft separated by 5 million km in an equilateral triangle, whose center follows the Earth in a heliocentric orbit with an orbital phase offset oF 20 degrees. Challenging technology is required to ensure pure geodetic trajectories of the six onboard test masses, whose distance fluctuations will be measured by interspacecraft laser interferometers with picometer accuracy. LISA Pathfinder is an ESA-launched technology demonstration mission of key LISA subsystems such us spacecraft control with micro-newton thrusters, test mass drag-free control, and precision laser interferometry between free-flying test masses. Ground testing of flight hardware of the Gravitational Reference Sensor and Optical Metrology subsystems of LISA Pathfinder is currently ongoing. An introduction to laser interferometric gravitational wave detection, ground-based observatories, and a detailed description of the two missions together with an overview of current investigations conducted by the community will bc discussed. The current status in development and implementation of LISA Pathfinder pre-flight systems and latest results of the ongoing ground testing efforts will also be presented

  4. The LISA PathFinder DMU Software, a Global Overview

    NASA Astrophysics Data System (ADS)

    Gesa, L.; Martin, V.; Conchillo, A.; Lobo, A.; Lloro, I.

    2013-01-01

    During the last 6 years, the IEEC software team has developed the Data Management Unit (DMU) software. It is a critical piece of engineering in the Lisa Pathfinder mission, in charge of the primary processing of data generated by the Phasemeter, acting also as an interface between the whole LISA Technology Package (LTP) and the On-Board Computer (OBC). It also manages and controls the diagnostics systems (Heaters, coils, magnetometers, radiation monitor, thermometers). This article briefly summarizes all the work performed, describing the complex environment built around the application generation.

  5. Symbolic PathFinder: Symbolic Execution of Java Bytecode

    NASA Technical Reports Server (NTRS)

    Pasareanu, Corina S.; Rungta, Neha

    2010-01-01

    Symbolic Pathfinder (SPF) combines symbolic execution with model checking and constraint solving for automated test case generation and error detection in Java programs with unspecified inputs. In this tool, programs are executed on symbolic inputs representing multiple concrete inputs. Values of variables are represented as constraints generated from the analysis of Java bytecode. The constraints are solved using off-the shelf solvers to generate test inputs guaranteed to achieve complex coverage criteria. SPF has been used successfully at NASA, in academia, and in industry.

  6. Rock and Soil Types at Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Type areas of rocks and soils. (A) Dark rock type and bright soil type: Shown is the dark rock Barnacle Bill. Reflectance spectra typical of fresh basalt and APXS spectra indicating more silica-rich basaltic andesite compositions characterize this type. These rocks are typically the small boulders and intermediate-sized cobbles at the Pathfinder site. The bright soil type is very common and in this case comprises Barnacle Bill's wind tail and much of the surround soil area. This soil has a high reflectance and a strongly reddened spectrum indicative of oxidized ferric minerals. (B) Bright rock type: Shown is the bright rock Wedge. Reflectance spectra typical of weathered basalt and APXS spectra indicating basaltic compositions characterize this type. These rocks are typically larger than 1 meter in diameter and many display morphologies indicating flood deposition. (C) Pink rock type: Shown is the pink rock Scooby Doo. APXS and reflectance spectra indicate a composition and optical characteristics similar to the drift soil. However, the morphology of the pink rock type indicates a cemented or rocklike structure. This material may be a chemically cemented hardpan that underlies much of the Pathfinder site. (D) Dark soil type: The dark soil type is typically found on the windward sides of rocks or in rock-free areas like Photometry Flats (shown here) where the bright soil has been striped away by aeolian action or in open areas. Other locations include the Mermaid Dune. (E) Disturbed soil type: The darkening of disturbed soil relative to its parent material, bright soil, as a result of changes in soil texture and compaction caused by movement of the rover and retraction of the lander airbag. (F) Lamb-like soil type: This soil type shows reflectance and spectral characteristics intermediate between the bright and dark soils. Its distinguishing feature is a weak spectral absorption near 900 nanometers not seen in either the bright or dark soils.

    NOTE: original

  7. Missile tracking and range safety: Tracking Interferometer Pathfinder System (TIPS)

    NASA Astrophysics Data System (ADS)

    Dowgiallo, David J.; Rauen, Stephen; Peters, Wendy M.; Polisensky, Emil J.

    2013-05-01

    The tracking of missiles at close range proximity has been an ongoing challenge for many launch environments. The ability to provide accurate missile trajectory information is imperative for range safety and early termination of flight. In an effort to provide a potential solution to tracking issues that have plagued many traditional techniques, the Tracking Interferometer Pathfinder System (TIPS) was developed at the Naval Research Laboratory, Washington, D.C. The paper herein describes the design, field test, and results of an interferometer deployed for missile tracking.

  8. Reduction and Analysis of Meteorology Data from the Mars Pathfinder Lander

    NASA Technical Reports Server (NTRS)

    Murphy, James R.; Bridger, Alison F. C.; Haberle, Robert M.

    1998-01-01

    Dr. James Murphy is a member of the Mars Pathfinder Atmospheric Structure Investigation Meteorology (ASI/MET) Science Team. The activities of Dr. Murphy, and his collaborators are summarized in this report, which reviews the activities in support of the analysis of the meteorology data from the Mars Pathfinder Lander.

  9. 77 FR 6554 - Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke-American Transmission...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-08

    ... Energy Regulatory Commission Zephyr Power Transmission, LLC; Pathfinder Power Transmission, LLC; Duke-American Transmission Company, LLC; Notice of Petition for Declaratory Order Take notice that on January 30... (Commission), 18 CFR 381.302, Zephyr Power Transmission, LLC (Zephyr), Pathfinder Power Transmission, LLC...

  10. Australian Mineral Foundation.

    ERIC Educational Resources Information Center

    Crowe, D. S.

    1980-01-01

    Provides details on the philosophy and operation of the Australian Mineral Foundation, established in 1970 to update professionals in the mining and petroleum industries. Services in continuing education courses and to secondary school teachers and students are described. (CS)

  11. Research Readings. Australian Apprenticeships.

    ERIC Educational Resources Information Center

    Smart, Nigel, Ed.

    This volume on apprenticeships in Australia summarizes 11 research studies. After an "Introduction" (Nigel Smart), the reports are: "Apprenticeship in Australia: A Concise History" (John Ray); "Issues and Directions from the Australian Apprenticeship and Traineeship Literature" (Stephen Saunders); "Determinants…

  12. CLARREO Pathfinder Mission: Enabling Faster Observation of Climate Change

    NASA Astrophysics Data System (ADS)

    Wielicki, B. A.; Baize, R. R.; Mlynczak, M. G.; Thome, K.; Lukashin, C.; Revercomb, H. E.; Pilewskie, P.; Kopp, G.

    2015-12-01

    CLARREO (Climate Absolute Radiance and Refractivity Observatory) is a Decadal Survey Tier 1 mission designed to accelerate the observation of global climate change by increasing the accuracy of reflected solar and infrared instruments by a factor of 5 to 10 over current instruments in space. The CLARREO mission has also been requested by the WMO GSICS (Global Space-based Inter-Calibration System) to serve as its reference calibration source. CLARREO will provide an in-orbit high spectral resolution SI transfer standard for up to 40 orbiting sensors across the entire infrared and reflected solar spectrum. These instruments include VIIRS, CrIS, IASI, CERES, Landsat, Sentinel MSI and other land imagers, as well as the constellation of geostationary imagers and sounders. A CLARREO Pathfinder mission on the International Space Station is included in the Presidents FY2016 budget for launch in late 2019 or 2020. The presentation will update the Pathfinder mission status including advances in understanding instrument accuracy requirements and reference intercalibration using the ISS orbit sampling. The presentation will also demonstrate the ability of more accurate observations to shorten the time required to observe anthropogenic climate change, thereby narrowing uncertainties in future climate change and allowing more efficient societal response planning.

  13. Mars Pathfinder and Mars Global Surveyor Outreach Compilation

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This videotape is a compilation of the best NASA JPL (Jet Propulsion Laboratory) videos of the Mars Pathfinder and Mars Global Surveyor missions. The mission is described using animation and narration as well as some actual footage of the entire sequence of mission events. Included within these animations are the spacecraft orbit insertion; descent to the Mars surface; deployment of the airbags and instruments; and exploration by Sojourner, the Mars rover. JPL activities at spacecraft control during significant mission events are also included at the end. The spacecraft cameras pan the surrounding Mars terrain and film Sojourner traversing the surface and inspecting rocks. A single, brief, processed image of the Cydonia region (Mars face) at an oblique angle from the Mars Global Surveyor is presented. A description of the Mars Pathfinder mission, instruments, landing and deployment process, Mars approach, spacecraft orbit insertion, rover operation are all described using computer animation. Actual color footage of Sojourner as well as a 360 deg pan of the Mars terrain surrounding the spacecraft is provided. Lower quality black and white photography depicting Sojourner traversing the Mars surface and inspecting Martian rocks also is included.

  14. Sedimentary Geochemistry of Martian Samples from the Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    McLennan, Scott M.

    2001-01-01

    The purpose of this research project was to evaluate the APXS data collected on soils and rocks at the Pathfinder site in terms of sedimentary geochemistry. Below are described the major findings of this research: (1) An influential model to explain the chemical variation among Pathfinder soils and rocks is a two component mixing model where rocks of fairly uniform composition mix with soil of uniform composition; (2) The very strong positive correlation between MgO and SO, points to a control by a MgSO4 mineral however, spectroscopic data continue to suggest that Fe-sulfates, notably schwertmannite and jarosite, may be important components; (3) In an attempt to better understand the causes of complexities in mixing relationships, the possible influence of sedimentary transport has been evaluated; (4) Another aspect of this research has been to examine the possibility of sedimentary silica being a significant phase on Mars; and (5) On Earth, the geochemistry of sedimentary rocks has been used to constrain the chemical composition of the continental crust and an important part of this research was to evaluate this approach for Mars.

  15. True Color of Mars - Pathfinder Sol 24 at 4 PM

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The brownish gray sky as it would be seen by an observer on Mars in this four-frame, true color mosaic taken on sol 24 (at approximately 1610 LST). The twin peaks can be seen on the horizon. The sky near the sun is a pale blue color. Azimuth extent is 60o and elevation extent is approximately 12odegrees. A description of the techniques used to generate this color image from IMP data can be found in Maki et al., 1999 (see full reference in Image Note). Note: a calibrated output device is required accurately reproduce the correct colors.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is an operating division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal investigator.

  16. NASA Ocean Altimeter Pathfinder Project. Report 2; Data Set Validation

    NASA Technical Reports Server (NTRS)

    Koblinsky, C. J.; Ray, Richard D.; Beckley, Brian D.; Bremmer, Anita; Tsaoussi, Lucia S.; Wang, Yan-Ming

    1999-01-01

    The NOAA/NASA Pathfinder program was created by the Earth Observing System (EOS) Program Office to determine how existing satellite-based data sets can be processed and used to study global change. The data sets are designed to be long time-series data processed with stable calibration and community consensus algorithms to better assist the research community. The Ocean Altimeter Pathfinder Project involves the reprocessing of all altimeter observations with a consistent set of improved algorithms, based on the results from TOPEX/POSEIDON (T/P), into easy-to-use data sets for the oceanographic community for climate research. Details are currently presented in two technical reports: Report# 1: Data Processing Handbook Report #2: Data Set Validation This report describes the validation of the data sets against a global network of high quality tide gauge measurements and provides an estimate of the error budget. The first report describes the processing schemes used to produce the geodetic consistent data set comprised of SEASAT, GEOSAT, ERS-1, TOPEX/ POSEIDON, and ERS-2 satellite observations.

  17. Disentangling the magnetic force noise contribution in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, L. I.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    Magnetically-induced forces on the inertial masses on-board LISA Pathfinder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end- to-end LISA Pathfinder simulation, and we describe the methods under development to map the magnetic field on-board.

  18. Pathfinder aircraft liftoff on altitude record setting flight of 71,500 feet

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Pathfinder aircraft has set a new unofficial world record for high-altitude flight of over 71,500 feet for solar-powered aircraft at the U.S. Navy's Pacific Missile Range Facility, Kauai, Hawaii. Pathfinder was designed and manufactured by AeroVironment, Inc, of Simi Valley, California, and was operated by the firm under a jointly sponsored research agreement with NASA's Dryden Flight Research Center, Edwards, California. Pathfinder's record-breaking flight occurred July 7, 1997. The aircraft took off at 11:34 a.m. PDT, passed its previous record altitude of 67,350 feet at about 5:45 p.m. and then reached its new record altitude at 7 p.m. The mission ended with a perfect nighttime landing at 2:05 a.m. PDT July 8. The new record is the highest altitude ever attained by a propellor-driven aircraft. Before Pathfinder, the altitude record for propellor-driven aircraft was 67,028 feet, set by the experimental Boeing Condor remotely piloted aircraft. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard

  19. MARS PATHFINDER SMALL ROVER MATED TO LANDER'S PETALS IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In KSC's Spacecraft Assembly and Encapsulation Facility-2 (SAEF- 2), Jet Propulsion Laboratory workers are mating the Mars Pathfinder small rover to one of the lander's three petals. When the lander touches down on the surface of Mars next year, the three petals of the lander -- closed for the six to seven month journey to the Red Planet -- will open like a flower to allow the rover to begin its quest to explore the Martian surface. The Mars Pathfinder is set for launch aboard a Delta II expendable launch vehicle on Dec. 2, the beginning of a 24-day launch period. The Jet Propulsion Laboratory is managing the Mars Pathfinder project for NASA.

  20. Quality Health Information on the Internet: Developing a Diabetes Pathfinder for the Chinese Population

    PubMed Central

    Cleveland, Ana D.; Philbrick, Jodi; Pan, Xuequn (Della); Yu, Xinyu; Chen, Jiangping; O'Neill, Marty; Smith, Lisa

    2010-01-01

    A Web-based bilingual diabetes information pathfinder was created to help the Chinese population access quality health information on the Internet as part of a collaborative outreach project in the Dallas-Fort Worth area. A survey was conducted to identify the demographics, Internet usage, health information needs, and preferences for training sessions of the Chinese population. Breast cancer, diabetes, and breast cancer were the top three diseases of interest. The process of developing the pathfinder is described from start to finish, and it can serve as a model for the development of others. Pathfinder training sessions were held. PMID:20526379

  1. Drill/borescope System for the Mars Polar Pathfinder

    NASA Technical Reports Server (NTRS)

    Paige, D. A.; Wood, S. E.; Vasavada, A. R.

    1993-01-01

    The primary goals of the Mars Polar Pathfinder (MPP) Discovery Mission are to characterize the composition and structure of Mars' north polar ice cap, and to determine whether a climate record may be preserved in layers of ice and dust. The MPP would land as close as possible to the geographic north pole of Mars and use a set of instruments similar to those used by glaciologists to study polar ice caps on Earth: a radar sounder, a drill/borescope system, and a thermal probe. The drill/borescope system will drill approximately 50 cm into the surface and image the sides of the hole at 10 micron resolution for compositional and stratigraphic analysis. Several uncertainties have guided the development of this instrument, and they are discussed.

  2. Dust devil vortices seen by the Mars Pathfinder camera

    USGS Publications Warehouse

    Metzger, S.M.; Carr, J.R.; Johnson, J. R.; Parker, T.J.; Lemmon, M.T.

    1999-01-01

    Discovery of dust devil vortices in Mars Pathfinder (MPF) images reveals a dust entrainment mechanism at work on Mars. Scattering of visible light by dust in the Martian atmosphere creates a pronounced haze, preventing conventional image processing from displaying dust plumes. Spectral differencing techniques have enhanced five localized dust plumes from the general haze in images acquired near midday, which we determine to be dust devils. Processing of 440 nm images highlights dust devils as distinct occultation features against the horizon. The dust devils are interpreted to be 14-79 m wide, 46-350 m tall, travel at 0.5-4.6 m/s, with dust loading of 7E-5 kg m-3, relative to the general haze of 9E-8 kg m-3, and total particulate transport of 2.2 - 700 kg. The vortices match predictions from terrestrial analog studies. Copyright 1999 by the American Geophysical Union.

  3. Exploring MEDLINE space with random indexing and pathfinder networks.

    PubMed

    Cohen, Trevor

    2008-11-06

    The integration of disparate research domains is a prerequisite for the success of the translational science initiative. MEDLINE abstracts contain content from a broad range of disciplines, presenting an opportunity for the development of methods able to integrate the knowledge they contain. Latent Semantic Analysis (LSA) and related methods learn human-like associations between terms from unannotated text. However, their computational and memory demands limits their ability to address a corpus of this size. Furthermore, visualization methods previously used in conjunction with LSA have limited ability to define the local structure of the associative networks LSA learns. This paper explores these issues by (1) processing the entire MEDLINE corpus using Random Indexing, a variant of LSA, and (2) exploring learned associations using Pathfinder Networks. Meaningful associations are inferred from MEDLINE, including a drug-disease association undetected by PUBMED search.

  4. State Space Modelling and Data Analysis Exercises in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Nofrarias, M.; Antonucci, F.; Armano, M.; Audley, H.; Auger, G.; Benedetti, M.; Binetruy, P.; Bogenstahl, J.; Bortoluzzi, D.; Brandt, N.; Caleno, M.; Cavalleri, A.; Congedo, G.; Cruise, M.; Danzmann, K.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Fauste, J.; Ferraioli, L.; Ferroni, V.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guzmán, F.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Huesler, J.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Korsakova, N.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Mateos, I.; McNamara, P.; Mendes, J.; Mitchell, E.; Nicolodi, D.; Perreur-Lloyd, M.; Plagnol, E.; Prat, P.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Schleicher, A.; Shaul, D.; Sopuerta, C. F.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Ziegler, T.; Zweifel, P.

    2013-01-01

    LISA Pathfinder is a mission planned by the European Space Agency (ESA) to test the key technologies that will allow the detection of gravitational waves in space. The instrument on-board, the LISA Technology package, will undergo an exhaustive campaign of calibrations and noise characterisation campaigns in order to fully describe the noise model. Data analysis plays an important role in the mission and for that reason the data analysis team has been developing a toolbox which contains all the functionality required during operations. In this contribution we give an overview of recent activities, focusing on the improvements in the modelling of the instrument and in the data analysis campaigns performed both with real and simulated data.

  5. Prediction and Validation of Mars Pathfinder Hypersonic Aerodynamic Data Base

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.; Braun, Robert D.; Weilmuenster, K. James; Mitcheltree, Robert A.; Engelund, Walter C.; Powell, Richard W.

    1998-01-01

    Postflight analysis of the Mars Pathfinder hypersonic, continuum aerodynamic data base is presented. Measured data include accelerations along the body axis and axis normal directions. Comparisons of preflight simulation and measurements show good agreement. The prediction of two static instabilities associated with movement of the sonic line from the shoulder to the nose and back was confirmed by measured normal accelerations. Reconstruction of atmospheric density during entry has an uncertainty directly proportional to the uncertainty in the predicted axial coefficient. The sensitivity of the moment coefficient to freestream density, kinetic models and center-of-gravity location are examined to provide additional consistency checks of the simulation with flight data. The atmospheric density as derived from axial coefficient and measured axial accelerations falls within the range required for sonic line shift and static stability transition as independently determined from normal accelerations.

  6. Soil-like deposits observed by Sojourner, the Pathfinder rover

    USGS Publications Warehouse

    Moore, Henry J.; Bickler, Donald B.; Crisp, Joy A.; Eisen, Howard J.; Gensler, Jeffrey A.; Haldemann, Albert F.C.; Matijevic, Jacob R.; Reid, Lisa K.; Pavlics, Ferenc

    1999-01-01

    Most of the soil-like materials at the Pathfinder landing site behave like moderately dense soils on Earth with friction angles near 34°-39° and are called cloddy deposits. Cloddy deposits appear to be poorly sorted with dust-sized to granule-sized mineral or rock grains; they may contain pebbles, small rock fragments, and clods. Thin deposits of porous, compressible drifts with friction angles near 26°-28° are also present. Drifts are fine grained. Cohesions of both types of deposits are small. There may be indurated soil-like deposits and/or coated or crusted rocks. Cloddy deposits may be fluvial sediments of the Ares-Tiu floods, but other origins, such as ejecta from nearby impact craters, should be considered. Drifts are probably dusts that settled from the Martian atmosphere. Remote-sensing signatures of the deposits inferred from rover observations are consistent with those observed from orbit and Earth.

  7. Exploring MEDLINE Space with Random Indexing and Pathfinder Networks

    PubMed Central

    Cohen, Trevor

    2008-01-01

    The integration of disparate research domains is a prerequisite for the success of the translational science initiative. MEDLINE abstracts contain content from a broad range of disciplines, presenting an opportunity for the development of methods able to integrate the knowledge they contain. Latent Semantic Analysis (LSA) and related methods learn human-like associations between terms from unannotated text. However, their computational and memory demands limits their ability to address a corpus of this size. Furthermore, visualization methods previously used in conjunction with LSA have limited ability to define the local structure of the associative networks LSA learns. This paper explores these issues by (1) processing the entire MEDLINE corpus using Random Indexing, a variant of LSA, and (2) exploring learned associations using Pathfinder Networks. Meaningful associations are inferred from MEDLINE, including a drug-disease association undetected by PUBMED search. PMID:18999236

  8. Mars Pathfinder and the exploration of southern Amazonis Planitia

    NASA Technical Reports Server (NTRS)

    Barlow, Nadine G.

    1994-01-01

    The southern region of Amazonis Planitia provides a variety of target terrains for a roving vehicle such as the Mars Pathfinder Mission. A landing site is proposed at 4 deg N latitude 162 deg W longitude. This area has a reference altitude of between 0 and -1 km and consists of relatively smooth Amazonian-aged deposits within the entire 100 x 200 km landing ellipse. The proposed landing site is within the Upper Member Medusae Fossae Formation deposits (Amu) and near the boundary with Middle Member Medusae Fossae Formation deposits (Amm) and Member 1 Arcadia Formation plains (Aa(sub 1)). Slightly further afield are 107-km-diameter Nicholson crater, its ejecta deposits, and knobby terrain of proposed Hesperian age (HNu). Depending on the exact landing site of the spacecraft and the traverse distance of the rover, these materials also may be sampled.

  9. LISA Pathfinder: A Summary of results to date

    NASA Astrophysics Data System (ADS)

    Thorpe, James; LISA Pathfinder Team; LTP Team; DRS Team

    2017-01-01

    The LISA Pathfinder mission is an ESA-led mission with contributions from several European member states and NASA which has the primary purpose of validating technologies for a future space-based observatory of gravitational waves. Launched on Dec. 3rd, 2015, LPF has been conducting science operations since March 1st, 2016 and is now entering an extended mission phase that is expected to last unitl June 2016. This poster will present an overview of the LPF results, the highlight of which is the exquiste measurement of differential acceleration at the femto-g level and interferometry at the femtometer level. In addition, I will describe auxilliary analyses that have been applied to the LPF data to search for impacts from micrometeorites and interactions with the Solar environment.

  10. Pathfinder: A parallel search algorithm for concerted atomistic events

    NASA Astrophysics Data System (ADS)

    Nakano, Aiichiro

    2007-02-01

    An algorithm has been designed to search for the escape paths with the lowest activation barriers when starting from a local minimum-energy configuration of a many-atom system. The pathfinder algorithm combines: (1) a steered eigenvector-following method that guides a constrained escape from the convex region and subsequently climbs to a transition state tangentially to the eigenvector corresponding to the lowest negative Hessian eigenvalue; (2) discrete abstraction of the atomic configuration to systematically enumerate concerted events as linear combinations of atomistic events; (3) evolutionary control of the population dynamics of low activation-barrier events; and (4) hybrid task + spatial decompositions to implement massive search for complex events on parallel computers. The program exhibits good scalability on parallel computers and has been used to study concerted bond-breaking events in the fracture of alumina.

  11. Wheel Abrasion Experiment Metals Selection for Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Fatemi, Navid S.; Wilt, David M.; Ferguson, Dale C.; Hoffman, Richard; Hill, Maria M.; Kaloyeros, Alain E.

    1996-01-01

    A series of metals was examined for suitability for the Wheel Abrasion Experiment, one of ten microrover experiments of the Mars Pathfinder Mission. The seven candidate metals were: Ag, Al, Au, Cu, Ni, Pt, and W. Thin films of candidate metals from 0.1 to 1.0 micrometer thick were deposited on black anodized aluminum coupons by e-beam and resistive evaporation and chemical vapor deposition. Optical, corrosion, abrasion, and adhesion criteria were used to select Al, Ni, and Pt. A description is given of the deposition and testing of thin films, followed by a presentation of experimental data and a brief discussion of follow-on testing and flight qualification.

  12. The LISA Pathfinder interferometry—hardware and system testing

    NASA Astrophysics Data System (ADS)

    Audley, H.; Danzmann, K.; García Marín, A.; Heinzel, G.; Monsky, A.; Nofrarias, M.; Steier, F.; Gerardi, D.; Gerndt, R.; Hechenblaikner, G.; Johann, U.; Luetzow-Wentzky, P.; Wand, V.; Antonucci, F.; Armano, M.; Auger, G.; Benedetti, M.; Binetruy, P.; Boatella, C.; Bogenstahl, J.; Bortoluzzi, D.; Bosetti, P.; Caleno, M.; Cavalleri, A.; Cesa, M.; Chmeissani, M.; Ciani, G.; Conchillo, A.; Congedo, G.; Cristofolini, I.; Cruise, M.; De Marchi, F.; Diaz-Aguilo, M.; Diepholz, I.; Dixon, G.; Dolesi, R.; Fauste, J.; Ferraioli, L.; Fertin, D.; Fichter, W.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gesa, L.; Gibert, F.; Giardini, D.; Grimani, C.; Grynagier, A.; Guillaume, B.; Guzmán, F.; Harrison, I.; Hewitson, M.; Hollington, D.; Hough, J.; Hoyland, D.; Hueller, M.; Huesler, J.; Jeannin, O.; Jennrich, O.; Jetzer, P.; Johlander, B.; Killow, C.; Llamas, X.; Lloro, I.; Lobo, A.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mitchell, E.; Nicolini, D.; Nicolodi, D.; Pedersen, F.; Perreur-Lloyd, M.; Perreca, A.; Plagnol, E.; Prat, P.; Racca, G. D.; Rais, B.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Sanjuan, J.; Schulte, M.; Shaul, D.; Stagnaro, L.; Strandmoe, S.; Sumner, T. J.; Taylor, A.; Texier, D.; Trenkel, C.; Tombolato, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Weber, W. J.; Zweifel, P.

    2011-05-01

    Preparations for the LISA Pathfinder mission have reached an exciting stage. Tests of the engineering model (EM) of the optical metrology system have recently been completed at the Albert Einstein Institute, Hannover, and flight model tests are now underway. Significantly, they represent the first complete integration and testing of the space-qualified hardware and are the first tests on an optical system level. The results and test procedures of these campaigns will be utilized directly in the ground-based flight hardware tests, and subsequently during in-flight operations. In addition, they allow valuable testing of the data analysis methods using the MATLAB-based LTP data analysis toolbox. This paper presents an overview of the results from the EM test campaign that was successfully completed in December 2009.

  13. Aeolian features and processes at the Mars Pathfinder landing site

    USGS Publications Warehouse

    Greeley, Ronald; Kraft, Michael; Sullivan, Robert; Wilson, Gregory; Bridges, Nathan; Herkenhoff, Ken; Kuzmin, Ruslan O.; Malin, Michael; Ward, Wes

    1999-01-01

    The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-size aggregates of finer grains, the discovery of ventifact flutes cut in rocks strongly suggests that at least some of the grains are crystalline, rather than aggregates. Excluding the ventifacts, the orientations of the wind-related features correlate well with the orientations of bright wind steaks seen on Viking Orbiter images in the general area. They also correlate with wind direction predictions from the NASA-Ames General Circulation Model (GCM) which show that the strongest winds in the area occur in the northern hemisphere winter and are directed toward 209°. Copyright 1999 by the American Geophysical Union.

  14. Aeolin Features and Processes at the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kraft, Michael; Sullivan, Robert; Wilson, Gregory; Bridges, Nathan; Herkenhoff, Ken; Kuzmin, Ruslan; Malin, Michael; Ward, Wes

    1999-01-01

    The Mars Pathfinder landing site contains abundant features attributed to aeolian, or wind, processes. These include wind tails, drift deposits, duneforms of various types, ripplelike features, and ventifacts (the first clearly seen on Mars). Many of these features are consistant with formation involving sand-size particles. Although some features, such as dunes, could develop from saltating sand-size aggregates of finer grains, the discovery of ventifact flutes cut in rocks strongly suggests that at least some of the grains are crystalline, rather than aggregates. Excluding the ventifacts, the orientations of the wind-related features correlate well with the orientations of bright wind steaks seen on Viking Orbiter images in the general area. They also correlate with wind direction predictions from the NASA-Ames General Circulation Model (GCM) which show that the strongest winds in the area occur in the northern hemisphere winter and are directed toward 209 degrees.

  15. Acquiring multiple stars with the LINC-NIRVANA Pathfinder

    NASA Astrophysics Data System (ADS)

    Conrad, Albert R.; Arcidiacono, Carmelo; Baumeister, Harald; Bergomi, Maria; Bertram, Thomas; Berwein, Jürgen; Briegel, Florian; Farinato, Jacopo; Herbst, Tom; Hofferbert, Ralph; Kittmann, Frank; Kürster, Martin; Kopon, Derek; Marafatto, Luca; Norris, Mark; Ragazzoni, Roberto; Viotto, Valentina

    2014-08-01

    The LINC-NIRVANA Pathfinder1 (LN-PF), a ground-layer adaptive optics (AO) system recently commissioned at the Large Binocular Telescope (LBT), is one of 4 sensors that provide AO corrected images to the full LINC-NIRVANA instrument. With first light having taken place on November 17, 2013,2, 3 the core goals for the LN-PF have been accomplished. In this report, we look forward to one of the LN-PF extended goals. In particular, we review the acquisition mechanism required to place each of several star probes on its corresponding star in the target asterism. For emerging AO systems in general, co-addition of light from multiple stars stands as one of several methods being pursued to boost sky coverage. With 12 probes patrolling a large field of view (an annulus 6-arcminutes in diameter), the LN-PF will provide a valuable testbed to verify this method.

  16. Wake Flow About the Mars Pathfinder Entry Vehicle

    NASA Technical Reports Server (NTRS)

    Mitcheltree, R. A.; Gnoffo, P. A.

    1995-01-01

    A computational approach is used to describe the aerothermodynamics of the Mars Pathfinder vehicle entering the Mars atmosphere at the maximum heating and maximum deceleration points in its trajectory. Ablating and nonablating boundary conditions are developed which produce maximum recombination of CO2 on the surface. For the maximum heating trajectory point, an axisymmetric, nonablating calculation predicts a stagnation-point value for the convective heating of 115 W/cm(exp 2). Radiative heating estimates predict an additional 5-12 W/cm(exp 2) at the stagnation point. Peak convective heating on the afterbody occurs on the vehicle's flat stern with a value of 5.9% of the stagnation value. The forebody flow exhibits chemical nonequilibrium behavior, and the flow is frozen in the near wake. Including ablation injection on the forebody lowers the stagnation-point convective heating 18%.

  17. Bayesian statistics for the calibration of the LISA Pathfinder experiment

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mitchell, E.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    The main goal of LISA Pathfinder (LPF) mission is to estimate the acceleration noise models of the overall LISA Technology Package (LTP) experiment on-board. This will be of crucial importance for the future space-based Gravitational-Wave (GW) detectors, like eLISA. Here, we present the Bayesian analysis framework to process the planned system identification experiments designed for that purpose. In particular, we focus on the analysis strategies to predict the accuracy of the parameters that describe the system in all degrees of freedom. The data sets were generated during the latest operational simulations organised by the data analysis team and this work is part of the LTPDA Matlab toolbox.

  18. Structural analyses of the JPL Mars Pathfinder impact

    SciTech Connect

    Gwinn, K.W.

    1994-12-31

    The purpose of this paper is to demonstrate that finite element analysis can be used in the design process for high performance fabric structures. These structures exhibit extreme geometric nonlinearity; specifically, the contact and interaction of fabric surfaces with the large deformation which necessarily results from membrane structures introduces great complexity to analyses of this type. All of these features are demonstrated here in the analysis of the Jet Propulsion Laboratory (JPL) Mars Pathfinder impact onto Mars. This lander system uses airbags to envelope the lander experiment package, protecting it with large deformation upon contact. Results from the analysis show the stress in the fabric airbags, forces in the internal tendon support system, forces in the latches and hinges which allow the lander to deploy after impact, and deceleration of the lander components. All of these results provide the JPL engineers with design guidance for the success of this novel lander system.

  19. The UFFO (Ultra Fast Flash Observatory) Pathfinder: Science and Mission

    NASA Astrophysics Data System (ADS)

    CHEN, Pisin

    Hundreds of gamma-ray burst (GRB) optical light curves have been measured since the discovery of optical afterglows. However, even after nearly 7 years of operation of the Swift Observatory, only a handful of measurements have been made soon (within a minute) after the gamma ray signal. This lack of early observations fails to address burst physics at short time scales associated with prompt emissions and progenitors. Because of this lack of sub-minute data, the characteristics of the rise phase of optical light curve of short-hard type GRB and rapid-rising GRB, which may account for ~30% of all GRB, remain practically unknown. We have developed methods for reaching sub-minute and sub-second timescales in a small spacecraft observatory. Rather than slewing the entire spacecraft to aim the optical instrument at the GRB position, we use rapidly moving mirror to redirect our optical beam. As a first step, we employ motorized slewing mirror telescope (SMT), which can point to the event within 1s, in the UFFO Pathfinder GRB Telescope onboard the Lomonosov satellite to be launched in Nov. 2011. UFFO's sub-minute measurements of the optical emission of dozens of GRB each year will result in a more rigorous test of current internal shock models, probe the extremes of bulk Lorentz factors, provide the first early and detailed measurements of fast-rise GRB optical light curves, and help verify the prospect of GRB as a new standard candle. We will describe the science and the mission of the current UFFO Pathfinder project, and our plan of a full-scale UFFO-100 as the next step.

  20. Techniques for identifying dust devils in mars pathfinder images

    USGS Publications Warehouse

    Metzger, S.M.; Carr, J.R.; Johnson, J. R.; Parker, T.J.; Lemmon, M.T.

    2000-01-01

    Image processing methods used to identify and enhance dust devil features imaged by IMP (Imager for Mars Pathfinder) are reviewed. Spectral differences, visible red minus visible blue, were used for initial dust devil searches, driven by the observation that Martian dust has high red and low blue reflectance. The Martian sky proved to be more heavily dust-laden than pre-Pathfinder predictions, based on analysis of images from the Hubble Space Telescope. As a result, these initial spectral difference methods failed to contrast dust devils with background dust haze. Imager artifacts (dust motes on the camera lens, flat-field effects caused by imperfections in the CCD, and projection onto a flat sensor plane by a convex lens) further impeded the ability to resolve subtle dust devil features. Consequently, reference images containing sky with a minimal horizon were first subtracted from each spectral filter image to remove camera artifacts and reduce the background dust haze signal. Once the sky-flat preprocessing step was completed, the red-minus-blue spectral difference scheme was attempted again. Dust devils then were successfully identified as bright plumes. False-color ratios using calibrated IMP images were found useful for visualizing dust plumes, verifying initial discoveries as vortex-like features. Enhancement of monochromatic (especially blue filter) images revealed dust devils as silhouettes against brighter background sky. Experiments with principal components transformation identified dust devils in raw, uncalibrated IMP images and further showed relative movement of dust devils across the Martian surface. A variety of methods therefore served qualitative and quantitative goals for dust plume identification and analysis in an environment where such features are obscure.

  1. The MARS pathfinder end-to-end information system: A pathfinder for the development of future NASA planetary missions

    NASA Technical Reports Server (NTRS)

    Cook, Richard A.; Kazz, Greg J.; Tai, Wallace S.

    1996-01-01

    The development of the Mars pathfinder is considered with emphasis on the End-to-End Information System (EEIS) development approach. The primary mission objective is to successfully develop and deliver a single flight system to the Martian surface, demonstrating entry, descent and landing. The EEIS is a set of functions distributed throughout the flight, ground and Mission Operation Systems (MOS) that inter-operate in order to control, collect, transport, process, store and analyze the uplink and downlink information flows of the mission. Coherence between the mission systems is achieved though the EEIS architecture. The key characteristics of the system are: a concurrent engineering approach for the development of flight, ground and mission operation systems; the fundamental EEIS architectural heuristics; a phased incremental EEIS development and test approach, and an EEIS design deploying flight, ground and MOS operability features, including integrated ground and flight based toolsets.

  2. Australian Film Studies.

    ERIC Educational Resources Information Center

    Breen, Myles P.

    Although Australia had a vigorous film industry in the silent film era, it was stifled in the 1930s when United States and British interests bought up the Australian distribution channels and closed down the indigenous industry. However, the industry and film study have undergone a renaissance since the advent of the Labor government in 1972,…

  3. Trialling the Australian Curriculum

    ERIC Educational Resources Information Center

    Ashman, Di

    2010-01-01

    In 2010, St. Leonards Primary School in Tasmania, along with other selected schools throughout Australia, trialled the draft Australian Curriculum: Mathematics. Mathematics had been a whole school focus at St. Leonards Primary School for several years, and the school found that the opportunity to be part of the trial strongly connected with their…

  4. Researching Australian Children's Literature

    ERIC Educational Resources Information Center

    Saxby, Maurice

    2004-01-01

    When in 1962 the author began to research the history of Australian children's literature, access to the primary sources was limited and difficult. From a catalogue drawer in the Mitchell Library of hand-written cards marked "Children's books" he could call up from the stacks, in alphabetical order, piles of early publications. His notes…

  5. Numeracy and Australian Teachers

    ERIC Educational Resources Information Center

    Forgasz, Helen; Leder, Gilah

    2016-01-01

    Australian teachers, recruited via Facebook, completed an online survey about aspects of numeracy. The survey was designed to explore views on numeracy and capacity to respond to numeracy tasks. In this paper, we focus primarily on responses to two numeracy tasks--one numerical, the other requiring critical evaluation. On the first item, 40%…

  6. Music in Australian Schools.

    ERIC Educational Resources Information Center

    Bartle, Graham

    This document is an English-language abstract (approximately 1,500 words) of a survey of music in Australian schools. The survey included all types of schools, and includes facilities and equipment for musical education, and the use made of them. The courses of study, organization of musical activities, finance, supervision, teacher training, and…

  7. Australian Curriculum Linked Lessons

    ERIC Educational Resources Information Center

    Hurrell, Derek

    2013-01-01

    In providing a continued focus on tasks and activities that help to illustrate key ideas embedded in the new Australian Curriculum, the focus in this issue is on Measurement in the Measurement and Geometry strand. The small unit of work on measurement presented in this article has activities that can be modified to meet the requirements of…

  8. James Webb Space Telescope (JWST) Optical Telescope Element (OTE) Pathfinder status and plans

    NASA Astrophysics Data System (ADS)

    Feinberg, Lee D.; Keski-Kuha, Ritva; Atkinson, Charlie; Booth, Andrew; Whitman, Tony

    2014-08-01

    A JWST OTE Pathfinder telescope that includes two spare primary mirror segments, a spare secondary mirror, and a large composite structure with a deployed secondary support structure is in the assembly stage and will be fully completed this year. This Pathfinder will check out key steps in the ambient mirror integration process and also be used at the Johnson Space Center (JSC) to check out the optical Ground Support Equipment (GSE) and associated procedures that will be used to test the full JWST telescope and instruments at JSC. This paper will summarize the Pathfinder integration and testing flow, the critical Ground Support Equipment it will test and the key tests planned with the Pathfinder.

  9. Processing and Analysis of Mars Pathfinder Science Data at JPL's Science Data Processing Section

    NASA Technical Reports Server (NTRS)

    LaVoie, S.; Green, W.; Runkle, A.; Alexander, D.; Andres, P.; DeJong, E.; Duxbury, E.; Freda, D.; Gorjian, Z.; Hall, J.; Hartman, F.; Levoe, S.; Lorre, J.; McAuley, J.; Suzuki, S.; Woncik, P.; Wright, J.

    1998-01-01

    The Mars Pathfinder mission required new capabilities and adaptation of existing capabilities in order to support science analysis and flight operations requirements imposed by the in-situ nature of the mission.

  10. Gambling on the Protestants: the Pathfinder Fund and birth control in Peru, 1958-1965.

    PubMed

    López, L Necochea

    2014-01-01

    Among the agencies involved in population control activities in the mid-twentieth century, none scored as many early victories in Latin America as did the Pathfinder Fund, founded by Procter & Gamble scion Clarence Gamble. This article analyzes a style in the delivery of family planning assistance in the developing world through the work of the Pathfinder Fund in Peru, the organization's hub in South America, and shows how Pathfinder personnel collaborated with local Protestant institutions. Its Protestant allies helped Pathfinder set up and manage rapid interventions such as the production of pamphlets, the smuggling of contraceptives, and the enrollment of physicians as advocates of the use of intrauterine devices. Although these rapid interventions helped quickly disseminate information and certain technologies among a fortunate few, they also weakened legitimate state agencies, neglected the monitoring of the safety of the drugs supplied, and alienated allies with their high-handed boldness.

  11. Old Desert Varnish-like Coatings and Young Breccias at the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Murchie, S.; Barnouin-Jha, O.; Barnouin-Jha, K.; Bishop, J.; Johnson, J.; McSween, H.; Morris, R.

    2004-01-01

    Many rocks at the Mars Pathfinder landing site exhibit evidence for desert varnish-like coatings that formed during an early, moist climate. Later eolian erosion partly stripped the coatings. Rocks excavated subsequently have shapes consistent with breccias or conglomerates.

  12. LISA Pathfinder and the road to space-based detection of gravitational waves

    NASA Astrophysics Data System (ADS)

    Thorpe, James

    2016-04-01

    The LISA Pathfinder spacecraft was launched on Dec 3rd, 2015 and began science operations in March 2016. Led by the European Space Agency with contributions from a number of European national agencies, universities, and NASA, LISA Pathfinder will demonstrate several key technologies and measurement technqiues for future space-based gravitational wave observatories. A successful LISA Pathfinder will retire much of the technical risk for such missions, which are the only proposed instruments capable of observing gravitational waves in the milliHertz band, a source-rich region expected to include singals from merging extragalactic massive black holes, capture of stellar-mass compact objects by massive black holes, and millions of individual close compact binaries in the Milky Way. I will present an overview of the LISA Pathfinder mission, it's current status, and the plans for operations and data analysis.

  13. Finally Here - The launch of LISA Pathfinder and the road to detecting Gravitational Waves in space

    NASA Astrophysics Data System (ADS)

    Thorpe, James; LISA Pathfinder Team

    2016-01-01

    The LISA Pathfinder spacecraft was launched in late 2015 and will begin science operations in early 2016. Led by the European Space Agency with contributions from a number of European national agencies, universities, and NASA, LISA Pathfinder will demonstrate several key technologies and measurement technqiues for future space-based gravitational wave observatories. A successful LISA Pathfinder will retire much of the technical risk for such missions, which are the only proposed instruments capable of observing gravitational waves in the milliHertz band, a source-rich region expected to include singals from merging extragalactic massive black holes, capture of stellar-mass compact objects by massive black holes, and millions of individual close compact binaries in the Milky Way. I will present an overview of the LISA Pathfinder mission, it's current status, and the plans for operations and data analysis.

  14. Pathfinder aircraft prepared for flight showing solar cell arrays on wing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The solar cell arrays, which cover about 75 percent of its upper wing surface, are clearly evident in this view of the Pathfinder solar-electric aircraft. The solar arrays are capable not only of absorbing direct sunlight, but can also absorb light reflected from the ground through the transparent lower surface of the 98-foot-long wing. Engineers and technicians from Pathfinder's developer, AeroVironment, Inc., conducted a successful two-hour check-out flight from NASA's Dryden Flight Research Center, Edwards, California, on Nov. 19, 1996. The craft then underwent preperations at AeroVironment's Simi Valley, California, facility for a new series of flight tests in Hawaii, during summer, 1997. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the

  15. Motoneuron axon pathfinding errors in zebrafish: Differential effects related to concentration and timing of nicotine exposure

    SciTech Connect

    Menelaou, Evdokia; Paul, Latoya T.; Perera, Surangi N.; Svoboda, Kurt R.

    2015-04-01

    Nicotine exposure during embryonic stages of development can affect many neurodevelopmental processes. In the developing zebrafish, exposure to nicotine was reported to cause axonal pathfinding errors in the later born secondary motoneurons (SMNs). These alterations in SMN axon morphology coincided with muscle degeneration at high nicotine concentrations (15–30 μM). Previous work showed that the paralytic mutant zebrafish known as sofa potato exhibited nicotine-induced effects onto SMN axons at these high concentrations but in the absence of any muscle deficits, indicating that pathfinding errors could occur independent of muscle effects. In this study, we used varying concentrations of nicotine at different developmental windows of exposure to specifically isolate its effects onto subpopulations of motoneuron axons. We found that nicotine exposure can affect SMN axon morphology in a dose-dependent manner. At low concentrations of nicotine, SMN axons exhibited pathfinding errors, in the absence of any nicotine-induced muscle abnormalities. Moreover, the nicotine exposure paradigms used affected the 3 subpopulations of SMN axons differently, but the dorsal projecting SMN axons were primarily affected. We then identified morphologically distinct pathfinding errors that best described the nicotine-induced effects on dorsal projecting SMN axons. To test whether SMN pathfinding was potentially influenced by alterations in the early born primary motoneuron (PMN), we performed dual labeling studies, where both PMN and SMN axons were simultaneously labeled with antibodies. We show that only a subset of the SMN axon pathfinding errors coincided with abnormal PMN axonal targeting in nicotine-exposed zebrafish. We conclude that nicotine exposure can exert differential effects depending on the levels of nicotine and developmental exposure window. - Highlights: • Embryonic nicotine exposure can specifically affect secondary motoneuron axons in a dose-dependent manner.

  16. The semantic pathfinder: using an authoring metaphor for generic multimedia indexing.

    PubMed

    Snoek, Cees G M; Worring, Marcel; Geusebroek, Jan-Mark; Koelma, Dennis C; Seinstra, Frank J; Smeulders, Arnold W M

    2006-10-01

    This paper presents the semantic pathfinder architecture for generic indexing of multimedia archives. The semantic pathfinder extracts semantic concepts from video by exploring different paths through three consecutive analysis steps, which we derive from the observation that produced video is the result of an authoring-driven process. We exploit this authoring metaphor for machine-driven understanding. The pathfinder starts with the content analysis step. In this analysis step, we follow a data-driven approach of indexing semantics. The style analysis step is the second analysis step. Here, we tackle the indexing problem by viewing a video from the perspective of production. Finally, in the context analysis step, we view semantics in context. The virtue of the semantic pathfinder is its ability to learn the best path of analysis steps on a per-concept basis. To show the generality of this novel indexing approach, we develop detectors for a lexicon of 32 concepts and we evaluate the semantic pathfinder against the 2004 NIST TRECVID video retrieval benchmark, using a news archive of 64 hours. Top ranking performance in the semantic concept detection task indicates the merit of the semantic pathfinder for generic indexing of multimedia archives.

  17. Validation of the Version 1 NOAA/NASA Pathfinder Sea Surface Temperature Data Set

    NASA Technical Reports Server (NTRS)

    Smith, Elizabeth A.

    1998-01-01

    A high-resolution, global satellite-derived sea surface temperature (SST) data set called Pathfinder, from the Advanced Very High Resolution Radiometer (AVHRR) aboard the NOAA Polar Orbiters, is available from the Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive Center (JPL PO.DAAC). Suitable for research as well as education, the Pathfinder SST data set is a result of a collaboration between the National Oceanographic and Atmospheric Administration (NOAA), the National Aeronautics and Space Administration (NASA) and investigators at several universities. NOAA and NASA are the sponsors of the Pathfinder Program, which takes advantage of currently archived Earth science data from satellites. Where necessary, satellite sensors have been intercalibrated, algorithms improved and processing procedures revised, in order to produce long time-series, global measurements of ocean, land and atmospheric properties necessary for climate research. Many Pathfinder data sets are available to researchers now, nearly a decade before the first launch of NASA's Earth Observing System (EOS). The lessons learned from the Pathfinder programs will facilitate the processing and management of terabytes of data from EOS. The Oceans component of Pathfinder has undertaken to reprocess all Global Area Coverage (GAC) data acquired by the 5-channel AVHRRs since 1981. The resultant data products are consistent and stably calibrated [Rao, 1993a, Rao, 1993b, Brown et al., 1993], Earth-gridded SST fields at a variety of spatial and temporal resolutions.

  18. Big Crater as Viewed by Pathfinder Lander - Anaglyph

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The 'Big Crater' is actually a relatively small Martian crater to the southeast of the Mars Pathfinder landing site. It is 1500 meters (4900 feet) in diameter, or about the same size as Meteor Crater in Arizona. Superimposed on the rim of Big Crater (the central part of the rim as seen here) is a smaller crater nicknamed 'Rimshot Crater.' The distance to this smaller crater, and the nearest portion of the rim of Big Crater, is 2200 meters (7200 feet). To the right of Big Crater, south from the spacecraft, almost lost in the atmospheric dust 'haze,' is the large streamlined mountain nicknamed 'Far Knob.' This mountain is over 450 meters (1480 feet) tall, and is over 30 kilometers (19 miles) from the spacecraft. Another, smaller and closer knob, nicknamed 'Southeast Knob' can be seen as a triangular peak to the left of the flanks of the Big Crater rim. This knob is 21 kilometers (13 miles) southeast from the spacecraft.

    The larger features visible in this scene - Big Crater, Far Knob, and Southeast Knob - were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The scene includes rocky ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of South Twin Peak. The largest rock in the nearfield, just left of center in the foreground, nicknamed 'Otter', is about 1.5 meters (4.9 feet) long and 10 meters (33 feet) from the spacecraft.

    This view of Big Crater was produced by combining 6 individual 'Superpan' scenes from the left and right eyes of the IMP camera. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution panchromatic frame that is sharper than an individual frame would be.

    The anaglyph view of Big Crater was

  19. Hardening: Australian for Transformation

    DTIC Science & Technology

    2004-01-01

    ADF towards homeland defense. For further details, see Jeffrey Grey. A Military History of Australia. Melbourne, Australia, Cambridge University...is a simplified explanation of the hardene d force structure proposed by FLW. The hardened concept encompasses other aspects that enhance Army...standardized with three rifle companies. A 196 Leahy “ A Land Force for the Future: The Australian Army in the Early 21st Century.” 2003: 19. 197 See Monk, Paul

  20. Effect of viewing mode on pathfinding in immersive Virtual Reality.

    PubMed

    White, Paul J; Byagowi, Ahmad; Moussavi, Zahra

    2015-08-01

    The use of Head Mounted Displays (HMDs) to view Virtual Reality Environments (VREs) has received much attention recently. This paper reports on the difference between actual humans' navigation in a VRE viewed through an HMD compared to that in the same VRE viewed on a laptop PC display. A novel Virtual Reality (VR) Navigation input device (VRNChair), designed by our team, was paired with an Oculus Rift DK2 Head-Mounted Display (HMD). People used the VRNChair to navigate a VRE, and we analyzed their navigational trajectories with and without the HMD to investigate plausible differences in performance due to the display device. It was found that people's navigational trajectories were more accurate while wearing the HMD compared to viewing an LCD monitor; however, the duration to complete a navigation task remained the same. This implies that increased immersion in VR results in an improvement in pathfinding. In addition, motion sickness caused by using an HMD can be reduced if one uses an input device such as our VRNChair. The VRNChair paired with an HMD provides vestibular stimulation as one moves in the VRE, because movements in the VRE are synchronized with movements in the real environment.

  1. Multiple Sun-Earth Saddle Point flybys for LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Fabacher, Emilien; Kemble, Stephen; Trenkel, Christian; Dunbar, Neil

    2013-07-01

    LISA Pathfinder is an ESA mission due to be launched in the next two years. The gravity gradiometer onboard has the sensitivity required to test predictions by gravitational theories proposed as alternatives to Dark Matter such as TeVeS. Within the Solar System measurable effects are predicted only in the vicinity of gravitational saddle points (SP). For this reason it has been proposed to fly LPF by the Earth-Sun SP, at some 259,000 km from Earth. This could be done in an extension to the nominal mission which uses a Lissajous orbit about the Earth-Sun L1 point. The responsibility for LPF mission design lies with ESA/ESOC, who have designed the transfer trajectories, orbits about L1, and station keeping strategies. This article describes an analysis performed by Astrium to support a suggestion for a possible mission extension to a saddle point crossing. With only very limited fuel availability, reaching the saddle point is a significant challenge. In this article, we present recent advances in the work on trajectory design. It is demonstrated that reaching the SP is feasible once the LPF mission is completed. Furthermore, in a significant enhancement, it is demonstrated that trajectories including more than one SP flyby are possible, thus improving the science return for this proposed mission extension.

  2. Polar Geophysics Products Derived from AVHRR: The "AVHRR Polar Pathfinder

    NASA Technical Reports Server (NTRS)

    Maslanik, James; Fowler, Charles; Scambos, Theodore

    1999-01-01

    This NOAA/NASA Pathfinder effort was established to locate, acquire, and process Advanced Very High Resolution Radiometer (AVHRR) imagery into geo-located and calibrated radiances, cloud masks, surface clear-sky broadband albedo, clear-sky skin temperatures, satellite viewing times, and viewing and solar geometry for the, high-latitude portions of the northern and southern hemispheres (all area north of 48N and south of 53S). AVHRR GAC data for August 1981 - July 1998 were acquired, with some gaps remaining, and processed into twice-daily 5-km grids, with some products also provided at 25-km resolution. AVHRR LAC data for 3.5 years of coverage in the northern hemisphere and 2.75 years of coverage in the southern hemisphere were processed into 1.25-km grids for the same suite of products. The resulting data sets are presently being transferred to the National Snow and Ice Data Center (NSIDC) for archiving and distribution. Using these data, researchers now have at their disposal an extensive AVHRR data set for investigations of high-latitude processes. In addition, the data lend themselves to development and testing of algorithms. The products are particularly relevant for climate research and algorithm development as applied to relatively long time periods and large areas.

  3. Antenna Deployment for a Pathfinder Lunar Radio Observatory

    NASA Technical Reports Server (NTRS)

    MacDowall, Robert J.; Minetto, F. A.; Lazio, T. W.; Jones, D. L.; Kasper, J. C.; Burns, J. O.; Stewart, K. P.; Weiler, K. W.

    2012-01-01

    A first step in the development of a large radio observatory on the moon for cosmological or other astrophysical and planetary goals is to deploy a few antennas as a pathfinder mission. In this presentation, we describe a mechanism being developed to deploy such antennas from a small craft, such as a Google Lunar X-prize lander. The antenna concept is to deposit antennas and leads on a polyimide film, such as Kapton, and to unroll the film on the lunar surface. The deployment technique utilized is to launch an anchor which pulls a double line from a reel at the spacecraft. Subsequently, the anchor is set by catching on the surface or collecting sufficient regolith. A motor then pulls in one end of the line, pulling the film off of its roller onto the lunar surface. Detection of a low frequency cutoff of the galactic radio background or of solar radio bursts by such a system would determine the maximum lunar ionospheric density at the time of measurement. The current design and testing, including videos of the deployment, will be presented. These activities are funded in part by the NASA Lunar Science Institute as an activity of the Lunar University Network for Astrophysical Research (LUNAR) consortium. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

  4. Slope Morphology of Twin Peaks, Mars Pathfinder Landing Site

    NASA Astrophysics Data System (ADS)

    Hobbs, Steven; Paine, Colin; Clarke, Jon; Caprarelli, Graziella

    2010-05-01

    Development of slope form over time has long been a concern of geomorphologists, although recently this concern has been moved to slope processes rather than form. There are two basic approaches. The first is theoretical, involving modeling of different types and rates of processes, and calculation of results in terms of slope evolution over time. Comparisons with real-life slopes can follow this approach [1], [2]. The second, inductive, approach involves field measurements to test ideas about slope evolution starting from the assumption that observed slopes represent different stages of an essentially similar evolution [3]. Space is substituted for time, and a number of slopes, assumed to be of increasing age, are measured and placed in an evolutionary sequence (e.g. [4], [5], [6]). [5] showed that slope angles are modally distributed, with the modal angles controlled by the materials (regolith) of which the slopes are formed, and by the processes operating on them. Data can be obtained directly from field work or from digital elevation models (DEM) derived from remote sensing investigations [7]. DEMs are particularly useful to study inaccessible planets, such as Mars, where on site observations are restricted to only a few landing sites. Here we present a study of slopes on the Twin Peaks, two small hills located 780 m north and 910 m south of the Mars Pathfinder landing site at the mouth of the Ares and Tiu flood channels. The presence of streamlined hills, jumbled surfaces and conglomerates suggested the region was modified by massive flooding 1.8 - 3.5 billion years ago [8], [9]. The streamlined forms and terraces of the Twin Peaks were taken to indicate catastrophic flood conditions that were believed to be prevalent in the area [8]. It was also suggested that the northernmost peak was topped by floodwater, causing its flatter appearance. Other researchers postulated alternative geomorphological origins for the features observed at the Pathfinder landing site

  5. Characterization of the LISA Pathfinder Drag Reduction System

    NASA Astrophysics Data System (ADS)

    Slutsky, Jacob; LISA Pathfinder Team

    2016-03-01

    The LISA Pathfinder (LPF) mission launched in December 2015 with operations beginning March 2016. LPF is a technology demonstration mission built to prove and fully characterize the performance of the use of drag free test masses as Gravitational Reference Sensors (GRS) for future space based gravitational-wave observatories. As a joint ESA-NASA mission, LPF is comprised of both European and NASA payloads, the LISA Technology Package (LTP) and Disturbance Reduction System (DRS), respectively. DRS includes Colloid Micro-Newton Thruster (CMNT) systems, to precisely maneuver the spacecraft without disturbing the GRS, and a control system that directs spacecraft and test mass actuation. In order to fully characterize DRS/CMNT performance, we have developed a series of experiments, to take place during DRS operations beginning later this year. We have built analysis pipelines, validated on simulated data, to rapidly process experimental data and to identify any performance issues as they occur. European partners have developed the LTP Data Analysis (LTPDA) Matlab extension, and we have adapted and expanded this to DRS missions as the basis of our analysis pipelines. I will discuss the anticipated DRS performance and measurement accuracy, illustrated on simulated data.

  6. The Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission

    NASA Technical Reports Server (NTRS)

    Crisp, David

    2003-01-01

    A viewgraph presentation describing the Earth System Science Pathfinder Orbiting Carbon Observatory (OCO) Mission is shown. The contents include: 1) Why CO2?; 2) What Processes Control CO2 Sinks?; 3) OCO Science Team; 4) Space-Based Measurements of CO2; 5) Driving Requirement: Precise, Bias-Free Global Measurements; 6) Making Precise CO2 Measurements from Space; 7) OCO Spatial Sampling Strategy; 8) OCO Observing Modes; 9) Implementation Approach; 10) The OCO Instrument; 11) The OCO Spacecraft; 12) OCO Will Fly in the A-Train; 13) Validation Program Ensures Accuracy and Minimizes Spatially Coherent Biases; 14) Can OCO Provide the Required Precision?; 15) O2 Column Retrievals with Ground-based FTS; 16) X(sub CO2) Retrieval Simulations; 17) Impact of Albedo and Aerosol Uncertainty on X(sub CO2) Retrievals; 18) Carbon Cycle Modeling Studies: Seasonal Cycle; 19) Carbon Cycle Modeling Studies: The North-South Gradient in CO2; 20) Carbon Cycle Modeling Studies: Effect of Diurnal Biases; 21) Project Status and Schedule; and 22) Summary.

  7. Model Checking Real Time Java Using Java PathFinder

    NASA Technical Reports Server (NTRS)

    Lindstrom, Gary; Mehlitz, Peter C.; Visser, Willem

    2005-01-01

    The Real Time Specification for Java (RTSJ) is an augmentation of Java for real time applications of various degrees of hardness. The central features of RTSJ are real time threads; user defined schedulers; asynchronous events, handlers, and control transfers; a priority inheritance based default scheduler; non-heap memory areas such as immortal and scoped, and non-heap real time threads whose execution is not impeded by garbage collection. The Robust Software Systems group at NASA Ames Research Center has JAVA PATHFINDER (JPF) under development, a Java model checker. JPF at its core is a state exploring JVM which can examine alternative paths in a Java program (e.g., via backtracking) by trying all nondeterministic choices, including thread scheduling order. This paper describes our implementation of an RTSJ profile (subset) in JPF, including requirements, design decisions, and current implementation status. Two examples are analyzed: jobs on a multiprogramming operating system, and a complex resource contention example involving autonomous vehicles crossing an intersection. The utility of JPF in finding logic and timing errors is illustrated, and the remaining challenges in supporting all of RTSJ are assessed.

  8. Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Pathfinder-Plus on flight over Hawaiian Islands, with N'ihau and Lehua in the background. Pathfinder was a remotely controlled, solar-powered flying wing, designed and built as a proof-of-concept vehicle for a much larger aircraft capable of flying at extremely high altitudes for weeks at a time. It was built by AeroVironment, Inc., a California company that developed the human-powered Gossamer Condor and Gossamer Albatross lightweight aircraft during the 1970s, and later made the solar-electric powered Gossamer Penguin and Solar Challenger. The basic configuration and concepts for Pathfinder were first realized with the HALSOL (High Altitude Solar) aircraft, built in 1983 by AeroVironment and the Lawrence Livermore Laboratory. Pathfinder was constructed of advanced composites, plastics, and foam, and despite a wingspan of nearly 100 feet, it weighed only about 600 pounds. Pathfinder was one of several unpiloted prototypes under study by NASA's ERAST (Environmental Research Aircraft and Sensor Technology) program, a NASA-industry alliance which is helping develop advanced technologies that will enable aircraft to study the earth's environment during extremely long flights at altitudes in excess of 100,000 feet. (See project description below for Pathfinder's conversion to Pathfinder Plus.) In 1998, the Pathfinder solar-powered flying wing (see its photographs and project description) was modified into the longer-winged Pathfinder Plus configuration and on Aug. 6, 1998, Pathfinder Plus set an altitude record (for propeller-driven aircraft) of approximately 80,285 feet at the Pacific Missile Range Facility. The goal of the Pathfinder Plus flights was to validate new solar, aerodynamic, propulsion, and systems technology developed for its successor, the Centurion, which was designed to reach and sustain altitudes in the 100,000-foot range. The Centurion was succeeded by the Helios Prototype with a goal of reaching and sustaining flight at an altitude of 100,000 feet

  9. Review of Australian Higher Education: An Australian Policy Perspective

    ERIC Educational Resources Information Center

    Montague, Alan

    2013-01-01

    Higher education is one of the key foundations that economic prosperity is founded upon. Government policies, funding and strategic planning require a fine balance to stimulate growth, prosperity health and well-being. The key Australian government policies influenced by a Review of Australian Higher Education report include attracting many more…

  10. Pathfinder ground preparations prior to altitude record setting flight of 71,500 feet

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Technicians make final adjustments on the solar-powered Pathfinder remotely piloted research aircraft prior to the craft's taking off on a flight which established a new unofficial world's altitude record for both propellor-driven and solar-powered aircraft. The new record of more than 71,500 feet was set during a 14 1/2-hour flight July 7, 1997, from the U.S. Navy's Pacific Missile Range Facility (PMRF) at Barking Sands, Kauai, Hawaii. The new altitude record is subject to verification by the National Aeronautics Association. The Pathfinder took off at 8:34 a.m. HDT, passed its previous record altitude of 67,350 feet about 2:45 p.m., and then reached its new mark at about 4 p.m. Controllers on the ground then initiated a slow decent, and Pathfinder landed seven hours later at 11:05 p.m. HDT. The experimental Boeing Condor remotely-piloted aircraft had held the previous record for propellor-driven craft of 67,028 feet. The Pathfinder had exceeded that height on a previous flight on June 9, 1997, but not by a large enough margin to be considered a new record. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the

  11. Towards Inclusion: An Australian Perspective

    ERIC Educational Resources Information Center

    Forbes, Fiona

    2007-01-01

    This article outlines the views of the Australian Special Education Principals' Association (ASEPA) on inclusion and the impact this is having on Australian Government Schools from a school based perspective. ASEPA is a relatively young association and was formed in 1997 out of the need to put forward the case to support students with special…

  12. Australian University International Student Finances

    ERIC Educational Resources Information Center

    Forbes-Mewett, Helen; Marginson, Simon; Nyland, Chris; Ramia, Gaby; Sawir, Erlenawati

    2009-01-01

    The omission of international students from the Australian Vice-Chancellor's Committee (AVCC) 2007 national study on student finances is indicative of a pattern of exclusion. The exclusion is unacceptable from a humane perspective and feeds the belief that Australians perceive international students primarily as "cash cows". This study…

  13. General geology and geomorphology of the Mars Pathfinder landing site

    USGS Publications Warehouse

    Ward, A.W.; Gaddis, L.R.; Kirk, R.L.; Soderblom, L.A.; Tanaka, K.L.; Golombek, M.P.; Parker, T.J.; Greeley, Ronald; Kuzmin, R.O.

    1999-01-01

    The Mars Pathfinder (MPF) spacecraft landed on relatively young (late Hesperian-early Amazonian; 3.1-0.7 Ga) plains in Chryse Planitia near the mouth of Ares Vallis. Images returned from the spacecraft reveal a complex landscape of ridges and troughs, large hills and crater rims, rocks and boulders of various sizes and shapes, and surficial deposits, indicating a complex, multistage geologic history of the landing site. After the deposition of one or more bedrock units, depositional and erosional fluvial processes shaped much of the present landscape. Multiple erosional events are inferred on the basis of observations of numerous channels, different orientations of many streamlined tails from their associated knobs and hills, and superposition of lineations and streamlines. Medium- and small-scale features, interpreted to be related to late-stage drainage of floodwaters, are recognized in several areas at the landing site. Streamlined knobs and hills seen in Viking orbiter images support this inference, as they seem to be complex forms, partly erosional and partly depositional, and may also indicate a series of scouring and depositional events that, in some cases, further eroded or partially buried these landforms. Although features such as these are cited as evidence for catastrophic flooding at Ares Vallis, some of these features may also be ascribed to alternative primary or secondary depositional processes, such as glacial or mass-wasting processes. Close inspection of the landing site reveals rocks that are interpreted to be volcanic in origin and others that may be conglomeratic. If such sedimentary rocks are confirmed, fluvial processes have had a greater significance on Mars than previously thought. For the last several hundred million to few billion years, eolian processes have been dominant. Dunes and dune-like features, ventifacts, and deflation and exhumation features around several rocks probably are the most recent landforms. The relatively pristine

  14. Detection and measurement of micrometeoroids with LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Thorpe, J. I.; Parvini, C.; Trigo-Rodríguez, J. M.

    2016-02-01

    The Solar System contains a population of dust and small particles originating from asteroids, comets, and other bodies. These particles have been studied using a number of techniques ranging from in-situ satellite detectors to analysis of lunar microcraters to ground-based observations of zodiacal light. In this paper, we describe an approach for using the LISA Pathfinder (LPF) mission as an instrument to detect and characterize the dynamics of dust particles in the vicinity of Earth-Sun L1. Launched on Dec. 3rd, 2015, LPF is a dedicated technology demonstrator mission that will validate several key technologies for a future space-based gravitational-wave observatory. The primary science instrument aboard LPF is a precision accelerometer which we show will be capable of sensing discrete momentum impulses as small as 4 × 10-8 N s. We then estimate the rate of such impulses resulting from impacts of micrometeoroids based on standard models of the micrometeoroid environment in the inner solar system. We find that LPF may detect dozens to hundreds of individual events corresponding to impacts of particles with masses >10-9g during LPF's roughly six-month science operations phase in a 5 × 105 km by 8 × 105 km Lissajous orbit around L1. In addition, we estimate the ability of LPF to characterize individual impacts by measuring quantities such as total momentum transferred, direction of impact, and location of impact on the spacecraft. Information on flux and direction provided by LPF may provide insight as to the nature and origin of the individual impact and help constrain models of the interplanetary dust complex in general. Additionally, this direct in situ measurement of micrometeoroid impacts will be valuable to designers of future spacecraft targeting the environment around L1.

  15. Preliminary Findings of the Photovoltaic Cell Calibration Experiment on Pathfinder Flight 95-3

    NASA Technical Reports Server (NTRS)

    Vargas-Aburto, Carlos

    1997-01-01

    The objective of the photovoltaic (PV) cell calibration experiment for Pathfinder was to develop an experiment compatible with an ultralight UAV to predict the performance of PV cells at AM0, the solar spectrum in space, using the Langley plot technique. The Langley plot is a valuable technique for this purpose and requires accurate measurements of air mass (pressure), cell temperature, solar irradiance, and current-voltage(IV) characteristics with the cells directed normal to the direct ray of the sun. Pathfinder's mission objective (95-3) of 65,000 ft. maximum altitude, is ideal for performing the Langley plot measurements. Miniaturization of electronic data acquisition equipment enabled the design and construction of an accurate and light weight measurement system that meets Pathfinder's low payload weight requirements.

  16. MARS PATHFINDER SMALL ROVER UNDERGOES FINAL FUNCTIONAL CHECK IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder small rover undergoes a final functional check in KSC's Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2) before being attached to the Pathfinder lander. The six- wheeled robotic vehicle will become the first autonomous rover to explore the surface of another planet when it begins crawling across the Martian terrain next year. The small rover will be attached to one of the three petals of the Mars Pathfinder lander. After the petals are closed, a protective aeroshell will be installed around the lander and parachutes attached to it. This assembled entry vehicle will then be mated to the cruise stage that will carry the spacecraft on its interplanetary trajectory. The completed spacecraft assembly will be mated with an upper stage booster before going to the launch pad. Liftoff on a Delta II expendable launch vehicle currently is set for Dec. 2 at the beginning of a 24-day launch period.

  17. AVHRR-Based Polar Pathfinder Products: Evaluation, Enhancement and Transition to MODIS

    NASA Technical Reports Server (NTRS)

    Fowler, Charles; Masalanik, James; Stone, Robert; Stroeve, Julienne; Emery, William

    2001-01-01

    The Advanced Very High Resolution Radiometer (AVHRR)-Based Polar Pathfinder (APP) products include calibrated AVHRR channel data, surface temperatures, albedo, satellite scan and solar geometries, and cloud mask, all composited into twice-per-day images, and daily averaged fields of sea ice motion, for regions poleward of 50 latitude. Our general goals under this grant: (1) Quantify the APP accuracy and sources of error by comparing Pathfinder products with field measurements; (2) Determine the consistency of mean fields and trends in comparison with longer time series of available station data and forecast model output; (3) Investigate the consistency of the products between the different AVHRR instruments over the 1982-present period of the NOAA program; and (4) Compare and annual cycle of the APP products with MODIS to establish a baseline for extending Pathfinder-type products into the new ESE period.

  18. Pathfinder technologies for bold new missions. [U.S. research and development program for space exploration

    NASA Technical Reports Server (NTRS)

    Sadin, Stanley R.; Rosen, Robert

    1987-01-01

    Project Pathfinder is a proposed U.S. Space Research and Technology program intended to enable bold new missions of space exploration. Pathfinder continues the advancement of technological capabilities and extends the foundation established under the Civil Space Technology Initiative, CSTI. By filling critical technological gaps, CSTI enhances access to Earth orbit and supports effective operations and science missions therein. Pathfinder, with a longer-term horizon, looks to a future that builds on Shuttle and Space Station and addresses technologies that support a range of exploration missions including: a return to the Moon to build an outpost; piloted missions to Mars; and continued scientific exploration of Earth and the other planets. The program's objective is to develop, within reasonable time frames, those emerging and innovative technologies that will make possible both new and enhanced missions and system concepts.

  19. The SKA and its pathfinders in the next decade: synergies with the TMT

    NASA Astrophysics Data System (ADS)

    Spekkens, Kristine

    2014-07-01

    The next decade will be extremely exciting for centimeter- and meter-wave radio astronomy. Large new facilities such as ASKAP, LOFAR and MeerKAT, as well as major retrofits to existing facilities such as the JVLA and WSRT, are under construction or have begun operations. While revolutionary in and of themselves, these facilities are also important pathfinders to the SKA, whose construction will begin towards the end of this decade. This talk will review the key science that will be delivered by the SKA pathfinders as well as that anticipated with SKA Phase One (2018-2023) and Phase Two (>2023), with a focus on potential synergies with the TMT.

  20. Mineralogic and compositional properties of Martian soil and dust: results from Mars Pathfinder

    USGS Publications Warehouse

    Bell, J.F.; McSween, H.Y.; Crisp, J.A.; Morris, R.V.; Murchie, S.L.; Bridges, N.T.; Johnson, J. R.; Britt, D.T.; Golombek, M.P.; Moore, H.J.; Ghosh, A.; Bishop, J.L.; Anderson, R.C.; Brückner, J.; Economou, T.; Greenwood, J.P.; Gunnlaugsson, H.P.; Hargraves, R.M.; Hviid, S.; Knudsen, J.M.; Madsen, M.B.; Reid, R.; Rieder, R.; Soderblom, L.

    2000-01-01

    Mars Pathfinder obtained multispectral, elemental, magnetic, and physical measurements of soil and dust at the Sagan Memorial Station during the course of its 83 sol mission. We describe initial results from these measurements, concentrating on multispectral and elemental data, and use these data, along with previous Viking, SNC meteorite, and telescopic results, to help constrain the origin and evolution of Martian soil and dust. We find that soils and dust can be divided into at least eight distinct spectral units, based on parameterization of Imager for Mars Pathfinder (IMP) 400 to 1000 nm multispectral images. The most distinctive spectral parameters for soils and dust are the reflectivity in the red, the red/blue reflectivity ratio, the near-IR spectral slope, and the strength of the 800 to 1000 nm absorption feature. Most of the Pathfinder spectra are consistent with the presence of poorly crystalline or nanophase ferric oxide(s), sometimes mixed with small but varying degrees of well-crystalline ferric and ferrous phases. Darker soil units appear to be coarser-grained, compacted, and/or mixed with a larger amount of dark ferrous materials relative to bright soils. Nanophase goethite, akaganeite, schwertmannite, and maghemite are leading candidates for the origin of the absorption centered near 900 nm in IMP spectra. The ferrous component in the soil cannot be well-constrained based on IMP data. Alpha proton X-ray spectrometer (APXS) measurements of six soil units show little variability within the landing site and show remarkable overall similarity to the average Viking-derived soil elemental composition. Differences exist between Viking and Pathfinder soils, however, including significantly higher S and Cl abundances and lower Si abundances in Viking soils and the lack of a correlation between Ti and Fe in Pathfinder soils. No significant linear correlations were observed between IMP spectral properties and APXS elemental chemistry. Attempts at constraining

  1. Climate Change on Mars Inferred from Erosion Rates at the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Bridges, N. T.

    1999-01-01

    The observation that the Mars Pathfinder landing site probably looks very similar to when it was deposited by catastrophic floods some 1.8-3.5 Ga allows quantitative constraints to be placed on the rate of change at the landing site since that time. When combined with interpretations of data recently returned by the Mars Pathfinder and Global Surveyor missions and perspectives drawn from 20 years of analysis and interpretation of Viking data, these observations and inferences suggest an early warmer and wetter environment with vastly different erosion rates and a major climatic change on Mars. Additional information is contained in the original extended abstract.

  2. Observations by the Mars 1994 orbiter and possible correlations with Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Keller, H. Uwe

    1994-01-01

    The Mars '94 spacecraft will still be operational when Mars Pathfinder begins its observations. While it will probably not be possible to detect the lander directly, the terrain, including the landing error ellipse, can be covered in high resolution (10 m) in various color bands. The stereo capability of the high resolution camera will provide a three-dimensional terrain map. The landing site of Pathfinder could possibly be chosen so that correlated observations of IMP and the remote sensing instruments onboard Mars '94 may be possible. We will discuss this scenario based on the presently adopted Mars '94 orbit and resulting enhancements stemming from correlations of data obtained by both spacecraft.

  3. HOWARD EISEN, JPL'S LEAD MECHANICAL TECHNICIAN, HOLDS MARS PATHFINDER 'SOJOURNER' ROVER 1:1 SCALE DU

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The Mars Pathfinder 'Sojourner' rover l:l scale duplicate test vehicle is held by Howard Eisen, its lead mechanical technician from the Jet Propulsion Laboratory, with Kennedy Space Center's Vehicle Assembly Building looming in the background. The launch of NASA's Mars Pathfinder spacecraft aboard a McDonnell Douglas Delta II rocket is scheduled for Monday, Dec. 2, at 2:09:11 a.m. EST. This is a single instantaneous target launch time without a second opportunity on that day. Liftoff will occur from Pad B at Launch Complex 17 on Cape Canaveral Air Station, Fla. There is a 24-day launch opportunity which extends through Dec. 31.

  4. MARS PATHFINDER 'SOJOURNER' ROVER 1:1 SCALE DUPLICATE TEST VEHICLE

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Mars Pathfinder's 'Sojourner' rover l:l scale duplicate test vehicle undergoes Earthbound tests at the Kennedy Space Center. The launch of NASA's Mars Pathfinder spacecraft aboard a McDonnell Douglas Delta II rocket is scheduled for Monday, Dec. 2, at 2:09:11 a.m. EST. This is a single instantaneous target launch time without a second opportunity on that day. Liftoff will occur from Pad B at Launch Complex 17 on Cape Canaveral Air Station, Fla. There is a 24-day launch opportunity which extends through Dec. 31.

  5. Examining Alternatives to Wavelet Denoising for Astronomical Source Finding

    NASA Astrophysics Data System (ADS)

    Jurek, R.; Brown, S.

    2012-08-01

    The Square Kilometre Array and its pathfinders ASKAP and MeerKAT will produce prodigious amounts of data that necessitate automated source finding. The performance of automated source finders can be improved by pre-processing a dataset. In preparation for the WALLABY and DINGO surveys, we have used a test HI datacube constructed from actual Westerbork Telescope noise and WHISP HI galaxies to test the real world improvement of linear smoothing, the Duchamp source finder's wavelet denoising, iterative median smoothing and mathematical morphology subtraction, on intensity threshold source finding of spectral line datasets. To compare these pre-processing methods we have generated completeness-reliability performance curves for each method and a range of input parameters. We find that iterative median smoothing produces the best source finding results for ASKAP HI spectral line observations, but wavelet denoising is a safer pre-processing technique. In this paper we also present our implementations of iterative median smoothing and mathematical morphology subtraction.

  6. FAT: Fully Automated TiRiFiC

    NASA Astrophysics Data System (ADS)

    Kamphuis, P.; Józsa, G. I. G.; Oh, S.-. H.; Spekkens, K.; Urbancic, N.; Serra, P.; Koribalski, B. S.; Dettmar, R.-J.

    2015-07-01

    FAT (Fully Automated TiRiFiC) is an automated procedure that fits tilted-ring models to Hi data cubes of individual, well-resolved galaxies. The method builds on the 3D Tilted Ring Fitting Code (TiRiFiC, ascl:1208.008). FAT accurately models the kinematics and the morphologies of galaxies with an extent of eight beams across the major axis in the inclination range 20°-90° without the need for priors such as disc inclination. FAT's performance allows us to model the gas kinematics of many thousands of well-resolved galaxies, which is essential for future HI surveys, with the Square Kilometre Array and its pathfinders.

  7. Predictions for ASKAP neutral hydrogen surveys

    NASA Astrophysics Data System (ADS)

    Duffy, Alan R.; Meyer, Martin J.; Staveley-Smith, Lister; Bernyk, Maksym; Croton, Darren J.; Koribalski, Bärbel S.; Gerstmann, Derek; Westerlund, Stefan

    2012-11-01

    The Australian Square Kilometre Array Pathfinder (ASKAP) will revolutionize our knowledge of gas-rich galaxies in the universe. Here we present predictions for two proposed extragalactic ASKAP neutral hydrogen (H I) emission-line surveys, based on semi-analytic models applied to cosmological N-body simulations. The ASKAP H I All-Sky Survey, known as Widefield ASKAP L-band Legacy All-sky Blind surveY (WALLABY), is a shallow 3 π survey (z = 0-0.26) which will probe the mass and dynamics of over 6 × 105 galaxies. A much deeper small-area H I survey, called Deep Investigation of Neutral Gas Origins (DINGO), aims to trace the evolution of H I from z = 0 to 0.43, a cosmological volume of 4 × 107 Mpc3, detecting potentially 105 galaxies. The high-sensitivity 30 antenna ASKAP core (diameter ˜2 km) will provide an angular resolution of 30 arcsec (at z = 0). Our simulations show that the majority of galaxies detected in WALLABY (87.5 per cent) will be resolved. About 5000 galaxies will be well resolved, i.e. more than five beams (2.5 arcmin) across the major axis, enabling kinematic studies of their gaseous discs. This number would rise to 1.6 × 105 galaxies if all 36 ASKAP antennas could be used; the additional six antennas provide baselines up to 6 km, resulting in an angular resolution of 10 arcsec. For DINGO this increased resolution is highly desirable to minimize source confusion, reducing confusion rates from a maximum of 10 per cent of sources at the survey edge to 3 per cent. We estimate that the sources detected by WALLABY and DINGO will span four orders of magnitude in total halo mass (from 1011 to 1015 M⊙) and nearly seven orders of magnitude in stellar mass (from 105 to 1012 M⊙), allowing us to investigate the process of galaxy formation across the last four billion years.

  8. The directional dependence of apertures, limits and sensitivity of the lunar Cherenkov technique to a UHE neutrino flux

    NASA Astrophysics Data System (ADS)

    James, C. W.; Protheroe, R. J.

    2009-06-01

    We use computer simulations to obtain the directional-dependence of the lunar Cherenkov technique for ultra-high energy (UHE) neutrino detection. We calculate the instantaneous effective area of past lunar Cherenkov experiments at Parkes, Goldstone (Goldstone Lunar Ultra-high energy neutrino Experiment, GLUE), and Kalyazin, as a function of neutrino arrival direction, finding that the potential sensitivity to a point source of UHE neutrinos for these experiments was as much as thirty times that to an isotropic flux, depending on the beam-pointing position and incident neutrino energy. Convolving our results with the known lunar positions during the Parkes and Goldstone experiments allows us to calculate an exposure map, and hence the directional-dependence of the combined limit imposed by these experiments. In the 10 21-10 23 eV range, we find parts of the sky where the GLUE limit likely still dominates, and areas where none of the limits from either Parkes, GLUE, or experiments such as the Antarctic Impulsive Transient Antenna (ANITA) balloon experiment or FORTE (Fast On-orbit Recording of Transient Events) satellite experiment are likely to be significant. Hence a large anisotropic flux of UHE neutrinos from these regions is not yet excluded. We also determine the directional dependence of the aperture of future planned experiments with the Australia Telescope Compact Array (ATCA), Australian SKA Pathfinder (ASKAP) and the Square Kilometre Array (SKA) to a UHE neutrino flux, and calculate the potential annual exposure to astronomical objects as a function of angular distance from the lunar trajectory through celestial coordinates. We find that the potential exposure of all experiments at 10 20 eV and below, integrated over a calendar year, is flat out to ˜25° from the lunar trajectory and then drops off rapidly. The region of greater sensitivity includes much of the Supergalactic Plane, including M87 and Cen A, as well as the Galactic Centre. At higher energies

  9. Comparison of algorithms for determination of rotation measure and Faraday structure. I. 1100–1400 MHz

    SciTech Connect

    Sun, X. H.; Akahori, Takuya; Anderson, C. S.; Farnes, J. S.; O’Sullivan, S. P.; Rudnick, L.; O’Brien, T.; Bell, M. R.; Bray, J. D.; Scaife, A. M. M.; Ideguchi, S.; Kumazaki, K.; Stepanov, R.; Stil, J.; Wolleben, M.; Takahashi, K.; Weeren, R. J. van E-mail: larry@umn.edu

    2015-02-01

    Faraday rotation measures (RMs) and more general Faraday structures are key parameters for studying cosmic magnetism and are also sensitive probes of faint ionized thermal gas. A definition of which derived quantities are required for various scientific studies is needed, as well as addressing the challenges in determining Faraday structures. A wide variety of algorithms has been proposed to reconstruct these structures. In preparation for the Polarization Sky Survey of the Universe's Magnetism (POSSUM) to be conducted with the Australian Square Kilometre Array Pathfinder and the ongoing Galactic Arecibo L-band Feeds Array Continuum Transit Survey (GALFACTS), we run a Faraday structure determination data challenge to benchmark the currently available algorithms, including Faraday synthesis (previously called RM synthesis in the literature), wavelet, compressive sampling, and QU-fitting. The input models include sources with one Faraday thin component, two Faraday thin components, and one Faraday thick component. The frequency set is similar to POSSUM/GALFACTS with a 300 MHz bandwidth from 1.1 to 1.4 GHz. We define three figures of merit motivated by the underlying science: (1) an average RM weighted by polarized intensity, RM{sub wtd}, (2) the separation Δϕ of two Faraday components, and (3) the reduced chi-squared χ{sub r}{sup 2}. Based on the current test data with a signal-to-noise ratio of about 32, we find the following. (1) When only one Faraday thin component is present, most methods perform as expected, with occasional failures where two components are incorrectly found. (2) For two Faraday thin components, QU-fitting routines perform the best, with errors close to the theoretical ones for RM{sub wtd} but with significantly higher errors for Δϕ. All other methods, including standard Faraday synthesis, frequently identify only one component when Δϕ is below or near the width of the Faraday point-spread function. (3) No methods as currently implemented

  10. Comparison of Algorithms for Determination of Rotation Measure and Faraday Structure. I. 1100-1400 MHz

    NASA Astrophysics Data System (ADS)

    Sun, X. H.; Rudnick, L.; Akahori, Takuya; Anderson, C. S.; Bell, M. R.; Bray, J. D.; Farnes, J. S.; Ideguchi, S.; Kumazaki, K.; O'Brien, T.; O'Sullivan, S. P.; Scaife, A. M. M.; Stepanov, R.; Stil, J.; Takahashi, K.; van Weeren, R. J.; Wolleben, M.

    2015-02-01

    Faraday rotation measures (RMs) and more general Faraday structures are key parameters for studying cosmic magnetism and are also sensitive probes of faint ionized thermal gas. A definition of which derived quantities are required for various scientific studies is needed, as well as addressing the challenges in determining Faraday structures. A wide variety of algorithms has been proposed to reconstruct these structures. In preparation for the Polarization Sky Survey of the Universe's Magnetism (POSSUM) to be conducted with the Australian Square Kilometre Array Pathfinder and the ongoing Galactic Arecibo L-band Feeds Array Continuum Transit Survey (GALFACTS), we run a Faraday structure determination data challenge to benchmark the currently available algorithms, including Faraday synthesis (previously called RM synthesis in the literature), wavelet, compressive sampling, and QU-fitting. The input models include sources with one Faraday thin component, two Faraday thin components, and one Faraday thick component. The frequency set is similar to POSSUM/GALFACTS with a 300 MHz bandwidth from 1.1 to 1.4 GHz. We define three figures of merit motivated by the underlying science: (1) an average RM weighted by polarized intensity, R{{M}wtd}, (2) the separation Δφ of two Faraday components, and (3) the reduced chi-squared χ r2. Based on the current test data with a signal-to-noise ratio of about 32, we find the following. (1) When only one Faraday thin component is present, most methods perform as expected, with occasional failures where two components are incorrectly found. (2) For two Faraday thin components, QU-fitting routines perform the best, with errors close to the theoretical ones for R{{M}wtd} but with significantly higher errors for Δφ . All other methods, including standard Faraday synthesis, frequently identify only one component when Δφ is below or near the width of the Faraday point-spread function. (3) No methods as currently implemented work well for

  11. Engaging Indigenous Students in the Australian SKA Project

    NASA Astrophysics Data System (ADS)

    Hollow, Robert; Harvey-Smith, Lisa; Brooks, Kate; Boddington, Leonie

    2015-08-01

    The Murchison region of Western Australia is the site of the Murchison Radio-astronomy Observatory (MRO) that includes the Australian SKA Pathfinder (ASKAP) and the Murchison Widefield Array (MWA) and soon the SKA. This is also traditional land of the Wajarri Yamatji people. As part of its development in the region CSIRO has extensive engagement with the Wajarri Yamatji people. This includes educational, cultural, training and commercial opportunities. We outline the Indigenous Land Use Agreement (ILUA) between the Wajarri Yamatji and CSIRO, focusing on the educational and training aspects. Starting with "Wildflowers in the Sky" program in 2006 we have made extensive tours to all schools in the region providing teacher training and student engagement. More recently we have implemented a program where CSIRO Astronomy and Space Science staff visit the Pia Wadjarri Remote Community School, the closest school to the MRO, to mentor students. Students and staff from the school visit the MRO annually to explore the ASKAP telescope and see what is involved in its operation. An educational resource about ASKAP and astronomy that also incorporates traditional sky stories and local ecology is being trialled and developed. A cadetship and trainee program supporting Indigenous students has been implemented with the goal of providing employment opportunities and work skills in a diverse range of areas.

  12. Rationale for Isidis Planitia as a back-up landing site for the Mars Pathfinder mission

    NASA Technical Reports Server (NTRS)

    Craddock, Robert A.

    1994-01-01

    The present engineering constraints imposed on the Mars Pathfinder mission leave only three broad regions available for site selection: Amazonis, Chryse, and Isidis Planitia. Because of the knowledge gained by the Viking 1 mission, Chryse Planitia would make an ideal primary landing site. Geological characteristics of Isidis Planitia are discussed with a view to making it a back-up landing site.

  13. Optimal path-finding through mental exploration based on neural energy field gradients.

    PubMed

    Wang, Yihong; Wang, Rubin; Zhu, Yating

    2017-02-01

    Rodent animal can accomplish self-locating and path-finding task by forming a cognitive map in the hippocampus representing the environment. In the classical model of the cognitive map, the system (artificial animal) needs large amounts of physical exploration to study spatial environment to solve path-finding problems, which costs too much time and energy. Although Hopfield's mental exploration model makes up for the deficiency mentioned above, the path is still not efficient enough. Moreover, his model mainly focused on the artificial neural network, and clear physiological meanings has not been addressed. In this work, based on the concept of mental exploration, neural energy coding theory has been applied to the novel calculation model to solve the path-finding problem. Energy field is constructed on the basis of the firing power of place cell clusters, and the energy field gradient can be used in mental exploration to solve path-finding problems. The study shows that the new mental exploration model can efficiently find the optimal path, and present the learning process with biophysical meaning as well. We also analyzed the parameters of the model which affect the path efficiency. This new idea verifies the importance of place cell and synapse in spatial memory and proves that energy coding is effective to study cognitive activities. This may provide the theoretical basis for the neural dynamics mechanism of spatial memory.

  14. Uncoupling nicotine mediated motoneuron axonal pathfinding errors and muscle degeneration in zebrafish

    SciTech Connect

    Welsh, Lillian; Tanguay, Robert L.; Svoboda, Kurt R.

    2009-05-15

    Zebrafish embryos offer a unique opportunity to investigate the mechanisms by which nicotine exposure impacts early vertebrate development. Embryos exposed to nicotine become functionally paralyzed by 42 hpf suggesting that the neuromuscular system is compromised in exposed embryos. We previously demonstrated that secondary spinal motoneurons in nicotine-exposed embryos were delayed in development and that their axons made pathfinding errors (Svoboda, K.R., Vijayaraghaven, S., Tanguay, R.L., 2002. Nicotinic receptors mediate changes in spinal motoneuron development and axonal pathfinding in embryonic zebrafish exposed to nicotine. J. Neurosci. 22, 10731-10741). In that study, we did not consider the potential role that altered skeletal muscle development caused by nicotine exposure could play in contributing to the errors in spinal motoneuron axon pathfinding. In this study, we show that an alteration in skeletal muscle development occurs in tandem with alterations in spinal motoneuron development upon exposure to nicotine. The alteration in the muscle involves the binding of nicotine to the muscle-specific AChRs. The nicotine-induced alteration in muscle development does not occur in the zebrafish mutant (sofa potato, [sop]), which lacks muscle-specific AChRs. Even though muscle development is unaffected by nicotine exposure in sop mutants, motoneuron axonal pathfinding errors still occur in these mutants, indicating a direct effect of nicotine exposure on nervous system development.

  15. Characterization of the Martian Surface Deposits by the Mars Pathfinder Rover, Sojourner

    NASA Technical Reports Server (NTRS)

    Matijevic, J.

    1997-01-01

    Sojourner, the pathfinder rover, has discovered pebbles on the surface and in rocks that may be semidentary-not volcanic-in origin. Surface pebbles may have been rounded by Ares Flood Waters or liberated by weathering of sedimentary rocks called conglomerates.

  16. Mars Pathfinder Microrover: A Small, Low-Cost, Low-Power Spacecraft

    NASA Technical Reports Server (NTRS)

    Stone, H. W.

    1996-01-01

    This paper provides an overview of the design of the Mars Pathfinder Microrover with an emphasis on how its integrated design enables it to perform all of the functions normally associated with entire spacecraft. The impact that mass, volume, and power constraints have had upon the design will also be discussed.

  17. Morning Martian Atmospheric Temperature Gradients and Fluctuations Observed by Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Mihalov, John D.; Haberle, R. M.; Murphy, J. R.; Seiff, A.; Wilson, G. R.

    1999-01-01

    We have studied the most prominent atmospheric temperature fluctuations observed during Martian mornings by Mars Pathfinder and have concluded, based on comparisons with wind directions, that they appear to be a result of atmospheric heating associated with the Lander spacecraft. Also, we have examined the morning surface layer temperature lapse rates, which are found to decrease as autumn approaches at the Pathfinder location, and which have mean (and median) values as large as 7.3 K/m in the earlier portions of the Pathfinder landed mission. It is plausible that brief isolated periods with gradients twice as steep are associated with atmospheric heating adjacent to Lander air bag material. In addition, we have calculated the gradient with height of the structure function obtained with Mars Pathfinder, for Mars' atmospheric temperatures measured within about 1.3 m from the surface, assuming a power law dependence, and have found that these gradients superficially resemble those reported for the upper region of the terrestrial stable boundary layer.

  18. A Strategy to Characterize the LISA-Pathfinder Cold Gas Thruster System

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; Garcia Marirrodriga, C.; Gerndt, R.; Gesa, L. I.; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Mance, D.; Martin, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    The cold gas micro-propulsion system that will be used during the LISA-Pathfinder mission will be one of the most important component used to ensure the "free-fall" of the enclosed test masses. In this paper we present a possible strategy to characterize the effective direction and amplitude gain of each of the 6 thrusters of this system.

  19. Global Climate Change Pathfinder: A Guide to Information Resources. Second Edition.

    ERIC Educational Resources Information Center

    Pintozzi, Chestalene; Jones, Douglas E.

    This pathfinder is a guide to scientific and technical aspects of global climate change including meteorological and climatological aspects; biological, agricultural, and public policy implications; and the chemical processes involved. Sources are arranged by type of publication and include: (1) 10 reference sources; (2) 12 bibliographies; (3) 44…

  20. Space Technology 5: Pathfinder for Future Micro-Sat Constellations

    NASA Technical Reports Server (NTRS)

    Carlisle, Candace; Finnegan, Eric

    2004-01-01

    research-quality science. Each ST-5 spacecraft will deploy a precision magnetometer to be used both for attitude determination and as a representative science instrument. The spacecraft has been developed with a low magnetic signature to avoid interference with the magnetometer. The spacecraft will be able to detect and respond autonomously to science events, i.e. significant changes in the magnetic field measurements. The three spacecraft will be a pathfinder for future constellation missions. They will be deployed to demonstrate an appropriate geometry for scientific measurements as a constellation. They will be operationally managed as a constellation, demonstrating automation and communication strategies that will be useful for future missions. The technologies and future mission concepts will be validated both on the ground and in space. Technologies will be validated on the ground by a combination of component level and system level testing of the flight hardware in a thermal vacuum environment. In flight, specific validation runs are planned for each of the technologies. Each validation run consists of one or more orbits with a specific validation objective. This paper will describe the ST-5 mission, and the applicability of the NMP technologies, spacecraft, and mission concepts to future missions. It will also discuss the validation approach for the ST-5 technologies and mission concepts.

  1. Simulation and template generation for LISA Pathfinder Data Analysis

    NASA Astrophysics Data System (ADS)

    Rais, Boutheina; Grynagier, Adrien; Diaz-Aguiló, Marc; Armano, Michele

    The LISA PathFinder (LPF) mission is a technology demonstration mission which aims at testing a number of critical technical challenges that the future LISA (Gravitational wave detection in space) mission will face: LPF can be seen as a complex laboratory experiment in space. It is therefore critical to be able to define which measurements and which actuations will be applied during the scientific part of the mission. The LISA Technology Package (LTP), part of ESA's hardware contribution to LPF, outlines hence the importance of developing an appropriate simulation tool in order to test these strate-gies before launch and to analyse the dynamical behaviour of the system during the mission. The detailed model of the simulation can be used in an off-line mode for further planning: cor-rect estimation of timeline priorities, risk factors, duty cycles, data analysis readiness. The Lisa Technology Package Data Analysis (LTPDA) team has developed an object-oriented MATLAB toolbox for general case of data analysis needs. However, to meet specific needs of LPF mis-sion, a template generation tool has been developed. It provides a recognizable data pattern, avoiding the risk of missing the model during mission's analysis. The aim of the template generator tool is to provide tools to analyse LTP system modeled in State Space Model (SSM). The SSM class, the aim of this poster, includes this tools within the LTPDA toolbox. It can be used to generate the time-domain response for any given actuation and/or noise, the frequency response using bode diagrams and the steady state of the system. It allows the user to project noises on system outputs to get spectra of outputs for given input noises spectra. This class is sufficiently general to be used with a variety of systems once the SSM of the system is provided in the library. Furthermore, one of the main objectives of the data analysis for LPF (the estimation of different parameters of the system), can be achieved by a new

  2. Rock Abrasion on Mars: Clues from the Pathfinder and Viking Landing Sites

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Parker, T. J.; Kramer, G. M.

    2000-01-01

    A significant discovery of the Mars Pathfinder (MPF) mission was that many rocks exhibit characteristics of ventifacts, rocks that have been sculpted by saltating particles. Diagnostic features identifying the rocks as ventifacts am elongated pits, flutes, and grooves (collectively referred to as "flutes" unless noted otherwise). Faceted rocks or rock portions, circular pits, rills, and possibly polished rock surfaces are also seen and could be due, to aeolian abrasion. Many of these features were initially identified in rover images, where spatial resolution generally exceeded that of the IMP (Imager for Mars Pathfinder) camera. These images had two major limitations: 1) Only a limited number of rocks were viewed by the rover, biasing flute statistics; and 2) The higher resolution obtained by the rover images and the lack of such pictures at the Viking landing sites hampered comparisons of rock morphologies between the Pathfinder and Viking sites. To avoid this problem, rock morphology and ventifact statistics have been examined using new "super-resolution" IMP and Viking Lander images. Analyses of these images show that: 1) Flutes are seen on about 50% or more of the rocks in the near field at the MPF site; 2) The orientation of these flutes is similar to that for flutes identified in rover images; and 3) Ventifacts are significantly more abundant at the Pathfinder landing site than at the two Viking Landing sites, where rocks have undergone only a limited amount of aeolian abrasion. This is most likely due to the ruggedness of the Pathfinder site and a greater supply of abrading particles available shortly after the Arcs and Tiu Valles outflow channel floods.

  3. Australian helminths in Australian rodents: an issue of biodiversity.

    PubMed

    Warner, L R

    1998-06-01

    The Australian public as well as Australian funding bodies are generally unsympathetic to native murids, rats and mice, in spite of the fact that 36% have either become extinct or critically endangered since European settlement. The endemic Australian parasites of these rats and mice have been even less sympathetically regarded. Prior to 1958 very little work was carried out on the helminths of Australian rodents and little more is known today. Records are known from only 28% of the extant host species, comprising some 109 species of helminth identified at least to generic level. The rodents invaded Australia from the north, perhaps through New Guinea in at least two separate waves, 5-8 then about 1 million years ago. The parasites they brought with them have adapted and speciated and there has been some host switching between rodent groups and between rodents and the Australian marsupials. This is illustrated particularly in the Trichostrongyloidea. The origins of the rodents from Southeast Asia down the Indonesian island chain are reflected in the presence of the nematode genus Tikusnema in both Australia and Indonesia, and Cyclodontostomum purvisi across Southeast Asia and into New Guinea. Hydromys chrysogaster, the Australian water-rat, illustrates how the biogeographical influences of the host's distribution and lifestyle can affect its parasite fauna. Most of the research to date is merely indicative of where more data are needed. The links between Australian and New Guinean helminth fauna, as well as the links between rodent and marsupial hosts and their fauna, cannot be determined without further research.

  4. The Civic Mission of Australian Universities.

    ERIC Educational Resources Information Center

    Brown, Lawrence; Muirhead, Bruce

    2003-01-01

    Discusses the origins and meaning of civic responsibility in the Australian model of the university, beginning with medieval European universities and progressing through Australian reforms of the 20th century. Warns against the university without a civic mission. (SLD)

  5. The National Snow and Ice Data Center's Polar Pathfinder Sampler CD-ROM

    NASA Astrophysics Data System (ADS)

    Thrasher Hybl, T. L.; Khalsa, S. S.; Holm, M.

    2001-05-01

    The NOAA/NASA Pathfinder Program is designed to facilitate user access to earth science data sets which address global change concerns. The Polar Pathfinders, a subgroup of the Pathfinder Program, addresses the comparison of parameters from different data sets with a common projection (the NSIDC Equal-Area Scalable Earth-Grid (EASE-Grid)), file naming conventions, and validation conventions. This ensures that consistently processed data sets are available to the cryospheric science community, for comparing and contrasting. The National Snow and Ice Data Center (NSIDC) has produced a CD-ROM called, "Polar Pathfinder Sampler: Combined AVHRR, SMMR-SSM/I, and TOVS Time Series and Samples." This CD-ROM includes sample data, time-series visualizations, and browse products, for temporal and spatial subsets of the AVHRR, SMMR-SSM/I and TOVS data sets, to illustrate the types of products available for the various data sets. Also included on this CD-ROM is the P-Cube, a multidimensional structure combining arctic SSM/I, AVHRR and TOVS data. The data highlighted on this CD-ROM serve a wide range of polar climate research applications, but are of particular interest to researchers working on large-scale atmospheric changes, sea ice modeling, and surface heat and mass balance studies. AVHRR products for both hemispheres, at 1.25 and 5 km resolutions, include calibrated channel data, surface broadband albedo, surface temperature, and ancillary data so that users can apply algorithms of their choice to calculate albedo and surface temperature. SSM/I brightness temperature data and time files are included, in each of three projections: Northern and Southern Hemispheres and an equatorial cylindrical projection. TOVS parameters derived from arctic (poleward of 60 degrees north latitude) radiances include atmospheric temperature profiles, water vapor, surface temperature, total effective cloud fraction, cloud top pressure and temperature, turning angle between geostrophic wind and

  6. Correspondence and Least Squares Analyses of Soil and Rock Compositions for the Viking Lander 1 and Pathfinder Sites

    NASA Technical Reports Server (NTRS)

    Larsen, K. W.; Arvidson, R. E.; Jolliff, B. L.; Clark, B. C.

    2000-01-01

    Correspondence and Least Squares Mixing Analysis techniques are applied to the chemical composition of Viking 1 soils and Pathfinder rocks and soils. Implications for the parent composition of local and global materials are discussed.

  7. "English" in the "Australian Curriculum: English"

    ERIC Educational Resources Information Center

    Dixon, Robert

    2012-01-01

    This is the text of a paper given at the 2011 Symposium of the Australian Academy of the Humanities on the theme, "Educating the Nation: The Humanities in the New Australian Curriculum", the 42nd Annual Symposium of the Australian Academy of the Humanities at the University of Melbourne, 17 November 2011. It was presented in a session on…

  8. Embracing Babel: The "Framework for Australian Languages"

    ERIC Educational Resources Information Center

    Troy, Jaky; Walsh, Michael

    2013-01-01

    The Australian Curriculum, Assessment and Reporting Authority (ACARA) has been developing language-specific curricula for a range of languages in the "Australian Curriculum: Language"s and has also undertaken development of a "Framework for Australian Languages", to provide guidance for the development of curricula for specific…

  9. Changing Patterns of Governance for Australian Universities

    ERIC Educational Resources Information Center

    Harman, Kay; Treadgold, Elaine

    2007-01-01

    Dissatisfaction with the "corporate" model for university governance, a model advocated by both sides of the Australian parliament and adopted by Australian universities over the past two decades, prompted the Australian Vice-Chancellors' Committee (AVCC) in 2003 to suggest an alternative "trusteeship" model. The paper…

  10. An Analysis of Coupling between the x1 and x12 Interferometers for LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Howard, Brittany

    2017-01-01

    Due to tolerances in the manufacturing process, noise from the jittering of the spacecraft housing LISA Pathfinder (LPF) is appearing in the differential measurement between its two test masses (TM's). This phenomenon manifests as a small but measurable coupling between the readouts of LPF's two heterodyne interferometers, x1 and x12. In this study, two LISA Pathfinder experiments are analyzed using three methods in an effort to characterize and quantify the coupling as well as to potentially identify its source. The main question considered is this: does the coupling change with the absolute displacement between the TM's? As a result of this work, reliable values for coupling between LPF's x1 and x12 interferometers are found, and they are seen to depend on the absolute displacement between the test masses to some degree. Completed at the Albert Einstein Institute for Gravitational Physics under the International REU program from the University of Florida.

  11. Kolmogorov-Smirnov like test for time-frequency Fourier spectrogram analysis in LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Ferraioli, Luigi; Armano, Michele; Audley, Heather; Congedo, Giuseppe; Diepholz, Ingo; Gibert, Ferran; Hewitson, Martin; Hueller, Mauro; Karnesis, Nikolaos; Korsakova, Natalia; Nofrarias, Miquel; Plagnol, Eric; Vitale, Stefano

    2015-03-01

    A statistical procedure for the analysis of time-frequency noise maps is presented and applied to LISA Pathfinder mission synthetic data. The procedure is based on the Kolmogorov-Smirnov like test that is applied to the analysis of time-frequency noise maps produced with the spectrogram technique. The influence of the finite size windowing on the statistic of the test is calculated with a Monte Carlo simulation for 4 different windows type. Such calculation demonstrate that the test statistic is modified by the correlations introduced in the spectrum by the finite size of the window and by the correlations between different time bins originated by overlapping between windowed segments. The application of the test procedure to LISA Pathfinder data demonstrates the test capability of detecting non-stationary features in a noise time series that is simulating low frequency non-stationary noise in the system.

  12. DSMC Simulations of Blunt Body Flows for Mars Entries: Mars Pathfinder and Mars Microprobe Capsules

    NASA Technical Reports Server (NTRS)

    Moss, James N.; Wilmoth, Richard G.; Price, Joseph M.

    1997-01-01

    The hypersonic transitional flow aerodynamics of the Mars Pathfinder and Mars Microprobe capsules are simulated with the direct simulation Monte Carlo method. Calculations of axial, normal, and static pitching coefficients were obtained over an angle of attack range comparable to actual flight requirements. Comparisons are made with modified Newtonian and free-molecular-flow calculations. Aerothermal results were also obtained for zero incidence entry conditions.

  13. Indoor A* Pathfinding Through an Octree Representation of a Point Cloud

    NASA Astrophysics Data System (ADS)

    Rodenberg, O. B. P. M.; Verbree, E.; Zlatanova, S.

    2016-10-01

    There is a growing demand of 3D indoor pathfinding applications. Researched in the field of robotics during the last decades of the 20th century, these methods focussed on 2D navigation. Nowadays we would like to have the ability to help people navigate inside buildings or send a drone inside a building when this is too dangerous for people. What these examples have in common is that an object with a certain geometry needs to find an optimal collision free path between a start and goal point. This paper presents a new workflow for pathfinding through an octree representation of a point cloud. We applied the following steps: 1) the point cloud is processed so it fits best in an octree; 2) during the octree generation the interior empty nodes are filtered and further processed; 3) for each interior empty node the distance to the closest occupied node directly under it is computed; 4) a network graph is computed for all empty nodes; 5) the A* pathfinding algorithm is conducted. This workflow takes into account the connectivity for each node to all possible neighbours (face, edge and vertex and all sizes). Besides, a collision avoidance system is pre-processed in two steps: first, the clearance of each empty node is computed, and then the maximal crossing value between two empty neighbouring nodes is computed. The clearance is used to select interior empty nodes of appropriate size and the maximal crossing value is used to filter the network graph. Finally, both these datasets are used in A* pathfinding.

  14. Characterization of the Martian surface deposits by the Mars Pathfinder rover, Sojourner. Rover Team.

    PubMed

    1997-12-05

    Sojourner, the Mars Pathfinder rover, discovered pebbles on the surface and in rocks that may be sedimentary-not volcanic-in origin. Surface pebbles may have been rounded by Ares flood waters or liberated by weathering of sedimentary rocks called conglomerates. Conglomerates imply that water existed elsewhere and earlier than the Ares flood. Most soil-like deposits are similar to moderately dense soils on Earth. Small amounts of dust are currently settling from the atmosphere.

  15. The Results of Dynamic Data Acquisition During Mars Pathfinder Prototype Airbag Drop Testing

    NASA Technical Reports Server (NTRS)

    Davis, Gregory L.

    1996-01-01

    The Mars Pathfinder mission, scheduled for launch in December 1996, will use an airbag system to safely deliver a lander to the Martian surface.The airbag landing system has undergone a comprehensive test program during its evolution from initial design phase to final qualification and acceptance testing. This paper outlines the test approach used in the airbag development program, describes the data acquisition system used to obtain and evaluate airbag performance data, and presents test results.

  16. Second Languages and Australian Schooling. Australian Education Review No. 54

    ERIC Educational Resources Information Center

    Lo Bianco, Joseph

    2009-01-01

    It is an underlying principle of Australian Education Review (AER) 54 that active efforts should be made to cultivate the latent bilingual potential within Australia's wider population and that this should be linked to major improvements in the quality of language teaching in schools. A combined approach of this kind will require investment in…

  17. Improving Bayesian analysis for LISA Pathfinder using an efficient Markov Chain Monte Carlo method

    NASA Astrophysics Data System (ADS)

    Ferraioli, Luigi; Porter, Edward K.; Armano, Michele; Audley, Heather; Congedo, Giuseppe; Diepholz, Ingo; Gibert, Ferran; Hewitson, Martin; Hueller, Mauro; Karnesis, Nikolaos; Korsakova, Natalia; Nofrarias, Miquel; Plagnol, Eric; Vitale, Stefano

    2014-02-01

    We present a parameter estimation procedure based on a Bayesian framework by applying a Markov Chain Monte Carlo algorithm to the calibration of the dynamical parameters of the LISA Pathfinder satellite. The method is based on the Metropolis-Hastings algorithm and a two-stage annealing treatment in order to ensure an effective exploration of the parameter space at the beginning of the chain. We compare two versions of the algorithm with an application to a LISA Pathfinder data analysis problem. The two algorithms share the same heating strategy but with one moving in coordinate directions using proposals from a multivariate Gaussian distribution, while the other uses the natural logarithm of some parameters and proposes jumps in the eigen-space of the Fisher Information matrix. The algorithm proposing jumps in the eigen-space of the Fisher Information matrix demonstrates a higher acceptance rate and a slightly better convergence towards the equilibrium parameter distributions in the application to LISA Pathfinder data. For this experiment, we return parameter values that are all within ˜1 σ of the injected values. When we analyse the accuracy of our parameter estimation in terms of the effect they have on the force-per-unit of mass noise, we find that the induced errors are three orders of magnitude less than the expected experimental uncertainty in the power spectral density.

  18. The Ultraviolet Spectro-Coronagraph Pathfinder Mission for the Detection of Coronal Suprathermal Seed Particles

    NASA Astrophysics Data System (ADS)

    Strachan, Leonard; Laming, J. Martin; Ko, Yuan-Kuen; Korendyke, Clarence M.; Tun Beltran, Samuel; Socker, Dennis G.; Brown, Charles; Provornikova, Elena

    2016-05-01

    The Ultraviolet Spectro-Coronagraph (UVSC) Pathfinder is a Naval Research Laboratory experiment designed to make the first detection of suprathermal seed particles close to the Sun. It uses an innovative “stacked” occulting system to significantly increase the effective light gathering power of a traditional, 1-meter length, externally occulted coronagraph. The external occultation in combination with a low scatter variable line spaced grating provide the stray light suppression needed to measure non-Maxwellian departures in the wings of the H Lyman alpha emission line profile. After the removal of other factors, these departures may be interpreted as the signature of suprathermal tails of the proton velocity distribution in the corona. UVSC Pathfinder will provide information on the origins and spatial/temporal variability of proton seed particle populations. We will discuss the accuracy needed to make such measurements and describe how the results can be used to develop a capability for predicting the onset of Solar Energetic Particle (SEP) storms. The experiment is scheduled for a launch by the DoD Space Test Program in late 2018/early 2019 and should have excellent overlap with the Solar Orbiter and Solar Probe Plus missions.UVSC Pathfinder is supported by funds from the Chief of Naval Research (via the NRL basic research program) and from NASA (via NDPR NNG13WF951 and NNH16AC29I).

  19. 'SOJOURNER,' MARS PATHFINDERS' SMALL ROVER UNPACKED AND RECEIVING INSPECTION IN SAEF-2

    NASA Technical Reports Server (NTRS)

    1996-01-01

    In the Spacecraft Assembly and Encapsulation Facility-2 (SAEF-2), the small rover for the Mars Pathfinder mission has been unpacked from its shipping container and is undergoing inspections. Called Sojourner, this compact, semi-autonomous six-wheeler will become the first vehicle to traverse the surface of Mars. Weighing just 22 pounds (10 kilograms) it will travel to the Red Planet inside the Mars Pathfinder lander. When fully deployed, the rover reaches about 11 inches (280 millimeters) in height, and is about 25 inches (630 mm) long by about 19 inches (480 mm) wide. Sojourner is expected to explore the Martian surface for a minimum of seven days, collecting data about soil and rock composition, and transmitting images of the terrain as well as of the lander itself. Micro-rover technology also will be demonstrated by the solar-powered Sojourner. The Mars Pathfinder is scheduled for liftoff aboard a Delta II expendable launch vehicle at the beginning of a 24-day launch period opening Dec. 2.

  20. Overview of the development of the pathfinder ultra-long duration balloon system

    NASA Astrophysics Data System (ADS)

    Said, Magdi A.; Stuchlik, David; Corbin, Brian; Smolinski, Michael; Abresch, Brian; Shreves, Christopher; Stancil, Robert; Cathey, Henry M.; Cannon, Scott

    2004-01-01

    The ultra-long duration balloon (ULDB) Pathfinder Project is developing a small pumpkin balloon system and a new communication package based on the iridium satellites technology to demonstrate a global, 100-day duration capability that is scalable to the full-scale ULDB. A set of trade studies has been conducted to determine the volume, mass and cost of the balloon system to support up to 90 kg payload mass to an altitude of 35 km. The Pathfinder test balloons will provide valuable data in the development of performance models for future ULDB flights. The iridium based communication package will include a power subsystem, a command and data-handling unit, a GPS receiver, and an iridium L-Band Transceiver (LBT) for global communications. The flight data will include, at a minimum: latitude, longitude, altitude, horizontal and vertical speeds, heading, time, and other balloon performance parameters (i.e., system voltages, temperatures, etc.). Although the system will be designed for global launch capability, initial flights will be launched from the proposed full-scale ULDB mission launch locations. This paper will present and discuss the initial series of trade studies conducted for the development of the pathfinder balloon and the design concept of the iridium based communication package.

  1. Atmosphere Processing Module Automation and Catalyst Durability Analysis for Mars ISRU Pathfinder

    NASA Technical Reports Server (NTRS)

    Petersen, Elspeth M.

    2016-01-01

    The Mars In-Situ Resource Utilization Pathfinder was designed to create fuel using components found in the planet’s atmosphere and regolith for an ascension vehicle to return a potential sample return or crew return vehicle from Mars. The Atmosphere Processing Module (APM), a subunit of the pathfinder, uses cryocoolers to isolate and collect carbon dioxide from Mars simulant gas. The carbon dioxide is fed with hydrogen into a Sabatier reactor where methane is produced. The APM is currently undergoing the final stages of testing at Kennedy Space Center prior to process integration testing with the other subunits of the pathfinder. The automation software for the APM cryocoolers was tested and found to perform nominally. The catalyst used for the Sabatier reactor was investigated to determine the factors contributing to catalyst failure. The results from the catalyst testing require further analysis, but it appears that the rapid change in temperature during reactor start up or the elevated operating temperature is responsible for the changes observed in the catalyst.

  2. Promoting Leadership in Australian Universities

    ERIC Educational Resources Information Center

    Bradley, Andrew P.; Grice, Tim; Paulsen, Neil

    2017-01-01

    In this paper we review current practices for developing and promoting academic leadership in universities. We consider the forms of leadership that are appropriate for academic organisations, while exploring the types of leadership favoured by recruitment and promotion committees. Using the Australian higher education context as a case study, we…

  3. Australian Circuses as Cooperative Communities.

    ERIC Educational Resources Information Center

    Moriarty, Beverley J.

    2000-01-01

    Studied how circus personnel of all ages interact in Australian circuses to preserve traditional circus lifestyles and entertainment. Interviews with 30 personnel from 4 circuses show the importance of learning to be a member of a cooperative society through immersion. Results provide information about the education of a community of occupational…

  4. Arabic in Australian Islamic Schools.

    ERIC Educational Resources Information Center

    Hall, Michael

    1996-01-01

    Presents census data on the Muslim population in Australia and overviews full-time independent Islamic schools offering a comprehensive education across the curriculum. Argues that these schools offer great potential for the successful development of Arabic language and cultural literacy skills required by Australian exporters and diplomats in the…

  5. The Spirituality of Young Australians

    ERIC Educational Resources Information Center

    Mason, Michael; Singleton, Andrew; Webber, Ruth

    2007-01-01

    A research project conducted in 2003-2006, the Spirit of Generation Y, using both extended interviews and a nationwide survey, revealed three main strands in the spirituality of young Australians: traditional, alternative and humanist. Their involvement in traditional religions was declining, like that of their parents, and although some adopted…

  6. The 2005 Australian Informatics Competition

    ERIC Educational Resources Information Center

    Clark, David

    2006-01-01

    This article describes the Australian Informatics Competition (AIC), a non-programming competition aimed at identifying students with potential in programming and algorithmic design. It is the first step in identifying students to represent Australia at the International Olympiad in Informatics. The main aim of the AIC is to increase awareness of…

  7. Catalogue of Australian Cynipoidea (Hymenoptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A catalogue of all families, subfamilies, genera, and species of Cynipoidea present in Australia is presented here. The Australian cynipoid fauna is very poorly known, with 37 genera cited: one each for Austrocynipidae, Ibaliidae, Liopteridae, two for Cynipidae, and 32 for Figitidae. The first Austr...

  8. Stress Literacy in Australian Adolescents

    ERIC Educational Resources Information Center

    Varlow, Megan; Wuthrich, Viviana; Murrihy, Rachael; Remond, Louise; Tuqiri, Rebekka; van Kessel, Jacobine; Wheatley, Anna; Dedousis-Wallace, Anna; Kidman, Antony

    2009-01-01

    Stress literacy is a term that refers to knowledge about stress and stress management techniques. Levels of stress literacy were examined in more than nine hundred Australian adolescents by providing a short stress-management education session and assessing stress literacy using a pre-post survey design. It was found that while adolescents had a…

  9. Staff Bullying in Australian Schools

    ERIC Educational Resources Information Center

    Riley, Dan; Duncan, Deirdre J.; Edwards, John

    2011-01-01

    Purpose: The purpose of this paper is to estimate the prevalence of staff bullying in Australian schools, to identify bullies and targets and to examine some implications for school leaders in dealing with staff bullying. Design/methodology/approach: The quantitative research design survey instrument contained 11 demographic items, 44 questions of…

  10. Skills Gaps in Australian Firms

    ERIC Educational Resources Information Center

    Lindorff, Margaret

    2011-01-01

    This paper reports the results of a survey of more than 2000 managers examining perceptions of skills gaps in a range of Australian firms. It finds that three quarters report a skills gap, and almost one third report skills gaps across the whole organisation. Firm size and industry differences exist in perceptions of the effect of the skills gap…

  11. Big Ideas for Australian Universities

    ERIC Educational Resources Information Center

    Schwartz, Steven

    2009-01-01

    Within weeks of taking office, Australia's new Labor government commissioned two major reviews--one of Australia's innovation system and one of Australian higher education. Taken together, these reviews will have major implications for the future of research and teaching in Australia for decades to come. This paper discusses the main…

  12. Future X Pathfinder: Quick, Low Cost Flight Testing for Tomorrow's Launch Vehicles

    NASA Technical Reports Server (NTRS)

    London, John, III; Sumrall, Phil

    1999-01-01

    The DC-X and DC-XA Single Stage Technology flight program demonstrated the value of low cost rapid prototyping and flight testing of launch vehicle technology testbeds. NASA is continuing this important legacy through a program referred to as Future-X Pathfinder. This program is designed to field flight vehicle projects that cost around $100M each, with a new vehicle flying about every two years. Each vehicle project will develop and extensively flight test a launch vehicle technology testbed that will advance the state of the art in technologies directly relevant to future space transportation systems. There are currently two experimental, or "X" vehicle projects in the Pathfinder program, with additional projects expected to follow in the near future. The first Pathfinder project is X-34. X-34 is a suborbital rocket plane capable of flights to Mach 8 and 75 kilometers altitude. There are a number of reusable launch vehicle technologies embedded in the X-34 vehicle design, such as composite structures and propellant tanks, and advanced reusable thermal protection systems. In addition, X-34 is designed to carry experiments applicable to both the launch vehicle and hypersonic aeronautics community. X-34 is scheduled to fly later this year. The second Pathfinder project is the X-37. X-37 is an orbital space plane that is carried into orbit either by the Space Shuttle or by an expendable launch vehicle. X-37 provides NASA access to the orbital and orbital reentry flight regimes with an experimental testbed vehicle. The vehicle will expose embedded and carry-on advanced space transportation technologies to the extreme environments of orbit and reentry. Early atmospheric approach and landing tests of an unpowered version of the X-37 will begin next year, with orbital flights beginning in late 2001. Future-X Pathfinder is charting a course for the future with its growing fleet of low-cost X- vehicles. X-34 and X-37 are leading the assault on high launch costs and

  13. Funding emergency care: Australian style.

    PubMed

    Bell, Anthony; Crilly, Julia; Williams, Ged; Wylie, Kate; Toloo, Ghasem Sam; Burke, John; FitzGerald, Gerry

    2014-08-01

    The ongoing challenge for ED leaders is to remain abreast of system-wide changes that impact on the day-to-day management of their departments. Changes to the funding model creates another layer of complexity and this introductory paper serves as the beginning of a discussion about the way in which EDs are funded and how this can and will impact on business decisions, models of care and resource allocation within Australian EDs. Furthermore it is evident that any funding model today will mature and change with time, and moves are afoot to refine and contextualise ED funding over the medium term. This perspective seeks to provide a basis of understanding for our current and future funding arrangements in Australian EDs.

  14. [Australian short-beaked echidna].

    PubMed

    Rismiller, P

    1995-12-01

    The Australian short-beaked echidna, a monotreme, is one of the oldest living mammals on earth. It is recorded to be the most widely distributed native mammal on the island continent and classed as 'common'. Yet, little is known about its natural history and biology in the wild. What science has learned about the echidna in the past 200 years and why there are still large gaps is reported here.

  15. Meteors in Australian Aboriginal Dreamings

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.; Norris, Ray P.

    2010-06-01

    We present a comprehensive analysis of Australian Aboriginal accounts of meteors. The data used were taken from anthropological and ethnographic literature describing oral traditions, ceremonies, and Dreamings of 97 Aboriginal groups representing all states of modern Australia. This revealed common themes in the way meteors were viewed between Aboriginal groups, focusing on supernatural events, death, omens, and war. The presence of such themes around Australia was probably due to the unpredictable nature of meteors in an otherwise well-ordered cosmos.

  16. Policy: Australian astronomy looks forward

    NASA Astrophysics Data System (ADS)

    Bhathal, Ragbir

    2005-12-01

    Over the next decade, a new generation of instruments will come into being for the benefit of astronomers across the world. Australian astronomers hope to build on their strong astronomical heritage and continue to take part in astronomy at the highest international level. To this end, they have prepared a Decadal Plan that envisages building, with international partners, a world-class radio telescope, greater invovlement with 8 metre telescopes, as well as making the most of the Antarctic opportunities that Australia offers.

  17. Australian Defence Force Demographic Data and Challenges

    DTIC Science & Technology

    2001-10-01

    AUSTRALIAN DEFENCE FORCE DEMOGRAPHIC DATA AND CHALLENGES Directorate of Strategic Personnel Planning and Research DSPPR Technical Note 10/2001...DATE 00 OCT 2001 2. REPORT TYPE N/A 3. DATES COVERED - 4. TITLE AND SUBTITLE Australian Defence Force Demographic Data and Challenges 5a...Prescribed by ANSI Std Z39-18 AUSTRALIAN DEFENCE FORCE DEMOGRAPHIC DATA AND CHALLENGES The findings and views expressed in this report are the results

  18. The Politics Are Personal: "The Australian" vs the Australian Curriculum in History

    ERIC Educational Resources Information Center

    Taylor, Tony; Collins, Sue

    2012-01-01

    This article reviews the relationship between the conservative newspaper "The Australian" and the development of a national history curriculum in Australia. The lead author surveyed the major Australian press in the five-year period between 2007 and 2012 and found clear patterns of difference between "The Australian" and other…

  19. The Australian Science Facilities Program: A Study of Its Influence on Science Education in Australian Schools.

    ERIC Educational Resources Information Center

    Ainley, John G.

    This report is a study conducted by the Australian Council for Educational Research to evaluate the influence of science material resources, provided under the Australian Science Facilities Program, on science education in Australia. Under the Australian Science Facilities Program some $123 million was spent, between July 1964 and June 1975, on…

  20. Free-Suspension Residual Flexibility Testing of Space Station Pathfinder: Comparison to Fixed-Base Results

    NASA Technical Reports Server (NTRS)

    Tinker, Michael L.

    1998-01-01

    Application of the free-suspension residual flexibility modal test method to the International Space Station Pathfinder structure is described. The Pathfinder, a large structure of the general size and weight of Space Station module elements, was also tested in a large fixed-base fixture to simulate Shuttle Orbiter payload constraints. After correlation of the Pathfinder finite element model to residual flexibility test data, the model was coupled to a fixture model, and constrained modes and frequencies were compared to fixed-base test. modes. The residual flexibility model compared very favorably to results of the fixed-base test. This is the first known direct comparison of free-suspension residual flexibility and fixed-base test results for a large structure. The model correlation approach used by the author for residual flexibility data is presented. Frequency response functions (FRF) for the regions of the structure that interface with the environment (a test fixture or another structure) are shown to be the primary tools for model correlation that distinguish or characterize the residual flexibility approach. A number of critical issues related to use of the structure interface FRF for correlating the model are then identified and discussed, including (1) the requirement of prominent stiffness lines, (2) overcoming problems with measurement noise which makes the antiresonances or minima in the functions difficult to identify, and (3) the use of interface stiffness and lumped mass perturbations to bring the analytical responses into agreement with test data. It is shown that good comparison of analytical-to-experimental FRF is the key to obtaining good agreement of the residual flexibility values.

  1. EOF analysis of long-term reconstructed AVHRR Pathfinder SST in the South China Sea

    NASA Astrophysics Data System (ADS)

    Huynh, Hong-Ngu T.; Alvera-Azcárate, Aida; Barth, Alexander; Beckers, Jean-Marie

    2014-05-01

    Sea surface temperature (SST) is one of the key variables often used to investigate ocean dynamics, ocean-atmosphere interaction, and climate change. For recent decades, the AVHRR Pathfinder SST, measured by infrared sensors, has been widely used because of its high resolution and long time-series. The disadvantage of the AVHRR Pathfinder SST is high percentage of missing data due to cloud coverage. This becomes more serious in the South China Sea (SCS) because it is located in the tropical region, frequently covered by clouds. In this study, we used the Data INterpolating Empirical Orthogonal Functions (DINEOF) method to reconstruct daily night-time 4 km AVHRR Pathfinder SST spanning from 1989 to 2009 for the whole SCS. In order to better understand the spatial and temporal variability of the SCS SST, an EOF analysis of the reconstructed field is performed in association with surface wind. The first SST mode, accounting for 69% of the variance, presents the cooling (warming) of the basin due to the solar inclination through seasons, water exchange, topography, and monsoon-induced cyclonic circulation. The second SST mode, explaining 24.8% of the variance, shows the advection of cold and warm water from two opposite directions along the southwest-northeast diagonal of the basin. The second SST mode is affected by the atmospheric anticyclone (cyclone) located over the Philippine Sea. Comparing both SST modes with Nino3.0 index, it shows that the interannual variability of the SCS SST is influenced by the moderate and strong ENSO events with a lag of 5-6 months. Moreover, the analysis of the high-resolution reconstructed dataset reveals some oceanic features that could not be captured in the previous EOF analyses.

  2. A simple neural network model of the hippocampus suggesting its pathfinding role in episodic memory retrieval.

    PubMed

    Samsonovich, Alexei V; Ascoli, Giorgio A

    2005-01-01

    The goal of this work is to extend the theoretical understanding of the relationship between hippocampal spatial and memory functions to the level of neurophysiological mechanisms underlying spatial navigation and episodic memory retrieval. The proposed unifying theory describes both phenomena within a unique framework, as based on one and the same pathfinding function of the hippocampus. We propose a mechanism of reconstruction of the context of experience involving a search for a nearly shortest path in the space of remembered contexts. To analyze this concept in detail, we define a simple connectionist model consistent with available rodent and human neurophysiological data. Numerical study of the model begins with the spatial domain as a simple analogy for more complex phenomena. It is demonstrated how a nearly shortest path is quickly found in a familiar environment. We prove numerically that associative learning during sharp waves can account for the necessary properties of hippocampal place cells. Computational study of the model is extended to other cognitive paradigms, with the main focus on episodic memory retrieval. We show that the ability to find a correct path may be vital for successful retrieval. The model robustly exhibits the pathfinding capacity within a wide range of several factors, including its memory load (up to 30,000 abstract contexts), the number of episodes that become associated with potential target contexts, and the level of dynamical noise. We offer several testable critical predictions in both spatial and memory domains to validate the theory. Our results suggest that (1) the pathfinding function of the hippocampus, in addition to its associative and memory indexing functions, may be vital for retrieval of certain episodic memories, and (2) the hippocampal spatial navigation function could be a precursor of its memory function.

  3. A simple neural network model of the hippocampus suggesting its pathfinding role in episodic memory retrieval

    PubMed Central

    Samsonovich, Alexei V.; Ascoli, Giorgio A.

    2005-01-01

    The goal of this work is to extend the theoretical understanding of the relationship between hippocampal spatial and memory functions to the level of neurophysiological mechanisms underlying spatial navigation and episodic memory retrieval. The proposed unifying theory describes both phenomena within a unique framework, as based on one and the same pathfinding function of the hippocampus. We propose a mechanism of reconstruction of the context of experience involving a search for a nearly shortest path in the space of remembered contexts. To analyze this concept in detail, we define a simple connectionist model consistent with available rodent and human neurophysiological data. Numerical study of the model begins with the spatial domain as a simple analogy for more complex phenomena. It is demonstrated how a nearly shortest path is quickly found in a familiar environment. We prove numerically that associative learning during sharp waves can account for the necessary properties of hippocampal place cells. Computational study of the model is extended to other cognitive paradigms, with the main focus on episodic memory retrieval. We show that the ability to find a correct path may be vital for successful retrieval. The model robustly exhibits the pathfinding capacity within a wide range of several factors, including its memory load (up to 30,000 abstract contexts), the number of episodes that become associated with potential target contexts, and the level of dynamical noise. We offer several testable critical predictions in both spatial and memory domains to validate the theory. Our results suggest that (1) the pathfinding function of the hippocampus, in addition to its associative and memory indexing functions, may be vital for retrieval of certain episodic memories, and (2) the hippocampal spatial navigation function could be a precursor of its memory function. PMID:15774943

  4. Mineralogy, Abundance, and Hydration State of Sulfates and Chlorides at the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Zolotov, M. Y.; Kuzmin, R. O.; Shock, E. L.

    2004-01-01

    Detection of elevated concentrations of S and Cl at the landing sites of Viking 1 and 2 [1], and Mars Pathfinder (MP) [2-5] reveals the presence of sulfates and chlorides in soil and rock samples [1-10]. These data are consistent with the findings of Ca sulfates and NaCl in Martian meteorites [11,12], and with Earth-based spectroscopic observations [13,14] tentatively indicating the presence of sulfates on Mars. Although the correlation of S and Mg in Viking and MP samples could reveal the occurrence of Mg sulfate [1-10], the mineralogy of sulfates and chlorides remains unclear.

  5. Multistate network model for the pathfinding problem with a self-recovery property.

    PubMed

    Ueda, Kei-Ichi; Yadome, Masaaki; Nishiura, Yasumasa

    2015-02-01

    In this study, we propose a continuous model for a pathfinding system. We consider acyclic graphs whose vertices are connected by unidirectional edges. The proposed model autonomously finds a path connecting two specified vertices, and the path is represented by a stable solution of the proposed model. The system has a self-recovery property, i.e., the system can find a path when one of the connections in the existing path is suddenly terminated. Further, we demonstrate that the appropriate installation of inhibitory interaction improves the search time.

  6. Towards a Framework for Generating Tests to Satisfy Complex Code Coverage in Java Pathfinder

    NASA Technical Reports Server (NTRS)

    Staats, Matt

    2009-01-01

    We present work on a prototype tool based on the JavaPathfinder (JPF) model checker for automatically generating tests satisfying the MC/DC code coverage criterion. Using the Eclipse IDE, developers and testers can quickly instrument Java source code with JPF annotations covering all MC/DC coverage obligations, and JPF can then be used to automatically generate tests that satisfy these obligations. The prototype extension to JPF enables various tasks useful in automatic test generation to be performed, such as test suite reduction and execution of generated tests.

  7. Geologic Measurements using Rover Images: Lessons from Pathfinder with Application to Mars 2001

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Haldemann, A. F. C.; Herkenhoff, K. E.

    1999-01-01

    The Pathfinder Sojourner rover successfully acquired images that provided important and exciting information on the geology of Mars. This included the documentation of rock textures, barchan dunes, soil crusts, wind tails, and ventifacts. It is expected that the Marie Curie rover cameras will also successfully return important information on landing site geology. Critical to a proper analysis of these images will be a rigorous determination of rover location and orientation. Here, the methods that were used to compute rover position for Sojourner image analysis are reviewed. Based on this experience, specific recommendations are made that should improve this process on the '01 mission.

  8. Interior structure and seasonal mass redistribution of Mars from radio tracking of Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Yoder, C. F.; Yuan, D. N.; Standish, E. M.; Preston, R. A.

    1997-01-01

    Doppler and range measurements to the Mars Pathfinder lander made using its radio communications system have been combined with similar measurements from the Viking landers to estimate improved values of the precession of Mars' pole of rotation and the variation in Mars' rotation rate. The observed precession of -7576 +/- 35 milliarc seconds of angle per year implies a dense core and constrains possible models of interior composition. The estimated annual variation in rotation is in good agreement with a model of seasonal mass exchange of carbon dioxide between the atmosphere and ice caps.

  9. Interior structure and seasonal mass redistribution of Mars from radio tracking of Mars Pathfinder.

    PubMed

    Folkner, W M; Yoder, C F; Yuan, D N; Standish, E M; Preston, R A

    1997-12-05

    Doppler and range measurements to the Mars Pathfinder lander made using its radio communications system have been combined with similar measurements from the Viking landers to estimate improved values of the precession of Mars' pole of rotation and the variation in Mars' rotation rate. The observed precession of -7576 +/- 35 milliarc seconds of angle per year implies a dense core and constrains possible models of interior composition. The estimated annual variation in rotation is in good agreement with a model of seasonal mass exchange of carbon dioxide between the atmosphere and ice caps.

  10. Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) Spacecraft: Independent Technical Assessment

    NASA Technical Reports Server (NTRS)

    Gilbrech, Richard J.; McManamen, John P.; Wilson, Timmy R.; Robinson, Frank; Schoren, William R.

    2005-01-01

    CALIPSO is a joint science mission between the CNES, LaRC and GSFC. It was selected as an Earth System Science Pathfinder satellite mission in December 1998 to address the role of clouds and aerosols in the Earth's radiation budget. The spacecraft includes a NASA light detecting and ranging (LIDAR) instrument, a NASA wide-field camera and a CNES imaging infrared radiometer. The scope of this effort was a review of the Proteus propulsion bus design and an assessment of the potential for personnel exposure to hydrazine propellant.

  11. Cloud-Aerosol LIDAR and Infrared Pathfinder Satellite Observation (CALIPSO) Spacecraft: Independent Technical Assessment

    NASA Technical Reports Server (NTRS)

    Gilbrech, Richard J.; McManamen, John P.; Wilson, Timmy R.; Robinson, Frank; Schoren, William R.

    2004-01-01

    CALIPSO is a joint science mission between the CNES, LaRC and GSFC. It was selected as an Earth System Science Pathfinder satellite mission in December 1998 to address the role of clouds and aerosols in the Earth's radiation budget. The spacecraft includes a NASA light detecting and ranging (LIDAR) instrument, a NASA wide-field camera and a CNES imaging infrared radiometer. The scope of this effort was a review of the Proteus propulsion bus design and an assessment of the potential for personnel exposure to hydrazine propellant.

  12. BAG: A code for predicting the performance of a gas bag impact attenuation system for the PATHFINDER lander

    SciTech Connect

    Cole, J.K.; Waye, D.E.

    1993-11-01

    The National Aeronautics and Space Administration (NASA) is planning to launch a network of scientific probes to Mars beginning in late 1996. The precursor to this network will be PATHFINDER. Decelerating PATHFINDER from the high speed of its approach to Mars will require the use of several deceleration techniques working in series. The Jet Propulsion Laboratory (JPL) has proposed that gas bags be used to cushion the payload`s ground impact on Mars. This report presents the computer code, BAG, which has been developed to calculate the pneumatic performance of gas bag impact attenuators and the one-dimensional rigid-body dynamic performance of a payload during ground impact.

  13. Neural network interpolation of the magnetic field for the LISA Pathfinder Diagnostics Subsystem

    NASA Astrophysics Data System (ADS)

    Diaz-Aguilo, Marc; Lobo, Alberto; García-Berro, Enrique

    2011-05-01

    LISA Pathfinder is a science and technology demonstrator of the European Space Agency within the framework of its LISA mission, which aims to be the first space-borne gravitational wave observatory. The payload of LISA Pathfinder is the so-called LISA Technology Package, which is designed to measure relative accelerations between two test masses in nominal free fall. Its disturbances are monitored and dealt by the diagnostics subsystem. This subsystem consists of several modules, and one of these is the magnetic diagnostics system, which includes a set of four tri-axial fluxgate magnetometers, intended to measure with high precision the magnetic field at the positions of the test masses. However, since the magnetometers are located far from the positions of the test masses, the magnetic field at their positions must be interpolated. It has been recently shown that because there are not enough magnetic channels, classical interpolation methods fail to derive reliable measurements at the positions of the test masses, while neural network interpolation can provide the required measurements at the desired accuracy. In this paper we expand these studies and we assess the reliability and robustness of the neural network interpolation scheme for variations of the locations and possible offsets of the magnetometers, as well as for changes in environmental conditions. We find that neural networks are robust enough to derive accurate measurements of the magnetic field at the positions of the test masses in most circumstances.

  14. Expansion of the piriform cortex contributes to corticothalamic pathfinding defects in Gli3 conditional mutants.

    PubMed

    Amaniti, Eleni-Maria; Fu, Chaoying; Lewis, Sean; Saisana, Marina; Magnani, Dario; Mason, John O; Theil, Thomas

    2015-02-01

    The corticothalamic and thalamocortical tracts play essential roles in the communication between the cortex and thalamus. During development, axons forming these tracts have to follow a complex path to reach their target areas. While much attention has been paid to the mechanisms regulating their passage through the ventral telencephalon, very little is known about how the developing cortex contributes to corticothalamic/thalamocortical tract formation. Gli3 encodes a zinc finger transcription factor widely expressed in telencephalic progenitors which has important roles in corticothalamic and thalamocortical pathfinding. Here, we conditionally inactivated Gli3 in dorsal telencephalic progenitors to determine its role in corticothalamic tract formation. In Emx1Cre;Gli3(fl/fl) mutants, only a few corticothalamic axons enter the striatum in a restricted dorsal domain. This restricted entry correlates with a medial expansion of the piriform cortex. Transplantation experiments showed that the expanded piriform cortex repels corticofugal axons. Moreover, expression of Sema5B, a chemorepellent for corticofugal axons produced by the piriform cortex, is similarly expanded. Finally, time course analysis revealed an expansion of the ventral pallial progenitor domain which gives rise to the piriform cortex. Hence, control of lateral cortical development by Gli3 at the progenitor level is crucial for corticothalamic pathfinding.

  15. Visualizing Mars Using Virtual Reality: A State of the Art Mapping Technique Used on Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Stoker, C.; Zbinden, E.; Blackmon, T.; Nguyen, L.

    1999-01-01

    We describe an interactive terrain visualization system which rapidly generates and interactively displays photorealistic three-dimensional (3-D) models produced from stereo images. This product, first demonstrated in Mars Pathfinder, is interactive, 3-D, and can be viewed in an immersive display which qualifies it for the name Virtual Reality (VR). The use of this technology on Mars Pathfinder was the first use of VR for geologic analysis. A primary benefit of using VR to display geologic information is that it provides an improved perception of depth and spatial layout of the remote site. The VR aspect of the display allows an operator to move freely in the environment, unconstrained by the physical limitations of the perspective from which the data were acquired. Virtual Reality offers a way to archive and retrieve information in a way that is intuitively obvious. Combining VR models with stereo display systems can give the user a sense of presence at the remote location. The capability, to interactively perform measurements from within the VR model offers unprecedented ease in performing operations that are normally time consuming and difficult using other techniques. Thus, Virtual Reality can be a powerful a cartographic tool. Additional information is contained in the original extended abstract.

  16. LISA Pathfinder Discharge Working Group: Activities, Results, and Lessons Learned for LISA/NGO

    NASA Astrophysics Data System (ADS)

    Ziegler, T.; Bergner, P.; Hechenblaikner, G.; Brandt, N.

    2013-01-01

    In 2011, the European Space Agency (ESA) entrusted Astrium GmbH to identify the root cause and corrective measures for the shortcomings of the LISA Pathfinder discharge system baseline that were identified during the system level testing in the torsion pendulum at the University of Trento. The main goal was to maximize the discharge system robustness under the given constraint to minimize the impact on manufacturing and the AIT process of the existing flight hardware. Astrium GmbH set-up a dedicated discharge working group (DWG) for 9 months, bringing together the expertise of surface scientists (DLR Stuttgart, Uni Würzburg, Uni Modena, BEAR Trieste) with the existing significant knowledge in the LTP community (Uni Trento, Imperial College London, CGS, Selex Galileo, TWT GmbH, ESA). The findings resulted in a recommendation to modify the baseline discharge system of LISA Pathfinder, including the definition of dedicated manufacturing and AIT requirements. These findings have relevance also for LISA/NGO, since they allow for a significantly more robust discharge system design.

  17. Coupling characterization and noise studies of the optical metrology system onboard the LISA Pathfinder mission.

    PubMed

    Hechenblaikner, Gerald; Gerndt, Rüdiger; Johann, Ulrich; Luetzow-Wentzky, Peter; Wand, Vinzenz; Audley, Heather; Danzmann, Karsten; Garcia-Marin, Antonio; Heinzel, Gerhard; Nofrarias, Miquel; Steier, Frank

    2010-10-10

    We describe the first investigations of the complete engineering model of the optical metrology system (OMS), a key subsystem of the LISA Pathfinder science mission to space. The latter itself is a technological precursor mission to LISA, a spaceborne gravitational wave detector. At its core, the OMS consists of four heterodyne Mach-Zehnder interferometers, a highly stable laser with an external modulator, and a phase meter. It is designed to monitor and track the longitudinal motion and attitude of two floating test masses in the optical reference frame with (relative) precision in the picometer and nanorad range, respectively. We analyze sensor signal correlations and determine a physical sensor noise limit. The coupling parameters between motional degrees of freedom and interferometer signals are analytically derived and compared to measurements. We also measure adverse cross-coupling effects originating from system imperfections and limitations and describe algorithmic mitigation techniques to overcome some of them. Their impact on system performance is analyzed within the context of the Pathfinder mission.

  18. Rock Statistics at the Mars Pathfinder Landing Site, Roughness and Roving on Mars

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Bridges, N. T.; Anderson, R. C.; Golombek, M. P.

    1999-01-01

    Several rock counts have been carried out at the Mars Pathfinder landing site producing consistent statistics of rock coverage and size-frequency distributions. These rock statistics provide a primary element of "ground truth" for anchoring remote sensing information used to pick the Pathfinder, and future, landing sites. The observed rock population statistics should also be consistent with the emplacement and alteration processes postulated to govern the landing site landscape. The rock population databases can however be used in ways that go beyond the calculation of cumulative number and cumulative area distributions versus rock diameter and height. Since the spatial parameters measured to characterize each rock are determined with stereo image pairs, the rock database serves as a subset of the full landing site digital terrain model (DTM). Insofar as a rock count can be carried out in a speedier, albeit coarser, manner than the full DTM analysis, rock counting offers several operational and scientific products in the near term. Quantitative rock mapping adds further information to the geomorphic study of the landing site, and can also be used for rover traverse planning. Statistical analysis of the surface roughness using the rock count proxy DTM is sufficiently accurate when compared to the full DTM to compare with radar remote sensing roughness measures, and with rover traverse profiles.

  19. Observations at the Mars Pathfinder site: Do they provide "unequivocal" evidence of catastrophic flooding?

    USGS Publications Warehouse

    Chapman, M.G.; Kargel, J.S.

    1999-01-01

    After Mars Pathfinder landed at the mouth of Ares Vallis, a large channel that drains into the Chryse Planitia basin, the mission reports unanimously supported the interpretation that the lander site is the locus of catastrophic flooding by noting that all aspects of the scene are consistent with this interpretation. However, alternatives cannot be ruled out by any site observations, as all aspects of the scene are equally consistent with other interpretations of origin, namely, ice and mass-flow processes subsequently modified by wind erosion. The authors discuss alternative explanations for the geologic history of the channel based on a regional view of the circum-Chryse channels from Viking images (our best broad-scale information to date) and the local view from the recent Pathfinder landing site. Mega-indicators of channel origin, the regional geomorphology, geology, and planetary climatic conditions, taken together suggest some combination of flood, mass flow, glacial, and eolian processes. The macro-indicators of channel origin (sedimentologic) are also not indicative of one process of emplacement, either as single criteria or taken cumulatively. Finally, the micro-indicators of channel origin (geochemical and mineralogic composition) do not provide very tight constraints on the deposits' possible origins other than that water was in some way involved.

  20. A Wind Tunnel Study on the Mars Pathfinder (MPF) Lander Descent Pressure Sensor

    NASA Technical Reports Server (NTRS)

    Soriano, J. Francisco; Coquilla, Rachael V.; Wilson, Gregory R.; Seiff, Alvin; Rivell, Tomas

    2001-01-01

    The primary focus of this study was to determine the accuracy of the Mars Pathfinder lander local pressure readings in accordance with the actual ambient atmospheric pressures of Mars during parachute descent. In order to obtain good measurements, the plane of the lander pressure sensor opening should ideally be situated so that it is parallel to the freestream. However, due to two unfavorable conditions, the sensor was positioned in locations where correction factors are required. One of these disadvantages is due to the fact that the parachute attachment point rotated the lander's center of gravity forcing the location of the pressure sensor opening to be off tangent to the freestream. The second and most troublesome factor was that the lander descends with slight oscillations that could vary the amplitude of the sensor readings. In order to accurately map the correction factors required at each sensor position, an experiment simulating the lander descent was conducted in the Martian Surface Wind Tunnel at NASA Ames Research Center. Using a 115 scale model at Earth ambient pressures, the test settings provided the necessary Reynolds number conditions in which the actual lander was possibly subjected to during the descent. In the analysis and results of this experiment, the readings from the lander sensor were converted to the form of pressure coefficients. With a contour map of pressure coefficients at each lander oscillatory position, this report will provide a guideline to determine the correction factors required for the Mars Pathfinder lander descent pressure sensor readings.

  1. A torsion pendulum test of the Lisa Pathfinder free-fall mode

    NASA Astrophysics Data System (ADS)

    Russano, Giuliana; Dolesi, Rita; Cavalleri, Antonella; Hueller, Mauro; Vitale, Stefano; Weber, William Joseph; Tu, HaiBo

    The LISA Pathfinder geodesic explorer mission for gravitational wave astronomy aims to demonstrate the proof of a low acceleration noise level. The relative acceleration between two test masses free falling in orbit is perturbed by the presence of a larger constant relative acceleration that must be actively compensated in order to keep the test particles centered inside an orbiting apparatus. The actuation force applied to compensate this effect introduces a dominant source of force noise. To suppress this noise source, a “free-fall” actuation control scheme has been designed: actuation is limited to brief impulses, with test masses in free fall in between two “kicks”, with this actuation-free motion then analyzed for the remaining sources of acceleration ultra noise. In this work, we will discuss and present preliminary data for an on-ground torsion pendulum experiment to test this technique, and the associated analysis algorithms, at a level nearing the sub-femto-g/sqrt(Hz) performance required for LISA Pathfinder.

  2. Percutaneous Transpedicular Fixation: Technical tips and Pitfalls of Sextant and Pathfinder Systems

    PubMed Central

    Hassan, Ahmed Salah Aldin

    2016-01-01

    Study Design The efficacy of the operative techniques, possible benefits as well as pitfalls and limitations of the techniques are discussed. Potential drawbacks are also detected. Purpose This study aims to report indications, techniques, and our experience with the use of the Sextant and PathFinder percutaneous transpedicular screw fixation systems. Overview of Literature Percutaneous pedicle screw insertion is a novel technique. Successful percutaneous placement of pedicle screws requires surgical skill and experience because of lack of anatomic surface landmarks. Fluoroscopy-guided percutaneous placement of pedicle screws is effective. Many systems are now available. Methods We conducted a prospective operative and postoperative analysis of 40 patients with absolute indication for thoracic or lumbar instability between January 2009 and June 2013. All procedures were performed with the Sextant (group A) and PathFinder (group B) systems under fluoroscopic guidance. Operative techniques are discussed and the results compared. Results Percutaneous transpedicular screw fixation minimizes the morbidity associated with open techniques without compromising the quality of fixation. A total of 190 screws were inserted. There was no additional morbidity. Postoperative computed tomography images and plain X-rays were analyzed. Reduction of visual analog scale scores of back pain was evident. Conclusions Fluoroscopy-guided percutaneous pedicular screws are feasible and can be safely done. Current systems allow multi-segmental fixation with significantly less difficulties. The described techniques have acceptable intra- and postoperative complication rates, and overall sufficient pain control with early mobilization of patients. PMID:26949466

  3. Relevance and feasibility of Diagnostics Subsystems in LISA PathFinder and LISA

    NASA Astrophysics Data System (ADS)

    Lobo, Alberto; Grimani, Catia; Canizares, Priscilla; Chmeissani, Mokhtar; Diaz-Aguilo, Marc; Conchillo, Aleix; Gesa, Lluis; Lloro, Ivan; Mateos, Ignacio; Nofrarias, Miquel; Ramos-Castro, Juan; Sanjuan, Josep; Sopuerta, Carlos

    LISA PathFinder will fly equipped with a Diagnostics Subsystem which includes: 1) a Radi-ation Monitor, providing almost real time charged particle counting and spectral resolution, 2) a thermal diagnostics set with high sensitivity temperature sensors and precision heaters, and 3) four fluxgate vector magnetometers plus a pair of induction coils. The role of this in-strumentation in LISA PathFinder is to provide the necessary tools to evaluate the effect of charging, temperature and magnetic fluctuations on the interferometer readout. The use of this is to understand how the mentioned fluctuations in the LTP (LISA Technology Package) can be modelled, then use the measured data to quantify their contribution to the overall LTP noise. In this presentation we will review the LPF Diagnostics System, recently delivered for LTP and spacecraft integration. We will also make some considerations on the meaning of the diagnostics for the future LISA, and propose lines of action to meet the more severe requirements which LISA will impose on environmental conditions.

  4. Characterizing Semaphorin-Mediated Effects on Sensory and Motor Axon Pathfinding and Connectivity During Embryonic Development.

    PubMed

    Huettl, Rosa Eva; Huber, Andrea B

    2017-01-01

    How are precise connectivity to peripheral targets and corresponding sensory-motor networks established during developmental innervation of the vertebrate extremities? The formation of functional sensory-motor circuits requires highly appropriate temporal and spatial regulation of axon growth which is achieved through the combination of different molecular mechanisms such as communication between heterotypic fiber systems, axon-environment, or axon-glia interactions that ensure proper fasciculation and accurate pathfinding to distal targets. Family members of the class 3 semaphorins and their cognate receptors, the neuropilins, were shown to govern various events during wiring of central and peripheral circuits, with mice lacking Sema3-Npn signaling showing deficits in timing of growth, selective fasciculation, guidance fidelity, and coupling of sensory axon growth to motor axons at developmental time points. Given the accuracy with which these processes have to interact in a stepwise manner, deficiency of the smallest cog in the wheel may impact severely on the faithful establishment and functionality of peripheral circuitries, ultimately leading to behavioral impairments or even cause the death of the animal. Reliable quantitative analyses of sensory-motor fasciculation, extension, and guidance of axons to their cognate target muscles and the skin during development, but also assessment of physiological and behavioral consequences at adult age, are therefore a necessity to extend our understanding of the molecular mechanisms of peripheral circuit formation. In this chapter we provide a detailed methodology to characterize class 3 semaphorin-mediated effects on peripheral sensory and motor axon pathfinding and connectivity during embryonic development.

  5. Overview of the development of the pathfinder ultra long duration balloon system

    NASA Astrophysics Data System (ADS)

    Said, M.; Stuchlik, D.; Corbin, B.

    The Ultra Long Duration Balloon (ULDB) Pathfinder Project is developing a small pumpkin balloon system and new payload support systems to demonstrate a global 100 day duration capability that is scalable to a full scale flight. The proposed 56,600 m3 pumpkin balloon will be capable of supporting a small tracking payload on the order of 20-40 kg, to an altitude of 24 to 33 km. The Pathfinder Test Balloons will provide valuable data in the development of performance models for future ULDB flights. Attempts will be made to design and fabricate the balloons as close as possible to the full scale ULDB in order to maintain conformity and accuracy of the two balloons' performance models. The balloon system will be designed to handle a small global command and telemetry payload also under development. The payload will include a photo-voltaic power system, command and data handling unit, GPS receiver, and IRIDIUM transceiver for global communications. The flight data will include, at a minimum, position (latitude, longitude, and altitude), and time as well as other balloon performance parameters. Although the system will be designed for global launch capability, initial flights will be launched from the proposed full-scale ULDB mission launch locations. The overall project objectives as well as the trade studies for determining the balloon design parameters, performance, system power requirements, data transmission rates, termination options and overall system configuration will be discussed.

  6. Ascending midbrain dopaminergic axons require descending GAD65 axon fascicles for normal pathfinding

    PubMed Central

    García-Peña, Claudia M.; Kim, Minkyung; Frade-Pérez, Daniela; Ávila-González, Daniela; Téllez, Elisa; Mastick, Grant S.; Tamariz, Elisa; Varela-Echavarría, Alfredo

    2014-01-01

    The Nigrostriatal pathway (NSP) is formed by dopaminergic axons that project from the ventral midbrain to the dorsolateral striatum as part of the medial forebrain bundle. Previous studies have implicated chemotropic proteins in the formation of the NSP during development but little is known of the role of substrate-anchored signals in this process. We observed in mouse and rat embryos that midbrain dopaminergic axons ascend in close apposition to descending GAD65-positive axon bundles throughout their trajectory to the striatum. To test whether such interaction is important for dopaminergic axon pathfinding, we analyzed transgenic mouse embryos in which the GAD65 axon bundle was reduced by the conditional expression of the diphtheria toxin. In these embryos we observed dopaminergic misprojection into the hypothalamic region and abnormal projection in the striatum. In addition, analysis of Robo1/2 and Slit1/2 knockout embryos revealed that the previously described dopaminergic misprojection in these embryos is accompanied by severe alterations in the GAD65 axon scaffold. Additional studies with cultured dopaminergic neurons and whole embryos suggest that NCAM and Robo proteins are involved in the interaction of GAD65 and dopaminergic axons. These results indicate that the fasciculation between descending GAD65 axon bundles and ascending dopaminergic axons is required for the stereotypical NSP formation during brain development and that known guidance cues may determine this projection indirectly by instructing the pathfinding of the axons that are part of the GAD65 axon scaffold. PMID:24926237

  7. LISA Pathfinder: testing the limits of pure geodesic motion for gravitational wave observation in space

    NASA Astrophysics Data System (ADS)

    Weber, William

    2009-05-01

    Placing a gravitational reference test mass in nearly perfect geodesic motion, without any perturbing forces, is a critical problem for space-based gravitational wave detection and for a wide class of precision gravitational measurements. For the Laser Interferometer Space Antenna (LISA), high resolution observation of gravitational radiation from distant coalescing massive black holes will require that the geodesic reference test masses that serve as interferometry end mirrors be in free-fall to within a residual acceleration noise of order femto-m / s^2/ √Hz at frequencies near 0.1 mHz. The LISA Pathfinder mission, scheduled for launch by ESA and NASA in 2010, aims to demonstrate geodesic purity for a LISA-like test mass inside a co-orbiting spacecraft at a level approaching this LISA free-fall goal. In this talk, I will discuss the LISA Pathfinder flight experiment and what we have learned, in ground-based preparations for the mission, about the limits of free-fall that are relevant to gravitation wave detection and to other precise small force measurements.

  8. Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J. T.; Bassan, M.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Caleno, M.; Carbone, L.; Cavalleri, A.; Cesarini, A.; Ciani, G.; Congedo, G.; Cruise, A. M.; Danzmann, K.; de Deus Silva, M.; De Rosa, R.; Diaz-Aguiló, M.; Di Fiore, L.; Diepholz, I.; Dixon, G.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fichter, W.; Fitzsimons, E. D.; Flatscher, R.; Freschi, M.; García Marín, A. F.; García Marirrodriga, C.; Gerndt, R.; Gesa, L.; Gibert, F.; Giardini, D.; Giusteri, R.; Guzmán, F.; Grado, A.; Grimani, C.; Grynagier, A.; Grzymisch, J.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hoyland, D.; Hueller, M.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johann, U.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C. J.; Lobo, J. A.; Lloro, I.; Liu, L.; López-Zaragoza, J. P.; Maarschalkerweerd, R.; Mance, D.; Martín, V.; Martin-Polo, L.; Martino, J.; Martin-Porqueras, F.; Madden, S.; Mateos, I.; McNamara, P. W.; Mendes, J.; Mendes, L.; Monsky, A.; Nicolodi, D.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Raïs, B.; Ramos-Castro, J.; Reiche, J.; Robertson, D. I.; Rozemeijer, H.; Rivas, F.; Russano, G.; Sanjuán, J.; Sarra, P.; Schleicher, A.; Shaul, D.; Slutsky, J.; Sopuerta, C. F.; Stanga, R.; Steier, F.; Sumner, T.; Texier, D.; Thorpe, J. I.; Trenkel, C.; Tröbs, M.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wand, V.; Wanner, G.; Ward, H.; Warren, C.; Wass, P. J.; Wealthy, D.; Weber, W. J.; Wissel, L.; Wittchen, A.; Zambotti, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2016-06-01

    We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2 ±0.1 fm s-2/√{Hz } , or (0.54 ±0.01 ) ×10-15 g/√{Hz } , with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8 ±0.3 ) fm /√{Hz } , about 2 orders of magnitude better than requirements. At f ≤0.5 mHz we observe a low-frequency tail that stays below 12 fm s-2/√{Hz } down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

  9. Longwave Radiative Flux Calculations in the TOVS Pathfinder Path A Data Set

    NASA Technical Reports Server (NTRS)

    Mehta, Amita; Susskind, Joel

    1999-01-01

    A radiative transfer model developed to calculate outgoing longwave radiation (OLR) and downwelling longwave, surface flux (DSF) from the Television and Infrared Operational Satellite (TIROS) Operational Vertical Sounder (TOVS) Pathfinder Path A retrieval products is described. The model covers the spectral range of 2 to 2800 cm in 14 medium medium spectral bands. For each band, transmittances are parameterized as a function of temperature, water vapor, and ozone profiles. The form of the band transmittance parameterization is a modified version of the approach we use to model channel transmittances for the High Resolution Infrared Sounder 2 (HIRS2) instrument. We separately derive effective zenith angle for each spectral band such that band-averaged radiance calculated at that angle best approximates directionally integrated radiance for that band. We develop the transmittance parameterization at these band-dependent effective zenith angles to incorporate directional integration of radiances required in the calculations of OLR and DSF. The model calculations of OLR and DSF are accurate and differ by less than 1% from our line-by-line calculations. Also, the model results are within 1% range of other line-by-line calculations provided by the Intercomparison of Radiation Codes in Climate Models (ICRCCM) project for clear-sky and cloudy conditions. The model is currently used to calculate global, multiyear (1985-1998) OLR and DSF from the TOVS Pathfinder Path A Retrievals.

  10. Australian Literature in the Primary Classroom.

    ERIC Educational Resources Information Center

    O'Sullivan, Colleen, Ed.

    This book was designed to supply information on available resources in Australian children's literature and a tradition of teaching which incorporates the Australian experience in an inclusive manner. Essays and their authors consist of the following: (1) "Children's Books in Australia: Two Hundred Years of Social Life" (Maurice Saxby);…

  11. Successful Principal Leadership: Australian Case Studies

    ERIC Educational Resources Information Center

    Gurr, David; Drysdale, Lawrie; Mulford, Bill

    2005-01-01

    Purpose: This paper aims to provide an Australian perspective on successful school leadership. Design/methodology/approach: The paper focuses on case studies in two Australian states (Tasmania and Victoria). Case studies for each state were developed independently and are reported separately. Findings: The findings show a remarkable degree of…

  12. Understanding Culture and Diversity: Australian Aboriginal Art

    ERIC Educational Resources Information Center

    Vize, Anne

    2009-01-01

    Australian Aboriginal culture is rich, complex and fascinating. The art of Aboriginal Australians shows a great understanding of the earth and its creatures. This article presents an activity which has been designed as a multi-age project. The learning outcomes have been written to suit both younger and older students. Aspects of the project could…

  13. A National Australian Curriculum: In Whose Interests?

    ERIC Educational Resources Information Center

    Ditchburn, Geraldine

    2012-01-01

    The introduction of an Australian curriculum is likely to have a widespread and long-term impact on schools, teachers and students, and yet there has been a swift and an almost unquestioning acceptance of its introduction by the Australian public and by educators. This paper will use theoretical frameworks informed by Gramsci's cultural hegemony…

  14. Career Intentions of Australian Physical Education Teachers

    ERIC Educational Resources Information Center

    Mäkelä, Kasper; Whipp, Peter R.

    2015-01-01

    The purpose of this study was to investigate Australian physical education (PE) teachers' career intentions and factors influencing their intentions. A sample (N = 234) of Western Australian PE teachers responded to a questionnaire determining PE teachers' work and the primary motivators for intention to leave the profession. Half (51.3%) of the…

  15. Australian Aboriginal Language Early Childhood Education Programmes.

    ERIC Educational Resources Information Center

    Holmes, Tony

    This report discusses the provision of culturally appropriate early childhood programs in Australian Aboriginal language in Australia, and the education of teachers for these programs. The first section of the report examines the education of indigenous peoples in the context of the current Australian education system. Evidence in support of the…

  16. The Australian Curriculum: Finding the Hidden Narrative?

    ERIC Educational Resources Information Center

    Ditchburn, Geraldine M.

    2012-01-01

    The Australian curriculum to be introduced in all Australian schools over the next few years provides two competing narratives about curriculum. An overt narrative provides an unproblematic view of curriculum where the rhetoric and discourse that promotes a "world-class curriculum" effectively obscures a second narrative. This second…

  17. Four Management Agendas for Australian Universities

    ERIC Educational Resources Information Center

    Sharrock, Geoff

    2012-01-01

    In a new mixed economy of higher learning, Australian universities require more strategic management to compete and collaborate sustainably. However, many scholars argue that new modes of university management are at odds with scholarly aims and values. This article examines how Australian universities frame their missions and communicate their…

  18. Australian developments in marine science

    NASA Astrophysics Data System (ADS)

    Coffin, Millard F.

    2012-07-01

    Australia is an island nation with about two thirds of its jurisdiction underwater. On 25 May 2012, Australia instituted the Seas and Submerged Lands (Limits of Continental Shelf) Proclamation 2012, confirming areas of seabed where Australia has exclusive rights to explore and exploit marine resources. This proclamation follows recommendations by the Commission on the Limits of the Continental Shelf, a body established under the United Nations Convention on the Law of the Sea, confirming Australia's entitlement to extended continental shelf, i.e., that beyond 200 nautical miles from the coastline, of some 2.56 million square kilometers, excluding Australian Antarctic Territory [Symonds et al., 2009] (Figure 1a).

  19. Aurorae in Australian Aboriginal Traditions

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.

    2013-07-01

    Transient celestial phenomena feature prominently in the astronomical knowledge and traditions of Aboriginal Australians. In this paper, I collect accounts of the Aurora Australis from the literature regarding Aboriginal culture. Using previous studies of meteors, eclipses, and comets in Aboriginal traditions, I anticipate that the physical properties of aurora, such as their generally red colour as seen from southern Australia, will be associated with fire, death, blood, and evil spirits. The survey reveals this to be the case and also explores historical auroral events in Aboriginal cultures, aurorae in rock art, and briefly compares Aboriginal auroral traditions with other global indigenous groups, including the Maori of New Zealand.

  20. Australian Aboriginal Astronomy and Cosmology

    NASA Astrophysics Data System (ADS)

    Clarke, Philip A.

    Australian Aboriginal ethnoastronomical traditions were recorded from a wide variety of sources in different periods. While the corpus of mythology concerning the heavens is diverse, it is unified by beliefs of a Skyworld as land with its own topography, containing plants and animals familiar to those living below. Spirits of the dead reside alongside the Creation Ancestors as celestial bodies in the Skyworld. Aboriginal hunter-gatherers used the regular movement of constellations and planets to measure time and to indicate the season, while unexpected change in the sky was seen as an omen.

  1. Comets in Australian Aboriginal Astronomy

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.; Norris, Ray P.

    2011-03-01

    We present 25 accounts of comets from 40 Australian Aboriginal communities, citing both supernatural perceptions of comets and historical accounts of historically bright comets. Historical and ethnographic descriptions include the Great Comets of 1843, 1861, 1901, 1910, and 1927. We describe the perceptions of comets in Aboriginal societies and show that they are typically associated with fear, death, omens, malevolent spirits, and evil magic, consistent with many cultures around the world. We also provide a list of words for comets in 16 different Aboriginal languages.

  2. Far-Field Rock Size-Frequency Distribution at the Mars Pathfinder Landing Site and Comparison to the Near Field

    NASA Technical Reports Server (NTRS)

    Haldemann, A. F. C.; Forsberg, N. K.; Golombek, M. P.; Bridges, N. T.

    2000-01-01

    Detailed measurements of rocks in the far field at the Mars Pathfinder landing site are consistent with the near field exponential drop off in the cumulative number or area covered by large diameter rocks (and with similar behavior at the Viking sites).

  3. Constraints on the Interior Structure and Seasonal Mass Redistribution of Mars from Radio Tracking of Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Preston, R. A.; Folkner, W. M.

    1997-01-01

    Doppler and range measurements to the Mars Pathfinder lander, made with its radio communications system, have been combined with similar measurements from the viking landers to estimate improved values of the precession of Mars' pole of rotation and the variation in Mars's rotation rate.

  4. Predictive Validity of Measures of the Pathfinder Scaling Algorithm on Programming Performance: Alternative Assessment Strategy for Programming Education

    ERIC Educational Resources Information Center

    Lau, Wilfred W. F.; Yuen, Allan H. K.

    2009-01-01

    Recent years have seen a shift in focus from assessment of learning to assessment for learning and the emergence of alternative assessment methods. However, the reliability and validity of these methods as assessment tools are still questionable. In this article, we investigated the predictive validity of measures of the Pathfinder Scaling…

  5. Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    First of NASA's Discovery missions. Launched in December 1996 and arrived at Mars on 4 July 1997. Mainly intended as a technology demonstration mission. Used airbags to cushion the landing on Mars. The Carl Sagan Memorial station returned images of an ancient flood plain in Ares Vallis. The 10 kg Sojourner rover used an x-ray spectrometer to study the composition of rocks and travelled about 100 ...

  6. Pathfinder Landing Site Observed by Mars Orbiter Camera - 'Big Crater' in Stereo View

    NASA Technical Reports Server (NTRS)

    1998-01-01

    On its 256th orbit of Mars, the camera on-board the Mars Global Surveyor spacecraft successfully observed the vicinity of the Pathfinder landing site. The images shown are a stereoscopic image pair in anaglyph format, made from the overlapping area of MOC 25603 and 23703. This image is reproduced at a scale of 5 m (16.4 feet) per pixel. Image 23703 was acquired on 13 April at 7:50 AM PDT; Image 25603 was acquired on 22 April at 1:11 PM PDT. The P237 observation was made from a distance of 675 km while the P256 measurement was made from 800 km. The viewing angle for 23703 was 21.2o, for 25603, 30.67o, giving an angular difference of about 9.5o. Owing to the relief on 'Big Crater,' this relatively small angular difference was in this case sufficient to show good stereo parallax.

    The resolution of the MOC image that covered the Pathfinder landing site (MOC 25603) was about 3.3 m or 11 feet per pixel. The Pathfinder lander and airbags form a roughly equilateral triangle 5 m on a side. Noting that the camera has not yet been focussed (it needs to be in the stable temperature conditions of the low altitude, circular mapping orbit in order to achieve best focus) and the hazy atmospheric conditions, the effective scale of the image is probably closer to 5 m (16.4 feet). Thus, the scale of the image was insufficient to resolve the lander (more than one pixel is needed to resolve a feature). In addition, the relatively high sun angle of the image (the sun was 40o above the horizon) reduced the length of shadows (for example, only a few boulders are seen), also decreasing the ability to discriminate small features. Work continues to locate intermediate-scale features in the lander and orbiter images in the hope of identifying the precise landing site based on these comparisons.

    Malin Space Science Systems and the California Institute of Technology built the MOC using spare hardware from the Mars Observer mission. MSSS operates the camera from its facilities in San Diego

  7. Constraints on Martian Soil Composition as Inferred from Viking XRFS and Pathfinder APXS and IMP Data

    NASA Technical Reports Server (NTRS)

    Bridges, N. T.; Crisp, J. A.

    2000-01-01

    With the successful operation of the Alpha Proton X-Ray Spectrometer (APXS) during 1997's Mars Pathfinder (MPF) mission, geochemistry data are now available from three sites on Mars. APXS raw spectra for six soils and five rocks have been converted to compositional abundances. The Viking Lander X-Ray Fluorescence Spectrometer (XRFS) successfully measured elemental abundances of nine soils at Viking 1 and eight soils at Viking 2. Although the three landing sites are located in different parts of Mars, the soils exhibit broad similarities, with an iron-rich chemistry similar to that of palagonite. However, the Pathfinder sods show some significant differences from Viking soils, notably an enrichment in silica and depletion in sulfur. The XRFS samples consisted of near-surface and deep (up to 22 cm) soils acquired by a collector head at the cod of a retractable boom. It was possible to collect and analyze pebbles as large a 2 cm, but only sod, some in the form of consolidated clods, was sampled. In contrast, the APXS measured materials in situ. This resulted in MPF "rock" analyses that probably had a significant dust component and, as explored here, "soil" analyses that may have contained a rocky component We examine several possibilities to explain these differences and other attributes of the APXS and XRFS data sets: 1) The APXS soil measurements actually sampled a mixture of Viking-like soil and small bits of high-silica, low-sulfur rock, 2) The soils were derived from high-silica rocks mixed with a minor component of globally-homogenized dust; these soils are chemically distinct and have a separate geologic history from the Viking soils. 3) The weathering environment was different at the Pathfinder landing site compared to the Viking sites, and 4) Uncertainties in the XRFS and APXS measurements result in reported elemental abundances different than those that are actually present We show that none of the possibilities can be discounted, but that an MPF soil

  8. The Twin Peaks in 3-D, as Viewed by the Mars Pathfinder IMP Camera

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The Twin Peaks are modest-size hills to the southwest of the Mars Pathfinder landing site. They were discovered on the first panoramas taken by the IMP camera on the 4th of July, 1997, and subsequently identified in Viking Orbiter images taken over 20 years ago. The peaks are approximately 30-35 meters (-100 feet) tall. North Twin is approximately 860 meters (2800 feet) from the lander, and South Twin is about a kilometer away (3300 feet). The scene includes bouldery ridges and swales or 'hummocks' of flood debris that range from a few tens of meters away from the lander to the distance of the South Twin Peak. The large rock at the right edge of the scene is nicknamed 'Hippo'. This rock is about a meter (3 feet) across and 25 meters (80 feet) distant.

    This view of the Twin Peaks was produced by combining 4 individual 'Superpan' scenes from the left and right eyes of the IMP camera to cover both peaks. Each frame consists of 8 individual frames (left eye) and 7 frames (right eye) taken with different color filters that were enlarged by 500% and then co-added using Adobe Photoshop to produce, in effect, a super-resolution pancromatic frame that is sharper than an individual frame would be.

    The anaglyph view of the Twin Peaks was produced by combining the left and right eye mosaics (above) by assigning the left eye view to the red color plane and the right eye view to the green and blue color planes (cyan), to produce a stereo anaglyph mosaic. This mosaic can be viewed in 3-D on your computer monitor or in color print form by wearing red-blue 3-D glasses.

    Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. JPL is a division of the California Institute of Technology (Caltech). The IMP was developed by the University of Arizona Lunar and Planetary

  9. Photodetector Development for the Wheel Abrasion Experiment on the Sojourner Microrover of the Mars Pathfinder Mission

    NASA Technical Reports Server (NTRS)

    Wilt, David M.; Jenkins, Phillip P.; Scheiman, David A.

    1997-01-01

    On-board the Mars Pathfinder spacecraft, launched in December of 1996, is a small roving vehicle named Sojourner. On Sojourner is an experiment to determine the abrasive characteristics of the Martian surface, called the Wheel Abrasion Experiment (WAE). The experiment works as follows: one of the wheels of the rover has a strip of black anodized aluminum bonded to the tread. The aluminum strip has thin coatings of aluminum, nickel and platinum deposited in patches. There are five (5) patches or samples of each metal, and the patches range in thickness from 200 A to 1000 A. The different metals were chosen for their differing hardness and their environmental stability. As the wheel is spun in the Martian soil, the thin patches of metal are abraded away, exposing the black anodization. The abrasion is monitored by measuring the amount of light reflected off of the samples. A photodetector was developed for this purpose, and that is the subject of this paper.

  10. Martian Temperatures Measured by the Thermal Emission Spectrometer (TES). Pathfinder landing site

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This image shows the nighttime (2AM) temperatures measured by the Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor wrapped on to a globe. The coldest temperatures (shown in purple) are -120C and the warmest temperatures (white) are -65C. The view is centered at 15N, 45W, near the Pathfinder landing site. The large warm (red) region in the north is Acidalia Planitia, which forms a low basin into which flowed a series of large channels. The floors of these channels can be seen as a pattern of warm (red and yellow) lines, indicating that they are covered with sandy and rocky material. Valles Marineris visible south of the equator as a linear, warm feature that stretches 3500 km. At this season the north polar region is in full sunlight as is relatively warm at night. It is winter in the southern hemisphere and the temperatures are extremely low (-120C).

  11. Chryse Planitia as a Mars Pathfinder landing site: The imperative of building on previous ground truth

    NASA Technical Reports Server (NTRS)

    Crumpler, Larry S.

    1994-01-01

    Based on consideration of the geological characteristics of Chryse Planitia, the requirements for Mars Pathfinder landing sites, the nature of the mission, the scale of the observations to be made, and the need to build outward from previous experience, a new mission to Chryse Planitia offers several advantages that are difficult to ignore as well as offering a low-gamble/high-return mission scenario. Considering the need to ensure a successful mission, and to ensure the continued health of planetary exploration, the reasons for a new mission to Chryse Planitia are compelling. Results of 1:500,000 mapping, operational benefits of Chryse Planitia, science benefits of Chryse Planitia, and conclusions and site recommendations are discussed.

  12. Injection of a Body into a Geodesic: Lessons Learnt from the LISA Pathfinder Case

    NASA Technical Reports Server (NTRS)

    Bortoluzzi, Daniele; Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Conklin, J.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Slutsky, J.; Thorpe, J.

    2016-01-01

    Launch lock and release mechanisms constitute a common space business, however, some science missions due to very challenging functional and performance requirements need the development and testing of dedicated systems. In the LISA Pathfinder mission, a gold-coated 2-kg test mass must be injected into a nearly pure geodesic trajectory with a minimal residual velocity with respect to the spacecraft. This task is performed by the Grabbing Positioning and Release Mechanism, which has been tested on-ground to provide the required qualification. In this paper, we describe the test method that analyzes the main contributions to the mechanism performance and focuses on the critical parameters affecting the residual test mass velocity at the injection into the geodesic trajectory. The test results are also presented and discussed.

  13. Initial Results from ST7-Disturbance Reduction System on LISA Pathfinder

    NASA Astrophysics Data System (ADS)

    Dunn, Charles; Barela, Phillip; Cutler, Curt; Denzin, Richard; Franklin, Garth; Gorelik, Jacb; Hsu, Oscar; Javidnia, Shahram; Li, Irena; Maghami, Peiman; Marrese-Reading, Colleen; Mehta, Jitendra; O'Donnell, James; Romero-Wolf, Andrew; Slutsky, Jacob; Thorpe, Ira; Umfress, S. Harper; Ziemer, John

    2017-01-01

    The European Space Agency LISA Pathfinder spacecraft was launched on December, 2, 2015 carrying the NASA contribution ST7-Disturbance Reduction System (ST7-DRS). The objective of ST7-DRS is to demonstrate drag-free control and noise reduction technologies for future missions, especially a future space-based gravitational wave observatory. The system consists of a pair of Colloid Micro-Newton Thruster clusters and a computer with control algorithms. Data from the host platform is used for inertial and attitude sensing. ST7-DRS was initially powered on in January 2016 for an on-orbit check out and was fully commissioned in late June and early July. This presentation will report results relative to the 0.1 micro-Newton/ rt Hertz thrust noise requirement and the 10 nanometer/rt Hertz position control requirement. Preliminary extended mission results will be discussed. The work described here was funded by NASA.

  14. LISA Pathfinder as a drag-free accelerometer powered thrust stand

    NASA Astrophysics Data System (ADS)

    Slutsky, Jacob; LISA Pathfinder Team

    2017-01-01

    The LISA Pathfinder (LPF) mission, launched to demonstrate technology for a future gravitational wave observatory in space, began in March 2016. ESA led, LPF is comprised of both European and NASA payloads, the LISA Technology Package (LTP) and Disturbance Reduction System (DRS), respectively. The LTP includes the two highest precision drag free accelerometers ever flown, as well as a high precision interferometer. DRS provides the Colloid Micro-Newton Thruster (CMNT) system, required to precisely maneuver the spacecraft. Additionally, DRS includes a complete Dynamic Control System (DCS) that maintains the drag free flight. While the LTP mission uses the residual of the differential acceleration between the accelerometers, each individual sensor provides an unparalleled measure of the full six-dimensional spacecraft motion. This talk will discuss the DRS experiments performed, and how this sensor data is analyzed to characterize the noise and performance of the CMNTs.

  15. Pathfinder: multiresolution region-based searching of pathology images using IRM.

    PubMed

    Wang, J Z

    2000-01-01

    The fast growth of digitized pathology slides has created great challenges in research on image database retrieval. The prevalent retrieval technique involves human-supplied text annotations to describe slide contents. These pathology images typically have very high resolution, making it difficult to search based on image content. In this paper, we present Pathfinder, an efficient multiresolution region-based searching system for high-resolution pathology image libraries. The system uses wavelets and the IRM (Integrated Region Matching) distance. Experiments with a database of 70,000 pathology image fragments have demonstrated high retrieval accuracy and high speed. The algorithm can be combined with our previously developed wavelet-based progressive pathology image transmission and browsing algorithm and is expandable for medical image databases.

  16. Flight Reconstruction of the Mars Pathfinder Disk-Gap-Band Parachute Drag Coefficient

    NASA Technical Reports Server (NTRS)

    Desai, Prasun; Schofield, John T.; Lisano, Michael E.

    2003-01-01

    On July 4, 1997, the Mars Pathfinder (MPF) mission successfully landed on Mars. The entry, descent, and landing (EDL) scenario employed the use of a Disk-Gap-Band parachute design to decelerate the Lander. Flight reconstruction of the entry using MPF flight accelerometer data revealed that the MPF parachute decelerated faster than predicted. In the summer of 2003, the Mars Exploration Rover (MER) mission will send two Landers to the surface of Mars arriving in January 2004. The MER mission utilizes a similar EDL scenario and parachute design as that employed by MPF. As a result, characterizing the degree of underperformance of the MPF parachute system is critical for the MER EDL trajectory design. This paper provides an overview of the methodology utilized to estimate the MPF parachute drag coefficient as experienced on Mars.

  17. Overview of the Mars Pathfinder mission and assessment of landing site predictions

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Cook, R. A.; Economou, T.; Folkner, W. M.; Haldemann, A. F.; Kallemeyn, P. H.; Knudsen, J. M.; Manning, R. M.; Moore, H. J.; Parker, T. J.; Rieder, R.; Schofield, J. T.; Smith, P. H.; Vaughan, R. M.

    1997-01-01

    Chemical analyses returned by Mars Pathfinder indicate that some rocks may be high in silica, implying differentiated parent materials. Rounded pebbles and cobbles and a possible conglomerate suggest fluvial processes that imply liquid water in equilibrium with the atmosphere and thus a warmer and wetter past. The moment of inertia indicates a central metallic core of 1300 to 2000 kilometers in radius. Composite airborne dust particles appear magnetized by freeze-dried maghemite stain or cement that may have been leached from crustal materials by an active hydrologic cycle. Remote-sensing data at a scale of generally greater than approximately 1 kilometer and an Earth analog correctly predicted a rocky plain safe for landing and roving with a variety of rocks deposited by catastrophic floods that are relatively dust-free.

  18. Pathfinder: multiresolution region-based searching of pathology images using IRM.

    PubMed Central

    Wang, J. Z.

    2000-01-01

    The fast growth of digitized pathology slides has created great challenges in research on image database retrieval. The prevalent retrieval technique involves human-supplied text annotations to describe slide contents. These pathology images typically have very high resolution, making it difficult to search based on image content. In this paper, we present Pathfinder, an efficient multiresolution region-based searching system for high-resolution pathology image libraries. The system uses wavelets and the IRM (Integrated Region Matching) distance. Experiments with a database of 70,000 pathology image fragments have demonstrated high retrieval accuracy and high speed. The algorithm can be combined with our previously developed wavelet-based progressive pathology image transmission and browsing algorithm and is expandable for medical image databases. Images Figure 4 Figure 6 Figure 7 Figure 5 Figure 8 Figure 9 PMID:11080011

  19. LISA and LISA PathFinder, the endeavour to detect low frequency GWs

    NASA Astrophysics Data System (ADS)

    Araújo, H.; Boatella, C.; Chmeissani, M.; Conchillo, A.; García-Berro, E.; Grimani, C.; Hajdas, W.; Lobo, A.; Martínez, Ll; Nofrarias, M.; Ortega, J. A.; Puigdengoles, C.; Ramos-Castro, J.; Sanjuán, J.; Wass, P.; Xirgu, X.

    2007-05-01

    This is a review about LISA and its technology demonstrator, LISAPathFinder. We first describe the conceptual problems which need to be overcome in order to set up a working interferometric detector of low frequency Gravitational Waves (GW), then summarise the solutions to them as currently conceived by the LISA mission team. This will show that some of these solutions require new technological abilities which are still under development, and which need proper test before being fully implemented. LISAPathFinder (LPF) is the the testbed for such technologies. The final part of the paper will address the ideas and concepts behind the PathFinder as well as their impact on LISA.

  20. Mars 2024/2026 Pathfinder Mission: Mars Architectures, Systems, and Technologies for Exploration and Resources Project

    NASA Technical Reports Server (NTRS)

    Zeitlin, Nancy; Mueller, Robert; Muscatello, Anthony

    2015-01-01

    Integrate In Situ Resource Utilization (ISRU) sub-systems and examine advanced capabilities and technologies to verify Mars 2024 Forward architecture precursor pathfinder options: Integrated spacecraft/surface infrastructure fluid architecture: propulsion, power, life support center dot Power system feed and propellant scavenging from propulsion system center dot High quality oxygen for life support and EVA Fluid/cryogenic zero-loss transfer and long-term storage center dot Rapid depot-to-rover/spacecraft center dot Slow ISRU plant-to-ascent vehicle Integration of ISRU consumable production center dot Oxygen only from Mars atmosphere carbon dioxide center dot Oxygen, fuel, water, from extraterrestrial soil/regolith Test bed to evaluate long duration life, operations, maintenance on hardware, sensors, and autonomy

  1. The Mars Pathfinder atmospheric structure investigation/meteorology (ASI/MET) experiment

    NASA Technical Reports Server (NTRS)

    Schofield, J. T.; Barnes, J. R.; Crisp, D.; Haberle, R. M.; Larsen, S.; Magalhaes, J. A.; Murphy, J. R.; Seiff, A.; Wilson, G.

    1997-01-01

    The Mars Pathfinder atmospheric structure investigation/meteorology (ASI/MET) experiment measured the vertical density, pressure, and temperature structure of the martian atmosphere from the surface to 160 km, and monitored surface meteorology and climate for 83 sols (1 sol = 1 martian day = 24.7 hours). The atmospheric structure and the weather record are similar to those observed by the Viking 1 lander (VL-1) at the same latitude, altitude, and season 21 years ago, but there are differences related to diurnal effects and the surface properties of the landing site. These include a cold nighttime upper atmosphere; atmospheric temperatures that are 10 to 12 degrees kelvin warmer near the surface; light slope-controlled winds; and dust devils, identified by their pressure, wind, and temperature signatures. The results are consistent with the warm, moderately dusty atmosphere seen by VL-1.

  2. Simulation-Based Verification of Autonomous Controllers via Livingstone PathFinder

    NASA Technical Reports Server (NTRS)

    Lindsey, A. E.; Pecheur, Charles

    2004-01-01

    AI software is often used as a means for providing greater autonomy to automated systems, capable of coping with harsh and unpredictable environments. Due in part to the enormous space of possible situations that they aim to addrs, autonomous systems pose a serious challenge to traditional test-based verification approaches. Efficient verification approaches need to be perfected before these systems can reliably control critical applications. This publication describes Livingstone PathFinder (LPF), a verification tool for autonomous control software. LPF applies state space exploration algorithms to an instrumented testbed, consisting of the controller embedded in a simulated operating environment. Although LPF has focused on NASA s Livingstone model-based diagnosis system applications, the architecture is modular and adaptable to other systems. This article presents different facets of LPF and experimental results from applying the software to a Livingstone model of the main propulsion feed subsystem for a prototype space vehicle.

  3. Development of a solar-cell dust opacity measurement instrument for Mars Pathfinder

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey; Jenkins, Phillip P.

    1996-01-01

    The atmosphere of Mars has a considerable load of suspended dust. Over time, this dust is deposited out of the atmosphere. The mechanism and the temporal and geographical variation of this deposition are not well characterized. Measurements of settling rates and dust properties are of considerable scientific interest. Atmospheric dust affects the atmospheric solar absorption and thus the heat balance of Mars, as well as serving as nucleation sites for water and CO2 frost. Knowledge of dust properties is of critical interest to design and prediction of the lifetime and power output of solar arrays, and also to design of mechanical mechanisms and radiators. An instrument has been designed and fabricated to measure the dust accumulation during the course of the Mars Pathfinder rover mission. The solar-cell coverglass transmission experiment will measure the change in optical opacity of a transparent coverglass as dust settles on the surface, and a quartz crystal monitor will measure the mass deposited.

  4. In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

    NASA Astrophysics Data System (ADS)

    Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, Ll; Gibert, F.; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Maghami, P.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Nofrarias, M.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-04-01

    Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations.

  5. In-flight thermal experiments for LISA Pathfinder: Simulating temperature noise at the Inertial Sensors

    NASA Astrophysics Data System (ADS)

    Gibert, F.; Nofrarias, M.; Armano, M.; Audley, H.; Auger, G.; Baird, J.; Binetruy, P.; Born, M.; Bortoluzzi, D.; Brandt, N.; Bursi, A.; Caleno, M.; Cavalleri, A.; Cesarini, A.; Cruise, M.; Danzmann, K.; Diepholz, I.; Dolesi, R.; Dunbar, N.; Ferraioli, L.; Ferroni, V.; Fitzsimons, E.; Freschi, M.; Gallegos, J.; García Marirrodriga, C.; Gerndt, R.; Gesa, Ll; Giardini, D.; Giusteri, R.; Grimani, C.; Harrison, I.; Heinzel, G.; Hewitson, M.; Hollington, D.; Hueller, M.; Huesler, J.; Inchauspé, H.; Jennrich, O.; Jetzer, P.; Johlander, B.; Karnesis, N.; Kaune, B.; Korsakova, N.; Killow, C.; Lloro, I.; Maarschalkerweerd, R.; Madden, S.; Maghami, P.; Mance, D.; Martín, V.; Martin-Porqueras, F.; Mateos, I.; McNamara, P.; Mendes, J.; Mendes, L.; Moroni, A.; Paczkowski, S.; Perreur-Lloyd, M.; Petiteau, A.; Pivato, P.; Plagnol, E.; Prat, P.; Ragnit, U.; Ramos-Castro, J.; Reiche, J.; Romera Perez, J. A.; Robertson, D.; Rozemeijer, H.; Russano, G.; Sarra, P.; Schleicher, A.; Slutsky, J.; Sopuerta, C. F.; Sumner, T.; Texier, D.; Thorpe, J.; Trenkel, C.; Tu, H. B.; Vetrugno, D.; Vitale, S.; Wanner, G.; Ward, H.; Waschke, S.; Wass, P.; Wealthy, D.; Wen, S.; Weber, W.; Wittchen, A.; Zanoni, C.; Ziegler, T.; Zweifel, P.

    2015-05-01

    Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations.

  6. Magnetic polarization effects of temperature sensors and heaters in LISA Pathfinder.

    PubMed

    Sanjuán, J; Lobo, A; Nofrarias, M; Mateos, N; Xirgu, X; Cañizares, P; Ramos-Castro, J

    2008-08-01

    Temperature sensors and heaters belong in the diagnostics subsystem of the LISA Technology Package (LTP) on board LISA Pathfinder, the technology demonstrator for LISA. A number of these diagnostics items are placed at short distances from the LTP proof masses and are negative temperature coefficient (NTC) thermistors. By design, these devices have tiny amounts of ferromagnetic materials, which therefore constitute a potential source of disturbance to the performance of the LTP. In this paper we report on detailed magnetic characterization of the NTCs and use the data to evaluate their impact on the acceleration noise budget of the LTP. The effect is seen to be small if the NTCs are submitted to a demagnetization process before they are attached. Remagnetization is unlikely, as rather strong fields (approximately millitesla) are required to produce enough NTC magnetic polarization.

  7. Thermo-elastic induced phase noise in the LISA Pathfinder spacecraft

    NASA Astrophysics Data System (ADS)

    Gibert, F.; Nofrarias, M.; Karnesis, N.; Gesa, L.; Martín, V.; Mateos, I.; Lobo, A.; Flatscher, R.; Gerardi, D.; Burkhardt, J.; Gerndt, R.; Robertson, D. I.; Ward, H.; McNamara, P. W.; Guzmán, F.; Hewitson, M.; Diepholz, I.; Reiche, J.; Heinzel, G.; Danzmann, K.

    2015-02-01

    During the on-station thermal test campaign of the LISA Pathfinder, the diagnostics subsystem was tested in nearly space conditions for the first time after integration in the satellite. The results showed the compliance of the temperature measurement system, obtaining temperature noise around {{10}-4} K H{{z}-1/2} in the frequency band 1-30 mHz. In addition, controlled injection of heat signals to the suspension struts anchoring the LISA Technology Package (LTP) core assembly to the satellite structure allowed us to experimentally estimate, for the first time, the phase noise contribution through thermo-elastic distortion of the LTP interferometer, the satellite's main instrument. Such contribution was found to be at {{10}-12} mH{{z}-1/2}, a factor of 30 below the measured noise at the lower end of the measurement bandwidth (1 mHz).

  8. Active Heat Rejection System on Mars Exploration Rover - Design Changes from Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Ganapathi, Gani B.; Birur, Gajanana C.; Tsuyuki, Glenn T.; McGrath, Paul L.; Patzold, Jack D.

    2003-01-01

    The active Heat Rejection System designed for Mars Pathfinder was modified for the Mars Exploration Rover (Mars '03) mission and will be used to remove excess heat from the Rover electronics during the cruise part of the mission. The Integrated Pump Assembly design from MPF remained essentially intact; changes were primarily made to reduce weight. However, the cooling loop was significantly redesigned to service totally different requirements for the MER rovers. In addition, the vent design was readdressed to alleviate potentially excessive nutation as was induced on the MPF spacecraft in the process of dumping the CFC-11 overboard prior to Entry/Descent/Landing. The current vent design was based on a better understanding of the flow characteristics during the blowdown process. This paper addresses some of the key design changes. This paper also addresses lessons learned from the performance testing, and potential changes to improve the HRS performance (e.g. temperature oscillations).

  9. Pathfinding the Flight Advanced Stirling Convertor Design with the ASC-E3

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Kyle; Smith, Eddie; Collins, Josh

    2012-01-01

    The Advanced Stirling Convertor (ASC) was initially developed by Sunpower, Inc. under contract to NASA Glenn Research Center (GRC) as a technology development project. The ASC technology fulfills NASA s need for high efficiency power convertors for future Radioisotope Power Systems (RPS). Early successful technology demonstrations between 2003 to 2005 eventually led to the expansion of the project including the decision in 2006 to use the ASC technology on the Advanced Stirling Radioisotope Generator (ASRG). Sunpower has delivered 22 ASC convertors of progressively mature designs to date to GRC. Currently, Sunpower with support from GRC, Lockheed Martin Space System Company (LMSSC), and the Department of Energy (DOE) is developing the flight ASC-F in parallel with the ASC-E3 pathfinders. Sunpower will deliver four pairs of ASC-E3 convertors to GRC which will be used for extended operation reliability assessment, independent validation and verification testing, system interaction tests, and to support LMSSC controller verification. The ASC-E3 and -F convertors are being built to the same design and processing documentation and the same product specification. The initial two pairs of ASC-E3 are built before the flight units and will validate design and processing changes prior to implementation on the ASC-F flight convertors. This paper provides a summary on development of the ASC technology and the status of the ASC-E3 build and how they serve the vital pathfinder role ahead of the flight build for ASRG. The ASRG is part of two of the three candidate missions being considered for selection for the Discovery 12 mission.

  10. Pathfinding the Flight Advanced Stirling Convertor Design with the ASC-E3

    NASA Technical Reports Server (NTRS)

    Wong, Wayne A.; Wilson, Kyle; Smith, Eddie; Collins, Josh

    2012-01-01

    The Advanced Stirling Convertor (ASC) was initially developed by Sunpower, Inc. under contract to NASA Glenn Research Center (GRC) as a technology development project. The ASC technology fulfills NASA's need for high efficiency power convertors for future Radioisotope Power Systems (RPS). Early successful technology demonstrations between 2003 to 2005 eventually led to the expansion of the project including the decision in 2006 to use the ASC technology on the Advanced Stirling Radioisotope Generator (ASRG). Sunpower has delivered 22 ASC convertors of progressively mature designs to date to GRC. Currently, Sunpower with support from GRC, Lockheed Martin Space System Company (LMSSC), and the Department of Energy (DOE) is developing the flight ASC-F in parallel with the ASC-E3 pathfinders. Sunpower will deliver four pairs of ASC-E3 convertors to GRC which will be used for extended operation reliability assessment, independent validation and verification testing, system interaction tests, and to support LMSSC controller verification. The ASC-E3 and -F convertors are being built to the same design and processing documentation and the same product specification. The initial two pairs of ASC-E3 are built before the flight units and will validate design and processing changes prior to implementation on the ASC-F flight convertors. This paper provides a summary on development of the ASC technology and the status of the ASC-E3 build and how they serve the vital pathfinder role ahead of the flight build for ASRG. The ASRG is part of two of the three candidate missions being considered for selection for the Discovery 12 mission.

  11. The LTP Experiment on LISA Pathfinder: Operational Definition of TT Gauge in Space

    NASA Astrophysics Data System (ADS)

    Armano, Michele

    2011-10-01

    The European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA) are planning the Laser Interferometer Space Antenna (LISA) mission in order to detect GW. The need of accurate testing of free-fall and knowledge of noise in a space environment similar to LISA's is considered mandatory a pre-phase for the project. Therefore the LISA Pathfinder mission has been designed by ESA to fly the LISA Technology Package (LTP), aiming at testing free-fall by measuring the residual acceleration between two test-bodies in the dynamical scheme we address as "drag-free". The spectral map of the residual acceleration as function of frequency will convey information on the local noise level, thus producing a picture of the environmental working conditions for LISA itself. The thesis contains abundant material on the problem of compensating static gravity, the development of a theory of orthogonalization of reference and cross-talk for the LTP experiment. The construction of the laser detection procedure starting from GR and differential geometry arguments is carried on. Effort was put in pointing out the physical motivations for the choices made in several other papers by the author and colleagues. In this perspective the thesis is meant as a summary tool for the LTP collaboration. In the second part of the thesis we summarize our contributions for a measurement of G onboard LTP and review on possible tests of fundamental physics the mission might embody. A wide part of the thesis is now part of the LTP Operation Master Plan, describing the real science and operations onboard LISA Pathfinder. This thesis was defended on September 26th, 2006 at the University of Como, Italy.

  12. Sub-Femto-g Free Fall for Space-Based Gravitational Wave Observatories: LISA Pathfinder Results.

    PubMed

    Armano, M; Audley, H; Auger, G; Baird, J T; Bassan, M; Binetruy, P; Born, M; Bortoluzzi, D; Brandt, N; Caleno, M; Carbone, L; Cavalleri, A; Cesarini, A; Ciani, G; Congedo, G; Cruise, A M; Danzmann, K; de Deus Silva, M; De Rosa, R; Diaz-Aguiló, M; Di Fiore, L; Diepholz, I; Dixon, G; Dolesi, R; Dunbar, N; Ferraioli, L; Ferroni, V; Fichter, W; Fitzsimons, E D; Flatscher, R; Freschi, M; García Marín, A F; García Marirrodriga, C; Gerndt, R; Gesa, L; Gibert, F; Giardini, D; Giusteri, R; Guzmán, F; Grado, A; Grimani, C; Grynagier, A; Grzymisch, J; Harrison, I; Heinzel, G; Hewitson, M; Hollington, D; Hoyland, D; Hueller, M; Inchauspé, H; Jennrich, O; Jetzer, P; Johann, U; Johlander, B; Karnesis, N; Kaune, B; Korsakova, N; Killow, C J; Lobo, J A; Lloro, I; Liu, L; López-Zaragoza, J P; Maarschalkerweerd, R; Mance, D; Martín, V; Martin-Polo, L; Martino, J; Martin-Porqueras, F; Madden, S; Mateos, I; McNamara, P W; Mendes, J; Mendes, L; Monsky, A; Nicolodi, D; Nofrarias, M; Paczkowski, S; Perreur-Lloyd, M; Petiteau, A; Pivato, P; Plagnol, E; Prat, P; Ragnit, U; Raïs, B; Ramos-Castro, J; Reiche, J; Robertson, D I; Rozemeijer, H; Rivas, F; Russano, G; Sanjuán, J; Sarra, P; Schleicher, A; Shaul, D; Slutsky, J; Sopuerta, C F; Stanga, R; Steier, F; Sumner, T; Texier, D; Thorpe, J I; Trenkel, C; Tröbs, M; Tu, H B; Vetrugno, D; Vitale, S; Wand, V; Wanner, G; Ward, H; Warren, C; Wass, P J; Wealthy, D; Weber, W J; Wissel, L; Wittchen, A; Zambotti, A; Zanoni, C; Ziegler, T; Zweifel, P

    2016-06-10

    We report the first results of the LISA Pathfinder in-flight experiment. The results demonstrate that two free-falling reference test masses, such as those needed for a space-based gravitational wave observatory like LISA, can be put in free fall with a relative acceleration noise with a square root of the power spectral density of 5.2±0.1  fm s^{-2}/sqrt[Hz], or (0.54±0.01)×10^{-15}  g/sqrt[Hz], with g the standard gravity, for frequencies between 0.7 and 20 mHz. This value is lower than the LISA Pathfinder requirement by more than a factor 5 and within a factor 1.25 of the requirement for the LISA mission, and is compatible with Brownian noise from viscous damping due to the residual gas surrounding the test masses. Above 60 mHz the acceleration noise is dominated by interferometer displacement readout noise at a level of (34.8±0.3)  fm/sqrt[Hz], about 2 orders of magnitude better than requirements. At f≤0.5  mHz we observe a low-frequency tail that stays below 12  fm s^{-2}/sqrt[Hz] down to 0.1 mHz. This performance would allow for a space-based gravitational wave observatory with a sensitivity close to what was originally foreseen for LISA.

  13. Summary of the results of the LISA-Pathfinder Test Mass release

    NASA Astrophysics Data System (ADS)

    Zanoni, C.; Bortoluzzi, D.; Conklin, J. W.; Köker, I.; Seutchat, B.; Vitale, S.

    2015-05-01

    The challenging goal of LISA-Pathfinder in terms of maximum non-gravitational forces applied on the test mass poses tight constraints on the design of the Gravitational Reference Sensor. In particular, large gaps (3-4 mm) must exist between the test mass and its housing and any system there located must be either gold coated or made of a gold-based material. As a consequence, a significant adhesion may arise between the test mass and the mechanism designed to cage it during the spacecraft launch and to release it to free-fall. The criticality of the latter phase is enhanced by the control force authority exerted to the test mass by the surrounding electrodes. Such a force is limited by the large gaps (order of μN). Since the expected adhesion force between the test mass and its holding devices is much larger than the force authority, a dynamic release must be realized. However, following this procedure adhesion converts into test mass velocity, which can be controlled by the capacitive force only if it is smaller than 5 μm/s. At the University of Trento (Italy) the Transferred Momentum Measurement Facility has been designed and developed to measure the impulse produced by metallic adhesion upon quick rupture, in representative conditions of the LISA-Pathfinder test mass release to free-fall. Large sets of data have been collected and a mathematical model of the in-flight release dynamics has been developed, in order to estimate the test mass release velocity. A summary of the results is presented, together with an overview of the recent developments and a prediction of the in-flight performance.

  14. Eclipses in Australian Aboriginal Astronomy

    NASA Astrophysics Data System (ADS)

    Hamacher, Duane W.; Norris, Ray P.

    2011-07-01

    We explore about fifty different Australian Aboriginal accounts of lunar and solar eclipses to determine how Aboriginal groups understood this phenomenon. We summarize the literature on Aboriginal references to eclipses. We show that many Aboriginal groups viewed eclipses negatively, frequently associating them with bad omens, evil magic, disease, blood and death. In many communities, elders or medicine men claimed to be able to control or avert eclipses by magical means, solidifying their roles as providers and protectors within their communities. We also show that some Aboriginal groups seem to have understood the motions of the Sun-Earth-Moon system, the connection between the lunar phases and tides, and acknowledged that solar eclipses were caused by the Moon blocking the Sun.

  15. Pyrogenic carbon in Australian soils.

    PubMed

    Qi, Fangjie; Naidu, Ravi; Bolan, Nanthi S; Dong, Zhaomin; Yan, Yubo; Lamb, Dane; Bucheli, Thomas D; Choppala, Girish; Duan, Luchun; Semple, Kirk T

    2017-02-16

    Pyrogenic carbon (PyC), the combustion residues of fossil fuel and biomass, is a versatile soil fraction active in biogeochemical processes. In this study, the chemo-thermal oxidation method (CTO-375) was applied to investigate the content and distribution of PyC in 30 Australian agricultural, pastoral, bushland and parkland soil with various soil types. Soils were sampled incrementally to 50cm in 6 locations and at another 7 locations at 0-10cm. Results showed that PyC in Australian soils typically ranged from 0.27-5.62mg/g, with three Dermosol soils ranging within 2.58-5.62mg/g. Soil PyC contributed 2.0-11% (N=29) to the total organic carbon (TOC), with one Ferrosol as high as 26%. PyC was concentrated either in the top (0-10cm) or bottom (30-50cm) soil layers, with the highest PyC:TOC ratio in the bottom (30-50cm) soil horizon in all soils. Principal component analysis - multiple linear regression (PCA-MLR) suggested the silt-associated organic C factor accounted for 38.5% of the variation in PyC. Our findings suggest that PyC is an important fraction of the TOC (2.0-11%, N=18) and chemically recalcitrant organic C (ROC) obtained by chemical C fractionation method accounts for a significant proportion of soil TOC (47.3-84.9%, N=18). This is the first study comparing these two methods, and it indicates both CTO-375 and C speciation methods can determine a fraction of recalcitrant organic C. However, estimated chemically recalcitrant organic carbon pool (ROC) was approximately an order of magnitude greater than that of thermally stable organic carbon (PyC).

  16. Population and Australian development assistance.

    PubMed

    Jones, R

    1992-07-01

    Australia's position on international population issues is consistent with the major international statements on population: the World Population Plan of Action (1974), the Mexico City Declaration (1984), and the Amsterdam Declaration (1989). Australia's policy emphasizes the importance of population policies as an integral part of social, economic, and cultural development aimed at improving the quality of life of the people. Factors that would promote smaller families include improving economic opportunities, old-age security, education and health (particularly for women), as well as improving the accessibility and quality of family planning services. The quality of care approach is directly complementary to the Australian International Development Assistance Bureau (AIDAB)'s Women-In-Development Policy and its Health Policy, which stresses the theme of Women And Their Children's Health (WATCH). Australia's support for population programs and activities has increased considerably over the last few years. Total assistance for the year 1990/91 was around $7 million out of a total aid program of $1216 million. In recent years AIDAB has funded family planning activities or health projects with family planning components in a number of countries in the Asia-Pacific region. In the South Pacific region AIDAB has funded a reproductive health video project taking into consideration the cultural sensitivities and customs of the peoples of the region. AIDAB has supported a UN Population Fund project in Thailand that aims to strengthen the capacity of the National Statistical Office to collect population data. The US currently accounts for around 40% of all population-related development assistance to improve the health of women and children through family planning. The other major donors are Japan, the Scandinavian countries, and the Netherlands. Funding for population has been a relatively low percentage of overall development assistance budgets in OECD countries. In the

  17. Australian Management Education for International Business Activity.

    ERIC Educational Resources Information Center

    Gniewosz, Gerhard

    2000-01-01

    As Australian corporations have increased overseas activity, there has been a significant increase in international business degrees at the undergraduate and graduate levels. The curriculum is balanced between business-technical knowledge courses and cultural knowledge courses. (SK)

  18. ANSTO: Australian Nuclear Science and Technology Organization

    NASA Astrophysics Data System (ADS)

    The Australian Nuclear Science and Technology Organization conducts or is engaged in collaborative research and development in the application of nuclear science and associated technology. Through its Australian radio-isotopes unit, it markets radioisotopes, their products and other services for the nuclear medicine industry and research. It also operates national nuclear facilities (HIFAR and Moata research reactors), promotes training, provides advice and disseminates information on nuclear science and technology. The booklet briefly outlines these activities.

  19. New Insights into the Geology of the Mars Pathfinder Landing Site from Spectral and Morphologic Analysis of the 12-Color Superpan Panorama

    NASA Astrophysics Data System (ADS)

    Murchie, S.; Barnouin-Jha, O.; Barnouin-Jha, K.; Bishop, J.; Johnson, J.; McSween, H.; Morris, R.

    2003-07-01

    The Pathfinder landing site contains a second lithology in addition to gray rock, consistent with highlands excavated from beneath a veneer of northern plains. Many rocks have cemented coatings that formed during an early, probably wetter climate.

  20. Why Do Chinese-Australian Students Outperform Their Australian Peers in Mathematics: A Comparative Case Study

    ERIC Educational Resources Information Center

    Zhao, Dacheng; Singh, Michael

    2011-01-01

    International comparative studies and cross-cultural studies of mathematics achievement indicate that Chinese students (whether living in or outside China) consistently outperform their Western counterparts. This study shows that the gap between Chinese-Australian and other Australian students is best explained by differences in motivation to…

  1. Australian Thesaurus of Education Descriptors. A Word-Stock for Indexing and Retrieving Australian Educational Literature.

    ERIC Educational Resources Information Center

    Lavender, G. B.; Findlay, Margaret A.

    This core thesaurus of terms suitable for indexing Australian educational literature was developed by the Australian Council for Educational Research by means of a systematic and thorough revision of the "Thesaurus of ERIC Descriptors." Based on the actual terminology of education in Australia, this thesaurus includes: key words and…

  2. Issues and Directions from a Review of the Australian Apprenticeship and Traineeship Literature. Australian Apprenticeships.

    ERIC Educational Resources Information Center

    Saunders, S.

    This paper synthesizes issues and directions that a review of Australian apprenticeship and traineeship literature suggested. An overview discusses the paper's basis, which was a survey of 125 Australian references from 1985-99. Chapter 2 categorizes issues into seven groups, discusses them, and draws out salient themes. (The groups concerned…

  3. Experiments and Spectral Studies of Martian Volcanic Rocks: Implications for the Origin of Pathfinder Rocks and Soils

    NASA Technical Reports Server (NTRS)

    Rutherford, Malcolm J.; Mustard, Jack; Weitz, Catherine

    2002-01-01

    The composition and spectral properties of the Mars Pathfinder rocks and soils together with the identification of basaltic and andesitic Mars terrains based on Thermal Emission Spectrometer (TES) data raised interesting questions regarding the nature and origin of Mars surface rocks. We have investigated the following questions: (1) are the Pathfinder rocks igneous and is it possible these rocks could have formed by known igneous processes, such as equilibrium or fractional crystallization, operating within SNC magmas known to exist on Mars? If it is possible, what P (depth) and PH2O conditions are required? (2) whether TES-based interpretations of plagioclase-rich basalt and andesitic terrains in the south and north regions of Mars respectively are unique. Are the surface compositions of these regions plagioclase-rich, possibly indicating the presence of old AI-rich crust of Mars, or are the spectra being affected by something like surface weathering processes that might determine the spectral pyroxene to plagioclase ratio?

  4. Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington

    NASA Technical Reports Server (NTRS)

    Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W., Jr. (Editor)

    1995-01-01

    This volume, the first of two comprising the technical report for this workshop, contains papers that have been accepted for presentation at the Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region, September 24-30, 1995, in Spokane, Washington. The Mars Pathfinder Project received a new start in October 1993 as one of the next missions in NASA's long-term Mars exploration program. The mission involves landing a single vehicle on the surface of Mars in 1997. The project is one of the first Discovery-class missions and is required to be a quick, low-cost mission and achieve a set of significant but focused engineering, science, and technology objectives. The primary objective is to demonstrate a low-cost cruise, entry, descent, and landing system required to place a payload on the martian surface in a safe, operational configuration. Additional objectives include the deployment and operation of various science instruments and a microrover. Pathfinder paves the way for a cost-effective implementation of future Mars lander missions. Also included in this volume is the field trip guide to the Channeled Scabland and Missoula Lake Break-out. On July 4, 1997, Mars Pathfinder is scheduled to land near 19.5 deg N, 32.8 deg W, in a portion of Ares Vallis. The landing ellipse covers a huge (100 x 200 km) area that appears to include both depositional and erosional landforms created by one or more giant, catastrophic floods. One of the best known terrestrial analogs to martian outflow channels (such as Ares Vallis) is the region known as the Channeled Scabland. The field trip guide describes some of the geomorphological features of the Channeled Scabland and adjacent Lake Missoula break-out area near Lake Pend Oreille, Idaho.

  5. Marine Biodiversity in the Australian Region

    PubMed Central

    Butler, Alan J.; Rees, Tony; Beesley, Pam; Bax, Nicholas J.

    2010-01-01

    The entire Australian marine jurisdictional area, including offshore and sub-Antarctic islands, is considered in this paper. Most records, however, come from the Exclusive Economic Zone (EEZ) around the continent of Australia itself. The counts of species have been obtained from four primary databases (the Australian Faunal Directory, Codes for Australian Aquatic Biota, Online Zoological Collections of Australian Museums, and the Australian node of the Ocean Biogeographic Information System), but even these are an underestimate of described species. In addition, some partially completed databases for particular taxonomic groups, and specialized databases (for introduced and threatened species) have been used. Experts also provided estimates of the number of known species not yet in the major databases. For only some groups could we obtain an (expert opinion) estimate of undiscovered species. The databases provide patchy information about endemism, levels of threat, and introductions. We conclude that there are about 33,000 marine species (mainly animals) in the major databases, of which 130 are introduced, 58 listed as threatened and an unknown percentage endemic. An estimated 17,000 more named species are either known from the Australian EEZ but not in the present databases, or potentially occur there. It is crudely estimated that there may be as many as 250,000 species (known and yet to be discovered) in the Australian EEZ. For 17 higher taxa, there is sufficient detail for subdivision by Large Marine Domains, for comparison with other National and Regional Implementation Committees of the Census of Marine Life. Taxonomic expertise in Australia is unevenly distributed across taxa, and declining. Comments are given briefly on biodiversity management measures in Australia, including but not limited to marine protected areas. PMID:20689847

  6. The JCMT 12CO(3-2) survey of the Cygnus X region. I. A pathfinder

    NASA Astrophysics Data System (ADS)

    Gottschalk, M.; Kothes, R.; Matthews, H. E.; Landecker, T. L.; Dent, W. R. F.

    2012-05-01

    Context. Cygnus X is one of the most complex areas in the sky, rich in massive stars; Cyg OB2 (2600 stars, 120 O stars) and other OB associations lie within its boundaries. This complicates interpretation, but also creates the opportunity to investigate accretion into molecular clouds and many subsequent stages of star formation, all within one small field of view. Understanding large complexes like Cygnus X is the key to understanding the dominant role that massive star complexes play in galaxies across the Universe. Aims: The main goal of this study is to establish feasibility of a high-resolution CO survey of the entire Cygnus X region by observing part of it as a pathfinder, and to evaluate the survey as a tool for investigating the star-formation process. We can investigate the mass accretion history of outflows, study interaction between star-forming regions and their cold environment, and examine triggered star formation around massive stars. Methods: A 2° × 4° area of the Cygnus X region has been mapped in the 12CO(3-2) line at an angular resolution of 15'' and a velocity resolution of ~0.4 km s-1 using HARP-B and ACSIS on the James Clerk Maxwell Telescope. The star formation process is heavily connected to the life-cycle of the molecular material in the interstellar medium. The high critical density of the 12CO(3-2) transition reveals clouds in key stages of molecule formation, and shows processes that turn a molecular cloud into a star. Results: We observed ~15% of Cygnus X, and demonstrated that a full survey would be feasible and rewarding. We detected three distinct layers of 12CO(3-2) emission, related to the Cygnus Rift (500-800 pc), to W75N (1-1.8 kpc), and to DR 21 (1.5-2.5 kpc). Within the Cygnus Rift, H i self-absorption features are tightly correlated with faint diffuse CO emission, while HISA features in the DR 21 layer are mostly unrelated to any CO emission. 47 molecular outflows were detected in the pathfinder, 27 of them previously

  7. William Herschel Telescope site characterization using the MOAO pathfinder CANARY on-sky data

    NASA Astrophysics Data System (ADS)

    Martin, O. A.; Correia, C. M.; Gendron, E.; Rousset, G.; Vidal, F.; Morris, T. J.; Basden, A. G.; Myers, R. M.; Ono, Y. H.; Neichel, B.; Fusco, T.

    2016-07-01

    CANARY is the Multi-Object Adaptive Optics (MOAO) pathfinder for the future MOAO-assisted Integral-Field Units (IFU) proposed for Extremely Large Telescopes (ELT). The MOAO concept relies on tomographically reconstructing the turbulence using multiple measurements along different lines of sight. Tomography requires the knowledge of the statistical turbulence parameters, commonly recovered from the system telemetry using a dedicated profiling technique. For demonstration purposes with the MOAO pathfinder CANARY, this identification is performed thanks to the Learn & Apply (L&A) algorithm, that consists in model-fitting the covariance matrix of WFS measurements dependant on relevant parameters: Cn2(h) profile, outer scale profile and system mis-registration. We explore an upgrade of this algorithm, the Learn 3 Steps (L3S) approach, that allows one to dissociate the identification of the altitude layers from the ground in order to mitigate the lack of convergence of the required empirical covariance matrices therefore reducing the required length of data time-series for reaching a given accuracy. For nominal observation conditions, the L3S can reach the same level of tomographic error in using five times less data frames than the L&A approach. The L3S technique has been applied over a large amount of CANARY data to characterize the turbulence above the William Herschel Telescope (WHT). These data have been acquired the 13th, 15th, 16th, 17th and 18th September 2013 and we find 0.67"/8.9m/3.07m.s-1 of total seeing/outer scale/wind-speed, with 0.552"/9.2m/2.89m.s-1 below 1.5 km and 0.263"/10.3m/5.22m.s-1 between 1.5 and 20 km. We have also determined the high altitude layers above 20 km, missed by the tomographic reconstruction on CANARY , have a median seeing of 0.187" and have occurred 16% of observation time.

  8. Selection and Assessment of Predictions of the Mars Pathfinder Landing Site

    NASA Technical Reports Server (NTRS)

    Golombek, M. P.; Moore, H. J.; Haldemann, A. F. C.; Cook, R. A.; Parker, T. J.; Schofield, J. T.

    1998-01-01

    The successful landing of the Mars Pathfinder spacecraft on Mars allows the review of the process of selecting the landing site and assessing predictions made for the site based on Viking and Earth-based data. Selection of the landing site for Mars Pathfinder was a two-phase process. The first phase took place from October 1993 to June 1994 and involved: initial identification of engineering constraints, definition of environmental conditions at the site for spacecraft design, and evaluation of the scientific potential of different landing sites. This phase culminated with the first "Mars Pathfinder Landing Site Workshop", held at the Lunar and Planetary Institute in Houston, Texas on April 18-19, 1994, in which suggested approaches and landing sites were solicited from the entire scientific community. A preliminary site was selected by the project for design purposes in June 1994. The second phase took place from July 1994 to March 1996 and involved: developing criteria for evaluating site safety using images and remote sensing data, testing of the spacecraft and landing subsystems (with design improvements) to establish quantitative engineering constraints on landing site characteristics, evaluating all potential landing sites on Mars, and certification of the site by the project. This phase included a second open workshop, "Mars Pathfinder Landing Site Workshop II: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington" held in Spokane and Moses Lake September 24-30, 1995 and formal acceptance of the site by NASA Headquarters. Engineering constraints on Pathfinder landing sites were developed from the initial design of the spacecraft and the entry, descent and landing scenario. The site must be within 5 degrees of the subsolar latitude at the time of landing (15N for maximum solar power and flexible communications with Earth. It also must be below 0 km elevation to enable enough time for the parachute to bring the lander

  9. Dust devils as aeolian transport mechanisms in southern Nevada and the Mars Pathfinder landing site

    NASA Astrophysics Data System (ADS)

    Metzger, Stephen M.

    Discovery of dust devils vortices in Mars Pathfinder images by this study is direct evidence of a dust entrainment mechanism at work on Mars. Dust devils on Earth can entrain fine material from crusted as well as unconsolidated surfaces, even when forced-convection wind speeds are below threshold. Terrestrial dust devils are commonly ``squat'' V-shaped vortices lasting several minutes. Well developed vortices consist of an outer cylinder of high rotation (<25 m/s), an Intermediate cylinder of moderate vertical lift (<13 m/s), and a inner cylindrical core of low pressure (<1.5% below ambient pressure) and elevated temperature (up to 20°C above ambient air temperature). Directly sampled dust devils on Earth were found to carry from 30 to over 2000 kg of soil. On average, the Eldorado Valley, NV, experienced 42 observable dust devils per summer day, each lofting over 200 kg for a daily total of 9 metric tonnes from this desert basin. Spectral differencing techniques have enhanced five localized dust plumes against the general haze in Mars Pathfinder images acquired near midday, which are determined to be dust devils. Given interpreted geographic locations relative to the lander, the dust devils are 14 to 79 m wide, 46 to over 350 m tall, and travel over ground at 0.5 to 4.6 m/s. Their dust loading was approximately 7 × 10-5 kg/m3, relative to the general haze of 9 × 10-8 kg/m3. With an estimated vertical dust flux of 0.5 g m-2 s-1, total particulate transport of these Martian dust devils may have ranged from 2.2 kg for a small dust devil lasting 35 s to over 700 kg for a large plume of 400 s duration. Observed characteristics of these plumes are consistent with expectations based on theory and the lessons of terrestrial field studies. The increasingly apparent role of dust devils in the dust aeolian transport cycle may largely explain the continued concentration of the general Martian dust haze and perhaps the Initiation mechanism for global dust storms.

  10. Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington

    NASA Technical Reports Server (NTRS)

    Golombek, M. P. (Editor); Edgett, K. S. (Editor); Rice, J. W. , Jr. (Editor)

    1995-01-01

    Mars Pathfinder will place a single lander on the surface of Mars on July 4, 1997, following a December 1996 launch. As a result of the very successful first Mars Pathfinder Landing Site Workshop, the project has selected the Ares Vallis outflow channel in Chryse Planitia as the landing site. This location is where a large catastrophic outflow channel debouches into the northern lowlands. A second workshop and series of field trips, entitled Mars Pathfinder Landing Site Workshop 2: Characteristics of the Ares Vallis Region and Field Trips in the Channeled Scabland, Washington, were held in Spokane and Moses Lake, Washington. The purpose of the workshop was to provide a focus for learning as much as possible about the Ares Vallis region on Mars before landing there. The rationale is that the more that can be learned about the general area prior to landing, the better scientists will be able interpret the observations made by the lander and rover and place them in the proper geologic context. The field trip included overflights and surface investigations of the Channeled Scabland (an Earth analog for the martian catastrophic outflow channels), focusing on areas particularly analogous to Ares Vallis and the landing site. The overflights were essential for placing the enormous erosional and depositional features of the Channeled Scabland into proper three-dimensional context. The field trips were a joint educational outreach activity involving K-12 science educators, Mars Pathfinder scientists and engineers, and interested scientists from the Mars scientific community. Part 1 of the technical report on this workshop includes a description of the Mars Pathfinder mission, abstracts accepted for presentation at the workshop, an introduction to the Channeled Scabland, and field trip guides for the overflight and two field trips. This part, Part 2, includes the program for the workshop, summaries of the workshop technical sessions, a summary of the field trips and ensuing

  11. Mars Pathfinder meteorological observations on the basis of results of an atmospheric global circulation model

    NASA Technical Reports Server (NTRS)

    Forget, Francois; Hourdin, F.; Talagrand, O.

    1994-01-01

    The Mars Pathfinder Meteorological Package (ASI/MET) will measure the local pressure, temperature, and winds at its future landing site, somewhere between the latitudes 0 deg N and 30 deg N. Comparable measurements have already been obtained at the surface of Mars by the Viking Landers at 22 deg N (VL1) and 48 deg N (VL2), providing much useful information on the martian atmosphere. In particular the pressure measurements contain very instructive information on the global atmospheric circulation. At the Laboratoire de Meteorologie Dynamique (LMD), we have analyzed and simulated these measurements with a martian atmospheric global circulation model (GCM), which was the first to simulate the martian atmospheric circulation over more than 1 year. The model is able to reproduce rather accurately many observed features of the martian atmosphere, including the long- and short-period oscillations of the surface pressure observed by the Viking landers. From a meteorological point of view, we think that a landing site located near or at the equator would be an interesting choice.

  12. Effects of Sonic Line Transition on Aerothermodynamics of the Mars Pathfinder Probe

    NASA Technical Reports Server (NTRS)

    Gnoffo, Peter A.; Weilmuenster, K. James; Braun, Robert D.; Cruz, Christopher I.

    1995-01-01

    Flow field solutions over the Mars Pathfinder Probe spanning the trajectory through the Martian atmosphere at angles of attack from 0 to 11 degrees are obtained. Aerodynamic coefficients derived from these solutions reveal two regions where the derivative of pitching moment with respect to angle of attack is positive at small angles of attack. The behavior is associated with the transition of the sonic line location between the blunted nose and the windside shoulder of the 70 degree half-angle cone in a gas with a low effective ratio of specific heats. The transition first occurs as the shock layer gas chemistry evolves from highly nonequilibrium to near equilibrium, above approximately 6.5 km/s and 40 km altitude, causing the effective specific heat ratio to decrease. The transition next occurs in an equilibrium flow regime as velocities decrease through 3.5 km/s and the specific heat ratio increases again with decreasing enthalpy. The effects of the expansion over the shoulder into the wake are more strongly felt on the fustrum when the sonic line sits on the shoulder. The transition also produces a counter-intuitive trend in which windside heating levels decrease with increasing angle of attack resulting from an increase in the effective radius of curvature. Six-degree-of-freedom trajectory analyses utilizing the computed aerodynamic coefficients predict a moderate, 3 to 4 degree increase in total angle of attack as the probe, spinning at approximately 2 revolutions per minute, passes through these regions.

  13. Project Icarus: Exploring the Interstellar Roadmap using the Icarus Pathfinder and Starfinder Probe Concepts

    NASA Astrophysics Data System (ADS)

    Swinney, R. W.; Long, K. F.; Hein, A.; Galea, P.; Mann, A.; Crowl, A.; Obousy, R.

    Project Icarus is a theoretical engineering design study tasked to explore the technical feasibility of sending an unmanned interstellar probe to a nearby star system. It is the successor study to the 1970s Project Daedalus conducted by members of The British Interplanetary Society. The Daedalus study showed that the performance of such a probe would require engines with approximately a million seconds or more specific impulse. The Daedalus solution was to use fusion based propulsion technology predicated on projected advancements in the technology. Fusion technology has also been chosen for the Icarus reference design mission so, given that current predictions of such propulsion systems are still many decades away, we introduce here two interstellar precursor missions which would test key Icarus technologies required for an interstellar mission.We introduce the Icarus Pathfinder Probe , a mission to 1,000 AU requiring a cruise velocity of between 50 - 100 AU/year. We also present the outline for the Icarus Starfinder Probe , designed to go to distances of 10,000-50,000 AU. In this paper we present the baseline concepts for these missions, which may be iterated to more credible configurations in the future in line with the Project Icarus timescales to complete the final Project Icarus study report by late 2014. This paper is a submission of the Project Icarus Study Group.

  14. Alignment test results of the JWST Pathfinder Telescope mirrors in the cryogenic environment

    NASA Astrophysics Data System (ADS)

    Whitman, Tony L.; Wells, Conrad; Hadaway, James B.; Knight, J. Scott; Lunt, Sharon

    2016-07-01

    After integration of the Optical Telescope Element (OTE) to the Integrated Science Instrument Module (ISIM) to become the OTIS, the James Webb Space Telescope OTIS is tested at NASA's Johnson Space Center (JSC) in the cryogenic vacuum Chamber A for alignment and optical performance. The alignment of the mirrors comprises a sequence of steps as follows: The mirrors are coarsely aligned using photogrammetry cameras with reflective targets attached to the sides of the mirrors. Then a multi-wavelength interferometer is aligned to the 18-segment primary mirror using cameras at the center of curvature to align reflected light from the segments and using fiducials at the edge of the primary mirror. Once the interferometer is aligned, the 18 primary mirror segments are then adjusted to optimize wavefront error of the aggregate mirror. This process phases the piston and tilt positions of all the mirror segments. An optical fiber placed at the Cassegrain focus of the telescope then emits light towards the secondary mirror to create a collimated beam emitting from the primary mirror. Portions of the collimated beam are retro-reflected from flat mirrors at the top of the chamber to pass through the telescope to the Science Instrument (SI) detector. The image on the detector is used for fine alignment of the secondary mirror and a check of the primary mirror alignment using many of the same analysis techniques used in the on-orbit alignment. The entire process was practiced and evaluated in 2015 at cryogenic temperature with the Pathfinder telescope.

  15. The Joint Milli-Arcsecond Pathfinder Survey (J-MAPS) Mission: Introduction and Science Goals

    NASA Astrophysics Data System (ADS)

    Gaume, Ralph A., Jr.; Dorland, B.; Hennessy, G.; Dudik, R.; Bartlett, J.; Dugan, Z.; Zacharias, N.; Johnston, K.; Makarov, V.

    2009-01-01

    The Joint Milli-Arcsecond Pathfinder Survey (J-MAPS) mission is a small, space-based, all-sky visible wavelength astrometric and photometric survey for 2nd through 15th magnitude stars with a 2012 launch goal. The primary mission goal for J-MAPS is the generation of a nearly 40 million star astrometric catalog with better than 1 milliarcsecond positional accuracy, and photometry to the 1% accuracy level, or better. A 1-mas (or better) all-sky survey will have a significant impact on our current understanding of galactic and stellar astrophysics. J-MAPS will impact our understanding of the origins of nearby young stars, provide insight into the dynamics of star formation regions and associations, investigate the dynamics and membership of nearby open clusters, and discover the smallest brown dwarfs at distances up to 5pc after a 2 year mission, and Jupiter-like planets out to 3pc after 4 years. J-MAPS will provide critical milliarcsecond level parallaxes of tens of millions of stars in the difficult 8-15th magnitude range, which when combined with stellar spectroscopy and relative radii determined from exoplanet transit surveys, allows a determination of stellar radii and exoplanet densities. In addition, the 20 year baseline between the groundbreaking Hipparcos mission and the J-MAPS mission allows the combination of J-MAPS and Hipparcos catalogs to produce common proper motions on the order of 50-100 microarcseconds per year.

  16. Morphology of APXS-Analyzed Rocks at the Mars Pathfinder Site

    NASA Astrophysics Data System (ADS)

    Basilevsky, A. T.; Markiewicz, W. J.; Thomas, N.; Keller, H. U.

    This paper considers the morphology of several rocks studied with the alpha proton X-ray spectrometer (APXS) at the Mars Pathfinder landing site. An analysis of the images (mainly stereo images) of these rocks has shown that six of the eight rocks have at least one, more often two or more, flat facets, which are likely formed along the planes of rock jointing or tectonic fracturing. The knobby-pitted and pitted textures on the surface of these and presumably other rocks at the landing site are largely the result of weathering. The rate of this weathering was lower by a factor of 100 than that in the Western Desert of Egypt, where similar textures were described. The studied rocks, with the exception maybe of Barnacle Bill and Wedge, were obviously brought to the place of their present occurrence by flows that formed the Ares and Tiu Valles. During their transportation, the rocks were rounded and episodically fragmented, which explains the presence of rounded and angular parts at most of these rocks. This specific feature of transportation, related presumably to catastrophic flow, prevents us from estimating the remoteness of the rocks from the source of their material. Two sources discussed in the literature-the material of the Noachian cratered crust and the material of Hesperian plains - should still be considered as tentative.

  17. Continuation of the NVAP Global Water Vapor Data Sets for Pathfinder Science Analysis

    NASA Technical Reports Server (NTRS)

    VonderHaar, Thomas H.; Engelen, Richard J.; Forsythe, John M.; Randel, David L.; Ruston, Benjamin C.; Woo, Shannon; Dodge, James (Technical Monitor)

    2001-01-01

    This annual report covers August 2000 - August 2001 under NASA contract NASW-0032, entitled "Continuation of the NVAP (NASA's Water Vapor Project) Global Water Vapor Data Sets for Pathfinder Science Analysis". NASA has created a list of Earth Science Research Questions which are outlined by Asrar, et al. Particularly relevant to NVAP are the following questions: (a) How are global precipitation, evaporation, and the cycling of water changing? (b) What trends in atmospheric constituents and solar radiation are driving global climate? (c) How well can long-term climatic trends be assessed or predicted? Water vapor is a key greenhouse gas, and an understanding of its behavior is essential in global climate studies. Therefore, NVAP plays a key role in addressing the above climate questions by creating a long-term global water vapor dataset and by updating the dataset with recent advances in satellite instrumentation. The NVAP dataset produced from 1988-1998 has found wide use in the scientific community. Studies of interannual variability are particularly important. A recent paper by Simpson, et al. that examined the NVAP dataset in detail has shown that its relative accuracy is sufficient for the variability studies that contribute toward meeting NASA's goals. In the past year, we have made steady progress towards continuing production of this high-quality dataset as well as performing our own investigations of the data. This report summarizes the past year's work on production of the NVAP dataset and presents results of analyses we have performed in the past year.

  18. Alignment Test Results of the JWST Pathfinder Telescope Mirrors in the Cryogenic Environment

    NASA Technical Reports Server (NTRS)

    Whitman, Tony L.; Wells, Conrad; Hadaway, James; Knight, J. Scott; Lunt, Sharon

    2016-01-01

    After integration of the Optical Telescope Element (OTE) to the Integrated Science Instrument Module (ISIM) to become the OTIS, the James Webb Space Telescope OTIS is tested at NASAs Johnson Space Center (JSC) in the cryogenic vacuum Chamber A for alignment and optical performance. The alignment of the mirrors comprises a sequence of steps as follows: The mirrors are coarsely aligned using photogrammetry cameras with reflective targets attached to the sides of the mirrors. Then a multi-wavelength interferometer is aligned to the 18-segment primary mirror using cameras at the center of curvature to align reflected light from the segments and using fiducials at the edge of the primary mirror. Once the interferometer is aligned, the 18 primary mirror segments are then adjusted to optimize wavefront error of the aggregate mirror. This process phases the piston and tilt positions of all the mirror segments. An optical fiber placed at the Cassegrain focus of the telescope then emits light towards the secondary mirror to create a collimated beam emitting from the primary mirror. Portions of the collimated beam are retro-reflected from flat mirrors at the top of the chamber to pass through the telescope to the SI detector. The image on the detector is used for fine alignment of the secondary mirror and a check of the primary mirror alignment using many of the same analysis techniques used in the on-orbit alignment. The entire process was practiced and evaluated in 2015 at cryogenic temperature with the Pathfinder telescope.

  19. Mars Pathfinder Spacecraft, Lander, and Rover Testing in Simulated Deep Space and Mars Surface Environments

    NASA Technical Reports Server (NTRS)

    Johnson, Kenneth R.

    1997-01-01

    The Mars Pathfinder (MPF) Spacecraft was built and tested at the Jet Propulsion Laboratory during 1995/96. MPF is scheduled to launch in December 1996 and to land on Mars on July 4, 1997. The testing program for MPF required subjecting the mission hardware to both deep space and Mars surface conditions. A series of tests were devised and conducted from 1/95 to 7/96 to study the thermal response of the MPF spacecraft to the environmental conditions in which it will be exposed during the cruise phase (on the way to Mars) and the lander phase (landed on Mars) of the mission. Also, several tests were conducted to study the thermal characteristics of the Mars rover, Sojourner, under Mars surface environmental conditions. For these tests, several special test fixtures and methods were devised to simulate the required environmental conditions. Creating simulated Mars surface conditions was a challenging undertaking since Mars' surface is subjected to diurnal cycling between -20 C and -85 C, with windspeeds to 20 m/sec, occurring in an 8 torr CO2 atmosphere. This paper describes the MPF test program which was conducted at JPL to verify the MPF thermal design.

  20. Combining IRIS/Hinode Observations and Modeling: a Pathfinder for Coronal Heating

    NASA Astrophysics Data System (ADS)

    Antolin, P.; Okamoto, J.; De Pontieu, B.

    2015-12-01

    The combination of imaging and spectroscopic instruments with multiple temperature diagnostics at high spatial, temporal and spectral resolution can allow to recover the 3D plasma flow and thermodynamic evolution associated with specific coronal heating mechanisms. Although very hard considering the complexity of the solar atmosphere, this approach is becoming possible now through combination of instruments such as IRIS and Hinode, and with proper guiding from advanced numerical simulations and forward modeling. In this talk I will review recent examples of this approach, focusing on a particular, recently published, case study, that serves as a pathfinder in the search for the dominant coronal heating mechanism. In this case, resonant absorption, a long hypothesised wave-related energy conversion mechanism is spotted in action for the first time, and is characterised by a peculiar 3D motion of the plasma. With the help of 3D MHD numerical simulations and forward modeling the observational signatures of resonant absorption are characterised, matching very well the observational results. The process through which this mechanism can lead to observed significant heating in the solar corona is further identified: the resonant flow becomes turbulent following dynamic instabilities and heats the plasma. I will show how this resonance + instability process is expected in different scenarios of the solar atmosphere (the corona, prominences and spicules) and can potentially explain several observed features that remain so far unexplained.

  1. CubeSats as pathfinders for planetary detection: the FIRST-S satellite

    NASA Astrophysics Data System (ADS)

    Lacour, S.; Lapeyrère, V.; Gauchet, L.; Arroud, S.; Gourgues, R.; Martin, G.; Heidmann, S.; Haubois, X.; Perrin, G.

    2014-08-01

    The idea behind FIRST (Fibered Imager foR a Single Telescope) is to use single-mode fibers to combine multiple apertures in a pupil plane as such as to synthesize a bigger aperture. The advantages with respect to a pure imager are i) relaxed tolerance on the pointing and cophasing, ii) higher accuracy in phase measurement, and iii) availability of compact, precise, and active single-mode optics like Lithium Niobate. The latter point being a huge asset in the context of a space mission. One of the problems of DARWIN or SIM-like projects was the difficulty to find low cost pathfinders missions. But the fact that Lithium Niobate optic is small and compact makes it easy to test through small nanosats missions. Moreover, they are commonly used in the telecom industry, and have already been tested on communication satellites. The idea of the FIRST-S demonstrator is to spatialize a 3U CubeSat with a Lithium Niobate nulling interferometer. The technical challenges of the project are: star tracking, beam combination, and nulling capabilities. The optical baseline of the interferometer would be 30 cm, giving a 2.2AU spatial resolution at distance of 10 pc. The scientific objective of this mission would be to study the visible emission of exozodiacal light in the habitable zone around the closest stars.

  2. NOVA2-mediated RNA regulation is required for axonal pathfinding during development

    PubMed Central

    Saito, Yuhki; Miranda-Rottmann, Soledad; Ruggiu, Matteo; Park, Christopher Y; Fak, John J; Zhong, Ru; Duncan, Jeremy S; Fabella, Brian A; Junge, Harald J; Chen, Zhe; Araya, Roberto; Fritzsch, Bernd; Hudspeth, A J; Darnell, Robert B

    2016-01-01

    The neuron specific RNA-binding proteins NOVA1 and NOVA2 are highly homologous alternative splicing regulators. NOVA proteins regulate at least 700 alternative splicing events in vivo, yet relatively little is known about the biologic consequences of NOVA action and in particular about functional differences between NOVA1 and NOVA2. Transcriptome-wide searches for isoform-specific functions, using NOVA1 and NOVA2 specific HITS-CLIP and RNA-seq data from mouse cortex lacking either NOVA isoform, reveals that NOVA2 uniquely regulates alternative splicing events of a series of axon guidance related genes during cortical development. Corresponding axonal pathfinding defects were specific to NOVA2 deficiency: Nova2-/- but not Nova1-/- mice had agenesis of the corpus callosum, and axonal outgrowth defects specific to ventral motoneuron axons and efferent innervation of the cochlea. Thus we have discovered that NOVA2 uniquely regulates alternative splicing of a coordinate set of transcripts encoding key components in cortical, brainstem and spinal axon guidance/outgrowth pathways during neural differentiation, with severe functional consequences in vivo. DOI: http://dx.doi.org/10.7554/eLife.14371.001 PMID:27223325

  3. SISTINE: a pathfinder for FUV imaging spectroscopy on future NASA astrophysics missions

    NASA Astrophysics Data System (ADS)

    Fleming, Brian T.; France, Kevin; Nell, Nicholas; Kruczek, Nicholas; Kane, Robert; Green, James; Quijada, Manuel A.; Del Hoyo, Javier; Siegmund, Oswald

    2016-07-01

    The University of Colorado ultraviolet sounding rocket program presents the motivation and design capabilities of the new Suborbital Imaging Spectrograph for Transition Region Irradiance from Nearby Exoplanet host stars (SISTINE). SISTINE is a pathfinder for future UV space instrumentation, incorporating advanced broadband refl ective mirror coatings and large format borosilicate microchannel plate detectors that address technology gaps identified by the NASA Cosmic Origins program. The optical design capitalizes on new capabilities enabled by these technologies to demonstrate optical pathlengths in a sounding rocket envelope that would otherwise require a prohibitive effective area penalty in the 1020 - 1150 Å bandpass. This enables SISTINE to achieve high signal-to-noise observations of emission lines from planet-hosting dwarf stars with moderate spectral resolution (R 10,000) and sub-arcsecond angular imaging. In this proceedings, we present the scientific motivation for a moderate resolution imaging spectrograph, the design of SISTINE, and the enabling technologies that make SISTINE, and future advanced FUV-sensitive instrumentation, possible.

  4. Assessment of Greenland albedo variability from the advanced very high resolution radiometer Polar Pathfinder data set

    NASA Astrophysics Data System (ADS)

    Stroeve, Julienne

    2001-12-01

    The advanced very high resolution radiometer Polar Pathfinder (APP) data set is used to examine the variability of the surface albedo over Greenland. Analysis of the APP albedo record from 1981 to 1998 show anomalously low albedo during 1995 and 1998 over most of the ice sheet as compared with the other years. The low albedo encountered during these years suggests that the ice sheet experienced considerable melt in 1995 and 1998, particularly near the western margin of the ice sheet. Conversely, anomalously high albedos were found in 1992 as a result of colder temperatures and hence less melt following the eruption of Mount Pinatubo. The relationship between the annual North Atlantic Oscillation (NAO) index and the mean summer albedo from all the stations reveals a positive correlation of 0.44 and a positive correlation of 0.55 for the southern part of the ice sheet. Therefore variations in the mean summer albedo over Greenland can, in part, be explained by variations in the NAO such that during periods of intensification of the normal mode of the NAO the mean summer albedo is above normal. Trend analysis reveals an overall downward trend in surface albedo from 1981 to 1998, which agrees with recent trends in melt and precipitation. However, the trend was found not to be statistically significant but rather influenced by the low albedo in recent years.

  5. Using virtual reality for science mission planning: A Mars Pathfinder case

    NASA Technical Reports Server (NTRS)

    Kim, Jacqueline H.; Weidner, Richard J.; Sacks, Allan L.

    1994-01-01

    NASA's Mars Pathfinder Project requires a Ground Data System (GDS) that supports both engineering and scientific payloads with reduced mission operations staffing, and short planning schedules. Also, successful surface operation of the lander camera requires efficient mission planning and accurate pointing of the camera. To meet these challenges, a new software strategy that integrates virtual reality technology with existing navigational ancillary information and image processing capabilities. The result is an interactive workstation based applications software that provides a high resolution, 3-dimensial, stereo display of Mars as if it were viewed through the lander camera. The design, implementation strategy and parametric specification phases for the development of this software were completed, and the prototype tested. When completed, the software will allow scientists and mission planners to access simulated and actual scenes of Mars' surface. The perspective from the lander camera will enable scientists to plan activities more accurately and completely. The application will also support the sequence and command generation process and will allow testing and verification of camera pointing commands via simulation.

  6. Intercomparison Between in situ and AVHRR Polar Pathfinder-Derived Surface Albedo over Greenland

    NASA Technical Reports Server (NTRS)

    Stroeve, Julienne C.; Box, Jason E.; Fowler, Charles; Haran, Terence; Key, Jeffery

    2001-01-01

    The Advanced Very High Resolution (AVHRR) Polar Pathfinder Data (APP) provides the first long time series of consistent, calibrated surface albedo and surface temperature data for the polar regions. Validations of these products have consisted of individual studies that analyzed algorithm performance for limited regions and or time periods. This paper reports on comparisons made between the APP-derived surface albedo and that measured at fourteen automatic weather stations (AWS) around the Greenland ice sheet from January 1997 to August 1998. Results show that satellite-derived surface albedo values are on average 10% less than those measured by the AWS stations. However, the station measurements tend to be biased high by about 4% and thus the differences in absolute albedo may be less (e.g. 6%). In regions of the ice sheet where the albedo variability is small, such as the dry snow facies, the APP albedo uncertainty exceeds the natural variability. Further work is needed to improve the absolute accuracy of the APP-derived surface albedo. Even so, the data provide temporally and spatially consistent estimates of the Greenland ice sheet albedo.

  7. Concept of Science Data Management for the Korea Pathfinder Lunar Orbiter

    NASA Astrophysics Data System (ADS)

    Kim, Joo Hyeon

    2016-10-01

    South Korea has a plan to explore the Moon in 2018 or 2019. For the plan, the Korea Aerospace Research Institute which is a government funded research institute kicked off the Korea Lunar Exploration Development Program in January, 2016 in support of Ministry of Science, ICT and Future Planning, South Korea.As the 1st stage mission of the program, named as the Korea Pathfinder Lunar Orbiter(KPLO), will perform acquisition of high resolution images and science data for investigation of lunar environment as well as the core technology demonstration and validation for space explorations. The scientific instruments consists of three Korean domestic developed science instruments except an imaging instrument and several foreign provided instruments. We are developing a science data management plan to encourage scientific activities using science data acquired by the science instruments.I introduce the Korean domestic developed science instruments and present concept of the science data management plan for data delivery, processing, and distribution for the science instruments.

  8. Mars Pathfinder Landing Site: Evidence for a Change in Wind Regime from Lander and Orbiter Data

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Kraft, Michael D.; Kuzmin, Ruslan O.; Bridges, Nathan T.

    2000-01-01

    Surface features related to the wind are observed in the vicinity of the Mars Pathfinder (MPR landing site data from the lander and in data from orbit by the Viking Orbiter and Mars Global Surveyor missions. Features seen from the surface include wind tails associated with small rocks, barchanoid duneforms, ripplelike patterns, and ventifact flutes cut into some rocks. Features seen from orbit include wind tails associated with impact craters, ridges inferred to be duneforms, and modified crater rims interpreted to have been eroded and mantled by windblown material. The orientations of these features show two prevailing directions. One is inferred to represent winds from the northeast, which is consistent with strongest winds predicted by a general circulation model to occur during the Martian northern winter under current conditions. A second wind blowing from the ESE was responsible for modifying the crater rims and cutting some of the ventifacts. The two wind regimes could reflect a change in climate related to Mars' obliquity or some other, unknown factor. Regardless of the cause, the MPF area has been subjected to a complex pattern of winds and supply of small particles, and the original surface formed by sedimentary processes from Tiu and Ares Vallis flooding events has been modified by repeated burial and exhumation.

  9. Terrestrial Analogs to Wind-Related Features at the Viking and Pathfinder Landing Sites on Mars

    NASA Technical Reports Server (NTRS)

    Greeley, Ronald; Bridges, Nathan T.; Kuzmin, Ruslan O.; Laity, Julie E.

    2002-01-01

    Features in the Mojave Desert and Iceland provide insight into the characteristics and origin of Martian wind-related landforms seen by the Viking and Pathfinder landers. The terrestrial sites were chosen because they exhibit diverse wind features that are generally well understood. These features have morphologies comparable to those on Mars and include origins by deposition and erosion, with erosional processes modifying both soils and rocks. Duneforms and drifts are the most common depositional features seen at the Martian landing sites and indicate supplies of sand-sized particles blown by generally unidirectional winds. Erosional features include lag deposits, moat-like depressions around some rocks, and exhumed soil horizons. They indicate that wind can deflate at least some sediments and that this process is particularly effective where the wind interacts with rocks. The formation of ripples and wind tails involves a combination of depositional and erosional processes. Rock erosional features, or ventifacts, are recognized by their overall shapes, erosional flutes, and characteristic surface textures resulting from abrasion by windblown particles. The physics of saltation requires that particles in ripples and duneforms are predominantly sand-sized (60-2000 microns). The orientations of duneforms, wind tails, moats, and ventifacts are correlated with surface winds above particle threshold. Such winds are influenced by local topography and are correlated with winds at higher altitudes predicted by atmospheric models.

  10. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    NASA Astrophysics Data System (ADS)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  11. An Alpha Proton X-Ray Spectrometer for Mars-96 and Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Rieder, R.; Wanke, H.; Economou, T.

    1996-09-01

    Mars Pathfinder and the Russian Mars-96 will carry an Alpha Proton X-Ray Spectrometer (APXS) for the determination of the chemical composition of Martian rocks and soil. The instrument will measure the concentration of all major and many minor elements, including C,N and O, at levels above typically 1%. The method employed consist of bombarding a sample of 50 mm diameter with alpha particles from a radioactive source (50 mCi of Cm-244) and measuring: (i) backscattered alpha particles (alpha mode) (ii) protons from (a,p) reactions with some light elements (proton mode) (iii) characteristic X-rays emitted from the sample (X-ray mode). The APXS has a long standing space heritage, going back to Surveyor V,VI and VII (1967/68) and the Soviet Phobos (1988) missions. The present design is the result of an endeavour to reduce mass and power consumption to 600g/ 300mW. It consist of a sensor head containing the alpha sources, a telescope of a silicon detectors for the detection of the alpha particles and protons and a separate X-ray detector with its preamplifier, and an electronics box (80x70x60 mm) containing a microcontroller based multichannel spectrometer. The paper will describe the APXS flight hardware and present results obtained with the flight instrument that will show the instrument capabili- ties and the expected results to be obtained during surface operations on Mars.

  12. Modelling Choice: Factors Influencing Modes of Delivery in Australian Universities

    ERIC Educational Resources Information Center

    Smith, Andrew; Ling, Peter; Hill, Doug

    2008-01-01

    This paper reports the findings of a study of Multiple Modes of Delivery in Australian universities that was commissioned by Australian Universities Teaching Committee over the period 2001-2004. The project examined and described the various means of educational delivery deployed by Australian universities. It identified the pedagogical,…

  13. Australian Indigenous Perspectives on Quality Assurance in Children's Services

    ERIC Educational Resources Information Center

    Hutchins, Teresa; Frances, Katie; Saggers, Sherry

    2009-01-01

    The Australian Government has recently committed to the development of an integrated system of assuring national quality standards for Australian childcare and preschool services (Australian Government, 2008). This article addresses two fundamental issues relating to the development of an integrated system as it applies to Indigenous children's…

  14. Drama in the Australian National Curriculum: Decisions, Tensions and Uncertainties

    ERIC Educational Resources Information Center

    Stinson, Madonna; Saunders, John Nicholas

    2016-01-01

    In September 2015, the Australian Federal Government endorsed the final version of the Australian Curriculum arts framework a document resulting from nearly seven years of consultation and development. "The Australian Curriculum: The Arts Version 8.0" comprises five subjects: dance, drama, media arts, music and visual arts. This article…

  15. Building Innovation: Learning with Technologies. Australian Education Review Number 56

    ERIC Educational Resources Information Center

    Moyle, Kathryn

    2010-01-01

    Australian Education Review (AER) 56 explores national and international policy priorities for building students' innovation capabilities through information and communication technologies (ICT) in Australian schools. Section 1 sets out the Australian policy context for digital education and highlights some of the emerging challenges. It provides…

  16. Data Convergence - An Australian Perspective

    NASA Astrophysics Data System (ADS)

    Allen, S. S.; Howell, B.

    2012-12-01

    Coupled numerical physical, biogeochemical and sediment models are increasingly being used as integrators to help understand the cumulative or far field effects of change in the coastal environment. This reliance on modeling has forced observations to be delivered as data streams ingestible by modeling frameworks. This has made it easier to create near real-time or forecasting models than to try to recreate the past, and has lead in turn to the conversion of historical data into data streams to allow them to be ingested by the same frameworks. The model and observation frameworks under development within Australia's Commonwealth and Industrial Research Organisation (CSIRO) are now feeding into the Australian Ocean Data Network's (AODN's) MARine Virtual Laboratory (MARVL) . The sensor, or data stream, brokering solution is centred around the "message" and all data flowing through the gateway is wrapped as a message. Messages consist of a topic and a data object and their routing through the gateway to pre-processors and listeners is determined by the topic. The Sensor Message Gateway (SMG) method is allowing data from different sensors measuring the same thing but with different temporal resolutions, units or spatial coverage to be ingested or visualized seamlessly. At the same time the model output as a virtual sensor is being explored, this again being enabled by the SMG. It is only for two way communications with sensor that rigorous adherence to standards is needed, by accepting existing data in less than ideal formats, but exposing them though the SMG we can move a step closer to the Internet Of Things by creating an Internet of Industries where each vested interest can continue with business as usual, contribute to data convergence and adopt more open standards when investment seems appropriate to that sector or business.Architecture Overview

  17. Encephalization of Australian and New Guinean marsupials.

    PubMed

    Ashwell, K W S

    2008-01-01

    Encephalization of Australian marsupials was analyzed using the endocranial volume (ECV) of 52 species of Dasyuromorphia and Notoryctemorphia, 14 species of Peramelemorphia and 116 species of Diprotodontia from Australia and New Guinea and compared with 16 species of Ameridelphian marsupials and 3 species of native and recently introduced Australian eutherian carnivores (dingo, feral cat and feral fox). Linear regression analysis of the relationship between ECV and body weight for marsupials revealed that allometric parameters for these groups are different from those previously derived for samples of (mainly eutherian) mammals, with higher slopes for Dasyuromorphia and Diprotodontia and lower slopes for Ameridelphians and Peramelemorphia. Absolute ECV for small Australian and New Guinea marsupial carnivores (Antechinus and Sminthopsis) were found to be comparable to eutherians of similar body weight, but large marsupial carnivores such as the Tasmanian devil and thylacine had substantially smaller ECVs than eutherian carnivores of similar body weight. Similarly, members of some superfamilies within Diprotodontia (Burramyoidea, Petauroidea, Tarsipedoidea) had ECVs comparable to prosimians, whereas bandicoots, bilbies and many macropods were found to be poorly encephalized. When both encephalization quotient (EQ) and residuals from regression analysis were used to compare relative ECV of extinct/threatened species with common species there were no significant differences for any of the orders of Australian marsupials, suggesting that encephalization is not a major factor in the current extinction crisis for Australian marsupials. Similarly there were no consistent differences in relative ECV between marsupials from New Guinea and associated islands compared to Australia or between arid and non-arid Australian regions for any of the marsupial orders. The results indicate that marsupials are not uniformly poorly encephalized and that small marsupial carnivores and

  18. Selection of the Australian indicator region

    NASA Technical Reports Server (NTRS)

    Reed, C. R. (Principal Investigator)

    1981-01-01

    Each Australian state was examined for the availability of LANDSAT data, area, yield, and production characteristics, statistics, crop calendars, and other ancillary data. Agrophysical conditions that could influence labeling and classification accuracies were identified in connection with the highest producing states as determined from available Australian crop statistics. Based primarily on these production statistics, Western Australia and New South Wales were selected as the wheat indicator region for Australia. The general characteristics of wheat in the indicator region, with potential problems anticipated for proportion estimation are considered. The varieties of wheat, the diseases and pests common to New South Wales, and the wheat growing regions of both states are examined.

  19. Successes, challenges and developments in Australian rheumatology.

    PubMed

    Morand, Eric F; Leech, Michelle T

    2015-07-01

    Australia is a geographically vast but sparsely populated country with many unique factors affecting the practice of rheumatology. With a population comprising minority Indigenous peoples, a historically European-origin majority population, and recent large-scale migration from Asia, the effect of ethnic diversity on the phenotype of rheumatic diseases such as systemic lupus erythematosus (SLE) is a constant of Australian rheumatology practice. Australia has a strong system of universal healthcare and subsidized access to medications, and clinical and research rheumatology are well developed, but inequitable access to specialist care in urban and regional centres, and the complex disconnected structure of the Australian healthcare system, can hinder the management of chronic diseases.

  20. Phenylphenalenones from the Australian plant Haemodorum simplex.

    PubMed

    Dias, Daniel Anthony; Goble, David James; Silva, Claudio Andres; Urban, Sylvia

    2009-06-01

    Chemical investigation of the Australian plant Haemodorum simplex resulted in the isolation of three new phenylphenalenones, haemodorone (10), haemodorol (11), and haemodorose (12), together with the previously reported compounds 5, dilatrin (6), and xiphidone (8). The first complete 2D NMR characterization for all of the compounds isolated, including several chemical shift reassignments for dilatrin (6), is reported. In addition this is one of the few reports to discuss the isolation of new phenylphenalenones from an Australian medicinal plant. The crude extract of both the bulbaceous and aerial components of the plant exhibited varying degrees of antibacterial, antifungal, and antiviral activity, and only the bulbs displayed potent cytotoxic activity.