Sample records for voyager space probes

  1. Simplistic propulsion analysis of a breakthrough space drive for Voyager

    NASA Astrophysics Data System (ADS)

    Boston, Malcolm D. K.

    2000-01-01

    When considering exploration beyond our solar system, speed is a critical factor. With the speeds achievable with current propulsion technology, interstellar distances cannot be traversed within a human life span. For example, the Voyager spacecraft would take approximately 80,000 years to traverse 4.3 light-years - the distance to our nearest neighboring star. In 1996 NASA established the Breakthrough Propulsion Physics program to search for further advances in physics to circumvent these limitations. One of the goals of this program is to discover a new method of propulsion that eliminates the need for propellant. A simplistic analysis is offered in this paper to assess the trip-time benefit of this single goal, using the Voyager spacecraft as a basis. The existing propulsion performance of the Voyager spacecraft is compared to its performance assuming it was equipped with a breakthrough physics space drive that could convert energy directly into kinetic energy. Given that the physics does not yet exist for such a space drive, these comparisons are at the most rudimentary level, based on energy comparisons. Specifically, the velocity and distance covered by the Voyager spacecraft are compared to that achievable by a hypothetical space drive using the same energy available to the existing Voyager. The additional benefit of having the Voyager's Radioisotope Thermoelectric Generators (RTGs) supply propulsion power is also considered. .

  2. A voyage to Mars: space radiation, aging, and nutrition

    Technology Transfer Automated Retrieval System (TEKTRAN)

    On exploratory class missions, such as a voyage to Mars, astronauts will be exposed to doses and types of radiation that are not experienced in low earth orbit where the space shuttle and International Space Station operate. Astronauts who participate in exploratory class missions outside the magne...

  3. Exploring the Planets: Voyager

    NSDL National Science Digital Library

    This site describes the Voyager exhibit at the National Air and Space Museum and gives additional information about the Voyagers that were launched into space and the one remaining in the museum. The Voyager spacecraft displayed in the Exploring the Planets gallery is similar to the two Voyagers sent to explore Jupiter, Saturn, Uranus, and Neptune. This portion of the exhibit details the Voyager missions, the spacecraft, and its instruments. Sixteen of the Voyager components and instrumentation are discussed in detail along with its unique power supply. The Museum's spacecraft is a full-scale replica of Voyager, parts of which were used for pre-launch engineering tests. Voyager is suspended above the Outer Planets display, which highlights some of the discoveries made through data and imagery returned by Voyagers 1 and 2.

  4. The Challenge of Space Futures: Starcomber's Galactic Voyage to Xeranthemom.

    ERIC Educational Resources Information Center

    Shimonauff, Jacqueline

    1998-01-01

    Describes a curriculum enrichment activity for gifted middle school students. Students design a long-range space travel vehicle and plan for colonizing a discovered planet. Students contact people in science and industry and produce a handbook for space travel and colonization. (DB)

  5. Your Mission: Investigate the geographical features on Venus and map the locations of space missions to Venus using a computer mapping program called Jules Verne Voyager

    E-print Network

    Smith-Konter, Bridget

    1 Your Mission: Investigate the geographical features on Venus and map the locations of space missions to Venus using a computer mapping program called Jules Verne Voyager Venus. Your Task: 1. Using the internet, navigate to the following webpage: http://jules.unavco.org/Voyager/Venus

  6. Gigapan Voyage for Robotic Recon

    NASA Technical Reports Server (NTRS)

    Lee, Susan Y.; Moorse, Theodore Fitzgerald; Park, Eric J.

    2010-01-01

    Gigapan Voyage (GV) is a self-contained remotely-operable Gigapan capturing system that is currently being developed by the Intelligent Robotics Group (IRG) at NASA Ames Research Center. Gigapan Voyage was primarily designed to be integrated onto Johnson Space Center s Lunar Electric Rovers (LER). While on LER, Gigapan Voyage was used by scientists and astronauts during the 2009 and 2010 Desert RATS field tests. The concept behind Gigapan Voyage is to merge all the sub-components of the commercial GigaPan system into an all-in-one system that can capture, stitch, and display Gigapans in an automated way via a simple web interface. The GV system enables NASA to quickly and easily add remote-controlled Gigapan capturing capability onto rovers with minimal integration effort. Key Words: Geology, NASA, Black Point Lava Flow, Robot, K10, LER, Gigapan Voyage, Desert RATS, Intelligent Robotics Group

  7. Ocean Voyagers

    NSDL National Science Digital Library

    Ocean Voyagers is an educational outreach initiative consisting of an interdisciplinary curriculum program. It is designed to allow middle school teachers and students to gain real-world knowledge about oceanographic science, social science, maritime cultures, communication, literature, and the language arts. This site includes: integrated lesson plans on oceanographic science, maritime life and lore, technology and communications, and profiles of the Navy oceanographic survey fleet.

  8. Space Place: What is the Secret Code Used by the Voyager Spacecraft?

    NSDL National Science Digital Library

    This module from the Space Place Web site allows students to learn the secret code spacecraft use to send images back from space. It introduces the language of computers and spacecraft. Binary and hexadecimal notations are explained. The Space Place is an educational NASA site for children and adults with activities and facts related to the exploration of space – past, current and future. Some activities are computer-interactive and many are real-world-interactive.

  9. Summary of Voyager Design and Flight Loads

    NASA Technical Reports Server (NTRS)

    Chen, J. C.; Garba, J. A.; Day, F. D., III

    1978-01-01

    Estimates of flight loads for Voyager 1 and Voyager 2 are summarized and compared to the Voyager design loads obtained from the shock spectra/impedance method and to the loads obtained using space vehicle transient loads analysis. These estimates were obtained by using the measured flight accelerations at the launch vehicle/spacecraft interface as forcing functions for the Voyager mathematical model. Based on these data, an assessment of the shock spectra/impedance loads method used for Voyager is presented. The following conclusions were reached: (1) the shock spectra approach provided reasonable conservative design loads for Voyager, (2) care has to be executed to insure that all critical events are accounted for in constructing shock spectra envelopes, (3) the selection of critical events is not always obvious, especially for those flight events wherein the spacecraft dynamic characteristics are important, and (4) the success of the method is strongly dependent on the analysts' experience and judgement.

  10. Exploring the Galaxy using space probes

    E-print Network

    Rasmus Bjoerk

    2007-04-23

    This paper investigates the possible use of space probes to explore the Milky Way, as a means both of finding life elsewhere in the Galaxy and as finding an answer to the Fermi paradox. I simulate exploration of the Galaxy by first examining how long time it takes a given number of space probes to explore 40,000 stars in a box from -300 to 300 pc above the Galactic thin disk, as a function of Galactic radius. I then model the Galaxy to consist of $\\sim{}260,000$ of these 40,000 stellar systems all located in a defined Galactic Habitable Zone and show how long time it takes to explore this zone. The result is that with 8 probes, each with 8 subprobes $\\sim{}4%$ of the Galaxy can be explored in $2.92\\cdot{}10^{8}$ years. Increasing the number of probes to 200, still with 8 subprobes each, reduces the exploration time to $1.52\\cdot{}10^{7}$ years.

  11. The Voyager Neptune travel guide

    NASA Technical Reports Server (NTRS)

    Kohlhase, Charles (editor)

    1989-01-01

    The Voyager mission to the giant outer planets of our solar system is described. Scientific highlights include interplanetary cruise, Jupiter, Saturn, Uranus, and their vast satellite and ring systems. Detailed plans are provided for the August 1989 Neptune encounter and subsequent interstellar journey to reach the heliopause. As background, the elements of an unmanned space mission are explained, with emphasis on the capabilities of the spacecraft and the scientific sensors. Other topics include the Voyager Grand Tour trajectory design, deep-space navigation, and gravity-assist concepts. The Neptune flyby is animated through the use of computer-generated, flip-page movie frames that appear in the corners of the publication. Useful historical information is also presented, including facts associated with the Voyager mission. Finally, short summaries are provided to describe the major objectives and schedules for several space missions planned for the remainder of the 20th century.

  12. Earth observations during Space Shuttle flight STS-29 - Discovery's voyage to the earth

    NASA Technical Reports Server (NTRS)

    Lulla, Kamlesh; Helfert, Michael; Whitehead, Victor; Amsbury, David; Coats, Michael; Blaha, John; Buchli, James; Springer, Robert; Bagian, James

    1989-01-01

    The environmental, geologic, meteorologic, and oceanographic phenomena documented by earth photography during the Space Shuttle STS-29 mission are reviewed. A map of the nadir point positions of earth-viewing photographs from the mission is given and color photographs of various regions are presented. The mission photographs include atmospheric dust and smoke over parts of Africa and Asia, Sahelian water sites, center pivot irrigation fields in the Middle East, urban smog over Mexico City, isolated burning in the Bolivian Amazon, and various ocean features and cloud formations.

  13. Employment of Asteroids for Movement Space Ship and Probes

    NASA Technical Reports Server (NTRS)

    Bolonkin, Alexander

    2002-01-01

    At present, rockets are used to change the trajectory of space ships and probes. This method is very expensive and requires a lot of fuel, which limits the feasibility of space stations, interplanetary space ships, and probes. Sometimes space probes use the gravity field of a planet. However, there are only 9 planets in our solar system and they are separated by great distances. There are tens of millions of asteroids in outer space. The author offers a revolutionary method for changing the trajectory of space probes. This method uses the kinetic or rotary energy of asteroids, meteorites or other space bodies (small planets, natural planet satellites, etc.). to increase (to decrease) ship (probe) speed up to 1000 m/sec (or more) and to get any new direction in outer space. The flight possibilities of space ships and probes are increased by a factor of millions.

  14. "Voyager": An Educational Card Game

    ERIC Educational Resources Information Center

    Smith, David Ryan

    2003-01-01

    "Voyager" is an educational card game involving scientific satellites, developed for use in schools with children aged 9 to 13 years. The idea of the game is to improve pupils' knowledge about the large number of scientific satellites there are in space in a fun way, while also practising numeracy skills. Several copies of the game were produced…

  15. Putting Voyager together

    NASA Technical Reports Server (NTRS)

    Mclaughlin, William I.

    1989-01-01

    The development of the Voyager missions is reviewed. The development of the technology is described, and the various components of the Voyager spacecraft are depicted and their functions identified. The budget pressures and their effects on the missions are discussed, and the problems experienced by the Voyager 2 spacecraft on its mission, and the way those were solved, are summarized.

  16. Wave Probe - New Instrument For Space Research

    NASA Astrophysics Data System (ADS)

    Korepanov, V.; Dudkin, F.

    2007-12-01

    The dispersion relations are very important for the wave activity study in space plasmas. One of the most efficient methods for their analysis is the simultaneous measurements of spatial current density and magnetic field fluctuations during such a wave process. Whereas the measurement of the magnetic field is a routine task realized onboard practically every spacecraft (SC), the direct measurement of spatial current density (SCD) still remains a complicated scientific and technological problem. First attempt to solve it was executed in late 60-ties by a group headed by F. Mozer. They proposed and launched in a rocket experiment the device named "Split Langmuir Probe" (SLP) - two conducting plates separated by a thin insulated split. Unfortunately this experiment failed what diverted the attention of experimenters in space branch from this instrument for many years, practically till now. But the importance to know the SCD stimulated the development of new principles and devices to measure it. A short review of known versions is discussed. The newly evoked interest to this problem caused next attempt to improve the SLP construction and methodology of its application for SCD measurements, which resulted in first successful attempt in 1985: the measured SCD onboard Prognos-10 SC in the bow shock region was in rather good agreement with the calculated value. This attempt was continued onboard Interball-Tail SC (1995-2000) where again a qualitatively good coincidence of measured and calculated values was observed. The obtained experience and further theoretical research allowed developing a new instrument - Wave Probe - which is a combination of induction magnetometer and SLP in one body. Both on-ground tests in plasma chamber and the spatial experiment executed onboard Ukrainian "Sich-1M" SC (2004) showed that the combined in-situ simultaneous measurements of SCD and magnetic field fluctuations allowed obtaining the wave number of the whistler wave. The same wave number was calculated theoretically from dispersion relations of whistler wave using known ionosphere model and the comparison of measured and calculated values of both wave number and SCD gave a good quantitative agreement. The details of theoretical and experimental study are discussed in the report. There is a pleasant duty of the authors to thank Prof. F. Mozer and Prof. S. Klimov for continuous attention and practical support of this work. It was also supported by NSAU contract No 1-02/03.

  17. Voyager program. Voyager 1 encounter at Jupiter, 5 March 1979

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Highlights of Voyager 1 activity during the observatory and far-encounter phases are summarized. Daily sequence of events for the spacecraft during the period of greatest encounter activity (Feb. 26 through Mar. 7) the near-encounter phase is given. Times shown designate the time of signal reception at Deep Space Network stations. Events listed emphasize activities pertaining to the four remote sensing instruments on the scan platforms. However, the other 7 experiments will continuously collect data throughout the encounter period.

  18. Reacting to nuclear power systems in space: American public protests over outer planetary probes since the 1980s

    NASA Astrophysics Data System (ADS)

    Launius, Roger D.

    2014-03-01

    The United States has pioneered the use of nuclear power systems for outer planetary space probes since the 1970s. These systems have enabled the Viking landings to reach the surface of Mars and both Pioneers 10 and 11 and Voyagers 1 and 2 to travel to the limits of the solar system. Although the American public has long been concerned about safety of these systems, in the 1980s a reaction to nuclear accidents - especially the Soviet Cosmos 954 spacecraft destruction and the Three Mile Island nuclear power plant accidents - heightened awareness about the hazards of nuclear power and every spacecraft launch since that time has been contested by opponents of nuclear energy. This has led to a debate over the appropriateness of the use of nuclear power systems for spacecraft. It has also refocused attention on the need for strict systems of control and rigorous checks and balances to assure safety. This essay describes the history of space radioisotope power systems, the struggles to ensure safe operations, and the political confrontation over whether or not to allow the launch the Galileo and Cassini space probes to the outer planets. Effectively, these efforts have led to the successful flights of 12 deep space planetary probes, two-thirds of them operated since the accidents of Cosmos 954, Three Mile Island, and Chernobyl.

  19. Voyager at Uranus: 1986

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The voyager 2 spacecraft begins its initial observations of Uranus November 4, 1985, and makes its final observation February 25, 1996. The data from the infrared interfermometer spectrometer, photopolarimeters, plasma wave, plasma detecter, and ultraviolet spectrometer will be processed to add a large block of infermation to the small amount already known. The trajectory of Voyager 2 is also discussed.

  20. Médecine des voyages

    PubMed Central

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  1. Galileo Probe battery system [space power

    Microsoft Academic Search

    B. P. Dagarin; R. K. Taenaka; E. J. Stofel

    1996-01-01

    This past year, the Galileo Probe successfully completed its ambitious mission-descending into Jupiter's atmosphere to measure its gaseous properties. This brought to fruition work that had been in progress for 18 years, the last 6 of which were required just for the long transit from Earth to Jupiter. The Probe's electrical source was a primary Li-SO2 battery, supplemented with thermally

  2. Solar System Voyage

    NASA Astrophysics Data System (ADS)

    Brunier, Serge

    2002-11-01

    In the last few decades, the exploration of our solar system has revealed fascinating details about the worlds that lie beyond our Earth. This lavishly illustrated book invites the reader on a journey through the solar system. After locating our planetary system in the Universe, Brunier describes the Sun and its planets, the large satellites, asteroids, and comets. Photographs and information taken from the latest space missions allow readers to experience spectacular scenes: the lunar plains scarred by asteroid impacts, the frozen deserts of Mars and Europa, the continuously erupting volcanoes of Io and the giant geysers of Triton, the rings of Saturn and the clouds of Venus and Titan, and the powerful crash of the comet Shoemaker-Levy into Jupiter. Inspired by the extraordinary photographs and incisive text, readers of Solar System Voyage will gain a greater appreciation of the hospitable planet we call home. Serge Brunier is chief editor of the journal Ciel et Espace, a photojournalist, and the author of many nonfiction books aimed at both specialists and the general public. His previous books include Space Odyssey (Cambridge, 2002), Glorious Eclipses with Jean-Pierre Luminet (Cambridge, 2000), and Majestic Universe (Cambridge, 1999).

  3. Tangible UIs for Media Control Probes Into the Design Space

    E-print Network

    Tangible UIs for Media Control ­ Probes Into the Design Space Andreas Butz University of Munich these are only small spotlights into a large design space, they nicely show the possible diversity. We also to simulate with standard PCs. Here we will report on the design process and the results of these students

  4. Voyager: Neptune Encounter Highlights

    NASA Technical Reports Server (NTRS)

    1989-01-01

    Voyager encounter data are presented in computer animation (CA) and real (R) animation. The highlights include a view of 2 full rotations of Neptune. It shows spacecraft trajectory 'diving' over Neptune and intercepting Triton's orbit, depicting radiation and occulation zones. Also shown are a renegade orbit of Triton and Voyager's encounter with Neptune's Magnetopause. A model of the spacecraft's complex maneuvers during close encounters of Neptune and Triton is presented. A view from Earth of Neptune's occulation experiment is is shown as well as a recreation of Voyager's final pass. There is detail of Voyager's Image Compensation technique which produces Voyager images. Eighteen images were produced on June 22 - 23, 1989, from 57 million miles away. A 68 day sequence which provides a stroboscopic view - colorization approximates what is seen by the human eye. Real time images recorded live from Voyager on 8/24/89 are presented. Photoclinometry produced the topography of Triton. Three images are used to create a sequence of Neptune's rings. The globe of Neptune and 2 views of the south pole are shown as well as Neptune rotating. The rotation of a scooter is frozen in images showing differential motion. There is a view of rotation of the Great Dark Spot about its own axis. Photoclinometry provides a 3-dimensional perspective using a color mosaic of Triton images. The globe is used to indicate the orientation of Neptune's crescent. The east and west plumes on Triton are shown.

  5. Voyager Encounter Highlights

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The following are presented: computer animation of trajectories for both Voyagers 1 and 2; view of Jupiter during one orbit of Ganymede; computer animation of Voyager 2's encounter with Jupiter and its satellites; time lapse of the planet's rotation and its satellites; stroboscopic sequence of selected frames; cloud motion; Jupiter's Great Red Spot (4/25 - 5/24, 1979) through a violet filter; and the Great Red Spot through a blue filter by Voyager 1. The dynamics of Jupiter's clouds are shown - the whole planet is shown first, then two closer looks are repeated several times. Also included are pans of stills of Jupiter's satellites and a computer simulation tour of Saturn system from POV just behind Voyager, made of 116 images of Saturn through a green filter and of 516 images taken by Voyager 1 (9/12 - 9/14, 1980). Frames are enhanced to show the motion of features in Saturn's rings. Pans of stills of Saturn's satellites are shown. There is computer animation of the planet's system, rings, and Sigma Sagittari. Images on January 14, 1986 are through an orange filter. Uranus's satellites are shown as is computer animation of an August 1989 encounter.

  6. Voyager electronic parts radiation program, volume 1

    NASA Technical Reports Server (NTRS)

    Stanley, A. G.; Martin, K. E.; Price, W. E.

    1977-01-01

    The Voyager spacecraft is subject to radiation from external natural space, from radioisotope thermoelectric generators and heater units, and from the internal environment where penetrating electrons generate surface ionization effects in semiconductor devices. Methods for radiation hardening and tests for radiation sensitivity are described. Results of characterization testing and sample screening of over 200 semiconductor devices in a radiation environment are summarized.

  7. Citizens in Space: Participating in sub orbital student space probe development

    NASA Astrophysics Data System (ADS)

    Adkins, J.

    2012-12-01

    Volunteer students from Deer Valley High School participated in the development of a microcomputer-based sensor probe to be deployed on a sub orbital rocket during the 2011-2012 school year. The design was initiated by a group formerly known as Teachers in Space and now designated as Citizens in Space. Masten Space Systems has offered to launch the probes. Our student volunteers worked on Friday afternoons for most of a school year to develop a radiation probe based on a Vernier radiation sensor. The design, software, and current status of the project will be shared.

  8. Voyager Saturn encounter press briefing

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The briefing reviewed the mission planning of the Voyager project. The near encounter trajectories of both Voyager spacecraft were examined. The Saturn system is discussed with particular emphasis on Saturn's moons.

  9. Features of the Gravity Probe B Space Vehicle

    Microsoft Academic Search

    William Reeve; Gaylord Green

    2007-01-01

    Space vehicle performance enabled successful relativity data collection throughout the Gravity Probe B mission. Precision pointing and drag-free translation control was maintained using proportional helium micro-thrusters. Electrical power was provided by rigid, double sided solar arrays. The 1.8 kelvin science instrument temperature was maintained using the largest cryogenic liquid helium dewar ever flown in space. The flight software successfully performed

  10. Probing mixed phase space dynamics using atom optics

    Microsoft Academic Search

    D. A. Steck; W. H. Oskay; M. G. Raizen

    2001-01-01

    Summary form only given. Atom optics has proven to be a fruitful testbed for the experimental study of quantum dynamics in classically chaotic systems. However, the quantum behavior in a mixed classical phase space, where both stable and chaotic regions are present, remains an interesting and challenging subject, with much left to understand. To probe local dynamics in mixed phase

  11. Ocean Voyagers Lesson Plans

    NSDL National Science Digital Library

    Ocean Voyagers is an educational outreach initiative consisting of an interdisciplinary curriculum program. It is designed to allow middle school teachers and students to gain real-world knowledge about oceanographic science, social science, maritime cultures, communication, literature, and the language arts. This collection features lesson plans on physical and biological oceanography, ecology, maritime heritage and culture.

  12. VOYAGER OBSERVATIONS OF THE DIFFUSE FAR-ULTRAVIOLET RADIATION FIELD

    SciTech Connect

    Murthy, Jayant [Indian Institute of Astrophysics, Bengalooru 560 034 (India); Henry, Richard Conn [Department of Physics and Astronomy, Johns Hopkins University, Baltimore, MD 21218 (United States); Holberg, Jay B., E-mail: jmurthy@yahoo.com [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

    2012-03-01

    The two Voyager spacecraft have completed their planetary exploration mission and are now probing the outer realms of the heliosphere. The Voyager ultraviolet spectrometers continued to operate well after the Voyager 2 Neptune encounter in 1989. We present a complete database of diffuse radiation observations made by both Voyagers: a total of 1943 spectra (500-1600 A) scattered throughout the sky. These include observations of dust-scattered starlight, emission lines from the hot interstellar medium, and a number of locations where no diffuse radiation was detected, with the very low upper limit of about 25 photons cm{sup -2} s{sup -1} sr{sup -1} A{sup -1}. Many of these observations were from late in the mission when there was significantly less contribution from interplanetary emission lines and thus less contamination of the interstellar signal.

  13. Van Allen Probes Science Gateway and Space Weather Data Processing

    NASA Astrophysics Data System (ADS)

    Romeo, G.; Barnes, R. J.; Weiss, M.; Fox, N. J.; Mauk, B.; Potter, M.; Kessel, R.

    2014-12-01

    The Van Allen Probes Science Gateway acts as a centralized interface to the instrument Science Operation Centers (SOCs), provides mission planning tools, and hosts a number of science related activities such as the mission bibliography. Most importantly, the Gateway acts as the primary site for processing and delivering the VAP Space Weather data to users. Over the past year, the web-site has been completely redesigned with the focus on easier navigation and improvements of the existing tools such as the orbit plotter, position calculator and magnetic footprint tool. In addition, a new data plotting facility has been added. Based on HTML5, which allows users to interactively plot Van Allen Probes summary and space weather data. The user can tailor the tool to display exactly the plot they wish to see and then share this with other users via either a URL or by QR code. Various types of plots can be created, including simple time series, data plotted as a function of orbital location, and time versus L-Shell. We discuss the new Van Allen Probes Science Gateway and the Space Weather Data Pipeline.

  14. Pu-powered space probes face uncertain future

    SciTech Connect

    NONE

    1994-10-01

    When fragments of comet Shoemaker-Levy 9 crashed into the gas clouds of Jupiter in July, the only representatives of humankind with a good view were a trio of spacecraft, Voyager 2, Galileo, and Ulysses. Radioisotope thermoelectric generators (RTGs) supplied by the Department of Energy provided the power to run the observing instruments on these spacecraft, but now that source of power-and all deep-space missions-may be in jeopardy. Despite the fact that the recently passed congressional appropriations bill increased funding for the RTG program by nearly 20 percent, from $51 million in 1994 to $61 million in 1995, rumors persist that the program is in danger of being discontinued. Peter Ulrich, chief of the Flight Programs Branch of the Solar System Exploration Division of the Office of Space Science at NASA, was confident that the program would stay alive through NASA`s next mission. RTGs will be on board the Cassini spacecraft scheduled to blast off in 1997 for an exploration of Saturn and its rings and moons. RTG`s use the heat produced by the alpha decay of plutonium-238 to heat a thermocouple, which generates electricity. Cassini is designed to carry three RTGs, producing a total of 750 W of electricity initially, decreasing to about 600 W by the time it reaches Saturn seven years after launch. The RTGs on Cassini will carry a total of about 70 lb of plutonium oxide. RTGs have no moving parts. They are simple, rugged, and reliable. According to Ulrich, {open_quotes}It`s really a very well-matched power source for something like a remote mission.{close_quotes} The political situation is less clear, though. {open_quotes}What I hear unofficially is funding looks dime,{close_quotes} said the DOE spokesperson, {open_quotes}and the lights are being turned off for these missions.{close_quotes} If that happens, the lights will go out on NASA`s deep-space missions to other parts of our solar system.

  15. The Gulf Stream Voyage

    NSDL National Science Digital Library

    The Gulf Stream Voyage is an online multidisciplinary project which utilizes both real time data and primary source materials to help guide students to discover the science and history of the Gulf Stream. Students investigate the driving forces behind this ocean current, how it affects the Atlantic Ocean and some of mankind's experiences dealing with it. This voyage includes activities for marine science, earth science, chemistry, physics, biology, math, history and language arts. This project has been developed to be used as a complete tutorial on the Gulf Stream. However, the activities are presented in a manner so that each may be used individually to supplement traditional classroom lessons. Students access real time ocean data, atmospheric data and historical primary source materials. Students utilize these resources, all in the context of an authentic real world problem.

  16. Voyager spies Uranus

    NASA Astrophysics Data System (ADS)

    Moore, P.

    1986-05-01

    In January 1986 Voyager 2 made its closest approach to Uranus, emerging with new information in such areas as ring and satellite number, rotation, temperature and hydrogen content. Nine rings were known to exist around Uranus before the Voyager 2 encounter; the spacecraft discovered three more. Ten new satellites were found, which were added to the original five. It became possible to fix the rotation period at 16.8 hrs, and the magnetic axis was found to be 55 deg away from the axis of rotation, with a northern polarity of the south magnetic pole. A feature unique to Uranian temperature variation is that the sunlit pole was found to be cooler than the night pole. The atmosphere, initially thought to have a helium content of 40 percent, contains a more conventional 10 percent. Moreover, present in the atmosphere is an electroglow, created by collisions between electrons and hydrogen molecules. It is noted that the Voyager 2, currently on its way to Neptune, after its initial launching in 1977, is still functioning perfectly.

  17. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with berth...

  18. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with berth...

  19. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with berth...

  20. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with berth...

  1. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...with voyage No. 1 having the prefixed designation NSA and followed by the General Agents' abbreviated designation and voyage number, as NSA-1/ABC-1. (b) The continuity of NSA voyage numbers shall not change with berth...

  2. Voyage to Kure

    NSDL National Science Digital Library

    The documentary film "Voyage to Kure" follows Jean-Michel Cousteau's team expedition to the Northwestern Hawaiian Islands, chronicling "the exploration of one of the last pristine coral reefs in the Pacific, a glimpse of paradise before the people." In this Web site from Ocean Futures Society, visitors can follow the expedition online with reports from the field, photos, and more. The site also includes links to the Web sites of state and federal agencies that worked with Ocean Futures Society on the film -- a good place to start for learning more about the islands and their unique coral reef ecosystems.

  3. Jules Verne Voyager, Jr.

    NSDL National Science Digital Library

    Chuck Meertens

    This interactive map tool enables students and scientists to better understand the relationships between geophysical and geological processes, structures, and measurements with high-precision GPS data. It contains prepared images taken from the Jules Verne Voyager. Users can choose from a variety of base maps, add a number of geographic and geophysical overlays (e.g. plate boundaries, earthquake and volcano locations), and then superimpose crustal motion velocity vectors to observe how the tectonic plates move in relation to one another. The tool can be used to explore topics such as plate tectonics, seafloor spreading, and seasonal land and ocean productivity.

  4. An Interesting Voyage

    NASA Astrophysics Data System (ADS)

    Rubin, Vera C.

    2011-09-01

    My life has been an interesting voyage. I became an astronomer because I could not imagine living on Earth and not trying to understand how the Universe works. My scientific career has revolved around observing the motions of stars within galaxies and the motions of galaxies within the Universe. In 1965, if you were very lucky and interested in using telescopes, you could walk into a research laboratory that was building instruments that reduced exposure times by a factor of 10 and end up making remarkable discoveries. Women generally required more luck and perseverance than men did. It helped to have supportive parents and a supportive husband.

  5. Voyager 1 examines Jupiter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    An overview of the Voyager mission to Jupiter, Saturn, and possibly Uranus is presented. Scientific instruments onboard the spacecraft are described as well as methods used for their calibration and evaluation during the cruise phase of the mission. Experiments to be performed cover the following areas: imaging science, radio science, cosmic rays, ultraviolet spectroscopy, photopolarimetry, planetary radio astronomy, magnetic fields, low-energy charged particles, plasma science, and infrared radiometry and spectroscopy. A list of the satellites of Jupiter and their diameters, distances, and periods is included.

  6. Voyager 1: Encounter with Jupiter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    An overview of the Voyager is presented along with samples of the nearly 19,000 photographs returned by Voyager 1 spacecraft at the midpoint of its 38-month mission to Jupiter and Saturn. Particular emphasis is given to color photographs of the Great Red Spot, and the surface features of the Gallilean satellites.

  7. IEC Thrusters for Space Probe Applications and Propulsion

    SciTech Connect

    Miley, George H.; Momota, Hiromu; Wu Linchun; Reilly, Michael P. [Dept. of Nuclear, Plasma and Radiological Engineering, University of Illinois, Urbana, IL (United States); Teofilo, Vince L. [Lockheed Martin Space Systems Co., Advanced Technology Center, Palo Alto, CA (United States); Burton, Rodney [Dept. of Aerospace Engineering, University of Illinois, Urbana, IL (United States); Dell, Richard; Dell, Dick [Advanced Aerospace Resource Center (AARC), Raleigh, NC (United States); Hargus, William A. [Air Force Research Laboratory, Edwards AFB, CA 217-333-3772 (United States)

    2009-03-16

    Earlier conceptual design studies (Bussard, 1990; Miley et al., 1998; Burton et al., 2003) have described Inertial Electrostatic Confinement (IEC) fusion propulsion to provide a high-power density fusion propulsion system capable of aggressive deep space missions. However, this requires large multi-GW thrusters and a long term development program. As a first step towards this goal, a progression of near-term IEC thrusters, stating with a 1-10 kWe electrically-driven IEC jet thruster for satellites are considered here. The initial electrically-powered unit uses a novel multi-jet plasma thruster based on spherical IEC technology with electrical input power from a solar panel. In this spherical configuration, Xe ions are generated and accelerated towards the center of double concentric spherical grids. An electrostatic potential well structure is created in the central region, providing ion trapping. Several enlarged grid opening extract intense quasi-neutral plasma jets. A variable specific impulse in the range of 1000-4000 seconds is achieved by adjusting the grid potential. This design provides high maneuverability for satellite and small space probe operations. The multiple jets, combined with gimbaled auxiliary equipment, provide precision changes in thrust direction. The IEC electrical efficiency can match or exceed efficiencies of conventional Hall Current Thrusters (HCTs) while offering advantages such as reduced grid erosion (long life time), reduced propellant leakage losses (reduced fuel storage), and a very high power-to-weight ratio. The unit is ideally suited for probing missions. The primary propulsive jet enables delicate maneuvering close to an object. Then simply opening a second jet offset 180 degrees from the propulsion one provides a 'plasma analytic probe' for interrogation of the object.

  8. GALILEO PROBE MEASUREMENTS OF D/H AND 3HE/4HE IN JUPITER'S ATMOSPHERE

    E-print Network

    Atreya, Sushil

    Goddard Space Flight Center, Greenbelt, MD 20771, USA Abstract. The Galileo Probe Mass Spectrometer to the mass peak at 3 amu. The D/H ratio is consistent with Voyager and ground based data and recent for D/H when compared with that for hydrogen in the local interstellar medium 1:6 0:12 10,5 implies

  9. Planetary radio astronomy from Voyager

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.

    1983-01-01

    The technique of radio astronomy makes it possible for a remote observer to detect the presence of magnetic fields and plasmas in planetary environments. Prior to the flights of the Voyager spacecraft, radio astronomical studies of Jupiter from earth and from earth orbit had correctly predicted the strength and orientation of Jupiter's magnetic field and trapped radiation belts. The Voyager Planetary Radio Astronomy investigations have now provided measurements of the complete spectrum of low frequency radio emissions from both planets. Each Voyager instrument consists of a pair of orthogonal, 10-m, electric monopole antennas which are connected to a step-tuned, superheterodyne receiver operating over the frequency range from 1.2 kHz to 40.5 MHz. The Voyager trajectory provided observations from above both the sunlit and nightside hemispheres of Jupiter. Saturn's nonthermal radio emission has been observed at frequencies as low as 3 kHz and as high as 1.2 MHz.

  10. Voyager Observations of the Heliosheath

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.; Decker, R. B.

    2014-12-01

    Voyager 2 has been observing plasma in the heliosheath since 2007. This paper presents the most recent data through 106 AU. The plasma flows at Voyager 2 have maintained a constant average speed throughout the heliosheath but have turned significantly. Flow angles are over 60 degrees in the azimuthal (RT) plane and 30 degrees in the meridional (RN) plane. Most of the plasma is moving around the side of the heliosphere. Average densities and temperatures have remained constant since an increase in 2011. This flow pattern is very different from that observed at Voyager 1 by the LECP partlcle instrument. We compare flows at Voyager 2 derived from the particle and plasma in the RT plane by the plasma and LECP instruments and find generally good agreement.

  11. The Voyager 2 Neptune encounter

    SciTech Connect

    Tsurutani, B.T. (JPL, Pasadena, CA (USA))

    1989-10-01

    The findings made by the Voyager 2 Neptune encounter are reviewed. Data on the bowshock, magnetic field, magnetosphere, rings, plasma sheet, aurora, moons, and dust of Neptune are discussed. Findings made concerning Triton are summarized.

  12. Virtual Voyages for Introductory Oceanography

    NSDL National Science Digital Library

    Karen Grove

    1998-12-10

    These Virtual Voyages were created as one-hour homework assignments for a freshman-level oceanography course at San Francisco State University (SFSU). Each voyage is structured around real-world images and includes five multiple-choice questions and five short-answer questions. Topics include seafloor bathymetry west of San Francisco, Earthquakes, Hawaiian hot spot, ocean waves, tides in San Francisco Bay, interaction of fresh and salt water in San Francisco Bay, ocean currents, sediments, and habitats for life.

  13. Magnetic field studies at Jupiter by Voyager 1: preliminary results

    Microsoft Academic Search

    N. F. Ness; M. H. Acuna; R. P. Lepping; L. F. Burlaga; K. W. Behannon; F. M. Neubauer

    1979-01-01

    Results obtained by the Goddard Space Flight Center magnetometers on Voyager 1 concerning the large scale configuration of the Jovian bow shock and magnetopause, and the magnetic field in both the inner and outer magnetosphere are highlighted. There is evidence that a magnetic tail extending away from the planet on the nightside is formed by the solar wind-Jovian field interaction.

  14. An integrated space physics instrument (ISPI) for Solar Probe

    Microsoft Academic Search

    B. T. Tsurutani; K. Leschly; S. Nikzad; E. R. Fossum; D. L. Chenette; I. Mann; G. Murphy; G. Musmann; F. Gliem; A. J. Tuzzolino; T. L. Killeen; B. C. Kennedy; S. L. Moses

    1997-01-01

    Instruments for the Solar Probe mission must be designed not only to address the unique scientific measurement requirements, but must be compatible with the modest resource dollars as well as tight constraints on mass and power. Another unique aspect of the Solar Probe mission is its constraint on telemetry and the fact that the prime science is conducted in a

  15. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...Shipping 3 2013-10-01 2013-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping...SAFETY STANDARDS AND COUNTRY OF REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means:...

  16. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...Shipping 3 2014-10-01 2014-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping...SAFETY STANDARDS AND COUNTRY OF REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means:...

  17. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...Shipping 3 2012-10-01 2012-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping...SAFETY STANDARDS AND COUNTRY OF REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means:...

  18. Space-Based Passing Time Estimation on a Freeway Using Cell Phones as Traffic Probes

    Microsoft Academic Search

    Keemin Sohn; Keeyeon Hwang

    2008-01-01

    This paper examines the usability of mobile cellular networks to obtain traffic information on a freeway. The question of whether a mobile station (cell phone) can play an acceptable role as a probe for collecting traffic information on a freeway is examined. A space-based approach, wherein the probe vehicles transmit information to roadside devices as they pass through reference points,

  19. november 2009 Darwin Virtual Voyage

    E-print Network

    Papautsky, Ian

    on natural selection, species change and even conflict between religion and Darwin's theories. Gushee, an art show on UC's campus celebrating Charles Darwin's legacy through linkages of science and artResearchUC november 2009 Darwin Virtual Voyage 4-D | Fashion Annual Report Edition #12;UC Wel

  20. And Then There Was Voyager

    NASA Technical Reports Server (NTRS)

    1990-01-01

    NASA's legendary grand tour of the outer solar system from the mission conception in the early 1970's is described. The search for the heliopause is discussed. This presentation is told in the words of the key members of the Voyager team.

  1. Enabling interstellar probe

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph L.; Wimmer-Schweingruber, Robert F.; International Interstellar Probe Team

    2011-04-01

    The scientific community has advocated a scientific probe to the interstellar medium for over 30 years. While the Voyager spacecraft have passed through the termination shock of the solar wind, they have limited lifetimes as their radioisotope power supplies decay. It remains unclear whether they can reach the heliopause, the boundary between shocked solar wind and interstellar plasmas, and, in any case, they will not reach the undisturbed interstellar medium. As with most exploratory space missions, their ongoing observations continue to raise even more questions about the nature of the interaction of our heliosphere and the interstellar medium. Scientific questions including: What is the nature of the nearby interstellar medium? How do the Sun and galaxy affect the dynamics of the heliosphere? What is the structure of the heliosphere? How did matter in the solar system and interstellar medium originate and evolve? can only be answered by an "interstellar precursor" probe. Such a mission is required to make in situ measurements in the interaction region and interstellar medium itself at distances far from the Sun, but in a finite mission lifetime. By launching a probe toward the incoming "interstellar wind," whose direction is known, the distance to be traveled can be minimized but is still large. The current consensus is that a scientifically compelling mission must function to at least a distance of 200 astronomical units (AU) from the Sun and return a reasonable stream of data during the voyage. The central problem is that of providing a means of propulsion to accelerate a probe from the Solar System. Even with a low-mass payload and spacecraft, achieving the high speeds needed, even with gravity assists, have remained problematic. Voyager 1, the fastest object ever to leave the system is now traveling ˜3.6 AU/yr, and a credible probe must reach at least 2-3 times this speed. The use of an Ares V is an approach for enabling a fast interstellar precursor mission. Maximum capability uses the combination of an Ares V, two-engine Centaur upper stage, close fly-by of Jupiter, and radioisotope electric propulsion (REP). Deletion of any of these pieces does not disable the mission, but does increase the flyout time to a given distance. This approach is more robust and provides a faster probe than an earlier alternative, designed for launch by a Delta IV 4050H plus twin Star 48A upper stages.

  2. VLA telemetry performance with concatenated coding for Voyager at Neptune

    NASA Technical Reports Server (NTRS)

    Dolinar, S. J., Jr.

    1988-01-01

    Current plans for supporting the Voyager encounter at Neptune include the arraying of the Deep Space Network (DSN) antennas at Goldstone, California, with the National Radio Astronomy Observatory's Very Large Array (VLA) in New Mexico. Not designed as a communications antenna, the VLA signal transmission facility suffers a disadvantage in that the received signal is subjected to a gap or blackout period of approximately 1.6 msec once every 5/96 sec control cycle. Previous analyses showed that the VLA data gaps could cause disastrous performance degradation in a VLA stand-alone system and modest degradation when the VLA is arrayed equally with Goldstone. New analysis indicates that the earlier predictions for concatenated code performance were overly pessimistic for most combinations of system parameters, including those of Voyager-VLA. The periodicity of the VLA gap cycle tends to guarantee that all Reed-Solomon codewords will receive an average share of erroneous symbols from the gaps. However, large deterministic fluctuations in the number of gapped symbols from codeword to codeword may occur for certain combinations of code parameters, gap cycle parameters, and data rates. Several mechanisms for causing these fluctuations are identified and analyzed. Even though graceful degradation is predicted for the Voyager-VLA parameters, catastrophic degradation greater than 2 dB can occur for a VLA stand-alone system at certain non-Voyager data rates inside the range of the actual Voyager rates. Thus, it is imperative that all of the Voyager-VLA parameters be very accurately known and precisely controlled.

  3. An Intergalactic Voyage.

    ERIC Educational Resources Information Center

    Wethered, Peggy Ann

    1997-01-01

    Describes an event called Star Week that involved families joining in their children's projects, attending an educational presentation by the National Aeronautics and Space Administration (NASA), and participating in a schoolwide star party. Contains resources for both students and teachers. (JRH)

  4. Radio science investigations with Voyager

    NASA Technical Reports Server (NTRS)

    Eshleman, V. R.; Tyler, G. L.; Anderson, J. D.; Fjeldbo, G.; Levy, G. S.; Wood, G. E.; Croft, T. A.

    1977-01-01

    Radio links to and from the Voyager spacecraft will be used for occultation measurements of planetary and satellite atmospheres and ionospheres, the rings of Saturn, the solar corona, and the general-relativistic time delay for radio wave propagation through the solar gravity field. In addition, the radio link measurements may provide information on the gravity fields of the planets, the masses of the satellites, properties of the interplanetary medium, and long-wavelength gravitational radiation propagation in the solar system.

  5. Voyager: The grandest tour. The mission to the outer planets

    NASA Astrophysics Data System (ADS)

    1991-04-01

    A history and general accomplishments of the Voyager 1 and 2 missions to the outer planets are presented. Over the course of 12 years, these spacecraft drew back the curtain on nearly half the solar system. They brought into sharp focus the faces of the four giant outer planets - Jupiter, Saturn, Uranus, and Neptune - and their families of disparate moons. The Voyagers showed us unimagined worlds: frozen beauty in the rings of Saturn, and molten violence in the explosive sulfur volcanoes on Jupiter's moon Io. They brought us close-ups of the florid and intricate storms of Jupiter itself. Voyager 2 went on to reveal the peculiarities of cockeyed Uranus and its equally skewed rings and moons. Then finally, Neptune, nearly invisible from earth, was unveiled in all its big, blue splendor, circled by shadowy rings and a bright pastel moon called Triton. Both Voyagers are headed toward the outer boundary of the solar system in search of the heliopause, the region where the sun's influence wanes and the beginning of interstellar space can be sensed.

  6. Voyager: The grandest tour. The mission to the outer planets

    NASA Technical Reports Server (NTRS)

    1991-01-01

    A history and general accomplishments of the Voyager 1 and 2 missions to the outer planets are presented. Over the course of 12 years, these spacecraft drew back the curtain on nearly half the solar system. They brought into sharp focus the faces of the four giant outer planets - Jupiter, Saturn, Uranus, and Neptune - and their families of disparate moons. The Voyagers showed us unimagined worlds: frozen beauty in the rings of Saturn, and molten violence in the explosive sulfur volcanoes on Jupiter's moon Io. They brought us close-ups of the florid and intricate storms of Jupiter itself. Voyager 2 went on to reveal the peculiarities of cockeyed Uranus and its equally skewed rings and moons. Then finally, Neptune, nearly invisible from earth, was unveiled in all its big, blue splendor, circled by shadowy rings and a bright pastel moon called Triton. Both Voyagers are headed toward the outer boundary of the solar system in search of the heliopause, the region where the sun's influence wanes and the beginning of interstellar space can be sensed.

  7. VOYAGER 1 NEAR THE HELIOPAUSE

    SciTech Connect

    Borovikov, S. N.; Pogorelov, N. V., E-mail: nikolai.pogorelov@uah.edu [Center for Space Physics and Aeronomic Research, The University of Alabama in Huntsville, Huntsville, AL 35805 (United States)

    2014-03-01

    Recent observations from the Voyager 1 spacecraft show that it is sampling the local interstellar medium (LISM). This is quite surprising because no realistic, steady-state model of the solar wind (SW) interaction with the LISM gives an inner heliosheath width as narrow as ?30 AU. This includes models that assume a strong redistribution of the ion energy to the tails in the pickup ion distribution function. We show that the heliopause (HP), which separates the SW from the LISM, is not a smooth tangential discontinuity, but rather a surface subject to Rayleigh-Taylor-type instabilities which can result in LISM material penetration deep inside the SW. We also show that the HP flanks are always subject to a Kelvin-Helmholtz instability. The instabilities are considerably suppressed near the HP nose by the heliospheric magnetic field in steady-state models, but reveal themselves in the presence of solar cycle effects. We argue that Voyager 1 may be in one such instability region and is therefore observing plasma densities much higher than those in the pristine SW. These results may explain the early penetration of Voyager 1 into the LISM. They also show that there is a possibility that the spacecraft may start sampling the SW again before it finally leaves the heliosphere.

  8. Relation between the solar wind dynamic pressure at Voyager 2 and the energetic particle events at Voyager 1

    Microsoft Academic Search

    J. D. Richardson; F. B. McDonald; E. C. Stone; C. Wang; J. Ashmall

    2005-01-01

    Starting in 2001, Voyager 1 observed three events characterized by enhanced fluxes of energetic particles. These events suggest that Voyager 1 made a close approach to, or a crossing of, the termination shock. Although the plasma experiment on Voyager 1 is not providing useful data, plasma data from Voyager 2 may shed light on the plasma conditions at Voyager 1.

  9. Voyage of Discovery - Duration: 95 seconds.

    NASA Video Gallery

    These animations show NASA's Voyager spacecraft encountering Jupiter, Saturn, Uranus and Neptune on their grand tour through the solar system. The artist's renderings were made based on navigationa...

  10. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...of the 1966 Convention, an international voyage means a sea voyage...every territory for the international relations of which any specific Contracting...considered as being on an international voyage for the purpose...

  11. Voyager-Neptune telemetry - The DSN 70 meter antenna upgrade

    NASA Astrophysics Data System (ADS)

    Hall, Justin R.; McClure, Donald H.

    The Deep Space Network (DSN) is responsible for the acquisition of in-situ science and engineering measurements and navigation data from spacecraft exploring the Solar System. Key characteristics of the DSN design approach, the costs to upgrade performance over the past several decades, and some fundamental constraints on performance are discussed. The specific 70-meter upgrade task and the resulting overall benefits to Voyager-Neptune and the mission set are addressed.

  12. Advances in Impedance Probe Applications and Design in the NRL Space Physics Simulation Chamber

    NASA Astrophysics Data System (ADS)

    Blackwell, David; Walker, David; Cothran, Christopher; Gatling, George; Tejero, Erik; Amatucci, William

    2013-10-01

    We will present recent progress in plasma impedance probe experiments and design at NRL's Space Physics Simulation Chamber. These include our network analyzer S-parameter methods as well as more portable self-contained diagnostics with an eye towards space vehicle applications. The experiments are performed under a variety of conditions with magnetized and unmagnetized collisionless, cold (Te ~ 1 - 2 eV) plasmas in density ranges of 105-108 cm-3. Large and small spheres, disks, floating dipoles and monopoles are all in development with various electronic setups, along with traditional emissive and Langmuir probes for measurement redundancy. New computational results provide experimental predictions over a larger parameter space. We will present recent progress in plasma impedance probe experiments and design at NRL's Space Physics Simulation Chamber. These include our network analyzer S-parameter methods as well as more portable self-contained diagnostics with an eye towards space vehicle applications. The experiments are performed under a variety of conditions with magnetized and unmagnetized collisionless, cold (Te ~ 1 - 2 eV) plasmas in density ranges of 105-108 cm-3. Large and small spheres, disks, floating dipoles and monopoles are all in development with various electronic setups, along with traditional emissive and Langmuir probes for measurement redundancy. New computational results provide experimental predictions over a larger parameter space. This work supported by the Naval Research Laboratory Base Program.

  13. The Future of NASA's Deep Space Network and Applications to Planetary Probe Missions

    NASA Technical Reports Server (NTRS)

    Deutsch, Leslie J.; Preston, Robert A.; Vrotsos, Peter

    2010-01-01

    NASA's Deep Space Network (DSN) has been an invaluable tool in the world's exploration of space. It has served the space-faring community for more than 45 years. The DSN has provided a primary communication pathway for planetary probes, either through direct- to-Earth links or through intermediate radio relays. In addition, its radiometric systems are critical to probe navigation and delivery to target. Finally, the radio link can also be used for direct scientific measurement of the target body ('radio science'). This paper will examine the special challenges in supporting planetary probe missions, the future evolution of the DSN and related spacecraft technology, the advantages and disadvantages of radio relay spacecraft, and the use of the DSN radio links for navigation and scientific measurements.

  14. Probing Chemical Space with Alkaloid-Inspired Libraries

    PubMed Central

    McLeod, Michael C.; Singh, Gurpreet; Plampin, James N.; Rane, Digamber; Wang, Jenna L.; Day, Victor W.; Aubé, Jeffrey

    2014-01-01

    Screening of small molecule libraries is an important aspect of probe and drug discovery science. Numerous authors have suggested that bioactive natural products are attractive starting points for such libraries, due to their structural complexity and sp3-rich character. Here, we describe the construction of a screening library based on representative members of four families of biologically active alkaloids (Stemonaceae, the structurally related cyclindricine and lepadiformine families, lupin, and Amaryllidaceae). In each case, scaffolds were based on structures of the naturally occurring compounds or a close derivative. Scaffold preparation was pursued following the development of appropriate enabling chemical methods. Diversification provided 686 new compounds suitable for screening. The libraries thus prepared had structural characteristics, including sp3 content, comparable to a basis set of representative natural products and were highly rule-of-five compliant. PMID:24451589

  15. Jupiter/Voyager data analysis

    NASA Technical Reports Server (NTRS)

    Veverka, J.

    1985-01-01

    The extent to which the unusual spectral properties of Io and Alamathea can be accounted for by sulfur glass or at least by sulfur rich glasses was investigated. Whether or not the temperature dependence of the characteristic spectrum of pure sulfur can be used to set limits on the abundance of sulfur as a surface constituent of Io was also explored. Data from Voyager imaging observations of Saturn's small satellites, of the unusual retrograde satellite Phoebe, and of Hyperion were also reduced, analyzed, and interpreted.

  16. 46 CFR Sec. 3 - Voyage commencements.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...a) All voyages shall commence at 0001 hours of the date on which any of the following activities occur first: (1) Vessel goes on loading berth, or (2) Vessel sails outward on a new voyage, or (3) Following termination of the previous...

  17. Astrographic Observations of Pheobe from Voyager 2

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.

    1996-01-01

    This article provides the reduced astrographic observations of the ninth Saturnian satellite, Pheobe, derived from star-satellite imaging data acquired by the Voyager 2 spacecraft. The data set contains 8 pairs of spacecraft-centered right ascension and declination observations and includes all of the observations used in Voyager encounter operations.

  18. Voyager at Neptune - A preliminary report

    SciTech Connect

    Kaufmann, W.J. (San Diego State Univ., CA (USA) Illinois Univ., Urbana (USA))

    1989-12-01

    Data obtained from the Voyager mission to Neptune are discussed. The atmosphere and magnetosphere of Neptune are described. Specific attention is given to Neptune's Great Dark Spot and its systems of thin, dark rings. The Voyager data regarding Neptune's satellites, in particular Triton and Nereid, are examined.

  19. IEC Thrusters for Space Probe Applications and Propulsion

    Microsoft Academic Search

    George H. Miley; Hiromu Momota; Linchun Wu; Michael P. Reilly; Vince L. Teofilo; Rodney Burton; Richard Dell; William A. Hargus

    2009-01-01

    Earlier conceptual design studies (Bussard, 1990; Miley et al., 1998; Burton et al., 2003) have described Inertial Electrostatic Confinement (IEC) fusion propulsion to provide a high-power density fusion propulsion system capable of aggressive deep space missions. However, this requires large multi-GW thrusters and a long term development program. As a first step towards this goal, a progression of near-term IEC

  20. Means to remove electrode contamination effect of Langmuir probe measurement in space.

    PubMed

    Oyama, K-I; Lee, C H; Fang, H K; Cheng, C Z

    2012-05-01

    Precaution to remove the serious effect of electrode contamination in Langmuir probe experiments has not been taken in many space measurements because the effect is either not understood or ignored. We stress here that one should pay extra attention to the electrode contamination effect to get accurate and reliable plasma measurements so that the long time effort for sounding rocket/satellite missions does not end in vain or becomes less fruitful. In this paper, we describe two main features of voltage-current characteristic curves associated with the contaminated Langmuir probe, which are predicted from the equivalent circuit model, which we proposed in 1970's. We then show that fast sweeping dc Langmuir probes can give reliable results in the steady state regime. The fast sweeping probe can also give reliable results in transient situations such as satellite moves through plasma bubble in the ionosphere where the electron density drastically changes. This fact was first confirmed in our laboratory experiment. PMID:22667663

  1. Space probe/satellite ejection apparatus for spacecraft

    NASA Technical Reports Server (NTRS)

    Smyly, H. M.; Miller, C. D.; Cloyd, R. A.; Heller, C. (inventors)

    1984-01-01

    An ejection apparatus for spinning and propelling objects for ejection from a spacecraft at a desired velocity and rotational speed is discussed. The apparatus includes a launch cradle on which the space object to be ejected rests. The cradle is rotatably supported by a central hub secured to the upper end of the pneumatic cylinder piston shaft. Release mechanisms consisting of a retractable pin and locking lug is utilized to hold the cradle and object to be ejected. The release mechanism has a fixed barrier member which holds the retractable pin in engagement with the locking lug until release by upward movement of the launch cradle beyond the barrier height.

  2. Launch summary for 1978 - 1982. [sounding rockets, space probes, and satellites

    NASA Technical Reports Server (NTRS)

    Hills, H. K.

    1984-01-01

    Data pertinent to the launching of space probes, soundings rockets, and satellites presented in tables include launch date, time, and site; agency rocket identification; sponsoring country or countries; instruments carried for experiments; the peak altitude achieved by the rockets; and the apoapsis and periapsis for satellites. The experimenter or institution involved in the launching is also cited.

  3. Plan for the flight of a space probe to the planetary system of a star

    NASA Astrophysics Data System (ADS)

    Marov, M. Ia.; Zakirov, U. N.

    A plan is proposed for the sending of an unmanned probe to study the physical characteristics of interstellar and circumstellar space, to investigate the planetary systems of nearby stars, and to search for signals from extraterrestrial civilizations. The plan relies on the possibility of developing a relativistic rocket system with microfusion engines.

  4. Gravity Probe B Experiment in 7D Space-and-Time Continuum

    E-print Network

    Yu. A. Portnov

    2012-04-24

    This study deals with application of field equations in seven-dimensional space-and-time continuum to calculate geodetic and orbital gyroscope precession. It was demonstrated that unlike the classic theory the assumptions made completely correspond to the Gravity Probe B findings.

  5. Probing mSUGRA via the Extreme Universe Space Observatory

    E-print Network

    Luis Anchordoqui; Haim Goldberg; Pran Nath

    2004-05-13

    An analysis is carried out within mSUGRA of the estimated number of events originating from upward moving ultra-high energy neutralinos that could be detected by the Extreme Universe Space Observatory (EUSO). The analysis exploits a recently proposed technique that differentiates ultra-high energy neutralinos from ultra-high energy neutrinos using their different absorption lengths in the Earth's crust. It is shown that for a significant part of the parameter space, where the neutralino is mostly a Bino and with squark mass $\\sim 1$ TeV, EUSO could see ultra-high energy neutralino events with essentially no background. In the energy range 10^9 GeV < E < 10^11 GeV, the unprecedented aperture of EUSO makes the telescope sensitive to neutralino fluxes as low as 1.1 \\times 10^{-6} (E/GeV)^{-1.3} GeV^{-1} cm^{-2} yr^{-1} sr^{-1}, at the 95% CL. Such a hard spectrum is characteristic of supermassive particles' $N$-body hadronic decay. The case in which the flux of ultra-high energy neutralinos is produced via decay of metastable heavy particles with uniform distribution throughout the universe is analyzed in detail. The normalization of the ratio of the relics' density to their lifetime has been fixed so that the baryon flux produced in the supermassive particle decays contributes to about 1/3 of the events reported by the AGASA Collaboration below 10^{11} GeV, and hence the associated GeV gamma-ray flux is in complete agreement with EGRET data. For this particular case, EUSO will collect between 4 and 5 neutralino events (with 0.3 of background) in ~ 3 yr of running. NASA's planned mission, the Orbiting Wide-angle Light-collectors (OWL), is also briefly discussed in this context.

  6. 46 CFR 46.05-20 - Great Lakes voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2 2010-10-01 2010-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20...Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States...

  7. 46 CFR 46.05-20 - Great Lakes voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 2 2012-10-01 2012-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20...Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States...

  8. 46 CFR 46.05-20 - Great Lakes voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2 2011-10-01 2011-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20...Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States...

  9. 46 CFR 46.05-20 - Great Lakes voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 2 2013-10-01 2013-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20...Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States...

  10. 46 CFR 46.05-20 - Great Lakes voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 2 2014-10-01 2014-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20...Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States...

  11. Probing minimal supergravity via the Extreme Universe Space Observatory

    NASA Astrophysics Data System (ADS)

    Anchordoqui, Luis; Goldberg, Haim; Nath, Pran

    2004-07-01

    An analysis is carried out within mSUGRA of the estimated number of events originating from upward moving ultrahigh energy neutralinos passing through Earth’s crust that could be detected by the Extreme Universe Space Observatory (EUSO). The analysis exploits a recently proposed technique that differentiates ultrahigh energy neutralinos from ultrahigh energy neutrinos using their different absorption lengths in the Earth’s crust. It is shown that for the part of the parameter space, where the neutralino is mostly a B-ino and with squark mass ˜1 TeV, EUSO could see ultrahigh energy neutralino events within mSUGRA models with essentially no background. In the energy range 109 GeV1.1×10-6 (E?˜/GeV)-1.3 GeV-1 cm-2 yr-1 sr-1, at the 95% confidence limit (CL). Such a hard spectrum is characteristic of supermassive particles’ N-body hadronic decay. The case in which the flux of ultrahigh energy neutralinos is produced via decay of metastable heavy (mX=2×1012 GeV) particles with uniform distribution throughout the Universe, and primary decay mode into 5 quarks + 5 squarks, is analyzed in detail. The normalization of the ratio of the relics’ density to their lifetime has been fixed so that the baryon flux produced in the supermassive particle decays contributes to about 1/3 of the events reported by the AGASA Collaboration below 1011 GeV, and hence the associated GeV ?-ray flux is in complete agreement with EGRET data. For this particular case, EUSO will collect between 4 and 5 neutralino events (with 0.3 of background) in ?3 yr of running. NASA’s planned mission, the Orbiting Wide-angle Light-collectors (OWL), is also briefly discussed in this context.

  12. Voyages Through Time: Everything Evolves

    NASA Astrophysics Data System (ADS)

    Pendleton, Y. J.; Tarter, J. C.; DeVore, E. K.; O'Sullivan, K. A.; Taylor, S. M.

    2001-12-01

    Evolutionary change is a powerful framework for studying our world and our place therein. It is a recurring theme in every realm of science: over time, the universe, the planet Earth, life, and human technologies all change, albeit on vastly different scales. Evolution offers scientific explanations for the age-old question, "Where did we come from?" In addition, historical perspectives of science show how our understanding has evolved over time. The complexities of all of these systems will never reveal a "finished" story. But it is a story of epic size, capable of inspiring awe and of expanding our sense of time and place, and eminently worthy of investigating. This story is the basis of Voyages Through Time. Voyages Through Time (VTT), provides teachers with not only background science content and pedagogy, but also with materials and resources for the teaching of evolution. The six modules, Cosmic Evolution, Planetary Evolution, Origin of Life, Evolution of Life, Hominid Evolution, and Evolution of Technology, emphasize student inquiry, and promote the nature of science, as recommended in the NSES and BSL. The modules are unified by the overarching theme of evolution and the meta questions: "What is changing?" "What is the rate of change?" and "What is the mechanism of change?" Determination of student outcomes for the project required effective collaboration of scientists, teachers, students and media specialists. The broadest curricula students outcomes are 1) an enjoyment of science, 2) an understanding of the nature of science, especially the understanding of evidence and re-evaluation, and 3) key science content. The curriculum is being developed by the SETI Institute, NASA Ames Research Center, California Academy of Sciences, and San Francisco State University, and is funded by the NSF (IMD 9730693), with support form Hewlett-Packard Company, The Foundation for Microbiology, Combined Federated Charities, NASA Astrobiology Institute, and NASA Fundamental Biology.

  13. Deep Space Chronicle: A Chronology of Deep Space and Planetary Probes 1958-2000

    NASA Technical Reports Server (NTRS)

    Siddiqi, Asif A.; Launius, Roger (Technical Monitor)

    2002-01-01

    This monograph contains brief descriptions of all robotic deep space missions attempted since the opening of the space age in 1957. The missions are listed strictly chronologically in order of launch date (not by planetary encounter).

  14. Voyager: Perils of advanced planning, 1960 - 1967

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Contract proposals; phased project planning; budgetary problems; Saturn 1 B-Centaur versus Saturn V; mission guidelines and management assignments; and the origins of the Voyager project are discussed.

  15. The Deep Space Network. An instrument for radio navigation of deep space probes

    NASA Technical Reports Server (NTRS)

    Renzetti, N. A.; Jordan, J. F.; Berman, A. L.; Wackley, J. A.; Yunck, T. P.

    1982-01-01

    The Deep Space Network (DSN) network configurations used to generate the navigation observables and the basic process of deep space spacecraft navigation, from data generation through flight path determination and correction are described. Special emphasis is placed on the DSN Systems which generate the navigation data: the DSN Tracking and VLBI Systems. In addition, auxiliary navigational support functions are described.

  16. Ancient voyaging and Polynesian origins.

    PubMed

    Soares, Pedro; Rito, Teresa; Trejaut, Jean; Mormina, Maru; Hill, Catherine; Tinkler-Hundal, Emma; Braid, Michelle; Clarke, Douglas J; Loo, Jun-Hun; Thomson, Noel; Denham, Tim; Donohue, Mark; Macaulay, Vincent; Lin, Marie; Oppenheimer, Stephen; Richards, Martin B

    2011-02-11

    The "Polynesian motif" defines a lineage of human mtDNA that is restricted to Austronesian-speaking populations and is almost fixed in Polynesians. It is widely thought to support a rapid dispersal of maternal lineages from Taiwan ~4000 years ago (4 ka), but the chronological resolution of existing control-region data is poor, and an East Indonesian origin has also been proposed. By analyzing 157 complete mtDNA genomes, we show that the motif itself most likely originated >6 ka in the vicinity of the Bismarck Archipelago, and its immediate ancestor is >8 ka old and virtually restricted to Near Oceania. This indicates that Polynesian maternal lineages from Island Southeast Asia gained a foothold in Near Oceania much earlier than dispersal from either Taiwan or Indonesia 3-4 ka would predict. However, we find evidence in minor lineages for more recent two-way maternal gene flow between Island Southeast Asia and Near Oceania, likely reflecting movements along a "voyaging corridor" between them, as previously proposed on archaeological grounds. Small-scale mid-Holocene movements from Island Southeast Asia likely transmitted Austronesian languages to the long-established Southeast Asian colonies in the Bismarcks carrying the Polynesian motif, perhaps also providing the impetus for the expansion into Polynesia. PMID:21295281

  17. Interagency telemetry arraying for Voyager-Neptune encounter

    NASA Technical Reports Server (NTRS)

    Brown, D. W.; Brundage, W. D.; Ulvestad, J. S.; Kent, S. S.; Bartos, K. P.

    1990-01-01

    The reception capability of the Deep Space Network (DSN) has been improved over the years by increasing both the size and number of antennas at each complex to meet spacecraft-support requirements. However, even more aperture was required for the final planetary encounters of the Voyager 2 spacecraft. This need was met by arraying one radio astronomy observatory with the DSN complex in the United States and another with the complex in Australia. Following a review of augmentation for the Uranus encounter, both the preparation at the National Radio Astronomy (NRAO) Very Large Array (VLA) and the Neptune encounter results for the Parkes-Canberra and VLA-Goldstone arrays are presented.

  18. ULF Waves Observed at MAGDAS Stations as Probes for Litho-Space Weather Study

    NASA Astrophysics Data System (ADS)

    Yumoto, Kiyohumi

    K.Yumoto, Space Environment Research Center (SERC), Kyushu University started the MAGDAS Project effectively in May of 2005, with the installation of the first unit in Hualien, Taiwan (Yumoto et al., 2006, 2007). Since then, over 50 units have been deployed around the world. They are concentrated along three chains: (1) North and South of Japan (the so-called "210o Magnetic Meridian Chain"), (2) Dip Equator Chain, and (3) Africa Chain (the so-called "96o Magnetic Meridian Chain"). The main goals of MAGDAS project are: (1) study magnetospheric pro-cesses by distinguishing between temporal changes and spatial variations in the phenomena, (2) clarify global structures and propagation characteristics of magnetospheric variations from higher to equatorial latitudes, and (3) understand global generation mechanisms of the Solar-Terrestrial phenomena (see Yumoto, 2004). From MAGDAS observations, ULF waves are found to be used as good probes for litho-space weather study in developing and developed countries. In the present paper, we will introduce the following examples: Pc 5 magnetic amplitudes at lower-latitude MAGDAS station show a linear relation with the solar wind velocity, thus we can use the Pc 5 amplitudes as a monitoring probe of the solar wind velocity. Pc 3-4 magnetic pulsations have skin depth comparable with the depth of epicentre of earthquakes in the lithosphere. Therefore, we can use Pc 3-4 as a probe for detecting ULF anomaly and precursors associated with great earthquakes. Pi 2 magnetic pulsations are observed globally at MAGDAS stations located at high, middle, low, and equatorial latitudes in night-and day-time. We can use the Pi 2s as a good indicator of onsets of magnetospheric substorms. Sudden commencements (sc), sudden impulse (si), and solar flare effects (sfe) create magnetic variations at MAGDAS stations. Therefore, MAGDAS data can be used as a probe of interplanetary shocks and interplanetary discontinuities in the solar wind, and solar flare on the solar surface, respectively.

  19. VOYAGER 2 OBSERVES A LARGE DENSITY INCREASE IN THE HELIOSHEATH

    E-print Network

    Wang, C.

    Voyager 2 (V2) entered the heliosheath in 2007 August at roughly the same time solar minimum conditions were reaching the outer heliosphere. Soon after crossing the termination shock the solar wind density at Voyager ...

  20. Voyager - Humanity's Farthest Journey - Duration: 3 minutes, 11 seconds.

    NASA Video Gallery

    After 33 years, NASA's twin Voyager spacecraft are still going strong and still sending home information. This video features highlights of the Voyager journeys to the outer planets, and looks at t...

  1. Estimation of a melting probe's penetration velocity range to reach icy moons' subsurface ocean

    NASA Astrophysics Data System (ADS)

    Erokhina, Olga; Chumachenko, Eugene

    2014-05-01

    In modern space science one of the actual branches is icy satellites explorations. The main interest is concentrated around Jovian's moons Europa and Ganymede, Saturn's moons Titan and Enceladus that are covered by thick icy layer according to "Voyager1", "Voyager2", "Galileo" and "Cassini" missions. There is a big possibility that under icy shell could be a deep ocean. Also conditions on these satellites allow speculating about possible habitability, and considering these moons from an astrobiological point of view. One of the possible tasks of planned missions is a subsurface study. For this goal it is necessary to design special equipment that could be suitable for planetary application. One of the possible means is to use a melting probe which operates by melting and moves by gravitational force. Such a probe should be relatively small, should not weight too much and should require not too much energy. In terrestrial case such kind of probe has been successfully used for glaciers study. And it is possible to extrapolate the usage of such probe to extraterrestrial application. One of the tasks is to estimate melting probe's penetration velocity. Although there are other unsolved problems such as analyzing how the probe will move in low gravity and low atmospheric pressure; knowing whether hole will be closed or not when probe penetrate thick enough; and considering what order could be a penetration velocity. This study explores two techniques of melting probe's movement. One of them based on elasto-plastic theory and so-called "solid water" theory, and other one takes phase changing into account. These two techniques allow estimating melting probe's velocity range and study whole process. Based on these technique several cases of melting probe movement were considered, melting probe's velocity range estimated, influence of different factors studied and discussed and an easy way to optimize parameters of the melting probe proposed.

  2. Voyager 1 encounter with the Saturnian system

    NASA Technical Reports Server (NTRS)

    Stone, E. C.; Miner, E. D.

    1981-01-01

    The Voyager 1 Saturn flyby mission of March 1979 is reviewed, with brief discussions of its flight, trajectory, science plan formulation and telemetered data. Analytical results of such data with respect to Saturn's atmosphere, rings, icy satellites, Titan satellite atmosphere and the Saturn magnetosphere, are summarized. The Voyager science investigations comprise imaging science (ISS), infrared radiation (IRIS), photopolarimetry (PPS), ultraviolet spectroscopy (UVS), radio science (RSS), magnetic fields (MAG), plasma particles (PLS), plasma waves (PWS), planetary radio astronomy (PRA), low energy charged particles (LECP), and cosmic-ray particles (CRS).

  3. What's new, Voyager: The discoveries continue

    NASA Technical Reports Server (NTRS)

    Miner, Ellis D.

    1995-01-01

    The twin Voyager spacecraft, launched nearly two decades ago, continue to operate and are now searching for the edge of our solar system, the heliopause. Voyager's giant-planet flybys of Jupiter, Saturn, Uranus, and Neptune have provided data that are likely to remain the definitive data set for the foreseeable future and have led to many ongoing discoveries. As the spacecraft move toward the heliopause, they are also providing data on the structure of the heliosphere. This article discusses the discoveries resulting from the flyby and heliosphere data that have been made within the past five years.

  4. The extraordinary voyages through the region of the giant planets

    NASA Astrophysics Data System (ADS)

    Danloux-Dumesnils, M.

    1983-01-01

    The astronautical achievements necessary for guiding Pioneer 10 and 11 and Voyager I and II to the giant planets are reviewed. The spacecraft were equipped with rocket exhausts for both orbital corrections and revolution about their axis. Calculations for the Hohmann transfer orbit are performed, noting that the most efficient trajectory to Jupiter is elliptical, and that the launch dates were strictly circumscribed by the condition that the heliocentric position of Jupiter was necessarily 97 deg longitudinally greater than earth's at the launch. Considerations given to the transition of the dominant gravitational force from the sun to Jupiter are described, together with the calculation procedures. The encounters of each planetary body (and their moons) by each of the probes is detailed. The benefits of gravity assists for gaining velocity are outlined, and the bext favorable window for another grand tour is identified in the 1993-1997 interval

  5. PROBING THE LOCAL-FEATURE SPACE OF INTEREST POINTS Wei-Ting Lee, Hwann-Tzong Chen

    E-print Network

    Chen, Sheng-Wei

    -of-Gaussian filter (DoG) and scale-invariant feature transform (SIFT) [2], affine invariant detector [3], [4PROBING THE LOCAL-FEATURE SPACE OF INTEREST POINTS Wei-Ting Lee, Hwann-Tzong Chen Department on the feature space of inter- est points for natural images. Although local features have been widely used

  6. Probing the mechanical properties of seismically active crust with space geodesy: Study of the co-seismic

    E-print Network

    Fialko, Yuri

    Probing the mechanical properties of seismically active crust with space geodesy: Study of the co of kilometer-scale compliant fault zones to stressing by nearby earthquakes [Fialko et al., 2002]. The co isotropic half-space models. The compliant zone model that best explains the deformation on the Calico

  7. Van Allen Probes Mission Space Academy: Educating middle school students about Earth's mysterious radiation belts

    NASA Astrophysics Data System (ADS)

    Butler, L.; Turney, D.; Matiella Novak, A.; Smith, D.; Simon, M.

    2013-12-01

    How's the weather in space? Why on Earth did NASA send two satellites above Earth to study radiation belts and space weather? To learn the answer to questions about NASA's Van Allen Probes mission, 450 students and their teachers from Maryland middle schools attended Space Academy events highlighting the Van Allen Probes mission. Sponsored by the Applied Physics Laboratory (APL) and Discovery Education, the events are held at the APL campus in Laurel, MD. Space Academies take students and teachers on behind-the-scenes exploration of how spacecraft are built, what they are designed to study, and introduces them to the many professionals that work together to create some of NASA's most exciting projects. Moderated by a public relations representative in the format of an official NASA press conference, the daylong event includes a student press conference with students as reporters and mission experts as panelists. Lunch with mission team members gives students a chance to ask more questions. After lunch, students don souvenir clean room suits, enjoy interactive science demonstrations, and tour APL facilities where the Van Allen Probes were built and tested before launch. Students may even have an opportunity to peek inside a clean room to view spacecraft being assembled. Prior to the event, teachers are provided with classroom activities, lesson plans, and videos developed by APL and Discovery Education to help prepare students for the featured mission. The activities are aligned to National Science Education Standards and appropriate for use in the classroom. Following their visit, student journalists are encouraged to write a short article about their field trip; selections are posted on the Space Academy web site. Designed to engage, inspire, and influence attitudes about space science and STEM careers, Space Academies provide an opportunity to attract underserved populations and emphasize that space science is for everyone. Exposing students to a diverse group of scientists and engineers may alleviate some common stereotypes about these careers. When students engage with the scientists and engineers at APL, they see first-hand that successful science and engineering requires a diverse team with multi-disciplinary backgrounds. Activities throughout the day develop student understanding about science and technology, and address the fundamental concepts that fall under the National Science Education Content Standards. Students are immersed in a hands-on experience designed to facilitate understanding of the History and Nature of Science. Throughout the day students interact with people of diverse backgrounds and interests while hearing about the specific ways various individuals and teams of people contribute to the science and technology of the mission, addressing the concepts which fall under the headings of Science as a Human Endeavor, Nature of Science, and History of Science. Getting students outside the classroom to visit APL is an exclusive opportunity; evaluations have indicated that students became interested in learning more about space science and STEM careers after attending a Space Academy event.

  8. Modeling of Saturn's magnetosphere during Voyager 1 and Voyager 2 encounters

    NASA Astrophysics Data System (ADS)

    Chou, M.; Cheng, C. Z.

    2010-08-01

    We model Saturn's magnetosphere during the Voyager 1 encounter on days 317 and 318 in 1980 and the Voyager 2 encounter on days 237 and 238 in 1981, respectively. The rotating magnetosphere of Saturn is modeled by two-dimensional axisymmetric equilibrium solutions of the Grad-Shafranov type equation, which includes effects of the plasma pressure gradient force and the centrifugal force due to plasma toroidal rotation, by prescribing the radial profiles of plasma density and temperature in the equatorial plane. By varying the equatorial plasma profiles the equilibrium solutions are obtained with reasonably good fit to the observed plasma and magnetic field data along the orbits of the Voyager 1 encounter with the Saturn's magnetosphere on days 317 and 318 in 1980 and the Voyager 2 encounter on days 237 and 238 in 1981. The numerical equilibrium solutions provide detailed information of the global distribution of plasma environment and magnetic field structure of the Saturn's inner magnetosphere (for L < 24), and the results show that the plasma environment and the magnetic field configuration of the Saturn's magnetosphere are very different between these two spacecraft encounters with the Saturn. In particular, the meridian distributions of heavy ion density, azimuthal current density, and heavy ion beta have thin disk-like shapes centered at the equator for the Voyager 1 case, but have fat torus shapes for the Voyager 2 case. The difference results from the difference in the equatorial plasma pressure profile which decreases with R for R > 5RS for the Voyager 1 case, but is quite flat between R $\\simeq$ 5 and 17RS for the Voyager 2 case.

  9. Voyager: Exploring through the Public Eye

    E-print Network

    Voyager: Exploring through the Public Eye Giny Cheong George Mason University September 25 2012 n began ding jupspacecraft data atmosphere solar m giant orbit times plan ace ct exp s time bill closest scientist euver million gency anetary manager early f webster o udy navig orbits ntire eastern lo

  10. Near Earth Asteroid Rendezvous - A Pictorial Voyage

    NSDL National Science Digital Library

    This site offers students an opportunity to participate in a pictorial voyage that follows the NEAR spacecraft from its inception through the cruise phase to asteroid 433 Eros. They will learn about the rationale for visiting an asteroid, the instruments and construction of the spacecraft, and follow its flyby of the asteroid Mathilde, swingby of Earth, and encounter with Eros.

  11. Voyager 2 at Neptune - Imaging science results

    Microsoft Academic Search

    B. A. Smith; L. A. Soderblom; D. Banfield; C. Barnet; R. F. Beebe; A. T. Bazilevskii; K. Bollinger; J. M. Boyce; G. A. Briggs; A. Brahic; E. M. Shoemaker; G. E. Danielson; E. DeJong; C. Howell; A. P. Ingersoll; J. Schwartz; D. I. Kuehn; A. T. Basilevsky; R. H. Brown; Crisp Collins; J. Goguen; H. Hammel; C. J. Hansen; T. V. Johnson; W. Owen; D. Rudy; S. P. Synnott; R. J. Terrile; I. Grenier; B. Sicardy; C. Chyba; C. P. Helfenstein; C. Sagan; D. Simonelli; P. Thomas; W. R. Thompson; J. Veverka; A. Verbiscer; P. Rogers; M. Showalter; J. Spencer; L. A. Sromovsky; C. Stoker; R. G. Strom; V. E. Suomi; S. P. Synott

    1989-01-01

    Neptune's atmosphere is revealed by Voyager 2 images to contain clouds of methane ice above a lower deck of hydrogen sulfide or ammonia ices, and to be dominated by an anticyclonic storm system designated the 'Great Dark Spot'; this bears both similarities and differences to the Great Red Spot of Jupiter. Like the rings of Uranus, those of Neptune are

  12. Polarisation measurements with Voyager and Cassini

    NASA Astrophysics Data System (ADS)

    West, R.

    2012-04-01

    The Voyager 1 and 2 missions to the outer planets carried a Photopolarimeter instrument, and the Cassini Imaging Science Subsystem includes linear polarisers to make polarisation images of Jupiter, Saturn, and its moons and rings. The Voyager 1 Photopolarimeter instrument failed before Jupiter encounter but the Voyager 2 instrument returned polarimetry data from Jupiter, Saturn, Titan, Uranus and Neptune at two wavelengths (240 nm and 750 nm), extending previous Pioneer polarisation measurements in wavelength and scattering angle. Its most important contribution to polarisation science came at Titan. The combined polarisation information from the Pioneer 11 IPP instrument, Voyager 2 PPS, and photometry from the Voyager cameras, led to the conclusion that the haze particles in Titan's atmosphere are aggregates of much smaller particles (~60 nm radius). This idea is now the paradigm for the morphology of the Titan haze particles. Observations by the Cassini ISS extended this finding to the polar haze of Saturn which is also highly polarizing, as is Jupiter's polar haze. An auroral mechanism is implicated. The Cassini polarisation measurements can be combined with passband filters to sample from the near-UV to the near-IR, including the narrow methane absorption bands. Outside of the polar regions, for both Jupiter and Saturn, the polarisation of the upper tropospheric clouds is quite low as expected from ice crystals larger than the wavelength. Polarisation measurements in those regions help define cloud altitudes from the signature of the overlying Rayleigh scattering by gas molecules. The Cassini polarisation images of icy satellites show correlation with surface albedo as expected if multiple scattering in surface grains is damped out for absorbing surfaces. This abstract was prepared by the Jet Propulsion Laboratory, California Institute of Technology.

  13. Getting together in deep space - The Rosetta space probe's long trek to Comet 67/P Churyumov-Gerasimenko

    NASA Astrophysics Data System (ADS)

    2004-02-01

    The countdown to Rosetta’s rendezvous in space began on 1 March 1997. At the end of February 2004, seven years and not a few headaches later, the European Space Agency (ESA) probe will at last be setting off on its journey to meet Comet Churyumov-Gerasimenko. The long-planned get-together will not however take place until the middle of 2014. A few months after arriving at the comet, Rosetta will release a small lander onto its surface. Then, for almost two years it will investigate Churyumov-Gerasimenko from close up. Dr Gerhard Schwehm, lead scientist for the Rosetta project, explains that, “With this mission we will be breaking new ground - this will be the first protracted cometary encounter.” The trip to the meeting place in space will certainly be a long one, located as it is some 4.5 astronomical units from the Sun, which translates into something like 675 million kilometres. Rosetta will be on the road for ten years, during which time it will clock up in excess of five billion kilometres. Launch in February 2004 Rosetta will be waved off on 26 February when it lifts off from the space centre in Kourou, French Guiana, aboard an Ariane 5 launcher. Shortly after the spacecraft’s release, its solar panels will be deployed and turned towards the Sun to build up the necessary power reserves. Its various systems and experiments will be gradually brought into operation and tested. Just three months into the mission the first active phase will be over, followed by final testing of the experiments in October 2004. Rosetta will then spend the following years flying a lonely path to the comet, passing by the Earth, Mars, the Earth and the Earth again. There is no alternative to this detour, for even Ariane 5, the most powerful launcher on the market today, lacks the power to hurl the probe on a direct route to the comet. To get the required momentum, it will rely on swing-by manœuvres, using the gravitation pull of Mars (in 2007) and the Earth (three times, in 2005, 2007 and 2008) to pick up speed. Asteroids for company A change is as good as a rest, and a meeting with at least one asteroid should help break the monotony for Rosetta. The spacecraft will come close to an asteroid at the end of 2008. Asteroids are, it will be remembered, rocky bodies, some as large as mountains, some even larger, that orbit the Sun in much the same way as planets. “These ‘brief encounters’ are a scientific opportunity and also a chance to test Rosetta’s instrument payload,” says Gerhard Schwehm. But asteroid exploration also serves an entirely practical purpose: “The more we find out about them, the better the prospect of being able one day to avert a possible collision.” Following a period of low-activity cruising, the probe’s course will be adjusted one last time in May 2011. From July 2011, a further two-and-a-half years' radio silence will be observed, and Rosetta, left entirely to its own resources, will fly close to the Jupiter orbit. Link-up in 2014 Finally, in January 2014, the probe will be reactivated and will, by October 2014, be only a few kilometres distant from Churyumov-Gerasimenko. This is where the dream of so many scientists becomes reality. Having deposited its precious lander cargo on the comet’s surface, Rosetta will continue to orbit Churyumov-Gerasimenko and together they will spend the next seventeen months flying towards the Sun. Rosetta was built by an international consortium led by Astrium. The lander probe was developed in Cologne under the aegis of the DLR, Germany’s space agency, with contributions from ESA and research centres in Austria, Finland, France, Hungary, Ireland, Italy and Great Britain. The comet explorer carries ten scientific instruments. Their job is to draw out the secrets of the comet’s chemical and physical composition and reveal its magnetic and electrical properties. Using a specially designed camera, the lander will take pictures in the macro and micro ranges and send all the data thus acquired back to Earth, via Rosetta. “This will be our first ever chance to

  14. Redshift-space distortions in deep redshift surveys as a probe of the invisible Universe

    NASA Astrophysics Data System (ADS)

    Guzzo, Luigi; Le Fèvre, Olivier

    2010-06-01

    Massive redshift surveys of galaxies beyond the local Universe (i.e.z>0.3) provide an exhaustive probe of the observed acceleration of cosmic expansion. While they have the ability to measure the expansion history H(z) through Baryonic Acoustic Oscillations in the galaxy power spectrum, they can at the same time probe f(z) using the redshift-space distortions introduced in the observed clustering pattern by galaxy peculiar motions. Coupling these two measurements one can in principle distinguish whether cosmic acceleration is due to a new form of `dark energy' in the cosmic budget, or rather requires a modification of General Relativity. These two radically alternative scenarios are degenerate when considering H(z) alone, as yielded, e.g., by the Hubble diagram of Type Ia supernovae. We review our recent measurements of redshift distortions at z~ 1 based on the VIMOS VLT Deep Survey ``Wide'' data and discuss the revived interest on this technique in the context of dark energy. Current results are consistent with the simplest cosmological-constant scenario, but error bars are still too large to rule out alternative models. Forecasts based both on extensive simulations and Fisher-matrix computations, show that next-generation deep surveys optimizing the combination of large volumes and good galaxy sampling will be able to use redshift distortions as a key tool to understand the physical origin of cosmic acceleration. Among these, we introduce the newly started VIMOS Public Extragalactic Redshift Survey (VIPERS) at the ESO VLT, which is building at ~0.8 a sample comparable to current local redshift surveys (105 redshifts in a volume 5×107 h-1 Mpc3). Finally, we provide an example of the exquisite accuracy that could be reached on measurements of redshift-space distortions (among many others), with a massive 20,000 deg2 near-infrared spectroscopic survey from space, as foreseen by the EUCLID mission for the ESA `Cosmic Vision' program.

  15. Gradual Diffusion and Punctuated Phase Space Density Enhancements of Highly Relativistic Electrons: Van Allen Probes Observations

    NASA Technical Reports Server (NTRS)

    Baker, D. N.; Jaynes, A. N.; Li, X.; Henderson, M. G.; Kanekal, S. G.; Reeves, G. D.; Spence, H. E.; Claudepierre, S. G.; Fennell, J. F.; Hudson, M. K.

    2014-01-01

    The dual-spacecraft Van Allen Probes mission has provided a new window into mega electron volt (MeV) particle dynamics in the Earth's radiation belts. Observations (up to E (is) approximately 10MeV) show clearly the behavior of the outer electron radiation belt at different timescales: months-long periods of gradual inward radial diffusive transport and weak loss being punctuated by dramatic flux changes driven by strong solar wind transient events. We present analysis of multi-MeV electron flux and phase space density (PSD) changes during March 2013 in the context of the first year of Van Allen Probes operation. This March period demonstrates the classic signatures both of inward radial diffusive energization and abrupt localized acceleration deep within the outer Van Allen zone (L (is) approximately 4.0 +/- 0.5). This reveals graphically that both 'competing' mechanisms of multi-MeV electron energization are at play in the radiation belts, often acting almost concurrently or at least in rapid succession.

  16. Time-resolved HAXPES at SACLA: probe and pump pulse-induced space-charge effects

    NASA Astrophysics Data System (ADS)

    Oloff, L.-P.; Oura, M.; Rossnagel, K.; Chainani, A.; Matsunami, M.; Eguchi, R.; Kiss, T.; Nakatani, Y.; Yamaguchi, T.; Miyawaki, J.; Taguchi, M.; Yamagami, K.; Togashi, T.; Katayama, T.; Ogawa, K.; Yabashi, M.; Ishikawa, T.

    2014-12-01

    Time-resolved hard x-ray photoelectron spectroscopy (trHAXPES) is established using the x-ray free-electron laser SACLA. The technique extends time-resolved photoemission into the hard x-ray regime and, as a core-level spectroscopy, combines element and atomic-site specificity and sensitivity to the chemical environment with femtosecond time resolution and bulk (sub-surface) sensitivity. The viability of trHAXPES using 8 keV x-ray free-electron-laser radiation is demonstrated by a systematic investigation of probe and pump pulse-induced vacuum space-charge effects on the V 1s emission of VO2 and the Ti 1s emission of SrTiO3. The time and excitation energy dependencies of the measured spectral shifts and broadenings are compared to the results of N-body numerical simulations and simple analytic (mean-field) models. Good agreement between the experimental and calculated results is obtained. In particular, the characteristic temporal evolution of the pump pulse-induced spectral shift is shown to provide an effective means to determine the temporal overlap of pump and probe pulses. trHAXPES opens a new avenue in the study of ultrafast atomic-site specific electron and chemical dynamics in materials and at buried interfaces.

  17. A Comment on "The Far Future of Exoplanet Direct Characterization" - the Case for Interstellar Space Probes

    E-print Network

    Crawford, Ian A

    2010-01-01

    Following on from ideas presented in a recent paper by Schneider et al. (2010) on "The Far Future of Exoplanet Direct Characterization", I argue that they have exaggerated the technical obstacles to performing such 'direct characterization' by means of fast (order 0.1c) interstellar space probes. A brief summary of rapid interstellar spaceflight concepts that may be found in the literature is presented. I argue that the presence of interstellar dust grains, while certainly something which will need to be allowed for in interstellar vehicle design, is unlikely to be the kind of 'show stopper' suggested by Schneider et al. Astrobiology as a discipline would be a major beneficiary of developing an interstellar spaceflight capability, albeit in the longer term, and I argue that astrobiologists should keep an open mind to the possibilities.

  18. Gravity Probe B: final results of a space experiment to test general relativity.

    PubMed

    Everitt, C W F; DeBra, D B; Parkinson, B W; Turneaure, J P; Conklin, J W; Heifetz, M I; Keiser, G M; Silbergleit, A S; Holmes, T; Kolodziejczak, J; Al-Meshari, M; Mester, J C; Muhlfelder, B; Solomonik, V G; Stahl, K; Worden, P W; Bencze, W; Buchman, S; Clarke, B; Al-Jadaan, A; Al-Jibreen, H; Li, J; Lipa, J A; Lockhart, J M; Al-Suwaidan, B; Taber, M; Wang, S

    2011-06-01

    Gravity Probe B, launched 20 April 2004, is a space experiment testing two fundamental predictions of Einstein's theory of general relativity (GR), the geodetic and frame-dragging effects, by means of cryogenic gyroscopes in Earth orbit. Data collection started 28 August 2004 and ended 14 August 2005. Analysis of the data from all four gyroscopes results in a geodetic drift rate of -6601.8±18.3??mas/yr and a frame-dragging drift rate of -37.2±7.2??mas/yr, to be compared with the GR predictions of -6606.1??mas/yr and -39.2??mas/yr, respectively ("mas" is milliarcsecond; 1??mas=4.848×10(-9)??rad). PMID:21702590

  19. Planetary Satellite Geodesy: Voyager to Galileo

    NASA Astrophysics Data System (ADS)

    Johnson, T. V.

    2002-12-01

    The Voyager mission provided the opportunity to explore not only the giant planets of the outer solar system, Jupiter, Saturn, Uranus and Neptune, but also their complex system of planetary satellites. A primary concern for the scientific exploration of these bodies was the development of map bases. Not only was this necessary for the correlation of other data and analyses of geological features, it also provide the key geophysical quantities of radius, shape and spin state required to constrain interior and dynamical models. The Galileo mission to the Jupiter system provided the first high resolution mapping of the Galilean moons, building on the information provided by Voyage. Mert Davies played a central role in developing the camera systems and analysis tools vital to all these projects and tasks, contributing in a multitude of ways to discoveries ranging from the discovery of volcanism on Io and Europa's putative ocean to the chaotic spin state of Hyperion.

  20. Voyaging canoes and the settlement of polynesia.

    PubMed

    Finney, B R

    1977-06-17

    Sailing trials with two reconstructed Polynesian double canoes indicate that these craft can make good a course to windward up to approximately 75 degrees off the wind on long ocean voyages. This windward performance would have enabled Polynesians to exert a degree of control over their movements that would have been denied them had they only been able to sail or drift before wind and current. Indeed, without this windward sailing capacity there probably never would have been a Polynesian people today, for in a sense they are a product of their maritime technology. Had there been no great voyaging canoes, the settlement of Polynesia might have had to await the relatively late entry into the Pacific of the European navigators. But the Pacific was the scene of early innovation in weatherly sailing canoes, and as the European navigators "discovered" island after island, they were surprised to find that neolithic seafarers had preceded them into this vast ocean realm. PMID:17831736

  1. Satellite ephemerides for the Voyager Uranus encounter

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Standish, E. M.

    1984-01-01

    Uranian satellite ephemerides are needed by the Voyager project to support both navigation and acquisition of scientific data. This paper presents the approach being taken to develop the ephemerides and details the initial phase of the development. That phase involves the analytical modeling of the satellites' motion and the adjustment of the model to fit astronomical observations. The paper describes the model and gives the result of a fit to 71 years of observations.

  2. Analysis of Clumps in Saturn's F Ring from Voyager and Cassini

    E-print Network

    French, Robert S; Showalter, Mark R; Antonsen, Adrienne K; Packard, Douglas R

    2014-01-01

    Saturn's F ring is subject to dynamic structural changes over short periods. Among the observed phenomena are diffuse extended bright clumps (ECs) ~ 3-40 degrees in longitudinal extent. These ECs appear, evolve, and disappear over a span of days to months. ECs have been seen by the two Voyager spacecraft, the Cassini orbiter, and various ground- and space-based telescopes. Showalter (2004, Icarus, 171, 356-371) analyzed all Voyager images of the F ring and found that there were 2-3 major and 20-40 minor ECs present in the ring at any given time. We expand upon these results by comparing the ECs seen by Voyager to those seen by Cassini in 2004-2010. We find that the number of minor ECs has stayed roughly constant and the ECs have similar distributions of angular width, absolute brightness, and semimajor axis. However, the common exceptionally bright ECs seen by Voyager are now exceedingly rare, with only two instances seen by Cassini in the six years, and they are now also much dimmer relative to the mean ring...

  3. Magnetic field studies at Jupiter by Voyager 1: Preliminary results

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Acuna, M. H.; Lepping, R. P.; Burlaga, L. F.; Behannon, K. W.; Neubauer, F. M.

    1979-01-01

    Results obtained by the Goddard Space Flight Center magnetometers on Voyager 1 concerning the large scale configuration of the Jovian bow shock and magnetopause, and the magnetic field in both the inner and outer magnetosphere are highlighted. There is evidence that a magnetic tail extending away from the planet on the nightside is formed by the solar wind-Jovian field interaction. This is much like Earth's magnetosphere but is a new configuration for Jupiter's magnetosphere not previously considered from earlier Pioneer data. Magnetic field perturbations associated with intense electrical currents (approximately 5 x 10 to the 6th power amps) flowing near or in the magnetic flux tube linking Jupiter with the satellite Io and induced by the relative motion between Io and the co-rotating Jovian magnetosphere are analyzed and interpreted. These currents may be an important source of heating the ionosphere and interior of Io through Joule dissipation.

  4. Probing cosmology and gravity with redshift-space distortions around voids

    E-print Network

    Nico Hamaus; P. M. Sutter; Guilhem Lavaux; Benjamin D. Wandelt

    2015-07-15

    Cosmic voids in the large-scale structure of the Universe affect the peculiar motions of objects in their vicinity. Although these motions are difficult to observe directly, the clustering pattern of their surrounding tracers in redshift space is influenced in a unique way. This allows to investigate the interplay between densities and velocities around voids, which is solely dictated by the laws of gravity. With the help of N-body simulations and derived mock-galaxy catalogs we calculate the average density fluctuations inside and outside voids identified with a watershed algorithm in redshift space and compare the results with the expectation from general relativity and the LCDM model of cosmology. We find that simple linear-theory predictions work remarkably well in describing the dynamics of voids even on relatively small scales. Adopting a Bayesian inference framework, we determine the full posterior probability distribution of our model parameters and forecast the achievable accuracy on measurements of the growth rate of structure and the geometric distortion through the Alcock-Paczy\\'nski effect. Their relative uncertainties in galaxy surveys with number densities comparable to the SDSS MAIN (CMASS) sample that probe a volume of $1h^{-3}{\\rm Gpc}^3$ yield $\\sigma_{f/b}/(f/b)\\sim40\\%$ ($60\\%$) and $\\sigma_{D_AH}/D_AH\\sim5\\%$ ($8\\%$), respectively. The presented method is highly model independent; its viability lies in the underlying assumption of statistical isotropy of the Universe.

  5. Real-space imaging of transient carrier dynamics by nanoscale pump-probe microscopy

    NASA Astrophysics Data System (ADS)

    Terada, Yasuhiko; Yoshida, Shoji; Takeuchi, Osamu; Shigekawa, Hidemi

    2010-12-01

    Smaller and faster are key concepts underlying the progress of current nanoscience and nanotechnology. The development of a method of exploring the transient carrier dynamics in organized nanostructures with pinpoint accuracy is therefore highly desirable. Here, we present a new microscopy that enables real-space measurement of the spatial variation of ultrafast dynamics. It is a pulse-laser-combined scanning tunnelling microscopy with a novel delay-time modulation method based on a pulse-picking technique. A non-equilibrium carrier distribution is generated with ultrashort laser pulses, and its relaxation processes are observed by scanning tunnelling microscopy using a pump-probe technique. We have directly analysed the recombination of excited carriers via the gap states associated with a cobalt nanoparticle/GaAs structure in real space. Through the site dependence of the decay time on the tunnelling current injection from the scanning tunnelling microscopy tip, the hole capture rate at the gap states has been imaged on the nanoscale for the first time.

  6. First steps of processing VLBI data of space probes with VieVS

    NASA Astrophysics Data System (ADS)

    Plank, L.; Böhm, J.; Schuh, H.

    2011-07-01

    Since 2008 the VLBI group at the Institute of Geodesy and Geophysics (IGG) of the Vienna University of Technology has developed the Vienna VLBI Software VieVS which is capable to process geodetic VLBI data in NGS format. Constantly we are working on upgrading the new software, e.g. by developing a scheduling tool or extending the software from single session solution to a so-called global solution, allowing the joint analysis of many sessions covering several years. In this presentation we report on first steps to enable the processing of space VLBI data with the software. Driven by the recently increasing number of space VLBI applications, our goal is the geodetic usage of such data, primarily concerning frame ties between various reference frames, e. g. by connecting the dynamic reference frame of a space probe with the kinematically defined International Celestial Reference Frame (ICRF). Main parts of the software extension w.r.t. the existing VieVS are the treatment of fast moving targets, the implementation of a delay model for radio emitters at finite distances, and the adequate mathematical model and adjustment of the particular unknowns. Actual work has been done for two mission scenarios so far: On the one hand differential VLBI (D-VLBI) data from the two sub-satellites of the Japanese lunar mission Selene were processed, on the other hand VLBI observations of GNSS satellites were modelled in VieVS. Besides some general aspects, we give details on the calculation of the theoretical delay (delay model for moving sources at finite distances) and its realization in VieVS. First results with real data and comparisons with best fit mission orbit data are also presented.'

  7. Spectrophotometric probe

    DOEpatents

    Prather, William S. (Augusta, GA); O'Rourke, Patrick E. (Martinez, GA)

    1994-01-01

    A support structure bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe.

  8. Organic Molecules in the Interstellar Medium, Comets, and Meteorites: A Voyage from Dark Clouds to the Early Earth

    Microsoft Academic Search

    Pascale Ehrenfreund; Steven B. Charnley

    2000-01-01

    Our understanding of the evolution of organic molecules, and their voyage from molecular clouds to the early solar system and Earth, has changed dramatically. Incorporating recent observational results from the ground and space, as well as laboratory simulation experiments and new methods for theoretical modeling, this review recapitulates the inventory and distribution of organic molecules in different environments. The evolution,

  9. A Voyage through Scales - Water in terrestrial systems

    NASA Astrophysics Data System (ADS)

    Roth, Kurt

    2015-04-01

    Terrestrial systems - a conglomerate that includes sediments, soils, and vegetation - are the third large compartment of our environment, besides the fluid systems atmosphere and ocean. All of them exhibit structures with a range of spatial and temporal scales that cover at least 9 orders of magnitude. There is a fundamental difference, however. For the fluid systems, structures and flow are one, with structures generated by the nonlinear nature of the flow and manifest in it. In contrast, the structures of terrestrial systems are predominantly formed by processes whose time scales are many orders of magnitude larger than those of the flow and transport within them. During our voyage, we will first consider the role of terrestrial systems in Earth's environmental machinery, will then stroll through their intricate multiscale architecture that covers some 14 orders of magnitude in space, and indeed also in time, have a short glimpse at the nature of the processes, predominantly the flow of water with just a nod to transport and interactions, and will finally formulate a key question: "Is an effective representation of processes in terrestrial systems possible, at a chosen scale of interest, and if so, how can it be gained?" There is no straight answer to this and we will visit several of its aspects - dissipative processes, representative and maximal averaging volumes, and time-scales -, will look at successes and failures, and will finally glance over to the working crews that attempt to blaze a way forward by dense observation networks, data assimilation, and high-performance computing. This voyage will be through Earth's terrestrial systems, with a focus on soils and porous media. It should also be informative for all who are facing nonlinear processes in hierarchically heterogeneous architectures.

  10. Voyager imaging of Triton's clouds and hazes

    NASA Technical Reports Server (NTRS)

    Rages, Kathy; Pollack, James B.

    1992-01-01

    Results are presented from a detailed analysis of Voyager images of Triton obtained at the highest solar phase angles; these have been fit to Mie scattering models in order to obtain the mean particle sizes, number densities, and the vertical extent of the two different scattering components of the Triton atmosphere. The 0.001-0.01 optical depths of about 0.17 micron particles are vertically distributed with scale heights of about 10 km throughout Triton. A number of properties of the haze particles in question suggest that they are composed of photochemically produced gases which have condensed in the cold lower atmosphere of Triton.

  11. Voyager telecommunications: the broadcast from jupiter.

    PubMed

    Edelson, R E; Madsen, B D; Davis, E K; Garrison, G W

    1979-06-01

    Sweeping past Jupiter, the Voyager 1 spacecraft presages a new era in the exploration of the solar system. Not since the TV return from Apollo has a spacecraft returned information of such volume and pictures of such startling clarity. Yet this feat was accomplished from a distance 1770 times as great as that of the lunar adventure. The communication system responsible for this remarkable achievement is a oompilation of elements ranging from tiny integrated circuits to enormous ground antennas. This article seeks to describe the way in which data are returned from these fascinating, faraway bodies and to convey the excitement of the engineering work that supports our scientific endeavors. PMID:17800407

  12. Io plasma torus electrons - Voyager 1

    NASA Astrophysics Data System (ADS)

    Sittler, E. C.; Strobel, D. F.

    1987-06-01

    A thermal Maxwellian component of the electron distribution function, together with a suprathermal, non-Maxwellian one, are featured in the present analysis of in situ plasma electron observations made by the Voyager 1 plasma science experiment in the Io plasma torus. A large difference in the hot electron pressure P(H) is noted between the inbound and the outbound data; this is interpreted as a latitudinal gradient, with P(H) being maximum at the magnetic equator. The presence of a neutral corona around Io is inferred from the observed decrease and symmetry with respect to Io of the cold electron temperature.

  13. Plasma waves near Saturn: initial results from Voyager 1

    Microsoft Academic Search

    D. A. Gurnett; W. S. Kurth; F. L. Scarf

    1981-01-01

    The Voyager 1 encounter with Saturn provided the first opportunity to investigate plasma wave interactions in the magnetosphere of Saturn. An overview of the principal results from the Voyager 1 plasma wave instrument is presented starting with the initial detection of Saturn and ending about four weeks after closest approach. A survey plot of the electric field intensities detected during

  14. Plasma observations near Neptune - Initial results from Voyager 2

    Microsoft Academic Search

    J. W. Belcher; H. S. Bridge; B. Coppi; G. S. Gordon Jr.; A. J. Lazarus; R. L. McNutt Jr.; F. Bagenal; O. Divers; A. Eviatar; K. W. Ogilvie; L. Villanueva; M. Zhang; E. C. Jr. Sittler; G. L. Siscoe; V. M. Vasyliunas

    1989-01-01

    The plasma science experiment on Voyager 2 made observations of the plasma environment in Neptune's magnetosphere and in the surrounding solar wind. Because of the large tilt of the magnetic dipole and fortuitous timing, Voyager entered Neptune's magnetosphere through the cusp region, the first cusp observations at an outer planet. Thus the transition from the magnetosheath to the magnetosphere observed

  15. SEAC 2011 Stars and Stones: Voyages in Archaeoastronomy and Cultural Astronomy

    NASA Astrophysics Data System (ADS)

    Pimenta, F.; Ribeiro, N.; Silva, F.; Campion, N.; Joaquinito, A.; Tirapicos, L.

    2015-05-01

    Since Prehistory the sky has always been integrated as part of the cosmovision of human societies. The sky played a fundamental role not only in the orientation in space, time organization, ritual practices or celestial divination but also as an element of power. Migrations and voyages are intrinsic to humankind, they opened the routes for cultural diffusion and trade, but also for power dominance. Following these routes is also to follow cultural diversity and how human societies met or clashed. The sky and astronomical phenomena provided the tools for time reckoning, calendar organization and celestial navigation that supported those voyages. Astronomy gives us today the capacity to reproduce the sky, opening a window through which we can glimpse how those societies perceived, integrated and manipulated the sky into their world-views and their myths and, ultimately, into their social organization. A voyage is always a meeting of different worlds and eventually a process to accept diversity and thus we challenged the participants of the 19th meeting of the European Society for Astronomy in Culture to present their papers in the form of a voyage or an encounter for the following topics: - Techniques of celestial navigation and orientation of the past. Astronomical navigation and nautical instruments in the XIVth, XVth and XVIth centuries; - Expressions of astronomical knowledge in architecture and monuments, rock art, archaeology and landscape. People migration, a meeting between different cultures; - History of astronomy. An encounter between different conceptions; - Astronomy and the Jesuits. A meeting between different worlds; - Astronomy in antiquity. A meeting between different knowledge; - Ethno-astronomy, Cultural Astronomy and myths, voyages in space and in time through different cultures; - To where is Archaeoastronomy voyaging? A round table about Archaeoastronomy, Cultural Astronomy and Education. The 19th meeting of the European Society for Astronomy in Culture was held in Évora, Portugal, from September 19th to 23th, 2011, and was attended by 85 participants from 29 countries. A total number of 71 talks and 4 posters were presented. Among them 20 invited lectures given by Michael Rappenglüück, José Manuel Malhão Pereira, Jarita Holbrook, Giulio Magli, Nicholas Campion, J. Kim Malville, David Pankenier, Alejandro Martín López, Ivan Sprajc, Mariusz Ziólkowski, Marciano da Silva, Lionel Sims, Emilia Pasztor, Frank Prendergast, Fernando Pimenta, A. César González-Garcia, Henrique Leitão, Shi Yunli and Stanislaw Iwaniszewski and 3 public lectures given by Luísa Pereira, Juan Belmonte Avilés and Clive Ruggles. Most of the contributions were submitted for publication and went through a peer-review process. The present volume is the result of this process, arranged in the same thematic sections as the Conference was organised.

  16. Modulation of the Foreign Body Reaction for Implants in the Subcutaneous Space: Microdialysis Probes as Localized Drug Delivery/Sampling Devices

    PubMed Central

    Mou, Xiaodun; Lennartz, Michelle R; Loegering, Daniel J; Stenken, Julie A

    2011-01-01

    Modulation of the foreign body reaction is considered to be an important step toward creation of implanted sensors with reliable long-term performance. In this work, microdialysis probes were implanted into the subcutaneous space of Sprague-Dawley rats. The probe performance was evaluated by comparing collected endogenous glucose concentrations with internal standard calibration (2-deoxyglucose, antipyrine, and vitamin B12). Probes were tested until failure, which for this work was defined as loss of fluid flow. In order to determine the effect of fibrous capsule formation on probe function, monocyte chemoattractant protein-1/CC chemokine ligand 2 (MCP-1/CCL2) was delivered locally via the probe to increase capsule thickness and dexamethasone 21-phosphate was delivered to reduce capsule thickness. Probes delivering MCP-1 had a capsule that was twice the thickness (500–600 ?m) of control probes (200–225 ?m) and typically failed 2 days earlier than control probes. Probes delivering dexamethasone 21-phosphate had more fragile capsules and the probes typically failed 2 days later than controls. Unexpectedly, extraction efficiency and collected glucose concentrations exhibited minor differences between groups. This is an interesting result in that the foreign body capsule formation was related to the duration of probe function but did not consistently relate to probe calibration. PMID:21722577

  17. Color Voyager 2 Image Showing Crescent Uranus

    NASA Technical Reports Server (NTRS)

    1990-01-01

    This image shows a crescent Uranus, a view that Earthlings never witnessed until Voyager 2 flew near and then beyond Uranus on January 24, 1986. This planet's natural blue-green color is due to the absorption of redder wavelengths in the atmosphere by traces of methane gas. Uranus' diameter is 32,500 miles, a little over four times that of Earth. The hazy blue-green atmosphere probably extends to a depth of around 5,400 miles, where it rests above what is believed to be an icy or liquid mixture (an 'ocean') of water, ammonia, methane, and other volatiles, which in turn surrounds a rocky core perhaps a little smaller than Earth.

  18. Voyages and Travels: Ancient and Modern

    NSDL National Science Digital Library

    Sir Walter Raleigh was a man who liked to travel the globe. He was in good company, as persons stretching all the way back to Herodotus (and before) had a certain wanderlust that could only be quenched by seeking out new lands and experiences. Some of their musings on the places they explored can be found within the electronic pages of the volume presented here by Bartleby.com. The Voyages and Travels work was originally part of the Harvard Classics series, and it contains seven accounts of travel and exploration. These accounts include "An Account of Egypt" by Herodotus, Sir Walter Raleigh's "The Discovery of Guiana", and a narrative of Sir Humphrey Gilbert's trip to Newfoundland in the 16th century.

  19. DSN radio science system design and testing for Voyager-Neptune encounter

    NASA Technical Reports Server (NTRS)

    Ham, N. C.; Rebold, T. A.; Weese, J. F.

    1989-01-01

    The Deep Space Network (DSN) Radio Science System presently implemented within the Deep Space Network was designed to meet stringent requirements imposed by the demands of the Voyager-Neptune encounter and future missions. One of the initial parameters related to frequency stability is discussed. The requirement, specification, design, and methodology for measuring this parameter are described. A description of special instrumentation that was developed for the test measurements and initial test data resulting from the system tests performed at Canberra, Australia and Usuda, Japan are given.

  20. The RF Probe: providing space situational awareness through broad-spectrum detection and characterization

    Microsoft Academic Search

    Raymond Zenick; Kimberly Kohlhepp; Russell Partch

    2004-01-01

    AeroAstro's patented RF Probe is a system designed to address the needs of spacecraft developers and operators interested in measuring and analyzing near-field RF emissions emanating from a nearby spacecraft of interest. The RF Probe consists of an intelligent spectrum analyzer with digital signal processing capabilities combined with a calibrated, wide-bandwidth antenna and RF front end that covers the 50

  1. Voyager Photometry of Saturn's A Ring

    NASA Technical Reports Server (NTRS)

    Dones, Luke; Cuzzi, Jeffrey N.; Showalter, Mark R.

    1993-01-01

    Saturn's A Ring samples a wide range of dynamical environments, from the relatively unperturbed, optically thick inner region to the outer part of the ring, which contains numerous density waves. We analyze Voyager images of the A Ring to determine how the reflectivity of different radial regions varies with lighting and viewing geometry. We model our data with a classical radiative transfer code that includes the illumination of the rings by the Sun and Saturn. The particles in the inner and mid-A Ring have Bond albedos near 0.5 and are more backscattering than satellites of comparable albedo. The region outside the Encke Gap becomes progressively less backscattering with increasing radius. Particle properties change abruptly outside the Keeler Gap; particles here have an albedo near 0.6 and a Lambert-like phase function. In contrast with previous suggestions, the abundance of free, submicrometer "dust" is small throughout the entire A Ring; this conclusion holds even in the outermost A Ring, which is strongly perturbed by density waves. Models derived from low-phase data, assuming only macroscopic particles, correctly predict the highphase reflectivity of the outer A Ring and individual strong density waves in the mid-A Ring. However, the inner and mid-A Ring are typically darker at high phase by a factor of two than our models predict. This discrepancy may be due to the reduced multiple scattering from a layer in which the particles are more closely packed. We have also studied the quadrupole azimuthal brightness asymmetry of the A Ring. The asymmetry has a full amplitude of 35% in the mid-A Ring in low-phase Voyager 2 images. We present results on its behavior and possible implications for the structure of the rings. Finally, we compare our results with studies using other data sets to synthesize our current understanding of the nature of the A Ring.

  2. Spectral Evolution of Anomalous Cosmic Rays at Voyager 1 Beyond the Termination Shock

    NASA Astrophysics Data System (ADS)

    Senanayake, U. K.; Florinski, V. A.; Cummings, A. C.; Stone, E. C.

    2014-12-01

    When Voyager 1 spacecraft crossed the termination shock on 16th December 2004, the energy spectra of anomalous cosmic rays (ACRs) could not have been produced by steady state diffusive shock acceleration. However, over the next few years, in the declining phase of the solar cycle, the spectra began to evolve into the expected power-law profile. Energetic particle transport coefficients, such as diffusion and drift, and also ACR source strength tend to increase with declining levels of solar activity. In this work, we propose that the solar cycle had an important effect on the "unrolling" spectra in the heliosheath at Voyager 1. To investigate the spectral evolution of ACRs, a magentohydrodynamic background model with stationary solar-wind inner boundary conditions will be used to model the transport of helium and oxygen ions. We use a backward-in- time stochastic integration technique where phase-space trajectories are integrated until the so called "injection energy" is reached. Our simulation results will be compared with Voyager 1 observations from 2005 to 2012.

  3. NASA Facts: Images of Saturn from Voyager 2

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Six color images of Saturn and four of her moons, acquired by Voyager 2, are presented. A brief narrative and explanatory captions, including explanations of the planet's atmosphere and rings, are presented.

  4. Voyager 1 Explores the "Magnetic Highway" - Duration: 47 seconds.

    NASA Video Gallery

    This set of animations show NASA's Voyager 1 spacecraft exploring a new region in our solar system called the "magnetic highway." In this region, the sun's magnetic field lines are connected to int...

  5. Space Software

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Xontech, Inc.'s software package, XonVu, simulates the missions of Voyager 1 at Jupiter and Saturn, Voyager 2 at Jupiter, Saturn, Uranus and Neptune, and Giotto in close encounter with Comet Halley. With the program, the user can generate scenes of the planets, moons, stars or Halley's nucleus and tail as seen by Giotto, all graphically reproduced with high accuracy in wireframe representation. Program can be used on a wide range of computers, including PCs. User friendly and interactive, with many options, XonVu can be used by a space novice or a professional astronomer. With a companion user's manual, it sells for $79.

  6. Sealing scientific probes against deep space and the Venusian environment A tough job

    NASA Technical Reports Server (NTRS)

    Pokras, J.; Reinert, R. P.; Switz, R. J.

    1978-01-01

    The Pioneer Venus mission evolved from studies conducted during the late 1960s and early 1970s. It was found that a need existed for low cost orbiters and landers to explore the planet. The considered mission was to be accomplished with six separate vehicles arriving at Venus nearly simultaneously in mid-December 1978. The probes are designed to survive entry and descent into the atmosphere. A description is presented of the approaches used to maintain sealing integrity for the large and small probes under the constraints imposed by the harsh Venusian environment. Attention is given to probe vehicle configuration, pressure vessel sealing requirements, material and configuration considerations, permanent seals, separable seals, development problems, and aspects of seal testing.

  7. Saturn's "String of Pearls” After Five Years: Still There, Moving Backwards Faster in the Voyager System

    NASA Astrophysics Data System (ADS)

    Baines, Kevin H.; Momary, T. W.; Fletcher, L. N.; Buratti, B. J.; Brown, R. H.; Clark, R. N.; Nicholson, P. D.

    2010-10-01

    Since July 2005, the Visual Infrared Mapping Spectrometer (VIMS) onboard the Cassini Orbiter has been following an enigmatic feature centered at 33.9 degrees (planetocentric ) north latitude. Observed in detail on 14 occasions between July 2005 and July 2010, the feature is seen only in the 5-micron thermal window which probes large-particle clouds down to the ˜ 4-bar level. This feature is comprised of a main cloud layer near 1.5-3 bar which has 21-25 regularly spaced, near- uniformly-sized, circularly-shaped clearings which together span, on average, 94 degrees of longitude. In VIMS 5-micron imagery, which observes the warm glow of Saturn generated at depth, these regularly spaced and shaped clearings appear bright while the surrounding cloud, observed in silhouette, appears dark- hence the colloquial name "String of Pearls". Each clearing is about 1 degree of longitude (˜900 km) wide, and is, on average over the five-years period, 4.3 degrees of longitude from its neighbor. In latitude, adjacent pearls are typically 0.4 degrees - or about 1 pearl radius - apart. At various times over the past five years of observations, the longitudinal length has varied from 76 to 104 degrees and the mean separation between clearings has varied from 3.6 to 5.0 degrees, while the mean latitude of the structure has ranged from 32.9 to 34.8 degrees - or by 2 mean diameters of the pearls. The pearl structure moves retrograde in the Voyager system (Desch and Kaiser, Geophys. Res. Lett 8, 253-256, 1981) with an average speed over five years of 21.84 ± 0.02 m/s. Since late 2007, the mean latitude increased from 34.0 ± 0.2 to 34.5 ± 0.2 deg as the retrograde speed increased from 21.73 ± 0.09 m/s to 22.02 ± 0.08 m/s, making it the fastest moving retrograde feature observed by Cassini/VIMS in non-polar regions.

  8. Performance model of the Argonne Voyager multimedia server

    Microsoft Academic Search

    Terrence Disz; Robert Olson; Rick L. Stevens

    1997-01-01

    The Argonne Voyager Multimedia Server is beingdeveloped in the Futures Lab of the Mathematics andComputer Science Division at Argonne National Laboratory.As a network-based service for recording andplaying multimedia streams, it is important that theVoyager system be capable of sustaining certain minimallevels of performance in order for it to be a viablesystem. In this article, we examine the performancecharacteristics of the

  9. ArcVoyager Makes ArcView Easy!

    NSDL National Science Digital Library

    ESRI

    This site from ESRI features ArcVoyager. The program is a 50-mb package of carefully selected data, ArcView projects, and help files in a tiered format, available as free downloads in both Windows and Macintosh formats. The goal of ArcVoyager is to give students and teachers a ramped approach for developing their spatial thinking and learning how to employ ArcView tools.

  10. Gravity Probe B: Examining Einstein's Spacetime with Gyroscopes. An Educator's Guide with Activities in Space Science.

    ERIC Educational Resources Information Center

    Range, Shannon K'doah; Mullins, Jennifer

    This teaching guide introduces a relativity gyroscope experiment aiming to test two unverified predictions of Albert Einstein's general theory of relativity. An introduction to the theory includes the following sections: (1) "Spacetime, Curved Spacetime, and Frame-Dragging"; (2) "'Seeing' Spacetime with Gyroscopes"; (3) "The Gravity Probe B…

  11. 1958 NASA/USAF Space Probes (ABLE-1). Volume 2; Payload and Experiments

    NASA Technical Reports Server (NTRS)

    1959-01-01

    The three NASA/USAF lunar probes of August 17, October 13, and November 8, 1958 are described. Details of the program, the vehicles, the payloads, the firings, the tracking, and the results are presented. Principal result was the first experimental verification of a confined radiation zone of the type postulated by Van Allen and others.

  12. New Voyager radio spectrograms of Uranus

    NASA Technical Reports Server (NTRS)

    Calvert, W.; Tsintikidis, D.

    1990-01-01

    New, high-resolution spectrograms of the Voyager-2 radio observations at Uranus were produced from the original, six-second Planetary Radio Astronomy (PRA) data and these show a number of new features which were not obvious in previous versions. Among these new features are the detailed structure of the so-called broadband-bursty (b-bursty) emissions, unexpected sloping striations in the smooth high-frequency (SHF) component, and the overlap of these two components during the first rotation after closest approach. In addition, a slightly different planetary rotation rate from the b-bursty emissions, was found, and at the initial onset of the SHF component, what appears to be the shadow of a Uranian plasmasphere. These new spectrograms were prepared using a special dithering algorithm to show signal strengths as gray shadings, and the data were also manually cleaned to suppress noise and interference. This produced spectrograms of exceptional quality and certain details of their production on a stand-alone personal computer are also discussed.

  13. Baccalaureate nursing studies: voyaging towards discovery.

    PubMed

    Birks, Melanie; Chapman, Ysanne; Francis, Karen

    2006-10-01

    Postregistration nursing courses are designed to enable registered nurses to convert their existing certificate or diploma qualifications to degree level. This paper presents the findings of a preliminary exploratory, descriptive investigation into the experience of nurses undertaking postregistration degree studies in Malaysian Borneo. The unique nature of this environment presents challenges for these students and these are examined using the metaphor of a ship's voyage. These experiences are explored within themes of setting sail, finding one's sea legs, all in the same boat and discovering the treasure. The findings indicate that, for most of the participants, completion of a baccalaureate postregistration course was a long-held goal. A number of challenges were faced during the course, including managing time, the stress of conflicting priorities and the adjustment to tertiary studies. Support from fellow students, faculty and family was crucial to successfully completing this course. Personal and professional changes were reported by all participants. These include an increased level of confidence and assertiveness, the development of critical thinking ability, and enhanced communication skills. Ultimately, participants reported a renewed attitude towards themselves and their profession. PMID:16942514

  14. Plasma electron analysis: Voyager plasma science experiment

    NASA Technical Reports Server (NTRS)

    Sittler, E. C., Jr.

    1983-01-01

    The Plasma Science Experiment (PLS) on the Voyager spacecraft provide data on the plasma ions and electrons in the interplanetary medium and the magnetospheres of the giant planets Jupiter and Saturn. A description of the analysis used to obtain electron parameters (density, temperature, etc.) from the plasma science experiment PLS electron measurements which cover the energy range from 10 eV to 5950 eV is presented. The electron sensor (D cup) and its transmission characteristics are described. A derivation of the fundamental analytical expression of the reduced distribution function F(e) is given. The electron distribution function F(e), used in the moment integrations, can be derived from F(e). Positive ions produce a correction current (ion feedthrough) to the measured electron current, which can be important to the measurements of the suprathermal electron component. In the case of Saturn, this correction current, which can either add to or subtract from the measured electron current, is less than 20% of the measured signal at all times. Comments about the corrections introduced by spacecraft charging to the Saturn encounter data, which can be important in regions of high density and shadow when the spacecraft can become negatively charged are introduced.

  15. Voyager spacecraft images of Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    Birnbaum, M. M.

    1982-01-01

    The Voyager imaging system is described, noting that it is made up of a narrow-angle and a wide-angle TV camera, each in turn consisting of optics, a filter wheel and shutter assembly, a vidicon tube, and an electronics subsystem. The narrow-angle camera has a focal length of 1500 mm; its field of view is 0.42 deg and its focal ratio is f/8.5. For the wide-angle camera, the focal length is 200 mm, the field of view 3.2 deg, and the focal ratio of f/3.5. Images are exposed by each camera through one of eight filters in the filter wheel on the photoconductive surface of a magnetically focused and deflected vidicon having a diameter of 25 mm. The vidicon storage surface (target) is a selenium-sulfur film having an active area of 11.14 x 11.14 mm; it holds a frame consisting of 800 lines with 800 picture elements per line. Pictures of Jupiter, Saturn, and their moons are presented, with short descriptions given of the area being viewed.

  16. Radial space potential measurements in the central cell of the tandem mirror experiment with a heavy-ion-beam probe

    SciTech Connect

    Hallock, G.A.

    1983-04-11

    Spatial and temporal profiles of the space potential in the central-cell midplane of TMX have been obtained with a heavy-ion-beam probe. The absolute accuracy of measurements is +- 25 volts (with respect to the machine vacuum walls) with a resolution of approx. 2 volts. During moderate fueling with the gas boxes (i/sub gas/ approx. = 1200 Atom-Amperes D/sub 2/), the plasma potential is parabolic to at least 25 cm radius, with phi/sub e/ approx. = phi/sub max/(1-(r/32)/sup 2/) and 300 < phi/sub max/ <450 volts. With puffer-valve fueling, the space potential is relatively flat to at least 27 cm radius, with 250 < phi/sub e/ < 350 volts.

  17. Fiber-Optic Imaging Probe Developed for Space Used to Detect Diabetes Through the Eye

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Chenault, Michelle V.; Datiles, Manuel B., III; Sebag, J.; Suh, Kwang I.

    2000-01-01

    Approximately 16 million Americans have diabetes mellitus, which can severely impair eyesight by causing cataracts, diabetic retinopathy, and glaucoma. Cataracts are 1.6 times more common in people with diabetes than in those without diabetes, and cataract extraction is the only surgical treatment. In many cases, diabetes-related ocular pathologies go undiagnosed until visual function is compromised. This ongoing pilot project seeks to study the progression of diabetes in a unique animal model by monitoring changes in the lens with a safe, sensitive, dynamic light-scattering probe. Dynamic light scattering (DLS), has the potential to diagnose cataracts at the molecular level. Recently, a new DLS fiber-optic probe was developed at the NASA Glenn Research Center at Lewis Field for noncontact, accurate, and extremely sensitive particle-sizing measurements in fluid dispersions and suspensions (ref. 1). This compact, portable, and rugged probe is free of optical alignment, offers point-and-shoot operation for various online field applications and challenging environments, and yet is extremely flexible in regards to sample container sizes, materials, and shapes. No external vibration isolation and no index matching are required. It can measure particles as small as 1 nm and as large as few micrometers in a wide concentration range from very dilute (waterlike) dispersions to very turbid (milklike) suspensions. It is safe and fast to use, since it only requires very low laser power (10 nW to 3 mW) with very short data acquisition times (2 to 10 sec).

  18. Improvements in Electron-Probe Microanalysis: Applications to Terrestrial, Extraterrestrial, and Space-Grown Materials

    NASA Technical Reports Server (NTRS)

    Carpenter, Paul; Armstrong, John

    2004-01-01

    Improvement in the accuracy of electron-probe microanalysis (EPMA) has been accomplished by critical assessment of standards, correction algorithms, and mass absorption coefficient data sets. Experimental measurement of relative x-ray intensities at multiple accelerating potential highlights errors in the absorption coefficient. The factor method has been applied to the evaluation of systematic errors in the analysis of semiconductor and silicate minds. Accurate EPMA of Martian soil stimulant is necessary in studies that build on Martian rover data in anticipation of missions to Mars.

  19. In vitro cultured cells as probes for space radiation effects on biological systems

    Microsoft Academic Search

    Antonella Meli; Giuseppina Perrella; Francesco Curcio; Francesco Saverio Ambesi-Impiombato

    1999-01-01

    Near future scenarios of long-term and far-reaching manned space missions, require more extensive knowledge of all possible biological consequences of space radiation, particularly in humans, on both a long-term and a short-term basis.In vitro cultured cells have significantly contributed to the tremendous advancement of biomedical research. It is therefore to be expected that simple biological systems such as cultured cells,

  20. Probing Galaxy Formation and Evolution with Space Born Sub-Millimeter Telescopes

    NASA Technical Reports Server (NTRS)

    Dwek, Eli; Arendt, Richard G.; Moseley, Harvey; Benford, Dominic; Shafer, Richard; Mather, John; Oegerle, William (Technical Monitor)

    2002-01-01

    A major unresolved question in cosmology is how the complex system of galaxies we see in the present universe evolved from an almost perfectly smooth beginning. Multiwavelength observations of galaxies have revealed that a significant fraction of their UV-visible starlight is absorbed and reradiated by dust at infrared JR) and submillimeter wavelengths. The cumulative IR-submm. emission from galaxies since the epoch of recombination, the cosmic IR background, has recently been recorded by the COBE satellite. The COBE observations in combination with recent submm surveys conducted with the SCUBA on the 15 m JCMT have shown that most of the radiation from star formation that has taken place in the early stages of galaxy evolution is reradiated by dust at submm wavelengths. Therefore, submm telescopes offer a unique probe of the early stages of galaxy formation and evolution. This talk will: (1) consider the impact of telescope diameter on the depth of the survey (what redshift can be probed) at different wavelengths; (2) discuss the relative scientific merits of high-resolution narrow-field surveys versus lower resolution deep surveys; and (3) show how both strategies offer complementary information crucial to our understanding of the structure and evolution of galaxies in the universe.

  1. 26 Octobre -2 Novembre 2012 VOYAGE D'ETUDE AU MAROC

    E-print Network

    Demouchy, Sylvie

    26 Octobre - 2 Novembre 2012 VOYAGE D'ETUDE AU MAROC Master Géologie des Réservoirs Promotion 2012-2013 VOYAGE D'ETUDE AU MAROC Master Géologie des Réservoirs Promotion 2012-2013 Grâce à nos partenaires : #12

  2. 33 CFR 169.210 - Where during its international voyage must a ship transmit position reports?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...Where during its international voyage must a ship transmit position reports? 169.210...CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Transmission of Long...Where during its international voyage must a ship transmit position reports? The...

  3. 33 CFR 169.210 - Where during its international voyage must a ship transmit position reports?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...Where during its international voyage must a ship transmit position reports? 169.210...CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Transmission of Long...Where during its international voyage must a ship transmit position reports? The...

  4. 33 CFR 169.210 - Where during its international voyage must a ship transmit position reports?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...Where during its international voyage must a ship transmit position reports? 169.210...CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Transmission of Long...Where during its international voyage must a ship transmit position reports? The...

  5. 33 CFR 169.210 - Where during its international voyage must a ship transmit position reports?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...Where during its international voyage must a ship transmit position reports? 169.210...CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Transmission of Long...Where during its international voyage must a ship transmit position reports? The...

  6. 33 CFR 169.210 - Where during its international voyage must a ship transmit position reports?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...Where during its international voyage must a ship transmit position reports? 169.210...CONTINUED) PORTS AND WATERWAYS SAFETY SHIP REPORTING SYSTEMS Transmission of Long...Where during its international voyage must a ship transmit position reports? The...

  7. Probing phase-space noncommutativity through quantum mechanics and thermodynamics of free particles and quantum rotors

    E-print Network

    Catarina Bastos; Alex E. Bernardini; Jonas F. G. Santos

    2014-11-12

    Novel quantization properties related to the state vectors and the energy spectrum of a two-dimensional system of free particles are obtained in the framework of noncommutative (NC) quantum mechanics (QM) supported by the Weyl-Wigner formalism. Besides reproducing the magnetic field aspect of a Zeeman-like effect, the momentum space NC parameter introduces mutual information properties quantified by the quantum purity related to the relevant coordinates of the corresponding Hilbert space. Supported by the QM in the phase-space, the thermodynamic limit is obtained, and the results are extended to three-dimensional systems. The noncommutativity imprints on the thermodynamic variables related to free particles are identified and, after introducing some suitable constraints to fix an axial symmetry, the analysis is extended to two- and- three dimensional quantum rotor systems, for which the quantization aspects and the deviation from standard QM results are verified.

  8. Considerations Affecting Satellite and Space Probe Research with Emphasis on the "Scout" as a Launch Vehicle

    NASA Technical Reports Server (NTRS)

    Posner, Jack (Editor)

    1961-01-01

    This report reviews a number of the factors which influence space flight experiments. Included are discussions of payload considerations, payload design and packaging, environmental tests, launch facilities, tracking and telemetry requirements, data acquisition, processing and analysis procedures, communication of information, and project management. Particular emphasis is placed on the "Scout" as a launching vehicle. The document includes a description of the geometry of the "Scout" as well as its flight capabilities and limitations. Although oriented toward the "Scout" vehicle and its payload capabilities, the information presented is sufficiently general to be equally applicable to most space vehicle systems.

  9. Reciprocal space XRD mapping with varied incident angle as a probe of structure variation within surface depth

    SciTech Connect

    Yang, Qiguang [Norfolk State University; Williams, Frances [Norfolk State University; Zhao, Xin [JLAB; Reece, Charles E. [JLAB; Krishnan, Mahadevan [AASC, San Leandro, California

    2013-09-01

    In this study, we used a differential-depth X-Ray diffraction Reciprocal Spacing Mapping (XRD RSM) technique to investigate the crystal quality of a variety of SRF-relevant Nb film and bulk materials. By choosing different X-ray probing depths, the RSM study successfully revealed evolution the of materials? microstructure after different materials processes, such as energetic condensation or surface polishing. The RSM data clearly measured the materials? crystal quality at different thickness. Through a novel differential-depth RSM technique, this study found: I. for a heteroepitaxy Nb film Nb(100)/MgO(100), the film thickening process, via a cathodic arc-discharge Nb ion deposition, created a near-perfect single crystal Nb on the surface?s top-layer; II. for a mechanically polished single-crystal bulk Nb material, the microstructure on the top surface layer is more disordered than that in-grain.

  10. 46 CFR 281.3 - Method of commencing and terminating voyages and of determining idle status.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...discharged and loaded at each port of the inward voyage; and that where, in the opinion of the operator, voyages as a general practice should terminate at the home or terminal port rather than at the last port of discharge, or a voyage...

  11. 46 CFR 281.3 - Method of commencing and terminating voyages and of determining idle status.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...discharged and loaded at each port of the inward voyage; and that where, in the opinion of the operator, voyages as a general practice should terminate at the home or terminal port rather than at the last port of discharge, or a voyage...

  12. Photons with sub-Planckian energy cannot efficiently probe space-time foam

    NASA Astrophysics Data System (ADS)

    Chen, Yanbei; Wen, Linqing; Ma, Yiqiu

    2014-09-01

    Extra-galactic sources of photons have been used to constrain space-time quantum fluctuations in the Universe. In these proposals, the fundamental "fuzziness" of distance caused by space-time quantum fluctuations has been directly identified with fluctuations in optical paths. Phase-front corrugations deduced from these optical-path fluctuations are then applied to light from extra-galactic point sources, and used to constrain various models of quantum gravity. However, when a photon propagates in three spatial dimensions, it does not follow a specific ray, but rather samples a finite, three-dimensional region around that ray—thereby averaging over space-time quantum fluctuations all through that region. We use a simple, random-walk type model to demonstrate that, once the appropriate wave optics is applied, the averaging of neighboring space-time fluctuations will cause much less distortion to the phase front. In our model, the extra suppression factor due to diffraction is the wave length in units of the Planck length, which is at least 1029 for astronomical observations.

  13. Participatory Sensing in Public Spaces: Activating Urban Surfaces with Sensor Probes

    E-print Network

    Paulos, Eric

    different communities, revealing design implications for future sensing systems as instruments of social and political discourse presents a new design space for enabling public participation and expression. We explore non-experts' use of place-based, modular sensors to activate, author and provoke urban landscapes. Our

  14. The atmospheric structure of Titan from Voyager to Cassini

    NASA Astrophysics Data System (ADS)

    Coustenis, A.

    2007-05-01

    Titan's stratosphere has been studied in the past from the Earth and also from space with Voyager, ISO (Coustenis et al., 1998; 2003) and more recently Cassini observations. In particular, spectra recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft became available during the Titan flybys spanning two years now since SOI (Flasar et al., 2005; Teanby et al., 2006, Vinatier et al., 2006; Nixon et al., 2006; Coustenis et al., 2007). The spectra characterize various regions on Titan from 85°S to 80°N with a variety of emission angles. We have studied the emission observed in the CIRS detector arrays (covering the 10-1500 cm-1 spectral range with apodized resolutions of 2.54 or 0.53 cm-1). We have used temperature profiles retrieved from the inversion of the emission observed in the methane _4 band at 1304 cm-1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan's stratosphere (Coustenis et al., 2007). The composite spectra show several signatures of previously identified molecules: hydrocarbons, nitriles, H2O and CO2. Besides these well-known trace species, a firm detection of benzene (C6H6) is provided by CIRS at 674 cm-1 and allows for the study of its latitudinal variations. No longitudinal variations were found for any of the gases. Information is retrieved on the meridional variations of the trace constituents and tied to predictions by dynamical-photochemical models (Hourdin et al., 2004; Lavvas et al., 2007). Molecules showing a significant enhancement at northern latitudes are the nitriles (HC3N, HCN) and the complex hydrocarbons (C4H2, C3H4). The D/H ratio on Titan was also determined from the CH3D band at 8.6 micron and found to be about 1.2 ± 0.2 10-4. We have also identified the presence of C2HD at 678 cm-1 (Coustenis et al., 2006). Constraints are also set on the vertical distribution of C2H2. We will describe the most relevant results from ground or space regarding Titan's atmospheric structure. References : Coustenis et al., 1998, A&A 336, L85; Coustenis et al., 2003, Icarus 161, 383; Coustenis et al., 2006, BAAS 38; Coustenis et al., 2007, Icarus, in press; Flasar et al., 2005, Science 308, 975 ; Hourdin et al., 2004, J. Geophys. Res. 109, E1205; Nixon et al., 2006, BAAS 38; Lavvas et al., 2007, Plan. Space Sci., submitted; Teanby et al., 2006, Icarus 181, 243; Vinatier et al., 2006, Icarus, in press.

  15. Spectral Evolution of Anomalous Cosmic Rays at Voyager 1 beyond the Termination Shock

    NASA Astrophysics Data System (ADS)

    Senanayake, U. K.; Florinski, V.; Cummings, A. C.; Stone, E. C.

    2015-05-01

    When the Voyager 1 spacecraft crossed the termination shock (TS) on 2004 December 16, the energy spectra of anomalous cosmic rays (ACRs) could not have been produced by steady-state diffusive shock acceleration. However, over the next few years, in the declining phase of the solar cycle, the spectra began to evolve into the expected power-law profile. Observations at the shock led to a broad range of alternative theories for ACR acceleration. In spite of that, in this work we show that the observations could be explained by assuming ACRs are accelerated at the TS. In this paper, we propose that the solar cycle had an important effect on the unrolling of the spectra in the heliosheath. To investigate the spectral evolution of ACRs, a magnetohydrodynamic background model with stationary solar-wind inner boundary conditions was used to model the transport of helium and oxygen ions. We used a backward-in-time stochastic integration technique where phase-space trajectories are integrated until the so-called “injection energy” is reached. Our simulation results were compared with Voyager 1 observations using three different diffusion models. It is shown that the spectral evolution of ACRs in the heliosheath at Voyager 1 could be explained by an increase in the source strength and an enhancement in diffusion as a result of a decrease of the turbulent correlation length in the declining phase of the solar cycle. At the same time, drift effects seem to have had a smaller effect on the evolution of the spectra.

  16. Probing cosmology and gravity with redshift-space distortions around voids

    E-print Network

    Hamaus, Nico; Lavaux, Guilhem; Wandelt, Benjamin D

    2015-01-01

    Cosmic voids in the large-scale structure of the Universe affect the peculiar motions of objects in their vicinity. Although these motions are difficult to observe directly, the clustering pattern of their surrounding tracers in redshift space is influenced in a unique way. This allows to investigate the interplay between densities and velocities around voids, which is solely dictated by the laws of gravity. With the help of N-body simulations and derived mock-galaxy catalogs we calculate the average density fluctuations inside and outside voids identified with a watershed algorithm in redshift space and compare the results with the expectation from general relativity and the LCDM model of cosmology. We find that simple linear-theory predictions work remarkably well in describing the dynamics of voids even on relatively small scales. Adopting a Bayesian inference framework, we determine the full posterior probability distribution of our model parameters and forecast the achievable accuracy on measurements of ...

  17. Weak Lensing from Space I: Prospects for The Supernova/Acceleration Probe

    E-print Network

    Rhodes, J; Aldering, G; Amanullah, R; Astier, Pierre; Barrelet, E; Bebek, C; Bergstr, L; Bercovitz, J; Bester, M; Bonissent, A; Bower, C; Carithers, W C; Commins, Eugene D; Day, C; Deustua, S; Di Gennaro, R S; Ealet, A; Eriksson, M; Fruchter, A S; Genat, J F; Goldhaber, G; Goobar, A; Groom, D; Harris, S; Harvey, P; Heetderks, H; Holland, S; Huterer, D; Karcher, A; Kolbe, W F; Krieger, B; Lafever, R; Lamoureux, J; Levi, M; Levin, D; Linder, E V; Loken, S; Malina, R; McKee, S; Miquel, R; Mostek, N; Mufson, S L; Musser, J; Nugent, P; Oluseyi, H; Pain, R; Palaio, N; Pankow, D; Perlmutter, S; Pratt, R; Prieto, E; Robinson, K; Roe, N; Sholl, M; Schubnell, M S; Smadja, G; Smoot, G F; Spadafora, A; Tarl, G; Tomasch, A; Von der Lippe, H; Vincent, D; Walder, J P; Wang, G; Rhodes, Jason; Refregier, Alexandre; Massey, Richard

    2003-01-01

    The proposed Supernova/Acceleration Probe (SNAP) satellite has been recognized as an ideal instrument to measure the accelerating expansion of the universe through the distance moduli to type Ia supernovae. We show that SNAP will also be excellent for surveys of weak gravitational lensing by large-scale structure. Many of the requirements for precise photometry are compatible with those to accurately measure the shapes of background galaxies. We describe two surveys to be performed by SNAP. A 15 square degree ``deep'' survey will find clusters/groups and allow two-and three-dimensional dark matter maps to be made. A 300 square degree ``wide'' survey will be used to provide global constraints on cosmological parameters including Omega_M and w, the dark energy equation of state parameter. Both surveys will be conducted in 9 wide-band optical and near-IR filters, enabling photometric redshifts to be calculated. This first paper in a three part series outlines the survey strategies and introduces the SNAP instrum...

  18. Voyager studies of the distant heliospheric magnetic fields and plasmas

    Microsoft Academic Search

    N. F. Ness; L. F. Burlaga; J. D. Richardson

    2003-01-01

    Launched in 1977, the twin Voyager spacecraft (V1, V2) are exiting the heliosphere and each one is now well beyond the orbits of the planets. Careful studies have been made of the observed heliospheric magnetic field (HMF) and solar wind plasma over a full solar solar cycle through 2001. At that time, V1 was at a radial distance of 87

  19. Titan interaction with Saturn's magnetosphere: Voyager 1 results revisited

    E-print Network

    Johnson, Robert E.

    Titan interaction with Saturn's magnetosphere: Voyager 1 results revisited E. C. Sittler Jr., R. E March 2005; published 10 September 2005. [1] We investigate the details of Titan's interaction in the outermost region with respect to Titan's ``ionopause,'' followed by CH4 + at intermediate distances and N2

  20. Encounter with Saturn - Voyager 1 imaging science results

    Microsoft Academic Search

    B. A. Smith; L. Soderblom; R. F. Beebe; J. M. Boyce; G. Briggs; A. Bunker; S. A. Collins; C. J. HANSEN; T. V. Johnson; J. L. Mitchell; R. J. Terrile; M. H. Carr; A. F. Cook; J. N. Cuzzi; J. B. Pollack; G. E. Danielson; A. P. Ingersoll; M. E. Davies; G. E. Hunt; H. Masursky; E. M. Shoemaker; D. Morrison; T. Owen; C. Sagan; J. Veverka; R. Strom; V. E. Suomi

    1981-01-01

    As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there

  1. Plasma observations near Saturn - Initial results from Voyager 1

    Microsoft Academic Search

    H. S. Bridge; J. W. Belcher; A. J. Lazarus; S. Olbert; J. D. Sullivan; F. Bagenal; P. R. Gazis; R. E. Hartle; K. W. Ogilvie; J. D. Scudder; E. C. Sittler; A. Eviatar; G. L. Siscoe; C. K. Goertz; V. M. Vasyliunas

    1981-01-01

    The Voyager 1 encounter with Saturn and its satellites yielded extensive measurements of magnetospheric low-energy plasma electrons and positive ions, both heavy and light, probably of hydrogen and nitrogen or oxygen. At radial distances between 15 and 7 Saturn radii on the inbound trajectory, the plasma appears to corotate with a velocity within 20% of that theoretically expected for rigid

  2. Voyager measurement of the rotation period of Saturn's magnetic field

    Microsoft Academic Search

    M. D. Desch; M. L. Kaiser

    1981-01-01

    We determine Saturn's radio rotation period using measurements made by the Planetary Radio Astronomy experiment onboard the Voyager spacecraft. The sidereal period deduced is 10 hr 39 min 24 sec +- 7 sec. The radio rotation period is presumably that of the planet's magnetic field. We propose a provisional Saturn longitude convention, and we provide equations to compute a longitude

  3. Overview of the Voyager Ultraviolet Spectrometry Results Through Jupiter Encounter

    Microsoft Academic Search

    A. L. Broadfoot; B. R. Sandel; D. E. SHEMANSKY; J. C. McConnell; G. R. Smith; J. B. Holberg; S. K. Atreya; T. M. Donahue; D. F. Strobel; J. L. Bertaux

    1981-01-01

    The Voyager ultraviolet spectrometers (UVS) have been making almost continuous observations, in the 500-A to 1700-A wavelength range, of sources in the solar system and galaxy since launch in 1977. Due to their sensitivity, stability, and dynamic range, the spectrometers have made a remarkable number of discoveries pertaining to the Jupiter system, the interstellar medium, astronomical, and astrophysical sources. The

  4. The Ocean Voyager II: an AUV designed for coastal oceanography

    Microsoft Academic Search

    Samuel M. Smith; Stanley E. Dunn

    1994-01-01

    The Ocean Voyager II is a small long-range AUV designed for coastal oceanography. A system overview and design constraints are given with reference to the specific mission of bottom classification through light reflectance and absorption measurement. This mission requires the AUV to fly above the sea floor at a constant altitude while measuring the albedo of the bottom and the

  5. The Europa Scene in the Voyager-Galileo Era

    Microsoft Academic Search

    L. M. V. Martel

    2001-01-01

    Current Galileo Mission data are giving us the closest views of Jupiter's icy moon, Europa, since Voyager images first revealed the surface 20 years ago. The icy crust is smooth and blocky, with a banded and broken-puzzle appearance. Europa's outer shell, intriguing to geologists and astrobiologists alike, has been cited as evidence supporting a subsurface-ocean hypothesis. Two articles in a

  6. The Polar Sea Voyage and the Northwest Passage Dispute

    Microsoft Academic Search

    Philip J. Briggs

    1990-01-01

    This study examines the Northwest Passage controversy between the United States and Canada beginning with the U.S. Coast Guard icebreaker Polar Sea voyage through the passage without permission from the Canadian Government in August 1985 to the signing of the executive agreement on Arctic cooperation in January 1988. Particular focus is placed upon U.S. national interests in the Arctic region,

  7. Voyager radio science observations of Neptune and triton

    Microsoft Academic Search

    G. L. Tyler; V. R. Eshleman; D. L. Gresh; E. M. Gurrola; D. P. Hinson; E. A. Marouf; P. A. Rosen; R. A. Simpson; D. N. Sweetnam; J. D. Anderson; S. E. Borutzki; J. K. Campbell; E. R. Kursinski; G. S. Levy; G. F. Lindal; J. R. Lyons; G. E. Wood; N. Kawashima

    1989-01-01

    The Voyager 2 encounter with the Neptune system included radio science investigations of the masses and densities of Neptune and Triton, the low-order gravitational harmonics of Neptune, the vertical structures of the atmospheres and ionospheres of Neptune and Triton, the composition of the atmosphere of Neptune, and characteristics of ring material. Demanding experimental requirements were met successfully, and study of

  8. Overview of the Voyager ultraviolet spectrometry results through Jupiter encounter

    NASA Technical Reports Server (NTRS)

    Broadfoot, A. L.; Sandel, B. R.; Shemansky, D. E.; Smith, G. R.; Holberg, J. B.; Mcconnell, J. C.; Atreya, S. K.; Donahue, T. M.; Strobel, D. F.; Bertaux, J. L.

    1981-01-01

    The observations of a number of objects by the Voyager EUV instruments are summarized. The summary is considered to demonstrate the wide ranging application of the EUV spectroscopy. It also marks an important step forward in spectrography and emphasizes the continuing importance of the search and discovery nature of spectroscopic techniques.

  9. The Voyages of Columbus: A Turning Point in World History.

    ERIC Educational Resources Information Center

    Crosby, Alfred W.; Nader, Helen

    The far-reaching and transforming interactions of the Old World and the New are known today as "the Columbian Exchange." Part 1 of this booklet is an introduction by John J. Patrick dealing with teaching about the voyages of Christopher Columbus. Part 2, "Columbus and Ecological Imperialism," by Alfred W. Crosby, provides an ecological perspective…

  10. 150 Day Periodicities in the Voyager 2 Plasma Data

    NASA Astrophysics Data System (ADS)

    Ashmall, J.; Richardson, J. D.

    2003-12-01

    Launched over 26 years ago, Voyager 2 is now at a radial distance greater than 71 AU and a latitude of -28.7 degrees out of the ecliptic plane. Voyager 2 and the MIT Plasma Spectrometer continue to return measurements daily. Periodicities with T ? 150 days have been observed in the solar wind by several authors. Fourier and Lomb-Scargle periodograms of the uniquely long Voyager 2 plasma density and bulk-speed data sets (1978-2003) similarly show a strong component at periods of approximately 150 days. Dividing the data into two (1978.0-1990.5 and 1990.5-2003.0) and taking periodograms of the subsets shows a strong ~150 day component in the earlier data but not the latter. Periodograms of further sub-divisions of the data demonstrate a definite time-variation in the spectral power at periods around 150 days. To give a more quantitative view of time-variation of the periodicities, wavelet-analysis was employed. Initial results showed little or no power in the wavelet power spectra around 150 days. By using unusually (temporally) large wavelets, we demonstrate the existence of episodes of persistent but low-power periodicities in the Voyager plasma data, not detected by the smaller scale wavelets. Using large-scale wavelets reveals two episodes of power at ? 150 day periods (both several years long) in the density data and one episode in the bulk-speed data. We compare the bulk-speed and density results and discuss the relationship of the episodes to spacecraft position (radial distance and latitude) as well as to the solar cycle. Results are also compared to measurements of ~150 day periodicities by other authors. Voyager observations are sponsored, in part, by NASA/JPL.

  11. Temporal and spectral variations of anomalous oxygen nuclei measured by Voyager 1 and Voyager 2 in the outer heliosphere

    E-print Network

    Jensen, Grant J.

    (V1) and 2 (V2) spacecraft in the outer heliosphere from 1990 to the present time in 2006 when V1. These changes have been observed throughout the heliosphere on Earth and at the Ulysses, Voyager, and Pioneer spacecraft. These changes are gener- ally much larger than those for galactic cosmic rays of the same charge

  12. Recent Observations of Anomalous Cosmic Rays as Voyager 1 Approaches the Heliopause

    NASA Astrophysics Data System (ADS)

    Cummings, A. C.; Stone, E. C.; McDonald, F. B.; Heikkila, B.; Lal, N.; Webber, W. R.

    2012-12-01

    The Voyager 1 spacecraft crossed the termination shock of the solar wind on 16 December 2004 at 94 AU from the Sun and is now approaching the heliopause, the final boundary between the heliosphere and interstellar space. Two recent particle intensity events suggest this crossing will be accomplished in a series of steps through a structured boundary region. Beginning 7 May 2012, the >70 MeV counting rate (mainly galactic cosmic ray protons) began increasing over a 30 day period to a level about 10% higher than it had been. At the same time, the intensity of ~7-60 MeV/nuc particles, dominated by anomalous cosmic ray (ACR) H, dropped by about the same percentage, suggesting Voyager 1 had entered a new region with reduced ACR intensity. A second particle intensity event that began on 28 July 2012 was even more dramatic, with larger intensity changes over shorter periods of time. The further increases in the GCR intensities were accompanied by decreases in the intensity of ACRs, and the counting rate of >0.5 MeV particles, dominated by termination shock particles, dropped by a factor of two in less than 18 hours. Significant anisotropies are sometimes observed in the ACRs and termination shock particles, and there are ~6-day periodicities in MeV electron rates. The latest observations will be presented at the meeting. This work was supported by NASA under contract NAS7-03001.

  13. Voyager 1 Observations of Galactic Cosmic Rays in the Local Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Cummings, A. C.; Stone, E. C.; Heikkila, B. C.; Lal, N.; Webber, W. R.

    2014-12-01

    The twin Voyager spacecraft were launched in 1977 and continue to be on a remarkable journey of exploration. Both spacecraft have crossed the termination shock of the solar wind and Voyager 1 (V1) crossed into interstellar space in ~mid-2012. At that crossing of the heliopause, the particles of heliospheric origin that had dominated the energy spectrum of most cosmic ray nuclei below approximately 50 MeV/nucleon disappeared, revealing for the first time the energy spectra of galactic cosmic rays (GCRs) down to about 3 MeV/nucleon. The intensity of GCRs has not shown any significant long-term gradient since the crossing, suggesting that V1 is observing the energy spectra of GCRs in the local interstellar medium unaffected by solar modulation. The energy spectra of H, He, C, and O have rather broad peaks in the ~20-100 MeV/nucleon energy range. The H/He ratio in this energy range is ~12 and that of C/O is ~1. We are also observing the local interstellar electron spectrum and find that a power-law energy dependence with spectral index approximately -1.5 from ~5-70 MeV is consistent with the data. We will report on the latest observations at the meeting. This work was supported by NASA under contract NNN12AA012.

  14. Voyager 1 Observations of Galactic Cosmic Rays in the Local Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Cummings, Alan; Stone, Edward C.; Heikkila, Bryant; Lal, Nand; Webber, William R.

    2014-08-01

    The twin Voyager spacecraft were launched in 1977 and continue to be on a remarkable journey of exploration. Both spacecraft have crossed the termination shock of the solar wind and Voyager 1 (V1) crossed into interstellar space in ~mid-2012. At that crossing of the heliopause, the particles of heliospheric origin that had dominated the energy spectrum of most cosmic ray nuclei below approximately 50 MeV/nucleon disappeared, revealing for the first time the energy spectra of galactic cosmic rays (GCRs) down to about 3 MeV/nucleon. The intensity of GCRs has not shown any significant long-term gradient since the crossing, suggesting that V1 is observing the energy spectra of GCRs in the local interstellar medium unaffected by solar modulation. The energy spectra of H, He, C, and O have rather broad peaks in the ~20-100 MeV/nucleon energy range. The H/He ratio in this energy range is ~12 and that of C/O is ~1. We are also observing the local interstellar electron spectrum and find that a power-law energy dependence with spectral index approximately -1.5 from ~5-70 MeV is consistent with the data. We will report on the latest observations at the meeting. This work was supported by NASA under contract NNN12AA012.

  15. From convicts to colonists: the health of prisoners and the voyage to Australia, 1823-53.

    PubMed

    Foxhall, Katherine

    2011-01-01

    From 1815, naval surgeons accompanied all convict voyages from Britain and Ireland to the Australian colonies. As their authority grew, naval surgeons on convict ships increasingly used their medical observations about the health of convicts to make pointed and sustained criticisms of British penal reforms. Beyond their authority at sea, surgeons' journals and correspondence brought debates about penal reform in Britain into direct conversation with debates about colonial transportation. In the 1830s, naval surgeons' claims brought them into conflict with their medical colleagues on land, as well as with the colonial governor, George Arthur. As the surgeons continued their attempts to combat scurvy, their rhetoric changed. By the late 1840s, as convicts' bodies betrayed the disturbing effects of separate confinement as they boarded the convict ships, surgeons could argue convincingly that the voyage itself was a space that could medically, physically and spiritually reform convicts. By the mid-1840s, surgeons took the role of key arbiters of convicts' potential contribution to the Australian colonies. PMID:21584986

  16. Study of the properties of the autonomous optical navigation of a space probe in a rendezvous with an asteroid

    Microsoft Academic Search

    V. V. Ivashkin

    1991-01-01

    Several countries are developing programs to send probes to small solar system objects. Properties of autonomous navigation are examined for a spacecraft on such a mission. In this case the main spacecraft approaches the object for remote study, then releases a probe for a closer study. The probe brakes as it approaches the surface and releases rods which embed in

  17. Formation of relief on Europa's surface and analysis of a melting probe movement through the ice

    NASA Astrophysics Data System (ADS)

    Erokhina, O. S.; Chumachenko, E. N.; Dunham, D. W.; Aksenov, S. A.; Logashina, I. V.

    2013-12-01

    These days, studies of planetary bodies' are of great interest. And of special interest are the icy moons of the giant planets like Jupiter and Saturn. Analysis of 'Voyager 1', 'Voyager 2', 'Galileo' and 'Cassini' spacecraft data showed that icy covers were observed on Jupiter's moons Ganymede, Europa and Calisto, and Saturn's moons Titan and Enceladus. Of particular interest is the relatively smooth surface of Europa. The entire surface is covered by a system of bands, valleys, and ridges. These structures are explained by the mobility of surface ice, and the impact of stress and large-scale tectonic processes. Also conditions on these moons allow speculation about possible life, considering these moons from an astrobiological point of view. To study the planetary icy body in future space missions, one of the problems to solve is the problem of design of a special device capable of penetrating through the ice, as well as the choice of the landing site of this probe. To select a possible landing site, analysis of Europa's surface relief formation is studied. This analysis showed that compression, extention, shearing, and bending can influence some arbitrarily separated section of Europe's icy surface. The computer simulation with the finite element method (FEM) was performed to see what types of defects could arise from such effects. The analysis showed that fractures and cracks could have various forms depending on the stress-strained state arising in their vicinity. Also the problem of a melting probe's movement through the ice is considered: How the probe will move in low gravity and low atmospheric pressure; whether the hole formed in the ice will be closed when the probe penetrates far enough or not; what is the influence of the probe's characteristics on the melting process; what would be the order of magnitude of the penetration velocity. This study explores the technique based on elasto-plastic theory and so-called 'solid water' theory to estimate the melting velocity and to study the melting process. Based on this technique, several cases of melting probe motion are considered, the velocity of the melting probe is estimated, the influence of different factors are studied and discussed, and an easy way to optimize the parameters of the probe is proposed.

  18. Voyages of Discovery through a Backpack Exchange

    ERIC Educational Resources Information Center

    Syz, Tracy Hong

    2008-01-01

    Backpacks are commonplace in American schools. Each day students transport them to and from the classroom as they manage to carve out a little oasis of space to gather their treasures, homework and books. In Fair Lawn's recently launched Chinese classes, backpacks take on new responsibility, becoming culture bearers that connect middle school…

  19. Voyager uplink planning in the interstellar mission era

    NASA Technical Reports Server (NTRS)

    Linick, Susan H.; Weld, Kathryn R.

    1993-01-01

    The Voyager Project has entered its last phase of discovery--the Voyager Interstellar Mission (VIM). Because of the reduced scope of the project and a lower budget, new ways had to be developed to program two spacecraft with fewer people and to allow for some sequence development flexibility without additional risk. In the previous cruise era, it took a seven-person sequence team 12 weeks to develop a nominal eight week cruise sequence. Today it takes a three-person team six weeks to develop a 13 week sequence load. This paper will describe in detail the sequencing strategy which reduces the volume and frequency of sequence loads, and the new tools and processes developed which reduce the manual effort required to generate these sequences without adding risk.

  20. The Voyage of the James Caird by Ernest Shackleton

    NSDL National Science Digital Library

    This is an excerpt from Ernest Shackleton's book, "The Voyage of the James Caird". It provides a firsthand report of Ernest Shackleton's epic 800-mile ocean crossing in a twenty-two foot lifeboat, the "James Caird", to find help after his specially constructed ship, the "Endurance", was trapped and crushed by the Antarctic pack ice. The material includes biographic information about Shackleton, who made four voyages to Antarctica and was knighted for one of his expeditions, his account of the rescue journey he embarked on with five men to obtain help for his stranded crew, and his report of sailing aboard the Chilean steamer Yelcho to rescue the rest of his crew on Elephant Island after 105 days.

  1. Plasma waves near Saturn: Initial results from Voyager 1

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Kurth, W. S.; Scarf, F. L.

    1981-01-01

    The Voyager 1 encounter with Saturn provided the first opportunity to investigate plasma wave interactions in the magnetosphere of Saturn. An overview of the principal results from the Voyager 1 plasma wave instrument is presented starting with the initial detection of Saturn and ending about four weeks after closest approach. A survey plot of the electric field intensities detected during the Saturn encounter is shown starting shortly before the inbound shock crossing and ending shortly after the outbound magnetopause crossing. Many intense waves were observed in the vicinity of Saturn. To provide a framework for presenting the observations, the results are discussed more or less according to the sequence in which the data were obtained.

  2. Titan's surface and rotation: new results from Voyager 1 images

    Microsoft Academic Search

    James Richardson; Ralph D. Lorenz; Alfred McEwen

    2004-01-01

    We present an analysis of images of Saturn's moon Titan, obtained by the Voyager 1 spacecraft on November 8–12, 1980. Orange filter (590–640 nm) images were photometrically corrected and a longitudinal average removed from them, leaving residual images with up to 5% contrast, and dominated by surface reflectivity. The resultant map shows the same regions observed at 673 nm by the Hubble

  3. The Orbit of Pheobe from Earthbased and Voyager Observations

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.

    1996-01-01

    This article presents the results of a fit of a numerically integrated orbit for the Saturnian satellite Pheobe to Earthbased astrometric observations (from 1904 to 1996) and imaging data acquired by the Voyager 2 spacecraft during its encounter with Saturn. The primary results are the epoch state vector used in the integration and a set of mean elements which provide a geometrical representation of the orbit. We also assess the quality of the fit and the accuracy of the orbit.

  4. Infrared observations of the Saturnian system from Voyager 1

    Microsoft Academic Search

    R. Hanel; B. Conrath; F. M. Flasar; V. Kunde; W. Maguire; J. C. Pearl; J. Pirraglia; R. Samuelson; L. Herath; M. Allison; D. P. Cruikshank; D. Gautier; P. J. Gierasch; L. Horn; R. Koppany; C. Ponnamperuma

    1981-01-01

    Atmospheric chemistry analyses of Saturn based on Voyager 1 infrared spectral and radiometric data are presented, including characteristics of the planet's rings and of Titan and other satellites. Infrared spectra of Saturn indicate the presence of H2, CH4, NH3, PH3, C2H2, and C2H6, with the possibility of C3H4 and C3H8. The atmospheric thermal structure of the planet shows hemispheric asymmetries

  5. Chez Anthony Browne Voyage autour de ses albums

    E-print Network

    Jeanjean, Louis

    Chez Anthony Browne Voyage autour de ses albums Pour qui s'intéresse à la littérature de jeunesse, publie depuis 1976 des albums au graphisme très reconnaissable : ses dessins, très travaillés, sont proches de la réalité. Mais si les décors sont souvent ancrés dans le quotidien, ses personnages sont vite

  6. Abundances of Jupiter's trace hydrocarbons from Voyager and Cassini

    NASA Astrophysics Data System (ADS)

    Nixon, C. A.; Achterberg, R. K.; Romani, P. N.; Allen, M.; Zhang, X.; Teanby, N. A.; Irwin, P. G. J.; Flasar, F. M.

    2010-11-01

    The flybys of Jupiter by the Voyager spacecraft in 1979, and over two decades later by Cassini in 2000, have provided us with unique datasets from two different epochs, allowing the investigation of seasonal change in the atmosphere. In this paper we model zonal averages of thermal infrared spectra from the two instruments, Voyager 1 IRIS and Cassini CIRS, to retrieve the vertical and meridional profiles of temperature, and the abundances of the two minor hydrocarbons, acetylene (C 2H 2) and ethane (C 2H 6). The spatial variation of these gases is controlled by both chemistry and dynamics, and therefore their observed distribution gives us an insight into both processes. We find that the two gases paint quite different pictures of seasonal change. Whilst the 2-D cross-section of C 2H 6 abundance is slightly increased and more symmetric in 2000 (northern summer solstice) compared to 1979 (northern fall equinox), the major trend of equator to pole increase remains. For C 2H 2 on the other hand, the Voyager epoch exhibits almost no latitudinal variation, whilst the Cassini era shows a marked decrease polewards in both hemispheres. At the present time, these experimental findings are in advance of interpretation, as there are no published models of 2-D Jovian seasonal chemical variation available for comparison.

  7. More Evidence that Voyager 1 Is Still in the Heliosphere

    NASA Astrophysics Data System (ADS)

    Gloeckler, G.; Fisk, L. A.

    2015-06-01

    The investigators of the Voyager mission currently exploring the heliosheath have concluded and announced that Voyager 1 (V1) has crossed the heliopause and is now in the interstellar medium. This conclusion is based primarily on the plasma wave observations of Gurnett et al., which reveal a plasma electron density that resembles the density expected in the local interstellar medium. Fisk & Gloeckler have disputed the conclusion that V1 has crossed the heliopause, pointing out that to account for all the V1 observations, particularly the magnetic field direction together with the density, it is necessary to conclude that the higher densities observed by Gurnett et al. are due to compressed solar wind. In this Letter it is shown that the model of Fisk & Gloeckler for the nose region of the heliosheath can account in detail for the intensity and spectral shape of Energetic Neutral Hydrogen observed by the Interstellar Boundary Explorer (IBEX) in the directions of V1 and Voyager 2 (V2). A key feature of the Fisk & Gloeckler model is the existence of a region in the heliosheath where the solar wind is compressed and heated, followed by a region where the solar wind is compressed but cold. The region of cold compressed solar wind provides a unique explanation for the low-energy IBEX observations, and since this is the region where V1 must now reside, the low-energy IBEX observations provide strong evidence that V1 is still in the heliosphere.

  8. Infrared observations of the jovian system from voyager 2.

    PubMed

    Hanel, R; Conrath, B; Flasar, M; Herath, L; Kunde, V; Lowman, P; Maguire, W; Pearl, J; Pirraglia, J; Samuelson, R; Gautier, D; Gierasch, P; Horn, L; Kumar, S; Ponnamperuma, C

    1979-11-23

    Infrared spectra obtainedfrom Voyager 2 have provided additional data on the Jovian system, complementing those obtained from Voyager 1. The abundance ratio of ethane to acetylene in Jupiter's atmosphere appears to be about three times larger in the polar regions than at lower latitudes. A decidedly hemispherical asymmetry exists, with somewhat higher ratios prevailing in northern latitudes. An overall increase in the abundance ratio by a factor of about 1.7 appears to have occurred between the Voyager 1 and 2 encounters. Global brightness temperature maps of Jupiter at 226 and 602 cm(-1) exhibit a large amount of local- and planetary-scale structure, as well as temporal variability. Although heterogeneous cloud structure and ammonia concentration in the lower troposphere may contribute to the appearance of the 226-cm(-1) map, the detail in the 602-cm(-1) maps probably represents the actual horizontal thermal structure near the tropopause and suggests that dynamical heating and cooling processes are important. Low-latitude surface temperatures on the Galilean satellites rangefrom approximately 80 K on the dark sides to 155 K at the subsolar point on Callisto. Below a thin insulating layer, the thermal inertia of Callisto is somewhat greater than that of Earth's moon. Upper limits on the infrared optical depth of the Jovian ring rangingfrom approximately 3 x 10(-4) at 250 cm(-1) to 3 x 10(-3) at 600 cm(-1) have been found. PMID:17733912

  9. Voyager electronic parts radiation program. Volume 2: Test requirements and procedures

    NASA Technical Reports Server (NTRS)

    Stanley, A. G.; Martin, K. E.; Price, W. E.

    1978-01-01

    Documents are presented outlining the conditions and requirements of the test program. The Appendixes are as follows: appendix A -- Electron Simulation Radiation Test Specification for Voyager Electronic Parts and Devices, appendix B -- Electronic Piece-Part Testing Program for Voyager, appendix C -- Test Procedure for Radiation Screening of Voyager Piece Parts, appendix D -- Boeing In Situ Test Fixture, and appendix E -- Irradiate - Anneal (IRAN) Screening Documents.

  10. DSN 70-meter antenna X-band gain, phase, and pointing performance, with particular application for Voyager 2 Neptune encounter

    NASA Technical Reports Server (NTRS)

    Slobin, S. D.; Bathker, D. A.

    1988-01-01

    The gain, phase, and pointing performance of the Deep Space Network (DSN) 70 m antennas are investigated using theoretical antenna analysis computer programs that consider the gravity induced deformation of the antenna surface and quadripod structure. The microwave effects are calculated for normal subreflector focusing motion and for special fixed-subreflector conditions that may be used during the Voyager 2 Neptune encounter. The frequency stability effects of stepwise lateral and axial subreflector motions are also described. Comparisons with recently measured antenna efficiency and subreflector motion tests are presented. A modification to the existing 70 m antenna pointing squint correction constant is proposed.

  11. Study of the properties of the autonomous optical navigation of a space probe in a rendezvous with an asteroid

    NASA Astrophysics Data System (ADS)

    Ivashkin, V. V.

    1991-04-01

    Several countries are developing programs to send probes to small solar system objects. Properties of autonomous navigation are examined for a spacecraft on such a mission. In this case the main spacecraft approaches the object for remote study, then releases a probe for a closer study. The probe brakes as it approaches the surface and releases rods which embed in the surface to study the soil. While a high landing speed is required for the soil study rods, a soft landing is desired for the probe. It is necessary to know the probe's exact distance from the surface. Previously, radar altitude measurements were made. The possibility of using optical navigation is examined. The object of the study is the asteroid Vesta. Navigation by measurements of the angular diameter of Vesta may be unsuitable. Sighting the asteroid on a star field is examined, and this method yields adequate results. Cases are examined where the distance to the target is known, as are cases where it must be determined. The examination includes a consideration of error analysis, and an analysis is made of the probe position determination accuracy and the landing speed accuracy of the probe.

  12. Net current measurements and secondary electron emission characteristics of the Voyager plasma science experiment and their impact on data interpretation

    NASA Technical Reports Server (NTRS)

    Mcnutt, Ralph L., Jr.

    1988-01-01

    The Voyager Plasma Science (PLS) instrument is capable of returning integral (DC) current measurements, similar in some respects to measurements made with a Langmuir probe or a retarding potential analyzer, although there are significant differences. The integral measurements were made during a calibration sequence in the solar wind, during Cruise Science Maneuvers, and within the magnetospheres of Jupiter and Saturn by Voyager 1. After the failure of the PLS experiment following the Saturn encounter, that instrument was placed in the DC return mode returning possibly usable data from early 1981 through early 1985. The DC return measurements are difficult to interpret and are above threshold values only for relatively large fluxes; the determination of the measured current level is dependent on the operating temperature of the preamplifiers which further complicates the interpretation. Nevertheless, these measurements can be used to determine the efficiency of the suppressor grid at preventing the loss of secondary electrons off the collector plate. Some DC return measurements have been invaluable in aiding in the interpretation of some electron plasma measurements not previously understood. It is found that electron spectra can be significantly modified by the presence of second generation secondary electrons produced by either first generation secondaries or photoelectrons on the support ring of the negative high voltage modulator grid within the instrument housing.

  13. Titan's atmospheric composition: from Voyager to Cassini and beyond

    NASA Astrophysics Data System (ADS)

    Coustenis, A.

    2007-12-01

    Titan's atmosphere was revealed by the Voyager missions in the 80s. The trace composition was in particular inferred from infrared spectra by the V1/IRIS Spectrometer. ISO gave us an opportunity to further explore this exciting milieu in 1997 (Coustenis et al., 1998; 2003) and brought the discovery of new molecules : H2O and C6H6. Our understanding of Titan's atmospheric chemical composition has recently been enhanced by the data returned by the Cassini instruments. Spectra recorded by the Composite Infrared Spectrometer (CIRS) aboard the Cassini spacecraft have been processed from the Titan flybys spanning three years now since SOI (Flasar et al., 2005; Teanby et al., 2006, Vinatier et al., 2006; Nixon et al., 2006; Coustenis et al., 2007). The spectra characterize various regions on Titan from 85°S to 80°N with a variety of emission angles. We have studied the emission observed in the CIRS detector arrays (covering the 10-1500 cm-1 spectral range with apodized resolutions of 2.54 or 0.53 cm-1). We have used temperature profiles retrieved from the inversion of the emission observed in the methane band at 1304 cm-1 and a line-by-line radiative transfer code to infer the abundances of the trace constituents and some of their isotopes in Titan's stratosphere (Coustenis et al., 2007a). The composite spectra show several signatures of previously identified molecules: hydrocarbons, nitriles, H2O and CO2. Besides these well-known trace species, a firm detection of benzene (C6H6) is provided by CIRS at 674 cm-1 and allows for the study of its latitudinal variations. No longitudinal variations were found for any of the gases. Information is retrieved on the meridional variations of the trace constituents and tied to predictions by dynamical-photochemical models (Hourdin et al., 2004; Lavvas et al., 2007). Molecules showing a significant enhancement at northern latitudes are the nitriles (HC3N, HCN) and the complex hydrocarbons (C4H2, C3H4). The D/H ratio on Titan was also determined from the CH3D band at 8.6 micron and found to be about 1.2 ± 0.2 × 10-4. We have also identified the presence of C2HD at 678 cm-1 for the first time (Coustenis et al., 2007b, in preparation). Constraints are also set on the vertical distribution of C2H2. However successful, the Cassini-Huygens mission has brought new enquiries that can only be answered by future missions to Titan. Such a mission, a collaboration between ESA and NASA in the spirit of Cassini, was recently proposed by the TANDEM Consortium in response to ESA's Cosmic Vision Call. References : Coustenis et al., 1989, Icarus 80, 54; Coustenis et al., 1998, A & A 336, L85-L89; Coustenis et al., 2003, Icarus 161, 383; Coustenis et al., 2007a, Icarus 1889, 35-62; Flasar et al., 2005, Science 308, 975 ; Hourdin et al., 2004, J. Geophys. Res. 109, E1205; Nixon et al., 2007, Icarus, in press; Lavvas et al., 2007, Plan. Space Sci., in press; Teanby et al., 2006, Icarus 181, 243; Vinatier et al., 2006, Icarus, 188, 120.

  14. Voyager image processing at the Image Processing Laboratory

    NASA Technical Reports Server (NTRS)

    Jepsen, P. L.; Mosher, J. A.; Yagi, G. M.; Avis, C. C.; Lorre, J. J.; Garneau, G. W.

    1980-01-01

    This paper discusses new digital processing techniques as applied to the Voyager Imaging Subsystem and devised to explore atmospheric dynamics, spectral variations, and the morphology of Jupiter, Saturn and their satellites. Radiometric and geometric decalibration processes, the modulation transfer function, and processes to determine and remove photometric properties of the atmosphere and surface of Jupiter and its satellites are examined. It is exhibited that selected images can be processed into 'approach at constant longitude' time lapse movies which are useful in observing atmospheric changes of Jupiter. Photographs are included to illustrate various image processing techniques.

  15. Jovian ionospheric conductivity and magnetospheric plasma outflow - Voyager 1

    NASA Astrophysics Data System (ADS)

    Hairston, M. R.; Hill, T. W.

    1985-10-01

    Using magnetic field and plasma data from the Voyager 1 inbound encounter, the authors have derived local values for the mass outflow rate and the radial bulk velocity in the dayside Jovian magnetosphere, and for the height-integrated Pedersen conductivity of the Jovian ionosphere. These values, accurate within a factor of 2, are compatible with previous order-of-magnitude estimates of these quantities. The results suggest that the shape of the plasma sheet is more complicated than previously suspected. A search for evidence of enhanced plasma outflow in the active sector was inconclusive.

  16. Post Voyager comparisons of the interiors of Uranus and Neptune

    NASA Technical Reports Server (NTRS)

    Podolak, M.; Reynolds, R. T.; Young, R.

    1990-01-01

    The recent Voyager flyby of Uranus and Neptune has provided refined values for the gravitational moments and rotation periods of those planets. Using these new parameters, models of the interiors of these planets show that their density distributions are very similar. This lends support to the conjecture that their compositions are similar as well. The models are indeed consistent with such a conjecture. The difference in the internal heat sources of these two planets may be due to the fact that heat transport from the interior of Uranus is inhibited by a statically stable interior.

  17. Voyager and the origin of the solar system

    NASA Technical Reports Server (NTRS)

    Prentice, A. J. R.

    1981-01-01

    A unified model for the formation of regular satellite systems and the planetary system is outlined. The basis for this modern Laplacian theory is that there existed a large supersonic turbulent stress arising from overshooting convective motions within the three primitive gaseous clouds which formed Jupiter, Saturn, and the Sun. Calculations show that if each cloud possessed the same fraction of supersonic turbulent energy, equal to about 5% of the cloud's gravitational potential energy, then the broad mass distribution and chemistry of all regular satellite and planetary systems can be simultaneously accounted for. Titan is probably a captured moon of Saturn. Several predictions about observations made by Voyager 2 at Saturn are presented.

  18. Voyager photometry of Triton - Haze and surface photometric properties

    NASA Technical Reports Server (NTRS)

    Hillier, J.; Helfenstein, P.; Verbiscer, A.; Veverka, J.

    1991-01-01

    The Voyager whole-disk observations of Triton at 0.41, 0.48, and 0.56 micron filter wavelengths are analyzed using a model which combines an improved version of Hapke's photometric equation with a thin atmospheric haze layer in the appropriate spherical geometry. The model is shown to describe accurately the phase curves over a range of phase angles and to agree with disk-resolved brightness scans along the photometric equator and mirror meridian. According to the model, the photometric parameters of Triton's regolith are reasonably typical of icy satellites, except for the extremely high (close to unity) single-scattering albedo.

  19. Thermal structure and dynamics of Neptune's atmosphere from Voyager measurements

    NASA Technical Reports Server (NTRS)

    Conrath, B. J.; Flasar, F. M.; Gierasch, P. J.

    1991-01-01

    The thermal structure of the Neptunian atmosphere between 50 and 10 mbar is characterized using spatially resolved Voyager IR spectra from a global mapping sequence. A zonal mean meridional temperature cross section was obtained which shows a minimum in the upper tropospheric and lower stratospheric temperatures at the southern mid-latitudes, and maxima at the equator and at high southern latitudes. This structure is qualitatively similar to the thermal structure of the Uranian atmosphere, even though the obliquities and the internal heat fluxes of the two planets are quite different.

  20. Voyager electron density measurements on Saturn: Analysis with a time dependent ionospheric model

    Microsoft Academic Search

    Tariq Majeed; John C. McConnell

    1996-01-01

    We have used a one-dimensional chemical diffusive model of the ionosphere, in conjunction with the measured Voyager ultraviolet spectrometer (UVS) upper atmospheric temperature and composition structure, to analyze the Voyager measurements of Saturn's upper ionospheric electron densities. Electron density measurements are available from the analysis of the radio science (RSS) experiments. In addition, if interpreted as an atmospheric phenomenon the

  1. Strong Temporal Variation Over One Saturnian Year: From Voyager to Cassini

    E-print Network

    Strong Temporal Variation Over One Saturnian Year: From Voyager to Cassini Liming Li1 , Richard K), from the Voyager encounters (1980­81) to the new Cassini reconnaissance (2009­10). The combined planets and conducted snapshot observa- tions. The Galileo and Cassini spacecrafts on the other hand made

  2. 46 CFR 14.201 - Voyages upon which shipping articles are required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... (iii) The West Indies. (2) Of 75 gross tons or more on a voyage between a port of the United States on the Atlantic Ocean and a port of the United States on the Pacific Coast; or (3) Of 50 gross tons or more on a voyage between a...

  3. 46 CFR 14.201 - Voyages upon which shipping articles are required.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (iii) The West Indies. (2) Of 75 gross tons or more on a voyage between a port of the United States on the Atlantic Ocean and a port of the United States on the Pacific Coast; or (3) Of 50 gross tons or more on a voyage between a...

  4. 46 CFR 14.201 - Voyages upon which shipping articles are required.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... (iii) The West Indies. (2) Of 75 gross tons or more on a voyage between a port of the United States on the Atlantic Ocean and a port of the United States on the Pacific Coast; or (3) Of 50 gross tons or more on a voyage between a...

  5. 46 CFR 14.201 - Voyages upon which shipping articles are required.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...or (iii) The West Indies. (2) Of 75 GRT or more on a voyage between a port of the United States on the Atlantic Ocean and a port of the United States on the Pacific Coast; or (3) Of 50 GRT or more on a voyage between a port...

  6. The Columbian Voyages, the Columbian Exchange, and Their Historians. Essays on Global and Comparative History.

    ERIC Educational Resources Information Center

    Crosby, Alfred W.

    The 500th anniversary of the Columbian discovery of America is upon us, and with it the obligation to assess existing interpretations of the significance of the voyage and establishment of permanent links between the Old and New Worlds. The traditional, or bardic, version of the Columbian voyages and their consequences was the product of narrative…

  7. Voyager 2's encounter with Neptune answered many questions about the 'blue' planet

    SciTech Connect

    Tsurutani, B.T. (JPL, Pasadena, CA (USA))

    1990-02-01

    Voyager 2 observations of Neptune from August 1989 are examined. Voyager 2 discovered 6 new moons around Neptune and collected information on the shape and composition of Neptune's rings. The spots and clouds detected in the planet's atmosphere are described. Consideration is given to Neptune's magnetic field and auroras.

  8. Abundances of Jupiter's Trace Hydrocarbons from Voyager and Cassini. Data Tables: Voyager IRIS Observations Planetary and Space Science, Forthcoming 2010

    NASA Technical Reports Server (NTRS)

    Nixon, C. A.; Achterberg, R. K.; Romani, P. N.; Allen, M.; Zhang, X.; Irwin, P. G. J.; Flasar, F. M.

    2010-01-01

    The following six tables give the retrieved temperatures and volume mixing ratios of C2H2 and C2H6 and the formal errors on these results from the retrieval, as described in the manuscript. These are in the form of two-dimensional tables, specified on a latitudinal and vertical grid. The first column is the pressure in bar, and the second column gives the altitude in kilometers calculated from hydrostatic equilibrium, and applies to the equatorial profile only. The top row of the table specifies the planetographic latitude.

  9. Magnetic field measurements at Jupiter by Voyagers 1 and 2: Daily plots of 48 second averages

    NASA Technical Reports Server (NTRS)

    Lepping, R. P.; Silverstein, M. J.; Ness, N. F.

    1981-01-01

    A series of 24 hour summary plots of the magnetic field, in 48-s average form, measured in the vicinity of Jupiter by the magnetometers onboard Voyagers 1 and 2 are presented. The Voyager 1 data cover the period from 27 February 1979 (day = 58) to 23 March (day = 82) inclusive, and the Voyager 2 data cover the period from 2 July 1979 (day = 183) to 14 August (day = 226) inclusive. Closest approach to the planet occurred on days 64 (AT 1205 UT) and 190 (AT 2230 UT) for Voyagers 1 and 2, respectively. Also included are: a description of the characteristics of the magnetometers, a brief description of the near-planet trajectories of the two spacecraft, a listing of the bow shock and magnetopause crossing times, and a bibliography containing Voyager-Jupiter related papers and reports.

  10. Shared Voyage: Learning and Unlearning from Remarkable Projects

    NASA Technical Reports Server (NTRS)

    Laufer, Alexander; Post, Todd; Hoffman, Edward J.

    2005-01-01

    Shared Voyage is about four remarkable projects: the Advanced Composition Explorer (NASA), the Joint Air-to-Surface Standoff Missile (U.S. Air Force), the Pathfinder Solar-Powered Airplane (NASA), and the Advanced Medium Range Air-to-Air Missile (U.S.Air Force). Each project is presented as a case study comprised of stories collected from key members of the project teams. The stories found in the book are included with the purpose of providing an effective learning source for project management, encouraging the unlearning of outdated project management concepts, and enhancing awareness of the contexts surrounding different projects. Significantly different from project concepts found in most project management literature, Shared Voyage highlights concepts like a will to win, a results-oriented focus, and collaboration through trust. All four project teams researched in this study applied similar concepts; however, they applied them differently, tailoring them to fit the context of their own particular projects. It is clear that the one best way approach which is still the prevailing paradigm in project management literature should be replaced by a new paradigm: Even though general project management principles exist, their successful application depends on the specifics of the situation.

  11. Encounter with Saturn: Voyager 1 imaging science results

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.; Beebe, R.; Boyce, J.; Briggs, G.; Bunker, A.; Collins, S.A.; Hansen, C.J.; Johnson, T.V.; Mitchell, J.L.; Terrile, R.J.; Carr, M.; Cook, A.F., II; Cuzzi, J.; Pollack, James B.; Edward, Danielson G.; Ingersoll, A.; Davies, M.E.; Hunt, G.E.; Masursky, H.; Shoemaker, E.; Morrison, D.; Owen, T.; Sagan, C.; Veverka, J.; Strom, R.; Suomi, V.E.

    1981-01-01

    As Voyager 1 flew through the Saturn system it returned photographs revealing many new and surprising characteristics of this complicated community of bodies. Saturn's atmosphere has numerous, low-contrast, discrete cloud features and a pattern of circulation significantly different from that of Jupiter. Titan is shrouded in a haze layer that varies in thickness and appearance. Among the icy satellites there is considerable variety in density, albedo, and surface morphology and substantial evidence for endogenic surface modification. Trends in density and crater characteristics are quite unlike those of the Galilean satellites. Small inner satellites, three of which were discovered in Voyager images, interact gravitationally with one another and with the ring particles in ways not observed elsewhere in the solar system. Saturn's broad A, B, and C rings contain hundreds of "ringlets," and in the densest portion of the B ring there are numerous nonaxisymmetric features. The narrow F ring has three components which, in at least one instance, are kinked and crisscrossed. Two rings are observed beyond the F ring, and material is seen between the C ring and the planet. Copyright ?? 1981 AAAS.

  12. Recent Results from the Voyager 1 and 2 Plasma Instruments

    NASA Astrophysics Data System (ADS)

    Ashmall, J.; Richardson, J. D.

    2004-12-01

    Voyager 1 and Voyager 2, launched in 1978, are now at radial distances of 94 AU and 75 AU and continue to return data daily. The plasma (PLS) instruments onboard both spacecraft were designed and built by M.I.T. The PLS instrument on V1 ceased normal operation after the Saturn fly-by in 1980 but is still able to return ``DC Mode" current measurements integrated over all energies when fluxes are high enough. Eventually the instrument was turned off for power-sharing reasons and remained off until May 2003 when, following the controversial termination shock event at V1 in August 2002, the V1 PLS instrument was turned back on. The V2 PLS instrument is undamaged and continues to work perfectly. In this paper we introduce interpretation of the recent DC Mode data from the V1 PLS instrument. Alongside this we present V2 plasma data from the largest events of recent years, notably the 2000 Bastille day event and the Halloween events of 2003. Using V2 plasma data we are able to estimate likely DC mode readings at V1 and we compare these predictions to actual measurements. Finally, a survey of the V2 data set shows the V2 Bastille and Halloween events may be members of a new class of events observed near interplanetary shocks. The events are characterised by pulses followed by "troughs" in the plasma density, which coincide with increases in plasma temperature and magnetic field strength.

  13. J. Phys. Chem. 1989, 93, 8149-8162 8149 Ultrafast Pump-Probe Spectroscopy: Femtosecond Dynamics in Liouville Space

    E-print Network

    Mukamel, Shaul

    consists of a sequential term and a tunneling (coherent) term which are formally analogous-probe experiment in a supersonic beam. In that experiment the photodissociation of ICN was directly monitored dynamics. Bersohn and &wail1& have offered a simple semiclassicalinterpretation of the ICN experiment using

  14. CALIBRATION OF PU INTENSITY PROBES

    Microsoft Academic Search

    Virginie Jaud; Finn Jacobsen

    A pressure-velocity sound intensity probe (or a 'p-u intensity probe') is a device that combines a pressure microphone with an acoustic particle velocity transducer. Such devices are mush more difficult to calibrate than sound intensity probes that combines closely spaced pressure microphones ('p-p intensity probes'). Various methods of calibrating p-u sound in- tensity probes are examined: a far field method

  15. Robots Explore the Farthest Reaches of Earth and Space

    NASA Technical Reports Server (NTRS)

    2008-01-01

    "We were the first that ever burst/Into that silent sea," the title character recounts in Samuel Taylor Coleridge s opus Rime of the Ancient Mariner. This famous couplet is equally applicable to undersea exploration today as surface voyages then, and has recently been applied to space travel in the title of a chronicle of the early years of human space flight ("Into That Silent Sea: Trailblazers of the Space Era, 1961-1965"), companion to the +n the Shadow of the Moon book and movie. The parallel is certainly fitting, considering both fields explore unknown, harsh, and tantalizingly inhospitable environments. For starters, exploring the Briny Deep and the Final Frontier requires special vehicles, and the most economical and safest means for each employ remotely operated vehicles (ROVs). ROVs have proven the tool of choice for exploring remote locations, allowing scientists to explore the deepest part of the sea and the furthest reaches of the solar system with the least weight penalty, the most flexibility and specialization of design, and without the need to provide for sustaining human life, or the risk of jeopardizing that life. Most NASA probes, including the historic Voyager I and II spacecraft and especially the Mars rovers, Spirit and Opportunity, feature remote operation, but new missions and new planetary environments will demand new capabilities from the robotic explorers of the future. NASA has an acute interest in the development of specialized ROVs, as new lessons learned on Earth can be applied to new environments and increasingly complex missions in the future of space exploration.

  16. Probing the Solar System

    ERIC Educational Resources Information Center

    Wilkinson, John

    2013-01-01

    Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

  17. NASA utilization of the International Space Station and the Vision for Space Exploration

    Microsoft Academic Search

    Julie A. Robinson; Tracy L. Thumm; Donald A. Thomas

    2007-01-01

    In response to the US President's Vision for Space Exploration (January 14, 2004), NASA has revised its utilization plans for International Space Station (ISS) to focus on (1) research on astronaut health and the development of countermeasures that will protect our crews from the space environment during long-duration voyages, (2) ISS as a test bed for research and technology developments

  18. Voyager infrared observations of Uranus' atmosphere - Thermal structure and dynamics

    NASA Technical Reports Server (NTRS)

    Flasar, F. M.; Conrath, B. J.; Pirraglia, J. A.; Gierasch, P. J.

    1987-01-01

    The temperature structure of the Uranus atmosphere is investigated on the basis of 325/cm and 225/cm Voyager 2 IRIS observations of a layer between 60 and 200 mbar (including the tropopause). The data are presented in graphs and analyzed in detail. The latitudinal variations of the temperature near the tropopause and the inferred thermal winds are shown to be in good agreement with the findings reported for lower altitudes by Hanel et al. (1986), although greater in amplitude. A linear zonally symmetric circulation model with no solar and condensation heating, a frictional damping time 1-2 times the radiative damping time, a subrotating atmosphere at low latitudes, and zonal winds decaying with altitude is proposed to account for the observed structures.

  19. The thermal structure of Triton's atmosphere - Pre-Voyager models

    NASA Technical Reports Server (NTRS)

    Mckay, Christopher P.; Pollack, James B.; Zent, Aaron P.; Cruikshank, Dale P.; Courtin, Regis

    1989-01-01

    Spectral data from earth observations have indicated the presence of N2 and CH4 on Triton. This paper outlines the use of the 1-D radiative-convective model developed for Titan to calculate the current pressure of N2 and CH4 on Triton. The production of haze material is obtained by scaling down from the Titan value. Results and predictions for the Voyager Triton encounter are as follows: A N2-CH4 atmosphere on Triton is thermodynamically self consistent and would have a surface pressure of approximately 50 millibar; due to the chemically produced haze, Triton has a hot atmosphere with a temperature of approximately 130 K; Triton's troposphere is a region of saturation of the major constituent of the atmosphere, N2.

  20. Exploring Our Dynamic Planet: Jules Verne Voyager, Jr.

    NSDL National Science Digital Library

    Chuck Meertens

    2002-02-28

    Exploring Our Dynamic Planet consists of interactive tools, curriculum, and background materials that enable students to better visualize geophysical and geological processes and structures. A classroom module explores plate tectonics using geodesy results from GPS to observe and measure crustal motion. Tools include Jules Verne Voyager, Jr., which allows students to choose from a variety of base maps, add a number of geographic and geophysical overlays (e.g. plate boundaries, earthquake and volcano locations), and then superimpose crustal motion velocity vectors to observe how the tectonic plates move in relation to one another. The tool can be used to explore topics such as plate tectonics, seafloor spreading, and seasonal land and ocean productivity.

  1. Uranus photochemistry and prospects for Voyager 2 at Neptune

    NASA Technical Reports Server (NTRS)

    Atreya, S. K.

    1990-01-01

    CH4 is the only photochemically active constituent in the atmospheres of Uranus and Neptune. NH3, H2O and H2S are all removed by condensation at pressures greater than 1.5 bars. Although the bulk mole fraction (about 2 percent) of CH4 is 20-30 times its solar value on both planets, it drops to its saturation limit (about 0.0001) at the Uranus tropopause, but remains high (about 2 percent) at the Neptune tropopause. This results in much greater mixing ratios of the product hydrocarbons in the stratosphere of Neptune. On both planets, the photolysis products of CH4 undergo condensation near the tropopause and the upper stratosphere. Voyager observations of the hydrocarbons at Uranus and those planned at Neptune are discussed, along with their implications for upper-atmospheric physics and thermochemistry.

  2. The voyager 2 encounter with the neptunian system.

    PubMed

    Stone, E C; Miner, E D

    1989-12-15

    An overview of the Voyager 2 encounter with Neptune is presented, including a brief discussion of the trajectory, the planned observations, and highlights of the results described in the 11 companion papers. Neptune's blue atmosphere has storm systems reminiscent of those in Jupiter's atmosphere. An optically thin methane ice cloud exists near the 1.5-bar pressure level, and an optically thick cloud exists below 3 bars. Neptune's magnetic field is highly tilted and offset from the planet's center; it rotates with a period of 16.11 hours. Two narrow and two broad rings circle the planet; the outermost of these rings has three optically thicker arc segments. Six new moons were discovered in circular prograde orbits, all well inside Triton's retrograde orbit. Triton has a highly reflective and geologically young surface, a thin nitrogen atmosphere, and at least two active geyser-like plumes. PMID:17755996

  3. The Voyager 2 encounter with the Neptunian system

    SciTech Connect

    Stone, E.C.; Miner, E.D. (California Institute of Technology, Pasadena (USA))

    1989-12-15

    An overview of the Voyager 2 encounter with Neptune is presented, including a brief discussion of the trajectory, the planned observations, and highlights of the results described in the 11 companion papers. Neptune's blue atmosphere has storm systems reminiscent of those in Jupiter's atmosphere. An optically thin methane ice cloud exists near the 1.5-bar pressure level, and an optically thick cloud exists below 3 bars. Neptune's magnetic field is highly tilted and offset from the planet's center; it rotates with a period of 16.11 hours. Two narrow and two broad rings circle the planet; the outermost of these rings has three optically thicker arc segments. Six moons were discovered in circular prograde orbits, all well inside Triton's retrograde orbit. Triton has a highly reflective and geologically young surface, a thin nitrogen atmosphere, and at least two active geyser-like plumes.

  4. Pioneer and Voyager observations of the solar wind at large heliocentric distances and latitudes

    NASA Technical Reports Server (NTRS)

    Gazis, P. R.; Mihalov, J. D.; Barnes, A.; Lazarus, A. J.; Smith, E. J.

    1989-01-01

    Data obtained from the electrostatic analyzers aboard the Pioneer 10 and 11 spacecraft and from the Faraday cup aboard Voyager 2 were used to study spatial gradients in the distant solar wind. Prior to mid-1985, both spacecraft observed nearly identical solar wind structures. After day 150 of 1985, the velocity structure at Voyager 2 became flatter, and the Voyager 2 velocities were smaller than those observed by Pioneer 11. It is suggested that these changes in the solar wind at low latitudes may be related to a change which occurred in the coronal hole structure in early 1985.

  5. The Solar Wind: Probing the Heliosphere with Multiple Spacecraft John D. Richardson

    E-print Network

    Richardson, John

    1 The Solar Wind: Probing the Heliosphere with Multiple Spacecraft John D. Richardson Center of the Voyager spacecraft in the outer heliosphere, Ulysses at high latitudes, and multiple solar wind monitors near Earth provides a unique opportunity to study the global structure and evolution of the solar wind

  6. The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe

    Microsoft Academic Search

    H. B. Niemann; S. K. Atreya; S. J. Bauer; G. R. Carignan; J. E. Demick; R. L. Frost; D. Gautier; J. A. Haberman; D. N. Harpold; D. M. Hunten; G. Israel; J. I. Lunine; W. T. Kasprzak; T. C. Owen; M. Paulkovich; F. Raulin; E. Raaen

    2005-01-01

    Saturn's largest moon, Titan, remains an enigma, explored only by remote sensing from Earth, and by the Voyager and Cassini spacecraft. The most puzzling aspects include the origin of the molecular nitrogen and methane in its atmosphere, and the mechanism(s) by which methane is maintained in the face of rapid destruction by photolysis. The Huygens probe, launched from the Cassini

  7. Comparison of Hapke's photometric theory with Voyager observations of Europa, Enceladus, Rhea and Mimas

    NASA Technical Reports Server (NTRS)

    Buratti, B.; Veverka, J.

    1984-01-01

    Voyager imaging observations of the satellites of Jupiter and Saturn provide an excellent test for various photometric theories that were proposed to describe the scattering properties of planetary and satellite surfaces. Not only does the Voyager data set include observations of surfaces ranging widely in albedo, but it provides measurements (in both disc-integrated and disc-resolved forms) over a wide range of phase angles. A detailed comparison of the above models with Voyager data for Europa, Enceladus, Rhea, and Mimas was described. These satellites were selected because they cover a range of reflectances from 0.65 to 1.0 and because for them the Voyager photometric data sets are most complete.

  8. 15 CFR 970.2501 - Notice of pre-license exploration voyages.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...2013-01-01 false Notice of pre-license exploration voyages. 970.2501 Section 970.2501...SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2501 Notice of...

  9. 15 CFR 970.2501 - Notice of pre-license exploration voyages.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 false Notice of pre-license exploration voyages. 970.2501 Section 970.2501...SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2501 Notice of...

  10. 15 CFR 970.2501 - Notice of pre-license exploration voyages.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 false Notice of pre-license exploration voyages. 970.2501 Section 970.2501...SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2501 Notice of...

  11. 15 CFR 970.2501 - Notice of pre-license exploration voyages.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...2012-01-01 false Notice of pre-license exploration voyages. 970.2501 Section 970.2501...SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2501 Notice of...

  12. Earth Exploration Toolbook Chapter: Investigating Earthquakes with ArcVoyager GIS

    NSDL National Science Digital Library

    Carla McAuliffe

    DATA: Recent and Historical Earthquake Data TOOL: ArcVoyager Special Edition GIS - Explore earthquake data and import them into a Geographic Information System (GIS). Analyze the data to predict where the next big earthquake will occur.

  13. Ephemerides of the Uranian satellites determined from earth-based astrometric and Voyager imaging observations

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Lewis, G. D.; Riedel, J. E.; Roth, D. C.; Synnot, S. P.

    1986-01-01

    Uranian satellite ephemerides were needed by the Voyager project to support both navigation and acquisition of scientific data. This paper outlines the mathematical modeling approach taken to generate those ephemerides and discusses their pre-encounter development, real time updating, and post-encounter refinement. The results presented include the final set of model parameters which generate the ephemerides that best fit the Voyager optical data as well as the earth based observations of the satellites.

  14. Vertical mixing and methane photochemistry in the atmosphere of Uranus: Analysis of Voyager UVS occultation experiments

    NASA Technical Reports Server (NTRS)

    Bishop, James

    1991-01-01

    Extensive capabilities were developed in the analysis of ultraviolet spectrometer (UVS) absorptive lightcurves. The application of these capabilities to the Voyager UVS data sets from Uranus and Neptune has provided significant findings regarding the stratospheres of these planets. In particular, the direct comparison between photochemical models and UVS measurements accomplished by these efforts is unique, and it helps to guarantee that the information returned by the Voyager 2 spacecraft is being used to the fullest extent possible.

  15. Monitor and Control of the Deep-Space network via Secure Web

    NASA Technical Reports Server (NTRS)

    Lamarra, N.

    1997-01-01

    (view graph) NASA lead center for robotic space exploration. Operating division of Caltech/Jet Propulsion Laboratory. Current missions, Voyagers, Galileo, Pathfinder, Global Surveyor. Upcoming missions, Cassini, Mars and New Millennium.

  16. Jovian modulation of interplanetary electrons as observed with Voyagers 1 and 2

    NASA Technical Reports Server (NTRS)

    Schardt, A. W.; Mcdonald, F. B.; Trainor, J. H.

    1982-01-01

    The release of magnetospheric electrons from Jupiter into interplanetary space is modulated by the Jovian rotation period. The Voyager 1 and 2 observations showed that the modulation period agrees on the average with the synodic period of Jupiter (9h 55m 33.12s), but over intervals of weeks it can differ from the synodic period by several minutes. The lack of exact synchronization is attributed to changes of the plasma population in the Jovian magnetosphere. The Jovian modulation appears to be a persistent feature of the interaction between the solar wind and the magnetosphere and the disappearance of the modulation away from Jupiter is attributed to interplanetary propagation conditions. This leads to the following limits on the diffuse coefficient for interplanetary electrons: kappa perpendicular is or = 8 x 10 to the 19th power sq cm/s and kappa parallel is or = 10 to the 21st power sq cm/s. Modulation was still detectable at 3.8 A.U. behind Jupiter in the far magnetotail. This requires a mean free path in the tail 0.75 A.U. and good field connection along the tail to Jupiter.

  17. Synthetic Micro/Nanomachines and Their Applications: Towards 'Fantastic Voyage'

    NASA Astrophysics Data System (ADS)

    Gao, Wei

    The 1966 movie Fantastic Voyage captured the world's imagination, portraying a tiny submarine navigating through the human bloodstream and treating life-threatening medical conditions. My PhD research focuses on the synthetic nano/microscale machines to realize the Fantastic Voyage vision. Various biomedical and environmental areas would benefit from the developments of efficient fuel-free and fuel-driven nano/microscale machines. The polymer-based catalytic tubular microengine is synthesized using a template based electrodeposition method. The oxygen bubble propelled microengine harvests the energy from chemical fuels (such as H2O2) and displays very efficient propulsion. It can serve as an ideal platform for diverse biomedical and environmental applications. For example, lectin modified polyaniline based microengines can be used for selective bacteria (E. Coli) isolation from food, clinical and environmental samples; poly(3-aminophenylboronic acid)/Ni/Pt microengine itself provides the 'built in' glucose recognition capability for 'on-the-fly' capture, transport and release of yeast cells. A series of micromotors which can be self-propelled in natural environments without additional chemical fuels are developed, holding great promise for in vivo biomedical applications: the polyaniline/zinc microrockets display effective autonomous motion in extreme acidic environments (such as human stomach); the Al-Ga/Ti based Janus micromotor can be propelled by the hydrogen bubbles generated from the rapid aluminum and water reaction; alkanethiols modified seawater-driven Mg Janus micromotors, which utilize macrogalvanic corrosion and chloride pitting corrosion processes, can be used for environmental oil remediation. Magnetically powered nanoswimmers have attracted considerable attention due to their great biocompatibility. A high-speed magnetically-propelled nanowire swimmer which mimics swimming microorganisms by exploiting the flexible nanowire as artificial flagella under rotating magnetic field is illustrated. New bioinspired microswimmers can also be prepared directly from isolated spiral vessels of plants, harnessing the intrinsic biological structures of nature. Potential applications of these cargo-towing nanoswimmers are demonstrated by the directed delivery of drug-loaded microparticles to HeLa cancer cells in biological media. With such innovations and developments, along with careful attention to key challenges and requirements, nano/microscale motors are expected to have tremendous impact on diverse biomedical and environmental applications, providing unlimited opportunities limited only by one's imagination.

  18. DSS 43 antenna gain analysis for Voyager Uranus encounter: 8.45-GHz radio science data correction

    NASA Technical Reports Server (NTRS)

    Slobin, S. D.; Imbriale, W. A.

    1987-01-01

    A malfunction of the Deep Space Network (DSN) 64-meter antenna in Australia forced the antenna to operate with a mispositioned subreflector during the Voyager Uranus encounter period (January 24, 1986). Because of changing main reflector shape and quadripod position as a function of elevation angle, the antenna gain and pointing were not as expected, and the 8.45 GHz received signal level changed during the pass. The study described here used the Geometrical Theory of Diffraction (GTD) analysis to determine actual antenna gain and pointing during that period in an attempt to reconstruct the radio science data. It is found that the 1.4 dB of signal variation can be accounted for by antenna geometry changes and pointing error. Suggested modifications to the values measured during the pass are presented. Additionally, an extremely useful tool for the analysis of gravity deformed reflectors was developed for use in future antenna design and analysis projects.

  19. Real space tests of the statistical isotropy and Gaussianity of the Wilkinson Microwave Anisotropy Probe cosmic microwave background data

    SciTech Connect

    Lew, Bartosz, E-mail: blew@a.phys.nagoya-u.ac.jp [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan) [National Astronomical Observatory, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Department of Physics and Astrophysics, Nagoya University, Nagoya 464-8602 (Japan); Torun Centre for Astronomy, Nicolaus Copernicus University, ulica Gagarina 11, 87-100 Torun (Poland)

    2008-08-15

    We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the Wilkinson Microwave Anisotropy Probe (WMAP) cosmic microwave background (CMB) foreground reduced temperature maps. We also test cross-channel difference maps to constrain levels of residual foreground contamination and systematic uncertainties. We divide the sky into regions of varying size and shape and measure the first four moments of the one-point distribution within these regions, and using their simulated spatial distributions we test the statistical isotropy and Gaussianity hypotheses. By randomly varying orientations of these regions, we sample the underlying CMB field in a new manner, that offers a richer exploration of the data content, and avoids possible biasing due to a single choice of sky division. In our analysis we account for all two-point correlations between different regions and also show the impact on the results when these correlations are neglected. The statistical significance is assessed via comparison with realistic Monte Carlo simulations. We find the three-year WMAP maps to agree well with the isotropic, Gaussian random field simulations as probed by regions corresponding to the angular scales ranging from 6 Degree-Sign to 30 Degree-Sign at 68% confidence level (CL). We report a strong, anomalous (99.8% CL) dipole 'excess' in the V band of the three-year WMAP data and also in the V band of the WMAP five-year data (99.3% CL). Using our statistics, we notice large scale hemispherical power asymmetry, and find that it is not highly statistically significant in the WMAP three-year data ( Less-Than-Or-Equivalent-To 97%) at scales l{<=}40. The significance is even smaller if multipoles up to l=1024 are considered ({approx}90% CL). We give constraints on the amplitude of the previously proposed CMB dipole modulation field parameter. We find some hints of foreground contamination in the form of a locally strong, anomalous kurtosis excess in the Q+V +W co-added map, which however is not significant globally. We easily detect the residual foregrounds in cross-band difference maps at rms level {approx}<7 {mu}K (at scales {approx}>6{sup o}) and limit the systematical uncertainties to {approx}<1.7 {mu}K (at scales {approx}>30{sup o})

  20. Current Sheets in the Heliosheath: Voyager 1, 2009

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Ness, N. F.

    2011-01-01

    We identified all of the current sheets for which we have relatively complete and accurate magnetic field (B) data from Voyager 1 (V1) from days of year (DOYs) 1 to 331, 2009, which were obtained deep in the heliosheath between 108.5 and 111.8 AU. Three types of current sheets were found: (1) 15 proton boundary layers (PBLs), (2) 10 and 3 magnetic holes and magnetic humps, respectively, and (3) 3 sector boundaries. The magnetic field strength changes across PBL, and the profile B(t) is linearly related to the hyperbolic tangent function, but the direction of B does not change. For each of the three sector boundaries, B rotated in a plane normal to the minimum variance direction, and the component of B along the minimum variance direction was zero within the uncertainties, indicating that the sector boundaries were tangential discontinuities. The structure of the sector boundaries was not as simple as that for PBLs. The average thickness of magnetic holes and humps (approx.30 RL) was twice that of the PBLs (approx.15 RL). The average thickness of the current sheets associated with sector boundaries was close to the thickness of the PBLs. Our observations are consistent with the hypothesis that magnetic holes and humps are solitons, which are initiated by the mirror mode instability, and evolve by nonlinear kinetic plasma processes to pressure balanced structures maintained by magnetization currents and proton drift currents in the gradients of B.

  1. Standing Alfven wave current system at Io: Voyager 1 observations

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.; Neubauer, F. M.; Ness, N. F.

    1980-01-01

    The enigmatic control of the occurrence frequency of Jupiter's decametric emissions by the satellite Io is explained theoretically on the basis of its strong electrodynamic interaction with the corotating Jovian magnetosphere leading to field aligned currents connecting Io with the Jovian ionosphere. Direct measurements of the perturbation magnetic fields due to this current system were obtained by the magnetic field experiment on Voyager 1 on 5 March 1979 when it passed within 20,500 km south of Io. An interpretation in the framework of Alfven waves radiated by Io leads to current estimates of 2.8 million amps. A mass density of 7400 to 13600 proton mass units per Cu cm is derived which compares very favorably with independent observations of the torus composition characterized by 7-9 proton mass units per electron for a local electron density of 1050 to 1500 per cu cm. The power dissipated in the current system may be important for heating the Io heavy ion torus, inner magnetosphere, Jovian ionosphere, and possibly the ionosphere or even the interior of Io.

  2. Rocket exhaust plume impingement on the Voyager spacecraft

    NASA Technical Reports Server (NTRS)

    Baerwald, R. K.

    1978-01-01

    In connection with the conduction of the long-duration Voyager missions to the outer planets and the sophisticated propulsion systems required, it was necessary to carry out an investigation to avoid exhaust plume impingement problems. The rarefied gas dynamics literature indicates that, for most engineering surfaces, the assumption of diffuse reemission and complete thermal accommodation is warranted in the free molecular flow regime. This assumption was applied to an analysis of a spacecraft plume impingement problem in the near-free molecular flow regime and yielded results to within a few percent of flight data. The importance of a correct treatment of the surface temperature was also demonstrated. Specular reflection, on the other hand, was shown to yield results which may be unconservative by a factor of 2 or 3. It is pointed out that one of the most difficult portions of an exhaust plume impingement analysis is the simulation of the impinged hardware. The geometry involved must be described as accurately and completely as possible.

  3. Climate windows for Polynesian voyaging to New Zealand and Easter Island.

    PubMed

    Goodwin, Ian D; Browning, Stuart A; Anderson, Atholl J

    2014-10-14

    Debate about initial human migration across the immense area of East Polynesia has focused upon seafaring technology, both of navigation and canoe capabilities, while temporal variation in sailing conditions, notably through climate change, has received less attention. One model of Polynesian voyaging observes that as tradewind easterlies are currently dominant in the central Pacific, prehistoric colonization canoes voyaging eastward to and through central East Polynesia (CEP: Society, Tuamotu, Marquesas, Gambier, Southern Cook, and Austral Islands) and to Easter Island probably had a windward capacity. Similar arguments have been applied to voyaging from CEP to New Zealand against prevailing westerlies. An alternative view is that migration required reliable off-wind sailing routes. We investigate the marine climate and potential voyaging routes during the Medieval Climate Anomaly (MCA), A.D. 800-1300, when the initial colonization of CEP and New Zealand occurred. Paleoclimate data assimilation is used to reconstruct Pacific sea level pressure and wind field patterns at bidecadal resolution during the MCA. We argue here that changing wind field patterns associated with the MCA provided conditions in which voyaging to and from the most isolated East Polynesian islands, New Zealand, and Easter Island was readily possible by off-wind sailing. The intensification and poleward expansion of the Pacific subtropical anticyclone culminating in A.D. 1140-1260 opened an anomalous climate window for off-wind sailing routes to New Zealand from the Southern Austral Islands, the Southern Cook Islands, and Tonga/Fiji Islands. PMID:25267611

  4. Climate windows for Polynesian voyaging to New Zealand and Easter Island

    PubMed Central

    Goodwin, Ian D.; Browning, Stuart A.; Anderson, Atholl J.

    2014-01-01

    Debate about initial human migration across the immense area of East Polynesia has focused upon seafaring technology, both of navigation and canoe capabilities, while temporal variation in sailing conditions, notably through climate change, has received less attention. One model of Polynesian voyaging observes that as tradewind easterlies are currently dominant in the central Pacific, prehistoric colonization canoes voyaging eastward to and through central East Polynesia (CEP: Society, Tuamotu, Marquesas, Gambier, Southern Cook, and Austral Islands) and to Easter Island probably had a windward capacity. Similar arguments have been applied to voyaging from CEP to New Zealand against prevailing westerlies. An alternative view is that migration required reliable off-wind sailing routes. We investigate the marine climate and potential voyaging routes during the Medieval Climate Anomaly (MCA), A.D. 800–1300, when the initial colonization of CEP and New Zealand occurred. Paleoclimate data assimilation is used to reconstruct Pacific sea level pressure and wind field patterns at bidecadal resolution during the MCA. We argue here that changing wind field patterns associated with the MCA provided conditions in which voyaging to and from the most isolated East Polynesian islands, New Zealand, and Easter Island was readily possible by off-wind sailing. The intensification and poleward expansion of the Pacific subtropical anticyclone culminating in A.D. 1140–1260 opened an anomalous climate window for off-wind sailing routes to New Zealand from the Southern Austral Islands, the Southern Cook Islands, and Tonga/Fiji Islands. PMID:25267611

  5. Reply to 'A Comment on '"The Far Future of Exoplanet Direct Characterization" - the Case for Interstellar Space Probes'

    E-print Network

    Schneider, Jean

    2010-01-01

    Reply to A Comment on The Far Future of Exoplanet Direct Characterization - the Case for Interstellar Space Probess by Ian Crawford. The paper The Far Future of Exoplanet Direct Characterization resulted from the collective work of TE-SAT, a team appointed by ESA in 2003 to assess a strategy to find and characterize Terrestrial Exoplanets. The interstellar flight aspect was not part of the TE-SAT work and was added afterward as side remarks in the chapter on {\\guillemotleft} The Far Future of Exoplanet Direct Characterization {\\guillemotright}. As an introductory general remark, the intention of the paper was not to discourage work on interstellar flight prospective. On the contrary, any advance in this field that makes interstellar travel closer to us is welcome. In the framework of this short reply, the discussion can only be qualitative; it would deserve a full future paper.

  6. Voyager studies of the distant heliospheric magnetic fields and plasmas

    NASA Astrophysics Data System (ADS)

    Ness, N. F.; Burlaga, L. F.; Richardson, J. D.

    2003-04-01

    Launched in 1977, the twin Voyager spacecraft (V1, V2) are exiting the heliosphere and each one is now well beyond the orbits of the planets. Careful studies have been made of the observed heliospheric magnetic field (HMF) and solar wind plasma over a full solar solar cycle through 2001. At that time, V1 was at a radial distance of 87 AU and heliographic latitude +35^o and V2 was at 69 AU and -26^o. These data have demonstrated that Parker's model of solar wind plasma flow and spatial structure of the solar originating field well describes these observations when due account of the temporal variations of the source field are taken into account by use of near-Earth observations at 1 AU. There has been continued study of the sector structure of the HMF delineating outward (outward) and inward (negative) directed fields. The Heliospheric Current Sheet (HCS) has thus been mapped to these distances and latitudes and its configuration shows agreement with predictions of the extrapolated solar surface magnetic field structure. Correlative studies with simultaneous cosmic ray observations have been conducted. All these data have helped delineate the manner in which solar originating disturbances such as shocks and Corotating Interaction Regions (CIRs) evolve at great heliospheric distances. The solar wind speed as observed by V2 has been showing a slow but steady decrease down to an average of ˜390 km/sec at 65 AU. Sufficient energy is transferred from the pickup ions to the solar wind protons to produce a temperature increase outside ˜30 AU. The structure of the magnetic field has been identified as becoming multi-fractal beginning at ˜40 AU. The field at V1 is primarily azimuthal and in 2000--2001 was averaging ˜0.05 nT at 87 AU. This paper summarizes the magnetic field and solar plasma observations in the outer heliosphere.

  7. A Voyager-style tour of comets and asteroids 1994-2005

    NASA Technical Reports Server (NTRS)

    Farquhar, Robert W.; Dunham, David W.; Hsu, Shao-Chiang

    1987-01-01

    A low cost program that links a dual-comet flyby sample-return mission with a multicomet/asteroid tour is proposed. Two spacecraft are used to carry out this program: a three-axis stabilized Observer-class spacecraft and a smaller spin-stabilized sample-return probe. The Observer spacecraft uses earth-swingby and propulsive maneuvers to accomplish the small-body tour, which includes flybys of three comets (Tempel-1, Tempel-2, and Encke) and two asteroids (46-Hestia and 433-Eros) over a 12-year period. Two of these comets (Tempel-1 and Tempel-2) are also the shared targets, the Observer serves as a navigational aid for the probe, which scoops up dust particles as it flies through the cometary atmosphere. After collecting the cometary dust samples, the probe returns to a low earth orbit where it is recovered by the Space Shuttle.

  8. PROBING VERY BRIGHT END OF GALAXY LUMINOSITY FUNCTION AT z {approx}> 7 USING HUBBLE SPACE TELESCOPE PURE PARALLEL OBSERVATIONS

    SciTech Connect

    Yan Haojing [Center for Cosmology and AstroParticle Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210 (United States); Yan Lin; Zamojski, Michel A. [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Windhorst, Rogier A. [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); McCarthy, Patrick J. [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Fan Xiaohui; Dave, Romeel [Astronomy Department, The University of Arizona, Tucson, AZ 85721 (United States); Roettgering, Huub J. A. [Leiden Observatory, University of Leiden, P.O. Box 9513, Leiden 2300 RA (Netherlands); Koekemoer, Anton M. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Robertson, Brant E. [Astronomy Department, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Cai Zheng [Physics Department, The University of Arizona, Tucson, AZ 85721 (United States)

    2011-02-10

    We report the first results from the Hubble Infrared Pure Parallel Imaging Extragalactic Survey, which utilizes the pure parallel orbits of the Hubble Space Telescope to do deep imaging along a large number of random sightlines. To date, our analysis includes 26 widely separated fields observed by the Wide Field Camera 3, which amounts to 122.8 arcmin{sup 2} in total area. We have found three bright Y{sub 098}-dropouts, which are candidate galaxies at z {approx}> 7.4. One of these objects shows an indication of peculiar variability and its nature is uncertain. The other two objects are among the brightest candidate galaxies at these redshifts known to date (L>2L*). Such very luminous objects could be the progenitors of the high-mass Lyman break galaxies observed at lower redshifts (up to z {approx} 5). While our sample is still limited in size, it is much less subject to the uncertainty caused by 'cosmic variance' than other samples because it is derived using fields along many random sightlines. We find that the existence of the brightest candidate at z {approx} 7.4 is not well explained by the current luminosity function (LF) estimates at z {approx} 8. However, its inferred surface density could be explained by the prediction from the LFs at z {approx} 7 if it belongs to the high-redshift tail of the galaxy population at z {approx} 7.

  9. Four years of zodiacal light observations from the Helios space probes - Evidence for a smooth distribution of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Leinert, C.; Richter, I.; Pitz, E.; Hanner, M.

    1980-01-01

    Zodiacal light experiments on Helios 2 that has been operating continually since January 1976 are discussed, with the purpose of elucidating the distribution of interplanetary dust. Results for the observed gradient of zodiacal light intensity between 1 A.U. and perihelion at 0.3 A.U. show that for all elongations, from 17.5 deg to 135 deg from the sun, the exponent of intensity increase is -2.3 plus or minus 0.1. Color investigations show no systematic variation with heliocentric distance, but a slight reddening is present, increasing towards small elongations. The degree of polarization is found to be higher at 1 A.U. than given previously and decreases towards the sun, even if no correction for electron scattering is made. All results thus fit the hypothesized power law for radial distribution of dust. It is concluded from the stability of zodiacal intensity that the distribution of interplanetary dust is rather simple in space and quite constant in time.

  10. Preliminary interpretation of Titan plasma interaction as observed by the Cassini Plasma Spectrometer: Comparisons with Voyager 1

    Microsoft Academic Search

    R. E. Hartle; E. C. Sittler; F. M. Neubauer; R. E. Johnson; H. T. Smith; F. Crary; D. J. McComas; D. T. Young; A. J. Coates; D. Simpson; S. Bolton; D. Reisenfeld; K. Szego; J. J. Berthelier; A. Rymer; J. Vilppola; J. T. Steinberg; N. Andre

    2006-01-01

    The Cassini Plasma Spectrometer (CAPS) instrument observed the plasma environment at Titan during the Cassini orbiter's TA encounter on October 26, 2004. Titan was in Saturn's magnetosphere during the Voyager 1 flyby and also during the TA encounter. CAPS measurements from this encounter are compared with measurements made by the Voyager 1 Plasma Science Instrument (PLS). The comparisons focus on

  11. Solar Cycle Dependence of the Solar Wind Dynamics: Pioneer, Voyager, and Ulysses from 1 to 5 AU

    NASA Technical Reports Server (NTRS)

    Gonzalez-Esparza, J. A.; Smith, E. J.

    1996-01-01

    Significant differences between Pioneer and Voyager observations were found in solar wind structure between 1 to 6 AU. These disagreements were attributed to temporal effects related to the solar cycle, but no unifying study of Pioneer-Voyager observations was performed.

  12. X-rays and neutrons as complementary probes to muons in magnetism: A view from reciprocal space

    NASA Astrophysics Data System (ADS)

    Lander, G. H.

    2000-08-01

    Twenty years ago magnetism and superconductivity appeared mutually exclusive and life was (relatively) simple. The discovery of heavy-fermion superconductivity (1979-1984) and high Tc (1986), changed our perceptions. Gradually, it was realised that either ordered magnetism or magnetic correlations are found in most of these materials. Here I shall concentrate on heavy fermions, in which the f electrons are responsible for the magnetism as well as (probably) the superconductivity. Muons have played a key role in elucidating these the so-called “small moment” systems, such as UPt 3, URu 2Si 2, UPd 2Al 3, etc. Recenty, at the ILL we have measured the low-energy inelastic magnetic signal from UPd 2Al 3 and the response will be compared to the conclusions derived from muon studies. Interestingly, it is accepted wisdom that muons will be sensitive to any small magnetic effects. UBe 13 is fascinating as it has long been the “exception”, with no sign of any magnetism. Now, at Risø National Laboratory, we have found evidence with neutrons for weak magnetic correlations of a most unusual form in UBe 13 - so that it no longer can be regarded as an exception. Neutrons, powerful though they are, are sometimes lost in reciprocal space. U 2Pt 2 In is a non-Fermi liquid, and there is a strong muon anomaly below 10 K, but we have been unable to find the correlations with neutrons. Finally, NpO 2 is one of the oldest “small-moment systems”, and recently muons were able to see an asymmetry below 25 K, and suggested an ordered moment of 0.1? B. However, the signal has been too small for neutrons. Here I will explain the emergence of a new technique, resonant magnetic X-ray scattering, that, especially in the actinides, has great promise. We have used this at the ESRF to determine the magnetic structure of NpO 2.

  13. Accretion Disk Models for VOYAGER, HUT, and FUSE Far--UV Spectra

    NASA Astrophysics Data System (ADS)

    Wade, R. A.; Hubeny, I.

    1995-12-01

    Several past and future space missions have the capability to observe spectra of cataclysmic variables in the far--UV spectral region (from just short of the Lyman limit to longward of Lyman-alpha ). These include the VOYAGER Far--UV Spectrometers (FUVS), the Hopkins Ultraviolet Telescope (HUT; flew on ASTRO--1 and ASTRO--2), and the planned FUSE mission. We present a model spectrum grid for axi\\-symmetric, steady--state accretion disks in cataclysmic variable systems, where the accreting object is a white dwarf. The white dwarf mass and radius are varied on the grid, 0.35 <= Mwd/Msun <= 1.21 and 1.14 >= Rwd/(10(9) cm) >= 0.38 respectively. The mass accretion rate is also varied, on the range -10.5 <= log dM/dt <= -8 (Msun yr(-1) ). A standard Reynolds number description of the viscous dissipation is adopted. The local plane--parallel approximation is used, LTE is assumed, and irradiation of the disk or communication between different radial zones of the disk is ignored. Within these assumptions the vertical structure is calculated in a self--consistent manner to ensure both hydrostatic equilibrium and energy balance, using a restricted set of opacities. Ring and full--disk spectra are constructed from these models using a full line list, taking into account self--consistent limb darkening and Doppler shifts due to Keplerian orbital motion of the gas. The spectral region from 850 Angstroms to 1350 Angstroms is covered, and spectra at several inclinations are tabulated. The spectra will be made available electronically with a sampling interval and resolution sufficient to allow the study of FUVS and HUT spectra, and can be resampled for FUSE and other missions. The models serve as a benchmark against which more complicated models, perhaps including winds, can be compared. Representative spectra and some interesting trends are shown. Supported by NASA grants NAG5--2125 and NAGW--3171.

  14. Ephemerides of the major Neptunian satellites determined from earth-based astrometric and Voyager imaging observations

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Lewis, G. D.; Owen, W. M.; Riedel, J. E.; Roth, D. C.; Synnott, S. P.; Taylor, A. H.

    1990-01-01

    The Voyager project used Neptunian satellite ephemerides to support both navigation and acquisition of scientific data. The development of postencounter ephemerides for the satellites Triton, Nereid, and 1989N1 is discussed. Primary results are the final set of model parameters which generate orbits that best fit both the earth-based satellite observations and data acquired by Voyager. The ephemerides are compared with those generated preencounter, and the accuracy of the final ephemerides is assessed. Mean orbital elements are also provided as a geometrical representation for the satellite orbits.

  15. A solution methodology for exact design space exploration in a three-dimensional design space

    Microsoft Academic Search

    Samit Chaudhuri; S. A. Blthye; Robert A. Walker

    1997-01-01

    This paper describes an exact solution methodology, implemented in Rensselaer's Voyager design space exploration system, for solving the scheduling problem in a three-dimensional (3-D) design space: the usual two-dimensional (2-D) design space (which trades off area and schedule length), plus a third dimension representing clock length. Unlike design space exploration methodologies which rely on bounds or estimates, this methodology is

  16. THICKNESS OF THE HELIOSHEATH, RETURN OF THE PICK-UP IONS, AND VOYAGER 1'S CROSSING THE HELIOPAUSE

    SciTech Connect

    Hsieh, K. C. [Department of Physics, University of Arizona, Tucson, AZ 85721 (United States); Giacalone, J.; Kota, J. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States); Czechowski, A.; Grzedzielski, S. [Space Research Centre, Polish Academy of Sciences, 00716 Warsaw (Poland); Hilchenbach, M. [Max-Planck-Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany)

    2010-08-01

    Using results of remote sensing by energetic neutral atoms from IBEX, SOHO/HSTOF, and Cassini/INCA, in situ measurements of {approx}40-4000 keV protons in the heliosheath (HS) from Low Energy Charged Particle on Voyager 1 and Voyager 2, and outputs from numerical modeling of the termination shock, we estimate L, the characteristic thickness of the HS in the 'upwind' direction ({+-}45{sup 0} in ecliptic longitude of the Nose at {lambda} = 255{sup 0}). A simple steady-state, internally consistent model gives L = 21 {+-} 6 AU for Voyager 1, L = 28 {+-} 8 AU for Voyager 2, and L = 25 {+-} 8 AU assuming that the same L value is valid for both spacecraft. We recognize that this is a very coarse cut at a very dynamic region of the heliosphere; but if the lower value L = 21 AU applies, one could expect Voyager 1 to cross the heliopause as early as late 2010.

  17. How we get pictures from space

    NASA Astrophysics Data System (ADS)

    Haynes, R.

    1990-06-01

    A brief overview is presented of the application and importance of telemetry technology, the technique of transmitting data by means of radio signals to distant locations. The process of scanning and transmitting images from outer space to earth is likened to the way a television set works and eloquent explanations of terms such as 'pixel' and 'rastar' are given. A brief history is presented of unmanned U.S. spacecraft and a list of pictures which they have rendered is provided. The missions, hardware, and capabilities of the Voyager-2 are discussed. The process of collection, transmission, and interpretation of Voyager data is detailed.

  18. Probing the steric space at the floor of the D1 dopamine receptor orthosteric binding domain: 7?-, 7?-, 8?-, and 8?-methyl substituted dihydrexidine analogues

    PubMed Central

    Cueva, Juan Pablo; Gallardo-Godoy, Alejandra; Juncosa, Jose I.; Vidi, Pierre A.; Lill, Markus A.; Watts, Val J.; Nichols, David E.

    2011-01-01

    To probe the space at the floor of the orthosteric ligand binding site in the dopamine D1 receptor, four methylated analogs of dihydrexidine (DHX) were synthesized with substitutions at the 7 and 8 positions. The 8?-axial, 8?-equatorial and 7?-equatorial were synthesized by photochemical cyclization of appropriately substituted N-benzoyl enamines, the 7?-axial analog was prepared by an intramolecular Henry reaction. All of the methylated analogs displayed losses in affinity when compared to DHX (20 nM): 8?-Meax-DHX (270 nM), 8?-Meeq-DHX (920 nM), 7?-Meeq-DHX (6540 nM), and 7?-Meax-DHX (>10000 nM). Molecular modeling studies suggest that although the disruption of an aromatic interaction between Phe2035.47 and Phe2886.51 is the cause for the 14-fold loss in affinity associated with 8?-axial substitution, unfavorable steric interactions with Ser1073.36 result in the more dramatic decreases in binding affinity suffered by the rest of the analogs. PMID:21714510

  19. Hot plasma environment at jupiter: voyager 2 results.

    PubMed

    Krimigis, S M; Armstrong, T P; Axford, W I; Bostrom, C O; Fan, C Y; Gloeckler, G; Lanzerotti, L J; Keath, E P; Zwickl, R D; Carbary, J F; Hamilton, D C

    1979-11-23

    Measurements of the hot (electron and ion energies >/=20 and >/= 28 kiloelectron volts, respectively) plasma environment at Jupiter by the low-energy charged particle (LECP) instrument on Voyager 2 have revealed several new and unusual aspects of the Jovian magnetosphere. The magnetosphere is populated from its outer edge into a distance of at least approximately 30 Jupiter radii (R(J)) by a hot (3 x 10(8) to 5 x 10(8) K) multicomponent plasma consisting primarily of hydrogen, oxygen, and sulfur ions. Outside approximately 30 R(J) the hot plasma exhibits ion densities from approximately 10(-1) to approximately 10(-6) per cubic centimeter and energy densities from approximately 10(-8) to 10(-13) erg per cubic centimeter, suggesting a high beta plasma throughout the region. The plasma is flowing in the corotation direction to the edge of the magnetosphere on the dayside, where it is confined by solar wind pressure, and to a distance of approximately 140 to 160 R(J) on the nightside at approximately 0300 local time. Beyond approximately 150 R(J) the hot plasma flow changes into a "magnetospheric wind" blowing away from Jupiter at an angle of approximately 20 degrees west of the sun-Jupiter line, characterized by a temperature of approximately 3 x 10(8) K (26 kiloelectron volts), velocities ranging from approximately 300 to > 1000 kilometers per second, and composition similar to that observed in the inner magnetosphere. The radial profiles of the ratios of oxygen to helium and sulfur to helium (

  20. Deep space navigation systems and operations

    Microsoft Academic Search

    J. F. Jordan

    1981-01-01

    The history of the deep space navigation system developed by NASA is outlined. Its application to Mariner, Viking and Pioneer missions is reviewed. Voyager navigation results for Jupiter and Saturn are commented on and velocity correction in relation to fuel expenditure and computer time are discussed. The navigation requirements of the Gahleo and Venus orbiting imaging radar (VOIR) missions are

  1. Space Nuclear Power: Opening the Final Frontier

    Microsoft Academic Search

    Gary L. Bennett

    Nuclear power sources have enabled or enhanced some of the most challenging and exciting space missions yet conducted, including missions such as the Pioneer flights to Jupiter, Saturn, and beyond; the Voyager flights to Jupiter, Saturn, Uranus, Neptune, and beyond; the Apollo lunar surface experiments; the Viking Lander studies of Mars; the Ulysses mission to study the polar regions of

  2. Atmospheric entry probes for outer planet exploration. Outer planet entry probe technical summary

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The use of unmanned space probes for investigating the conditions existing on and around the outer planets of the solar system is discussed. The subjects included in the report are: (1) the design of a common entry probe for outer planet missions, (2) the significant trades related to the development of a common probe design, (3) the impact of bus selection on probe design, (4) the impact of probe requirements on bus modifications, and (5) the key technology elements recommended for advanced development. Drawings and illustrations of typical probes are included to show the components and systems used in the space probes.

  3. Mass spectrometric study of various coated targets utilizing the PUPR Mirror/Cusp plasma machine for the NASA Solar Probe space mission

    NASA Astrophysics Data System (ADS)

    Lleonart-Davila, G.; Gaudier, J.; Rivera, R.; González-Lizardo, A.; Leal-Quirós, E.

    2008-10-01

    The NASA Solar Probe space mission will be a historic operation, flying for the first time into one of the last unexplored regions of the solar system, the Sun's atmosphere or corona; hopefully revolutionizing our knowledge of the physics of the origin and evolution of the solar wind phenomenon. The spacecraft's most prominent feature is the thermal protection system (TPS), composed of a large carbon-carbon conical shield, designed to withstand the Sun's violent temperatures. Thermal testing will be conducted on various coatings on the carbon-carbon targets in order to study mass loss components using mass spectrometry. Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio of ions. It is more generally used to find the composition of a physical sample by generating a mass spectrum representing the masses of sample components. By using a quadrupole mass spectrometer, the effects of plasma on various coated targets were analyzed and the effects of various gases on the plasma were studied on the PUPR Mirror/Cusp (M/C) plasma machine. A series of five tests was performed for this experiment; the first four tests consist of creating plasma with four different gases, and studying the effects of each gas on the plasma using mass spectrometry, in order to decide which plasma resembles the Sun's atmosphere or corona. The fifth test consists of introducing various coated targets, which represent the spacecraft's shield, inside the PUPR M/C plasma machine, to study how the different coatings react with the plasma that best bears a resemblance to the Sun's atmosphere, for approximately 12 h of exposure. After studying the results for the first four tests, it is evident that each gas has a distinctive effect on the plasma. For the fifth test following the study of the mass spectrometry results, it is clear that the quadrupole mass spectrometer was able to detect mass loss components for the introduced targets, and the presence of the coatings were successfully identified inside the PUPR M/C plasma machine, therefore assisting in the shield coating selection for the solar probe aircraft.

  4. Robert J. Richards What if Charles Darwin, during the Beagle voyage, had been swept

    E-print Network

    Richards, Robert J.

    undermine the claim that the theory of natural selection inspired the various forms of social Darwinism" (6Robert J. Richards What if Charles Darwin, during the Beagle voyage, had been swept overboard and had drown, never to have developed his theory of the descent of species by natural selection, never

  5. Preliminary results on Saturn's inner plasmasphere as observed by Cassini: Comparison with Voyager

    E-print Network

    Johnson, Robert E.

    Preliminary results on Saturn's inner plasmasphere as observed by Cassini: Comparison with Voyager 15 June 2005. [1] We present an analysis of Saturn's inner plasmasphere as observed by the Cassini Plasma Spectrometer (CAPS) experiment during Cassini's initial entry into Saturn's magnetosphere when

  6. From Voyager-IRIS to Cassini-CIRS: Interannual Variability in Saturn's Stratosphere

    NASA Astrophysics Data System (ADS)

    Sinclair, J. A.; Irwin, P. G. J.; Fletcher, L. N.; Hurley, J.; Merlet, C.

    2013-09-01

    We present an intercomparison of Saturn's atmosphere from Voyager-IRIS observations in 1980 with Cassini-CIRS observations in 2009/2010. Over a Saturn year (˜29.5 years) has now passed since the Voyager flyby of Saturn in 1980/1981. Cassini observations in 2009/2010 and those from Voyager therefore capture Saturn in the same season (at approximately the vernal equinox, solar longitude, Ls~˜0°). Any differences in Saturn's stratospheric properties implied by a comparison of these two datasets will therefore highlight interannual variability. We retrieve temperature and stratospheric acetylene and ethane concentrations from Voyager 1-IRIS (FWHM = 4.3 cm-1) in 1980 and Cassini-CIRS 'FIRMAP' (FWHM = 15.5 cm-1) observations in 2009/2010. Preliminary results show the equator to be warmer by 7.3 ± 1.6 K at ˜2.1 mbar in 2009 than in 1980 implying a differing phase of the SSAO (Saturn's semi-annual oscillation). Ethane's meridional distribution at 2.1 mbar appears consistent between 1980 and 2009/2010. However, the concentrations of acetylene at the same altitude appear enhanced at ˜25°S and ˜25°N in 1980 when compared to 2009/2010. A global-circulation model shows cells of downwelling at these latitudes [3]: the richer concentrations of acetylene at these latitudes in 1980 suggests that there was stronger downwelling at this time than in 2009.

  7. A new look at the Saturn system - The Voyager 2 images

    Microsoft Academic Search

    B. A. Smith; L. Soderblom; R. M. Batson; P. M. Bridges; J. L. Inge; H. Masursky; E. Shoemaker; R. F. Beebe; J. Boyce; G. Briggs; A. Bunker; S. A. Collins; C. J. HANSEN; T. V. Johnson; J. L. Mitchell; R. J. Terrile; A. F. Cook; J. N. Cuzzi; J. B. Pollack; G. E. Danielson; A. P. Ingersoll; M. E. Davies; G. E. Hunt; D. Morrison; T. Owen; C. Sagan; J. Veverka; R. Strom; V. E. Suomi

    1982-01-01

    Images of the Saturn system acquired by Voyager 2 in its encounter in August 1981 are presented and information gained from the imagery on the atmosphere, satellites, and rings of Saturn is discussed. The images have shown the Saturn atmosphere to contain persistent oval clouds similar to those of Jupiter, and small irregular features indicative of a pattern of zonal

  8. Voyager observations of the interaction of the heliosphere with the interstellar medium

    PubMed Central

    Richardson, John D.

    2012-01-01

    This paper provides a brief review and update on the Voyager observations of the interaction of the heliosphere with the interstellar medium. Voyager has found many surprises: (1) a new energetic particle component which is accelerated at the termination shock (TS) and leaks into the outer heliosphere forming a foreshock region; (2) a termination shock which is modulated by energetic particles and which transfers most of the solar wind flow energy to the pickup ions (not the thermal ions); (3) the heliosphere is asymmetric; (4) the TS does not accelerate anomalous cosmic rays at the Voyager locations; and (5) the plasma flow in the Voyagers 1 (V1) and 2 (V2) directions are very different. At V1 the flow was small after the TS and has recently slowed to near zero, whereas at V2 the speed has remained constant while the flow direction has turned tailward. V1 may have entered an extended boundary region in front of the heliopause (HP) in 2010 in which the plasma flow speeds are near zero. PMID:25685423

  9. Albedo, internal heat, and energy balance of Jupiter, preliminary results of the Voyager infrared investigation

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.; Conrath, B. J.; Herath, L. W.; Kunde, V. G.; Pirraglia, J. A.

    1980-01-01

    The in flight calibration of the radiometer and the Michelson interferometer of the Voyager 1 infrared instrument is discussed. The calibrated full disk measurements are applied to derive values of the albedo, the thermal emission and the global energy balance of Jupiter.

  10. Nicolas Bouvier ou la rinvention du voyage en Orient au XXe

    E-print Network

    Boyer, Edmond

    'Antiquité. Mais le père de la littérature de voyage au sens moderne du terme est incontestablement Marco Polo évoquera explicitement, dans les années 1970, la figure de Marco Polo, mais pour insister sur le fait que, semble faire écho à celui de Polo. Il y a là, assurément, un clin d'oeil2 . Pourtant, la situation

  11. Space.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2001

    2001-01-01

    This annotated subject guide to Web sites and additional resources focuses on space and astronomy. Specifies age levels for resources that include Web sites, CD-ROMS and software, videos, books, audios, and magazines; offers professional resources; and presents a relevant class activity. (LRW)

  12. EMISSION-LINE GALAXIES FROM THE HUBBLE SPACE TELESCOPE PROBING EVOLUTION AND REIONIZATION SPECTROSCOPICALLY (PEARS) GRISM SURVEY. II. THE COMPLETE SAMPLE

    SciTech Connect

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Grogin, Norman A.; Dahlen, Tomas; Noeske, Kai G.; Bellini, Andrea [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21210 (United States); Malhotra, Sangeeta; Rhoads, James E.; Cohen, Seth H.; Mechtley, Matthew; Windhorst, Rogier A. [School of Earth And Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States); Meurer, Gerhardt R. [International Centre for Radio Astronomy Research, The University of Western Australia, 35 Stirling Highway, Crawley, WA 6009 (Australia); Walsh, Jeremy R. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Hathi, Nimish P. [Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Holwerda, Benne W. [ESA-ESTEC, Keplerlaan 1, 2200 AG, Noordwijk (Netherlands); Straughn, Amber N. [Astrophysics Science Division, Goddard Space Flight Center, Code 665, Greenbelt, MD 20771 (United States)

    2013-07-20

    We present a full analysis of the Probing Evolution And Reionization Spectroscopically (PEARS) slitess grism spectroscopic data obtained with the Advanced Camera for Surveys on board Hubble Space Telescope. PEARS covers fields within both the Great Observatories Origins Deep Survey (GOODS) North and South fields, making it ideal as a random survey of galaxies, as well as the availability of a wide variety of ancillary observations complemented by the spectroscopic results. Using the PEARS data, we are able to identify star-forming galaxies (SFGs) within the redshift volume 0 < z < 1.5. Star-forming regions in the PEARS survey are pinpointed independently of the host galaxy. This method allows us to detect the presence of multiple emission-line regions (ELRs) within a single galaxy. We identified a total of 1162 H{alpha}, [O III], and/or [O II] emission lines in the PEARS sample of 906 galaxies to a limiting flux of {approx}10{sup -18} erg s{sup -1} cm{sup -2}. The ELRs have also been compared to the properties of the host galaxy, including morphology, luminosity, and mass. From this analysis, we find three key results: (1) the computed line luminosities show evidence of a flattening in the luminosity function with increasing redshift; (2) the star-forming systems show evidence of complex morphologies with star formation occurring predominantly within one effective (half-light) radius. However, the morphologies show no correlation with host stellar mass. (3) Also, the number density of SFGs with M{sub *} {>=} 10{sup 9} M{sub Sun} decreases by an order of magnitude at z {<=} 0.5 relative to the number at 0.5 < z < 0.9, supporting the argument of galaxy downsizing.

  13. Probing the depths of space

    Microsoft Academic Search

    R. W. Chapman

    1928-01-01

    Ever since the time when Copernicus advanced, with convincing logical argument, the theory that it is the earth that revolves round the sun and not the sun that moves round the earth, the problem of the distances of the stars has exercised a fascinating hold upon the attention of astronomers. When the Copernican theory was put forward there were three

  14. Science investigation options with a NASA New Frontiers Program Saturn entry probe mission

    NASA Astrophysics Data System (ADS)

    Spilker, T. R.; Atreya, S. K.; Atkinson, D. H.; Colaprete, A.; Coustenis, A.

    2012-09-01

    In 2011 the Space Studies Board of the US National Research Council released its report, "Vision and Voyages for Planetary Science in the Decade 2013- 2022" [1] (PSDS). This document is intended to be the guiding document for NASA's planetary science and space flight mission priorities for that decade. The PSDS treats three classes of flight missions: small, medium, and large. Small missions are ones that could be flown within the resource constraints of NASA's Discovery Program, a program of PI-led, competed missions, including a US 500 million (FY 2015) recommended cost cap, excluding the launch vehicle. The PSDS makes no specific recommendations for science objectives or destinations for small missions. Medium missions could be flown under NASA's New Frontiers Program, also a program of PI-led, competed missions, with a recommended cost cap of US 1 billion excluding the launch vehicle. Both of these competed mission programs have been highly successful, with multiple spacecraft currently in flight and more either under development or in the final steps of competition. Large missions, generally called flagship missions, would have total mission costs exceeding US $1 billion and would be directed by NASA, not PI-led. Unlike Small class missions, the PSDS recommends specific science objectives for Medium class missions. Four Medium class mission concepts and their science objectives carry over from the previous PSDS [2]: • Comet Surface Sample Return • Lunar South-Pole Aitken Basin Sample Return • Trojan Tour and Rendezvous • Venus In Situ Explorer The current PSDS adds a fifth mission concept to the list for the next New Frontiers Program AO ("NF-4"), currently anticipated in 2016: a Saturn probe mission. This mission would deliver an atmospheric entry probe into Saturn's atmosphere to make composition and atmospheric structure measurements critical to understanding the materials, processes, and time scales of Saturn's formation, and by comparison to Jupiter and the ice giants, understanding these for the outer solar system as a whole.

  15. Logic Probes

    NSDL National Science Digital Library

    Bartelt, Terry L. M.

    This brief interactive activity, by the Electromechanical Digital Library and Wisconsin Technical College System faculty, introduces Logic Probes. There is an overview which illustrates the probe's application and operation and how to operate a logic probe in multifamily use, steady states, and changing states. There is also a set of three review questions for students to answer at the end. This is an excellent resource, as are the others in this digital library, for reviewing fundamental concepts for electromechanical devices, systems, and applications.

  16. Jules Verne Voyager, Jr: An Interactive Map Tool for Teaching Plate Tectonics

    NASA Astrophysics Data System (ADS)

    Hamburger, M. W.; Meertens, C. M.

    2010-12-01

    We present an interactive, web-based map utility that can make new geological and geophysical results accessible to a large number and variety of users. The tool provides a user-friendly interface that allows users to access a variety of maps, satellite images, and geophysical data at a range of spatial scales. The map tool, dubbed 'Jules Verne Voyager, Jr.', allows users to interactively create maps of a variety of study areas around the world. The utility was developed in collaboration with the UNAVCO Consortium for study of global-scale tectonic processes. Users can choose from a variety of base maps (including "Face of the Earth" and "Earth at Night" satellite imagery mosaics, global topography, geoid, sea-floor age, strain rate and seismic hazard maps, and others), add a number of geographic and geophysical overlays (coastlines, political boundaries, rivers and lakes, earthquake and volcano locations, stress axes, etc.), and then superimpose both observed and model velocity vectors representing a compilation of 2933 GPS geodetic measurements from around the world. A remarkable characteristic of the geodetic compilation is that users can select from some 21 plates' frames of reference, allowing a visual representation of both 'absolute' plate motion (in a no-net rotation reference frame) and relative motion along all of the world's plate boundaries. The tool allows users to zoom among at least three map scales. The map tool can be viewed at http://jules.unavco.org/VoyagerJr/Earth. A more detailed version of the map utility, developed in conjunction with the EarthScope initiative, focuses on North America geodynamics, and provides more detailed geophysical and geographic information for the United States, Canada, and Mexico. The ‘EarthScope Voyager’ can be accessed at http://jules.unavco.org/VoyagerJr/EarthScope. Because the system uses pre-constructed gif images and overlays, the system can rapidly create and display maps to a large number of users simultaneously and does not require any special software installation on users' systems. In addition, a javascript-based educational interface, dubbed "Exploring our Dynamic Planet", incorporates the map tool, explanatory material, background scientific material, and curricular activities that encourage users to explore Earth processes using the Jules Verne Voyager, Jr. tool. Exploring our Dynamic Planet can be viewed at http://www.dpc.ucar.edu/VoyagerJr/. Because of its flexibility, the map utilities can be used for hands-on exercises exploring plate interaction in a range of academic settings, from high school science classes to entry-level undergraduate to graduate-level tectonics courses.

  17. Stormtime Relativistic Electron Phase Space Density Profiles Measured by the Van Allen Probes Using L* Computed From the Rice Convection Model-Equilibrium

    NASA Astrophysics Data System (ADS)

    Roeder, J. L.; Lemon, C. L.; Chen, M.; Fennell, J. F.; Claudepierre, S. G.; Mulligan, T. L.; Blake, J. B.; Clemmons, J. H.; Spence, H.

    2013-12-01

    Relativistic radiation belt electrons during geomagnetic storms are often analyzed using phase space density (PSD) radial profiles in coordinates derived from the three adiabatic invariants of particle motion in the magnetosphere. The radial coordinate in these profiles is L*, which is equivalent to the third adiabatic invariant defined as the magnetic flux enclosed by the drift of the particle around the Earth. L* is a global quantity and cannot be easily measured, so its values are highly model dependent. Previous work has used L* derived from empirical geomagnetic field models. These models represent an average field for a given set of solar wind and activity levels, and only rarely reproduce the measured field values during storms. Typically, the investigators compare the results from several such models to assess the possible level of error in their PSD results. The self-consistent ring current model Rice Convection Model-Equilibrium (RCM-E) has been shown previously to perform better at reproducing spacecraft magnetic field measurements during storms. We analyze a recent moderate storm event to assess the difference in the electron PSD analysis with the L* computed with the two methods. The first method uses L* computed from the empirical geomagnetic field models of Tsganenko-Sitnov and Olsen-Pfitzer. We compare those results with a similar analysis including L* calculated from the RCM-E simulation of the storm. The storm on June 1, 2013 had a main phase of 8-hour duration and a minimum Dst of -118 nT. The energetic electrons in the energy range from 30 keV to 4 MeV were measured by the Magnetic Electron and Ion Spectrometers onboard the Van Allen Probes. These measurements display the classic profile with a pronounced drop in flux during the main phase and a slow rise in flux during the recovery phase. The observations show that by June 5th, the flux had not yet recovered fully to the measured pre-storm levels, especially above 1 MeV. We discuss the implications of the PSD analysis on our ability to diagnose accurately the radiation belts for the effects of wave-particle interactions.

  18. [State of the circulatory system in sailors as an indicator of adaptation to long sea voyage].

    PubMed

    Matsevich, L M; Poroshenko, A S; Vinnikova, V N

    1976-09-01

    The peculiarities of the circulatory functions were examined in sailors following nautical voyages of varying duration and directly on board during a 6-month cruise. Over 1200 persons were subjected to the examination. The overall morbidity was analyzed in a contingent of about 6000 persons. The whole material was statistically processed. The sailors were found to develop hypotensive reactions during the voyage that persisted following its termination. Cruises lasting over 2-3 months cause a significant tension of the adaptation mechanisms in the sailors, thus favouring the formation of persistent hypotensive states, inadequate reactions of the arterial pressure and heart rate, ECG changes that reflect the impairment of the functional state of the myocardium, etc. A lack of adaptation to cruises exceeding 2-3 months was established. The functional state of the cardiovascular system of sailors is considered to be one of the leading criteria for substantiating physiologically permissible duration of cruises. PMID:1011529

  19. Heliospheric plasma flow at Voyager 2 is almost coplanar with the hydrogen deflection plane

    NASA Astrophysics Data System (ADS)

    Grygorczuk, J.; Czechowski, A.; Grzedzielski, S.

    2015-06-01

    We show that for the undisturbed interstellar velocity vector V_IS and magnetic field direction B_IS defined by IBEX (Interstellar Boundary Explorer) Ribbon centre, the radial direction of Voyager 2 over the last decade, and the (thermal proton) plasma velocity measured by the spacecraft since 2010.5, are almost parallel to the (B_IS, V_IS)-plane, which coincides in practice with the hydrogen deflection plane. In consequence the plasma flow velocity measured by Voyager 2 in the inner heliosheath rotates more in the transverse than in the polar direction (explanation alternative to McComas & Schwadron). Note that the (B_IS, V_IS) plane is a symmetry plane of the interstellar plasma flow at large heliocentric distances.

  20. Cassini ENA images of the heliosheath and Voyager ``ground truth'': Thickness of the heliosheath

    NASA Astrophysics Data System (ADS)

    Roelof, E. C.; Krimigis, S. M.; Mitchell, D. G.; Decker, R. B.; Dialynas, K.

    2012-05-01

    Cassini/INCA (Ion and Neutral Camera) ENA images of the heliosheath, when combined with the ``ground truth'' of in situ measurements of ion intensities throughout the heliosheath obtained by Voyager/LECP (Low Energy Charged Particle Experiment), allow us to estimate a thickness parameter (L) along the two lines of sight (LOS) to the Voyager 1/2 spacecraft. The Compton-Getting effect due to the radial velocity of the heliosheath plasma is now taken into account. Our new estimates are LVGR1 = 31(+31,-18) AU and LVGR2 = 71(+30,-15) AU, so to the extent that our assumptions in deriving them are valid, the heliosheath appears to be twice as thick along the VGR2 LOS as it is along the LOS to VGR1.

  1. Voyager 2 Observations of Plasmas and Flows out to 104 AU

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.; Decker, R. B.

    2014-09-01

    Voyager 2 has crossed through 20 AU of the heliosheath; assuming the same heliosheath thickness as at Voyager 1, it is now two-thirds of the way to the heliopause. The plasma data are generally of good quality, although the increasing flow angle of the plasma makes analysis more difficult. The average plasma speed has remained constant but the flow angles have increased to almost 60° in the RT plane and to almost 30° in the RN plane. The average density and thermal speed have been constant since a density increase observed in 2011. Comparison of V2 plasma flows derived from plasma science experiment (PLS) data and Low Energy Charged Particle (LECP) proton anisotropies give good agreement except when heavy ion contributions or non-convective proton anisotropies are observed in the LECP data.

  2. Geology and Topography of Ra Patera, Io, in the Voyager era: Prelude to Eruption

    NASA Technical Reports Server (NTRS)

    Schenk, Paul M.; McEwen, Alfred; Davies, A. G.; Davenport, Trevor; Jones, Kevin; Fessler, Brian

    1997-01-01

    Voyager era stereo images are used to map the geology and topography of Ra Patera (a major active volcanic center and possible site of sulfur eruptions on Io). The summit of Ra Patera reaches only approx.1 km above the surrounding plains. Pre-Voyager-era lava flows occur on slopes of 0.1-0.3 deg, comparable to the lunar mare. These flows were emplaced at either low viscosities, high eruption rates, or both. A 600- km-long ridged mountain unit (rising to approx. 8 km near Carancho Patera) forms a 60 by 90 km wide plateau approx. 0.5 km high 50 km east of Ra Patera. The new lava flows observed by Galileo flowed around the southern edge of this plateau.

  3. Forward and reverse shocks in the outer heliosphere: Observations from Voyager 2

    SciTech Connect

    Lazarus, A.J.; Belcher, J.W.; Paularena, K.I.; Richardson, J.D. [Center for Space Research, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Pizzo, V.J. [San Juan Institute, San Juan Capistrano, California (United States)]|[NOAA/SEL, Boulder, Colorado (United States); Gosling, J.T. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

    1996-07-01

    Observations from Voyager 2 as it moved from 10{degree}S to 14{degree}S heliographic latitude in the period from 1993 through 1994 were used to search for forward and reverse shocks. These results were compared with observations from the Ulysses spacecraft which are in agreement with a 3-D, magnetohydrodynamic model of the evolution of a steady, tilted-solar-dipole, solar wind flow configuration such as was prevalent in 1993. (AIP) {copyright} {ital 1996 American Institute of Physics.}

  4. Survey of low energy plasma electrons in Saturn's magnetosphere: Voyagers 1 and 2

    Microsoft Academic Search

    E. C. Jr. Sittler; K. W. Ogilvie; J. D. Scudder

    1983-01-01

    The low energy plasma electron environment within Saturn's magnetosphere was surveyed by the Plasma Science Experiment (PLS) during the Voyager encounters with Saturn. Over the full energy range of the PLS instrument (10 eV to 6 keV) the electron distribution functions are clearly non-Maxwellian in character. They are composed of a cold (thermal) component with Maxwellian shape and a hot

  5. A Voyage to Vardoe. A Scientific Account of an Unscientific Expedition

    NASA Astrophysics Data System (ADS)

    Sterken, Christiaan; Aspaas, Per Pippin; Duner, David; Kontler, Laszlo; Neul, Reinhard; Pekonen, Osmo; Posch, Thomas

    2013-05-01

    After the "Venus Transit Conference" that took place at the University of Tromsoe from June 2 to June 3, 2012, participants were given the opportunity to either stay in Tromsoe until the night of June 5-6, or to participate in a voyage to Finnmark, where the historical sites Vardoe, Hammerfest, and the North Cape were to be visited. This voyage culminated in the observation of the 2012 transit of Venus at Vardoe. This paper gives a detailed account of this voyage that lasted from June 3 to June 6, and emphasizes the historical, scientific, philosophical, educational and cultural involvement of the participants of the voyage and of the local population. The paper concludes with reflections on the prime condition for success of any of the Venus transit expeditions of the past: the weather must cooperate in the first place - not only during the quarter of a day of the transit, but also during the preceding weeks and months in order to allow the explorers to rightly determine their geographic positions and correctly set their clocks. The latter factor is no longer an issue nowadays, but the weather aspect remains today a limiting factor as much as it was 250 years ago. Despite the variable and partly clouded weather at Vardoe during the time of the transit, the participants of this expedition were able to observe Venus in front of the Sun - with interruptions due to quickly moving clouds - between 4.30 a.m. and the fourth contact at 06:53:20 a.m. A large number of impressive, partly `dramatic' photographs have been taken especially in this time interval.

  6. The Gulf Stream Voyage: Using Real Time Data in the Classroom

    NSDL National Science Digital Library

    Liesl Hotaling

    This paper describes the Gulf Stream Voyage, an Internet-based multidisciplinary project which utilizes both real time data and primary source materials to help guide students to discover the science and history of the Gulf Stream. There are several advantages of using real time data in the classroom, including: the infusion of inquiry-based learning; fostering problem solving skills; addressing several learning styles; and student relevance.

  7. Quantitative measurements of Jupiter, Saturn, their rings and satellites made from Voyager imaging data

    NASA Technical Reports Server (NTRS)

    Collins, S. A.; Bunker, A. S.

    1983-01-01

    The Voyager spacecraft cameras use selenium-sulfur slow scan vidicons to convert focused optical images into sensible electrical signals. The vidicon-generated data thus obtained are the basis of measurements of much greater precision than was previously possible, in virtue of their superior linearity, geometric fidelity, and the use of in-flight calibration. Attention is given to positional, radiometric, and dynamical measurements conducted on the basis of vidicon data for the Saturn rings, the Saturn satellites, and the Jupiter atmosphere.

  8. Characteristic of hot plasma in the Jovian magnetosphere: Results from the Voyager spacecraft

    Microsoft Academic Search

    S. M. Krimigis; J. F. Carbary; E. P. Keath; C. O. Bostrom; W. I. Axford; G. Gloeckler; L.J. Lanzerotti; T. P. Armstrong

    1981-01-01

    The low-energy charged particle (LECP) experiment on the Voyager 1 and 2 spacecraft made measurements of the intensity, energy spectra, angular distributions and composition of ions (30 keV< or approx. =E< or approx. = 150 MeV) and the electrons (14 keV< or approx. =E< or approx. =10 MeV) during encounters with the Jovian magnetosphere in 1979. Detailed analysis of the

  9. Multispectral imaging probe

    DOEpatents

    Sandison, D.R.; Platzbecker, M.R.; Descour, M.R.; Armour, D.L.; Craig, M.J.; Richards-Kortum, R.

    1999-07-27

    A multispectral imaging probe delivers a range of wavelengths of excitation light to a target and collects a range of expressed light wavelengths. The multispectral imaging probe is adapted for mobile use and use in confined spaces, and is sealed against the effects of hostile environments. The multispectral imaging probe comprises a housing that defines a sealed volume that is substantially sealed from the surrounding environment. A beam splitting device mounts within the sealed volume. Excitation light is directed to the beam splitting device, which directs the excitation light to a target. Expressed light from the target reaches the beam splitting device along a path coaxial with the path traveled by the excitation light from the beam splitting device to the target. The beam splitting device directs expressed light to a collection subsystem for delivery to a detector. 8 figs.

  10. Non-Classical Light 20 Years Later: An Assessment of the Voyage into Hilbert Space

    Microsoft Academic Search

    H. J. Kimble

    1997-01-01

    Although diverse manifestations of the quantum or non-classical character of the electromagnetic field have arisen over the past two decades in quantum optics, almost without exception these observations have been made in a domain of weak coupling for which dissipation is dominant over the coherent dynamical processes associated with single quanta. By contrast, research in the area of cavity quantum

  11. Space Missions

    NSDL National Science Digital Library

    Randy Russell

    2004-05-10

    With three levels to choose from on each page - beginner, intermediate or advanced - this site provides in formation on past and current exploration ideas and achievements. The advances science has made in the space exploration area, such as having a permanent space station in space and the hundreds of probes, satellite, and space shuttles that have been launched. Advanced telescopes have given scientists the opportunity to see far beyond we ever imagined, and new explorations are found every day. Also featured are details about the International space station and what kinds of experiments scientists do in outer space.

  12. Reanalyses of Voyager Ultraviolet Spectrometer Limits to the EUV and FUV Diffuse Astronomical Flux

    E-print Network

    Jerry Edelstein; Stuart Bowyer; Michael Lampton

    2000-03-15

    We re-examine {\\em Voyager} Ultraviolet Spectrograph data used to establish upper limits to the $\\lambda$ 500-900 \\AA and $\\lambda$ 900-1100 \\AA cosmic diffuse background. The measurement of diffuse flux with the {\\em Voyager} UVS data requires complex corrections for noise sources which are far larger than the astronomical signal. In the analyses carried out to date, the upper limits obtained on the diffuse background show statistical anomalies which indicate that substantial systematic errors are present. We detail these anomalies and identify specific problems with the analysis. We derive statistically robust 2~$\\sigma$ upper limits for continuum flux of 570~photons~s$^{-1}$ cm$^{-2}$~ster$^{-1}$~\\AA$^{-1}$ and for the 1000 \\AA~ diffuse line flux of 11,790~photons~s$^{-1}$ cm$^{-2}$~ster$^{-1}$. The true limits may be substantially higher because of unknown systematic uncertainties. The new statistical limits alone are insufficient to support previous conclusions based on the {\\em Voyager} data including work on the character of interstellar dust and estimates of the diffuse extragalactic far UV background as absorbed by intergalactic dust.

  13. A report on SHARP (Spacecraft Health Automated Reasoning Prototype) and the Voyager Neptune encounter

    NASA Technical Reports Server (NTRS)

    Martin, R. G. (editor); Atkinson, D. J.; James, M. L.; Lawson, D. L.; Porta, H. J.

    1990-01-01

    The development and application of the Spacecraft Health Automated Reasoning Prototype (SHARP) for the operations of the telecommunications systems and link analysis functions in Voyager mission operations are presented. An overview is provided of the design and functional description of the SHARP system as it was applied to Voyager. Some of the current problems and motivations for automation in real-time mission operations are discussed, as are the specific solutions that SHARP provides. The application of SHARP to Voyager telecommunications had the goal of being a proof-of-capability demonstration of artificial intelligence as applied to the problem of real-time monitoring functions in planetary mission operations. AS part of achieving this central goal, the SHARP application effort was also required to address the issue of the design of an appropriate software system architecture for a ground-based, highly automated spacecraft monitoring system for mission operations, including methods for: (1) embedding a knowledge-based expert system for fault detection, isolation, and recovery within this architecture; (2) acquiring, managing, and fusing the multiple sources of information used by operations personnel; and (3) providing information-rich displays to human operators who need to exercise the capabilities of the automated system. In this regard, SHARP has provided an excellent example of how advanced artificial intelligence techniques can be smoothly integrated with a variety of conventionally programmed software modules, as well as guidance and solutions for many questions about automation in mission operations.

  14. Multilocus genotypes from Charles Darwin's finches: biodiversity lost since the voyage of the Beagle

    PubMed Central

    Petren, Kenneth; Grant, Peter R.; Grant, B. Rosemary; Clack, Andrew A.; Lescano, Ninnia V.

    2010-01-01

    Genetic analysis of museum specimens offers a direct window into a past that can predate the loss of extinct forms. We genotyped 18 Galápagos finches collected by Charles Darwin and companions during the voyage of the Beagle in 1835, and 22 specimens collected in 1901. Our goals were to determine if significant genetic diversity has been lost since the Beagle voyage and to determine the genetic source of specimens for which the collection locale was not recorded. Using ‘ancient’ DNA techniques, we quantified variation at 14 autosomal microsatellite loci. Assignment tests showed several museum specimens genetically matched recently field-sampled birds from their island of origin. Some were misclassified or were difficult to classify. Darwin's exceptionally large ground finches (Geospiza magnirostris) from Floreana and San Cristóbal were genetically distinct from several other currently existing populations. Sharp-beaked ground finches (Geospiza difficilis) from Floreana and Isabela were also genetically distinct. These four populations are currently extinct, yet they were more genetically distinct from congeners than many other species of Darwin's finches are from each other. We conclude that a significant amount of the finch biodiversity observed and collected by Darwin has been lost since the voyage of the Beagle. PMID:20194164

  15. On the latitudinal distribution of Titan's haze at the Voyager epoch

    NASA Astrophysics Data System (ADS)

    Negrao, A.; Roos-Serote, M.; Rannou, P.; Rages, K.; McKay, C.

    2002-09-01

    In this work, we re-analyse a total of 10 high phase angle images of Titan (2 from Voyager 1 and 8 from Voyager 2). The images were acquired in different filters of the Voyager Imaging Sub System in 1980 - 1981. We apply a model, developed and used by Rannou etal. (1997) and Cabane etal. (1992), that calculates the vertical (1-D) distribution of haze particles and the I/F radial profiles as a function of a series of parameters. Two of these parameters, the haze particle production rate (P) and imaginary refractive index (xk), are used to obtain fits to the observed I/F profiles at different latitudes. Differerent from previous studies is that we consider all filters simultaneously, in an attempt to better fix the parameter values. We also include the filter response functions, not considered previously. The results show that P does not change significantly as a function of latitude, eventhough somewhat lower values are found at high northern latitudes. xk seems to increase towards southern latitudes. We will compare our results with GCM runs, that can give the haze distribution at the epoch of the observations. Work financed by portuguese Foundation for Science and Tecnology (FCT), contract ESO/PRO/40157/2000

  16. Radio range measurements of coronal electron densities at 13 and 3.6 centimeter wavelengths during the 1988 solar conjunction of Voyager 2

    NASA Technical Reports Server (NTRS)

    Krisher, T. P.; Anderson, J. D.; Morabito, D. D.; Asmar, S. W.; Borutzki, S. E.; Delitsky, M. L.; Densmore, A. C.; Eshe, P. M.; Lewis, G. D.; Maurer, M. J.

    1991-01-01

    Radio range measurements of total solar plasma delay obtained during the solar conjunction of the Voyager 2 spacecraft in December 1988, which occurred near solar maximum activity in the 11 yr cycle are reported. The radio range measurements were generated by the Deep Space Network at two wavelengths on the downlink from the spacecraft: 3.6 and 13 cm. A direct measurement of the integrated electron density along the ray path between the earth stations and the spacecraft was obtained by differencing the range at the two wavelengths. Coronal electron density profiles have been derived during ingress and egress of the ray path, which approached the sun to within 5 solar radii. At 10 solar radii, the derived density profiles yield 34079 + or - 611/cu cm on ingress and 49688 + or - 983/cu cm on egress. These density levels are significantly higher than observed near previous solar maxima.

  17. Preservation Methods Utilized for Space Food

    NASA Technical Reports Server (NTRS)

    Vodovotz, Yael; Bourland, Charles

    2000-01-01

    Food for manned space flight has been provided by NASA-Johnson Space Center since 1962. The various mission scenarios and space craft designs dictated the type of food preservation methodologies required to meet mission objectives. The preservation techniques used in space flight include freeze-dehydration, thermostabilization, irradiation, freezing and moisture adjustment. Innovative packaging material and techniques enhanced the shelf-stability of the food items. Future space voyages may include extended duration exploration missions requiring new packaging materials and advanced preservation techniques to meet mission goals of up to 5-year shelf-life foods.

  18. An unmanned probe to Pluto

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Now that Voyager II has completed its grand tour of the solar system, all the planets in the solar system, with the exception of Pluto, have been studied. Even now, missions to return to Mercury, Venus, Mars Jupiter, and Saturn are currently flying or are planned. However, a mission to explore Pluto is not, at the present time, being considered seriously. The design problem presented to the students was very general, i.e., design an unmanned mission to Pluto with a launch window constraint of the years 2000 to 2010. All other characteristics of the mission, such as mission type (flyby, orbiter, lander, penetrator), scientific objectives and payload, and the propulsion system were to be determined by the design teams. The design studies exposed several general problems to be solved. Due to the extreme distance to Pluto (and a corresponding travel time in the range of 10 to 25 years), the spacecraft had to be lighter and more robust than current spacecraft designs. In addition, advanced propulsion concepts had to be considered. These included the new generation of launch vehicles and upper stages and nuclear electric propulsion. The probe design offered an abundance of synthesis and analysis problems. These included sizing trade studies, selection of subsystem components, analysis of spacecraft dynamics, stability and control, structural design and material selection, trajectory design, and selection of scientific equipment. Since the characteristics of the mission, excluding the launch window, were to be determined by the design teams, the solutions varied widely.

  19. A JPL Report: AI Takes on Space Tasks

    Microsoft Academic Search

    Ware Myers

    1990-01-01

    The growing use of artificial intelligence (AI) at the Jet Propulsion Laboratory in mission operations and other areas of the space program is discussed. Mission operations is furthest along, two systems having begun operation in parallel with existing methods in time for Voyager 2's Neptune encounter in August 1989. One is called Sharp (spacecraft health automated reasoning prototype) and the

  20. LASP Highlights The Laboratory for Atmospheric and Space Physics (LASP)

    E-print Network

    Mojzsis, Stephen J.

    , New Horizons, RBSP, SDO, SORCE, THEMIS, TIMED, Voyager LASP is developing 15 instruments for 8 spacecraft. LASP has developed scientific instrumentation for twelve deep-space missions, fourteen Earth and science operations for spacecraft and instruments. In addition, LASP is responsible for the delivery

  1. Droplet monitoring probe

    NASA Technical Reports Server (NTRS)

    Baughman, J. R.; Thys, P. C.

    1973-01-01

    A droplet monitoring system is disclosed for analysis of mixed-phase fluid flow in development of gas turbines. The system uses a probe comprising two electrical wires spaced a known distance apart and connected at one end to means for establishing a dc potential between the wires. A drop in the fluid stream momentarily contacting both wires simultaneously causes and electrical signal which is amplified, detected and counted.

  2. Experimental modal survey of the probe mass mock-up

    Microsoft Academic Search

    P. A. Manning; T. G. Woehrle

    1992-01-01

    The Lawrence Livermore National Laboratory is engaged in a technology development project which includes designing a lightweight, autonomous, highly maneuverable space vehicle, commonly referred to as a probe. The current probe design includes a guidance and control system that requires complete information on the dynamic response of the probe during operation. A finite element model of the probe was constructed

  3. Burstman: A portable GRB detector for really long voyages

    SciTech Connect

    Hurley, K.; Primbsch, J. H.; Berg, P.; Ziock, K.; Mitrofanov, I.; Anfimov, D.; Chernenko, A.; Dolidze, V.; Loznikov, V.; Pozanenko, A.; Tonshev, A.; Ushakov, D.; Cline, T.; Baker, R.; Stilwell, D.; Sheppard, D.; Madden, N. [UC Berkeley Space Sciences Laboratory, Berkeley, California 94720-7450 (United States); Lawrence Livermore National Laboratory, L-296, Livermore, California 94550 (United States); Institute for Space Research Profsoyouznaya 34/32, 117810 Moscow (Russian Federation); NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Lawrence Berkeley Laboratory, 29-204, Berkeley, California 94720 (United States)

    1996-08-01

    The renewal of the Ulysses mission to the year 2001, and the failure of Mars Observer, once more leave the Interplanetary Network with only two widely spaced components. We have therefore developed and begun to build a small GRB detector for the Russian Mars '96 mission. The first flight unit has now been delivered to Russia for spacecraft tests. Three interesting features of this experiment are first, that it measures both particles and gamma rays, second, that it is not much larger than a Walkman (hence the name), and third, that it is being constructed with support only from discretionary funds at a number of institutes. We discuss the types of measurements that Burstman will make, as well as the quantity and quality of the small error boxes that will be obtained during the two year (nominal) Mars '96 mission.

  4. Burstman: A portable GRB detector for really long voyages

    SciTech Connect

    Hurley, K.; Primbsch, J.H.; Berg, P. [UC Berkeley Space Sciences Laboratory, Berkeley, California 94720-7450 (United States); Ziock, K. [Lawrence Livermore National Laboratory, L-296, Livermore, California 94550 (United States); Mitrofanov, I.; Anfimov, D.; Chernenko, A.; Dolidze, V.; Loznikov, V.; Pozanenko, A.; Tonshev, A.; Ushakov, D. [Institute for Space Research Profsoyouznaya 34/32, 117810 Moscow (Russia); Cline, T.; Baker, R.; Stilwell, D.; Sheppard, D. [NASA/Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States); Madden, N. [Lawrence Berkeley Laboratory, 29-204, Berkeley, California 94720 (United States)

    1996-08-01

    The renewal of the Ulysses mission to the year 2001, and the failure of Mars Observer, once more leave the Interplanetary Network with only two widely spaced components. We have therefore developed and begun to build a small GRB detector for the Russian Mars {close_quote}96 mission. The first flight unit has now been delivered to Russia for spacecraft tests. Three interesting features of this experiment are first, that it measures both particles and gamma rays, second, that it is not much larger than a Walkman (hence the name), and third, that it is being constructed with support only from discretionary funds at a number of institutes. We discuss the types of measurements that Burstman will make, as well as the quantity and quality of the small error boxes that will be obtained during the two year (nominal) Mars {close_quote}96 mission. {copyright} {ital 1996 American Institute of Physics.}

  5. Burstman: a portable GRB detector for really long voyages

    SciTech Connect

    Hurley, K.; Primbsch, J.H.; Berg, P. [and others

    1995-10-01

    The renewal of the Ulysses mission to the year 2001, and the failure of Mars Observer, once more leave the Interplanetary Network with only two widely spaced components. We have therefore developed and begun to build a small GRB detector for the Russian Mars `96 mission. A prototype has now been delivered to Russia for spacecraft tests. Three interesting features of this experiment are first, that it measures both particles and gamma rays, second, that it is not much larger than a Walkman (hence the name), and third, that it is being constructed with support only from discretionary funds at a numbs of institutes. We discuss the types of measurements that Burstman will make, as well as the quantity and quality of the small error boxes that will be obtained during the two year (nominal) Mars `96 mission.

  6. A three dimensional probe positioner.

    PubMed

    Intrator, T; Sun, X; Dorf, L; Furno, I; Lapenta, G

    2008-10-01

    In order to sort out the physics that is important in many plasma experiments, data in three dimensions (3D) are becoming necessary. Access to the usual cylindrical vacuum vessel is typically restricted to radially or axially insertable probes that can pivot. The space that can be explored usually has significant restrictions either because probe travel must be along a travel path, or a "wobbly" probe positioner requires one to map between a moveable coordinate system and a preferred laboratory coordinate system. This could for example introduce errors in measurements of vector quantities such as magnetic field or flow. We describe the design and implementation of a 3D probe positioner that slides in two dimensions on a double O-ring seal and radially inserts along the third dimension. The net result is that a 3D space can be explored in a laboratory Cartesian reference frame. PMID:19044613

  7. A three dimensional probe positioner

    SciTech Connect

    Intrator, T.; Sun, X.; Furno, I. [Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States); Dorf, L. [Applied Materials, 3050 Bowers Avenue, Santa Clara, California 95054-3299 (United States); Lapenta, G. [Centrum voor Plasma-Astrofysica, Katholieke Universiteit Leuven, 3001 Belgium (Belgium)

    2008-10-15

    In order to sort out the physics that is important in many plasma experiments, data in three dimensions (3D) are becoming necessary. Access to the usual cylindrical vacuum vessel is typically restricted to radially or axially insertable probes that can pivot. The space that can be explored usually has significant restrictions either because probe travel must be along a travel path, or a 'wobbly' probe positioner requires one to map between a moveable coordinate system and a preferred laboratory coordinate system. This could for example introduce errors in measurements of vector quantities such as magnetic field or flow. We describe the design and implementation of a 3D probe positioner that slides in two dimensions on a double O-ring seal and radially inserts along the third dimension. The net result is that a 3D space can be explored in a laboratory Cartesian reference frame.

  8. Space 2000. Meeting the challenge of a new era.

    NASA Astrophysics Data System (ADS)

    Shipman, H. L.

    Contents: Part I: Voyaging into orbit and beyond. 1. Challenger. 2. NASA and its foreign competitors in the 1980s. 3. Highways to heaven.Part II: The practical uses of space. 4. Communications satellites. 5. The orbital high ground: weather watching, spying and star wars. 6. Earth science: a global view of a green planet. 7. Materials processing in space: making pie in the sky, or the next industrial revolution?Part III: Exploring thenear and distant universe. 8. The golden age of planetary exploration. 9. Earthlike planets and the magnet that is Mars. 10. Voyage to the land of the giants. 11. Exploration of the distant universe. 12. Intelligent life in the universe.Part IV: The future. 13. The human roles in space. 14. Permanent stations in space and on the Moon. 15. Space in the twenty-first century.

  9. Space engineering

    NASA Technical Reports Server (NTRS)

    Alexander, Harold L.

    1991-01-01

    Human productivity was studied for extravehicular tasks performed in microgravity, particularly including in-space assembly of truss structures and other large objects. Human factors research probed the anthropometric constraints imposed on microgravity task performance and the associated workstation design requirements. Anthropometric experiments included reach envelope tests conducted using the 3-D Acoustic Positioning System (3DAPS), which permitted measuring the range of reach possible for persons using foot restraints in neutral buoyancy, both with and without space suits. Much neutral buoyancy research was conducted using the support of water to simulate the weightlessness environment of space. It became clear over time that the anticipated EVA requirement associated with the Space Station and with in-space construction of interplanetary probes would heavily burden astronauts, and remotely operated robots (teleoperators) were increasingly considered to absorb the workload. Experience in human EVA productivity led naturally to teleoperation research into the remote performance of tasks through human controlled robots.

  10. Wheel probes

    SciTech Connect

    Bull, R.B.

    1981-12-01

    By employing a flexible diaphragm in the wall of the fluid chamber, an improved ultrasonic wheel probe for internal pipe inspection avoids the loss of the liquid acoustic coupling medium that can occur in high-pressure environments. This diaphragm deflects in response to pressure changes thus balancing the liquid pressure with the pressure of the gas in the pipe.

  11. Pollution Probe.

    ERIC Educational Resources Information Center

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  12. Estimation of a genetically viable population for multigenerational interstellar voyaging: Review and data for project Hyperion

    NASA Astrophysics Data System (ADS)

    Smith, Cameron M.

    2014-04-01

    Designing interstellar starships for human migration to exoplanets requires establishing the starship population, which factors into many variables including closed-ecosystem design, architecture, mass and propulsion. I review the central issues of population genetics (effects of mutation, migration, selection and drift) for human populations on such voyages, specifically referencing a roughly 5-generation (c. 150-year) voyage currently in the realm of thought among Icarus Interstellar's Project Hyperion research group. I present several formulae as well as concrete numbers that can be used to help determine populations that could survive such journeys in good health. I find that previously proposed such populations, on the order of a few hundred individuals, are significantly too low to consider based on current understanding of vertebrate (including human) genetics and population dynamics. Population genetics theory, calculations and computer modeling determine that a properly screened and age- and sex-structured total founding population (Nc) of anywhere from roughly 14,000 to 44,000 people would be sufficient to survive such journeys in good health. A safe and well-considered Nc figure is 40,000, an Interstellar Migrant Population (IMP) composed of an Effective Population [Ne] of 23,400 reproductive males and females, the rest being pre- or post-reproductive individuals. This number would maintain good health over five generations despite (a) increased inbreeding resulting from a relatively small human population, (b) depressed genetic diversity due to the founder effect, (c) demographic change through time and (d) expectation of at least one severe population catastrophe over the 5-generation voyage.

  13. Phenomenology of Neptune's radio emissions observed by the Voyager planetary radio astronomy experiment

    NASA Technical Reports Server (NTRS)

    Pedersen, B. M.; Lecacheux, A.; Zarka, P.; Aubier, M. G.; Kaiser, M. L.; Desch, M. D.

    1992-01-01

    The Neptune flyby in 1989 added a new planet to the known number of magnetized planets generating nonthermal radio emissions. We review the Neptunian radio emission morphology as observed by the planetary radio astronomy experiment on board Voyager 2 during a few weeks before and after closest approach. We present the characteristics of the two observed recurrent main components of the Neptunian kilometric radiation, i.e., the 'smooth' and the 'bursty' emissions, and we describe the many specific features of the radio spectrum during closest approach.

  14. Saturn's rings through a microscope - Particle size constraints from the Voyager PPS scan

    NASA Technical Reports Server (NTRS)

    Showalter, Mark R.; Nicholson, Philip D.

    1990-01-01

    The Voyager-2 photopolarimeter PPS experiment obtained the highest resolution of any ring observation of Saturn, profiling the variation of optical depth in radial steps of about 100 meters. A detailed treatment of the PPS statistics is presented here, and it is shown how these statistics can be related to the particle size distribution. An expression for the excess noise in the scan due to large particles is obtained, and the observed noise is used to constrain the upper end of the size distribution through the rings. It is shown that the Cassini Division and the C Ring have the smallest proportion of large particles, while the A ring has the largest proportion.

  15. Triton's surface properties - A preliminary analysis from ground-based, Voyager photopolarimeter subsystem, and laboratory measurements

    NASA Technical Reports Server (NTRS)

    Buratti, B. J.; Lane, A. L.; Gibson, J.; Burrows, H.; Nelson, R. M.; Bliss, D.; Smythe, W.; Garkanian, V.; Wallis, B.

    1991-01-01

    The surface properties of Triton were investigated using data from the ground-based and Voyager photopolarimeter subsystem (PPS) observations of Triton's phase curve. The results indicate that Triton has a high single-scattering albedo (0.96 +/-0.01 at 0.75 micron) and an unusually compacted surface, possibly similar to that of Europa. Results also suggest that Triton's single-particle phase function and the macroscopically rough character of its surface are similar to those of most other icy satellites.

  16. Remote sensing of the magnetic moment of Uranus - Predictions for Voyager

    NASA Astrophysics Data System (ADS)

    Hill, T. W.; Dessler, A. J.

    1985-03-01

    The current understanding of the power transfer mechanisms by which power is supplied to a planet's magnetosphere by the kinetic energy of planetary spin and the energy flux of the impinging solar wind is applied to the case of Uranus, in order to predict the detectability of radio and auroral emissions by the planetary radio astronomy (PRA) and UV spectrometer (UVS) instruments of the Voyager spacecraft. The power available for the two energy transfer phenomena cited is a function of Uranus' magnetic moment, which is presently derived for each power source as a function of the date of first detection of radio emissions by the PRA or auroral emissions by the UVS.

  17. Titan's atmosphere from Voyager infrared observations. I - The gas composition of Titan's equatorial region

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Bezard, B.; Gautier, D.

    1989-07-01

    After inferring minor atmospheric-constituent abundances in Titan's equatorial region from Voyager 1 IR spectra, a stratospheric temperature profile is derived. An analysis of three different sections has yielded stratospheric mole fractions for C2H2, C2H4, C2H6, C3H4, C3H8, C4H2, HCN, and CO2; an altitude-dependent CO2 profile has been tested against observations, but no conclusive data on vertical distribution could be extracted. Emission-line formation for all minor components originates from the 1-20 mbar, or 75-200 km, pressure levels.

  18. Gravity field of the Saturnian system from Pioneer and Voyager tracking data

    NASA Technical Reports Server (NTRS)

    Campbell, J. K.; Anderson, J. D.

    1989-01-01

    Doppler-tracking data and star-satellite imaging from the Voyager 1 and 2 spacecraft are used along with Pioneer 11 Doppler tracking data to study the gravity field of the Saturnian system. The present analysis has yielded improved values for the masses of Rhea, Titan, and Iapetus, and Saturn. The results are consistent with the findings of Null et al. (1981) and Nicholson and Porco (1988) for the Saturn zonal harmonic coefficients J2, J4, and J6. The ratio of the mass of the sun to the mass of the Saturnian system is found to be 3497.898 + or - 0.018

  19. Voyage dans le noir. Trous noirs, matière noire, énergie noire et antimatière

    ScienceCinema

    None

    2011-10-06

    Et si nous faisions avec les physiciens un voyage dans le noir ? De l'astrophysique à la physique des particules les trois noirs, la matière noire, l'énergie noire ou l?antimatière intriguent et fascinent. Que sont ces objets qui bousculent nos idées et qui véhiculent parfois des craintes irraisonnées? Luis Alvarez-Gaume, Michael Doser et Christophe Grojean, physiciens du CERN vous invitent à mettre en lumière (!) les constituants de base de la matière et à explorer les mystères de la physique contemporaine. Une soirée lumineuse pour éclairer des concepts et ne plus avoir peur du noir.

  20. Multi-spacecraft study of five ICMEs and their shock waves: Helios, IMP-8 and Voyagers observations

    NASA Astrophysics Data System (ADS)

    Romero-Hernandez, E.; Gonzalez-Esparza, J. A.

    2013-06-01

    We studied the characteristics of five interplanetary coronal mass ejections (ICMEs) detected during the ascending phase of the solar cycle 21, employing simultaneous measurements of five spacecraft: Helios 1, Helios 2, IMP-8, Voyager 1, and Voyager 2. The study covers a time interval of four months (November 1977 to February 1978). We estimated different parameters of the ICMEs and their shock waves: magnetic cloud (MC) signatures, ICME and sheath radial width, ICME front velocity, total perpendicular pressure (Pt), and magnetosonic Mach number (M). In general, the ICME front velocities were slow (| V | ~ 457km/s); but four out of the five ICMEs were preceded by shock waves. Comparing the ICME radial width registered by the Voyagers, we find a clear expansion beyond 1.5 AU. We classified the Pt profiles in three groups depending on its signature within the ejecta (G1, G2, and G3) (Russell et al. (2005)), and we correlated them with the MC signatures.

  1. Automation for deep space vehicle monitoring

    NASA Technical Reports Server (NTRS)

    Schwuttke, Ursula M.

    1991-01-01

    Information on automation for deep space vehicle monitoring is given in viewgraph form. Information is given on automation goals and strategy; the Monitor Analyzer of Real-time Voyager Engineering Link (MARVEL); intelligent input data management; decision theory for making tradeoffs; dynamic tradeoff evaluation; evaluation of anomaly detection results; evaluation of data management methods; system level analysis with cooperating expert systems; the distributed architecture of multiple expert systems; and event driven response.

  2. Atmospheric Circulation Changes in the Tropical Pacific Inferred from the Voyages of the Manila Galleons in the Sixteenth-Eighteenth Centuries

    Microsoft Academic Search

    Rolando R. Garcia; Henry F. Díaz; Ricardo García Herrera; Jon Eischeid; María del Rosario Prieto; Emiliano Hernández; Luis Gimeno; Francisco Rubio Durán; Ana María Bascary

    2001-01-01

    Historical accounts of the voyages of the Manila galleons derived from the Archivo General de Indias (General Archive of the Indies, Seville, Spain) are used to infer past changes in the atmospheric circulation of the tropical Pacific Ocean. It is shown that the length of the voyage between Acapulco, Mexico, and the Philippine Islands during the period 1590-1750 exhibits large

  3. Probing recursion.

    PubMed

    Lobina, David J

    2014-11-01

    The experimental probing of recursion in human performance is faced with non-trivial problems. Here, I analyse three case studies from the literature and argue that they tell us little about the underlying mental processes at play within each of these domains: (a) the question of whether experimental participants employ recursive rules in parsing artificial strings of nonsense syllables; (b) the role of self-embedded structures in reasoning and general cognition; and (c) the reputed connection between structural features of a given object and the corresponding, recursive rules needed to represent/generate it. I then outline what a recursive process would actually look like and how one could go about probing its presence in human behaviour, concluding, however, that recursive processes in performance are very unlikely, at least as far as fast, mandatory, and automatic modular processes are concerned. PMID:24817314

  4. Charles Darwin's beagle voyage, fossil vertebrate succession, and "the gradual birth & death of species".

    PubMed

    Brinkman, Paul D

    2010-01-01

    The prevailing view among historians of science holds that Charles Darwin became a convinced transmutationist only in the early spring of 1837, after his Beagle collections had been examined by expert British naturalists. With respect to the fossil vertebrate evidence, some historians believe that Darwin was incapable of seeing or understanding the transmutationist implications of his specimens without the help of Richard Owen. There is ample evidence, however, that he clearly recognized the similarities between several of the fossil vertebrates he collected and some of the extant fauna of South America before he returned to Britain. These comparisons, recorded in his correspondence, his diary and his notebooks during the voyage, were instances of a phenomenon that he later called the "law of the succession of types." Moreover, on the Beagle, he was following a geological research agenda outlined in the second volume of Charles Lyell's Principles of Geology, which implies that paleontological data alone could provide an insight into the laws which govern the appearance of new species. Since Darwin claims in On the Origin of Species that fossil vertebrate succession was one of the key lines of evidence that led him to question the fixity of species, it seems certain that he was seriously contemplating transmutation during the Beagle voyage. If so, historians of science need to reconsider both the role of Britain's expert naturalists and the importance of the fossil vertebrate evidence in the development of Darwin's ideas on transmutation. PMID:20665232

  5. Cross and magnetic helicity in the outer heliosphere from Voyager 2 observations

    E-print Network

    Iovieno, M; Fraternale, F; Richardson, J D; Opher, M; Tordella, D

    2015-01-01

    Plasma velocity and magnetic field measurements from the Voyager 2 mission are used to study solar wind turbulence in the slow solar wind at two different heliocentric distances, 5 and 29 astronomical units, sufficiently far apart to provide information on the radial evolution of this turbulence. The magnetic helicity and the cross-helicity, which express the correlation between the plasma velocity and the magnetic field, are used to characterize the turbulence. Wave number spectra are computed by means of the Taylor hypothesis applied to time resolved single point Voyager 2 measurements. The overall picture we get is complex and difficult to interpret. A substantial decrease of the cross-helicity at smaller scales (over 1-3 hours of observation) with increasing heliocentric distance is observed. At 5 AU the only peak in the probability density of the normalized residual energy is negative, near -0.5. At 29 AU the probability density becomes doubly peaked, with a negative peak at -0.5 and a smaller peak at a ...

  6. A Far-Ultraviolet Study of the Cygnus Loop Using the VOYAGER Ultraviolet Spectrometers

    NASA Technical Reports Server (NTRS)

    Vancura, Olaf; Blair, William P.; Long, Knox S.; Raymond, John C.; Holberg, J. B.

    1993-01-01

    We have used the Voyager 1 and 2 Ultraviolet Spectrometers to study the far-ultraviolet emissions from different types of shock waves in the Cygnus Loop. In the southeast and northern parts of the supernova remnant (SNR), we have measured the O(VI) lambda1035 surface brightness from the main blast wave. This value is several times below the average and more than one order of magnitude below the peak O(VI) brightness in the SNR as measured with Voyager. A simple blast wave model appears able to reproduce the observations in the southeast and the northern parts of the Cygnus Loop but can only account for 10%-15% of the total O(VI) emission from the Cygnus Loop. The brightest O(VI) and C(III) lambda977 emission is found coincident with optical filamentation and X-ray enhancements in the northeast. We interpret the observations in the northeast in terms of nonradiative and incomplete shocks whose surface area rises in the optical filamentary regions. We conclude that the bulk of the O(VI) emission from the Cygnus Loop arises from optically bright clouds within which intermediate-velocity (200 + 50 km/s) nonradiative and incomplete shocks are widespread.

  7. Voyager Observations of Magnetic Fields and Cosmic Rays in the Heliosheath

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Ness, N. F.; Stone, E.; McDonald, F. B.

    2011-01-01

    The major features of the profile of greater than 70 MeV/nuc cosmic ray intensity (CRI) observed by Voyager 1 (VI) in the heliosheath from 2005.8-2010.24 are described by the empirical "CR-B" relation as the cumulative effect of variations of the magnetic field strength B. The CRI profile observed by Voyager 2 (V2) from 2008.60 to 2010.28 in the heliosheath is also described by the CR-B relation. On a smaller scale, of the order of a hundred days, a sequence on CRI decreases observed by V 1 during 2006 was interpreted as the effect of a propagating interplanetary shock first interacting with the termination shock, then moving past V1, and finally reflecting from the heliopause and propagating back to V1. Our observations show that the second CRI decrease in this sequence began during the passage of a "Global Merged Interaction Region" (GMIR), 40 days after the arrival of the GMIR and its possible shock. The first and third CRI decreases in the sequence were associated with local enhancements of B. The magnetic field observations associated with the second sequence of 3 cosmic ray intensity decreases observed by V 1 in 2007/2008 are more difficult to reconcile with the scenario of Webber et al. (2009) and the CR-B relation. The discrepancy might indicate the importance of latitudinal effects

  8. A new look at the Saturn system: The Voyager 2 images

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.; Batson, R.; Bridges, P.; Inge, J.; Masursky, H.; Shoemaker, E.; Beebe, R.; Boyce, J.; Briggs, G.; Bunker, A.; Collins, S.A.; Hansen, C.J.; Johnson, T.V.; Mitchell, J.L.; Terrile, R.J.; Cook, A.F., II; Cuzzi, J.; Pollack, James B.; Danielson, G.E.; Ingersoll, A.P.; Davies, M.E.; Hunt, G.E.; Morrison, D.; Owen, T.; Sagan, C.; Veverka, J.; Strom, R.; Suomi, V.E.

    1982-01-01

    Voyager 2 photography has complemented that of Voyager 1 in revealing many additional characteristics of Saturn and its satellites and rings. Saturn's atmosphere contains persistent oval cloud features reminiscent of features on Jupiter. Smaller irregular features track out a pattern of zonal winds that is symmetric about Saturn's equator and appears to extend to great depth. Winds are predominantly eastward and reach 500 meters per second at the equator. Titan has several haze layers with significantly varying optical properties and a northern polar "collar" that is dark at short wavelengths. Several satellites have been photographed at substantially improved resolution. Enceladus' surface ranges from old, densely cratered terrain to relatively young, uncratered plains crossed by grooves and faults. Tethys has a crater 400 kilometers in diameter whose floor has domed to match Tethys' surface curvature and a deep trench that extends at least 270?? around Tethys' circumference. Hyperion is cratered and irregular in shape. Iapetus' bright, trailing hemisphere includes several dark-floored craters, and Phoebe has a very low albedo and rotates in the direction opposite to that of its orbital revolution with a period of 9 hours. Within Saturn's rings, the "birth" of a spoke has been observed, and surprising azimuthal and time variability is found in the ringlet structure of the outer B ring. These observations lead to speculations about Saturn's internal structure and about the collisional and thermal history of the rings and satellites. Copyright ?? 1982 AAAS.

  9. Space: The New Frontier.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This document is designed primarily to describe the U.S. Space Program, its history, its current state of development, and its goals for the future. Chapter headings include: Space and You; The Early History of Space Flight; The Solar System; Space Probes and Satellites; Scientific Satellites and Sounding Rockets; Application Satellites, Unmanned…

  10. NMR fingerprints of the drug-like natural-product space identify iotrochotazine A: a chemical probe to study Parkinson's disease.

    PubMed

    Grkovic, Tanja; Pouwer, Rebecca H; Vial, Marie-Laure; Gambini, Luca; Noël, Alba; Hooper, John N A; Wood, Stephen A; Mellick, George D; Quinn, Ronald J

    2014-06-10

    The NMR spectrum of a mixture of small molecules is a fingerprint of all of its components. Herein, we present an NMR fingerprint method that takes advantage of the fact that fractions contain simplified NMR profiles, with minimal signal overlap, to allow the identification of unique spectral patterns. The approach is exemplified in the identification of a novel natural product, iotrochotazine?A (1), sourced from an Australian marine sponge Iotrochota?sp. Compound 1 was used as a chemical probe in a phenotypic assay panel based on human olfactory neurosphere-derived cells (hONS) from idiopathic Parkinson's disease patients. Compound 1 at 1??M was not cytotoxic but specifically affected the morphology and cellular distribution of lysosomes and early endosomes. PMID:24737726

  11. NMR Fingerprints of the Drug-like Natural-Product Space Identify Iotrochotazine A: A Chemical Probe to Study Parkinson’s Disease**

    PubMed Central

    Grkovic, Tanja; Pouwer, Rebecca H; Vial, Marie-Laure; Gambini, Luca; Noël, Alba; Hooper, John N A; Wood, Stephen A; Mellick, George D; Quinn, Ronald J

    2014-01-01

    The NMR spectrum of a mixture of small molecules is a fingerprint of all of its components. Herein, we present an NMR fingerprint method that takes advantage of the fact that fractions contain simplified NMR profiles, with minimal signal overlap, to allow the identification of unique spectral patterns. The approach is exemplified in the identification of a novel natural product, iotrochotazine A (1), sourced from an Australian marine sponge Iotrochota sp. Compound 1 was used as a chemical probe in a phenotypic assay panel based on human olfactory neurosphere-derived cells (hONS) from idiopathic Parkinson’s disease patients. Compound 1 at 1 ?m was not cytotoxic but specifically affected the morphology and cellular distribution of lysosomes and early endosomes. PMID:24737726

  12. National Space Science Data Center (NSSDC) Photo Gallery

    NSDL National Science Digital Library

    This photo gallery features an extensive selection of imagery of many types of objects in space. The gallery is divided by type of object: solar system (planets, asteroids, comets, etc.), astronomical objects (nebulae, galaxies. etc.), and other images (sun, spacecraft). Detailed captions are provided for some images. Indices are provided for imagery from three major sources: Galileo, the Hubble Space Telescope, and Voyager. A section on frequently asked questions and links to other imagery and related topics are also included.

  13. Human Probe "HumanProbe"

    E-print Network

    Fonseca, Rodrigo

    Probe WIC_DataControl WIC_Access Control Local_Interface RF_Interface WINFO++_SERVER (WIS) WIS_Access Control WIS_DataControl MappingDataBase RF_Interface Buffer WINFO++_CLIENT (WIC) GPSSensors WIC_LocControl WIC_DataControlWIC_DataControl WIC_Access Control Local_Interface RF_Interface WINFO++_SERVER (WIS

  14. Large-scale variations of the interplanetary magnetic field: Voyager 1 and 2 observations between 1-5 AU

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Lepping, R. P.; Behannon, K. W.; Klein, L. W.; Neubauer, F. M.

    1981-01-01

    Observations by the Voyager 1 and 2 spacecraft of the interplanetary magnetic field between 1 and 5 AU were used to investigate the large scale structure of the IMF in a period of increasing solar activity. The Voyager spacecraft found notable deviations from the Parker axial model. These deviations are attributed both to temporal variations associated with increasing solar activity, and to the effects of fluctuations of the field in the radial direction. The amplitude of the latter fluctuations were found to be large relative to the magnitude of the radial field component itself beyond approximately 3 AU. Both Voyager 1 and Voyager 2 observed decreases with increasing heliocentric distance in the amplitude of transverse fluctuations in the averaged field strength (B) which are consistent with the presence of predominantly undamped Alfven waves in the solar wind, although and necessarily implying the presence of them. Fluctuations in the strength of B (relative to mean field strength) were found to be small in amplitude, with a RMS which is approximately one third of that for the transverse fluctuations and they are essentially independent of distance from the Sun.

  15. External control of the Saturn kilometric radiation by the solar wind - Comparison between Voyager 1 and 2 observations

    Microsoft Academic Search

    H. O. Rucker; G. K. F. Rabl; M. D. Desch

    1989-01-01

    The long-term modulation of Saturn's nonthermal radio emission in the kilometric wavelength range has been studied based upon data obtained by Voyagers 1 and 2. A comparison of the ballistic and hydrodynamic propagation of solar wind features from the spacecraft to Saturn allows the uncertainty inherent in the projection to be determined. The results confirm the previous suggestion that momentum,

  16. Preliminary interpretation of Titan plasma interaction as observed by the Cassini Plasma Spectrometer: Comparisons with Voyager 1

    E-print Network

    Johnson, Robert E.

    Preliminary interpretation of Titan plasma interaction as observed by the Cassini Plasma] The Cassini Plasma Spectrometer (CAPS) instrument observed the plasma environment at Titan during the Cassini orbiter's TA encounter on October 26, 2004. Titan was in Saturn's magnetosphere during the Voyager 1 flyby

  17. Composition and thermal profiles of the Jovian upper atmosphere determined by the Voyager ultraviolet stellar occultation experiment

    Microsoft Academic Search

    M. C. Festou; S. K. Atreya; T. M. Donahue; B. R. Sandel; D. E. Shemansky; A. L. Broadfoot

    1981-01-01

    During the occultation of the star Regulus (B7 type) by Jupiter as seen from the Voyager 2 spacecraft on July 9, 1979, two absorbing regions were detected. Between 911 and 1200 A, H2 was absorbing over a 600 km altitude range. Above 1300 A, the rapid increase of the absorption by the hydrocarbons was observed over an altitude interval of

  18. "Marijuana has been compared to walking a foot off the ground as opposed to the intergalactic voyage produced

    E-print Network

    Squire, Larry R.

    to the intergalactic voyage produced by LSD" (source- unknown) Original LSD experience "In afternoon of 16 April, 1943 of Albert Hofmann at Sandoz) when synthesizing LSD-25) #12;2 First LSD Dosing Experiment "After 40 minutes synthesizing LSD-25) Synesthesia "The guide asked me how I felt and I responded `Good'. As I uttered the word

  19. Asteroids as Propulsion Systems of Space Ships

    NASA Astrophysics Data System (ADS)

    Bolonkin, A.

    Currently, rockets are used to change the trajectory of space ships and probes. This method is very expensive and requires a lot of fuel, which limits the feasibility of space stations, interplanetary space ships, and probes. Sometimes space probes use the gravity field of a planet. However, there are only nine planets in the Solar System, all separated by great distances. There are tens of millions of asteroids in outer space. This paper offers a revolutionary method for changing the trajectory of space probes. The method uses the kinetic or rotary energy of asteroids, comet nuclei, meteorites or other space bodies (small planets, natural planetary satellites, space debris, etc.) to increase (to decrease) ship (probe) speed up to 1000 m/sec (or more) and to achieve any new direction in outer space. The flight possibilities of space ships and probes are increased by a factor of millions.

  20. Asteroids as Propulsion Systems of Space Ships

    NASA Technical Reports Server (NTRS)

    Bolonkin, Alexander

    2003-01-01

    Currently, rockets are used to change the trajectory of space ships and probes. This method is very expensive and requires a lot of fuel, which limits the feasibility of space stations, interplanetary space ships, and probes. Sometimes space probes use the gravity field of a planet However, there am only nine planets in the Solar System, all separated by great distances. There are tons of millions of asteroids in outer space. This paper offers a revolutionary method for changing the trajectory of space probes. The method uses the kinetic or rotary energy of asteroids, comet nuclei, meteorites or other space bodies (small planets, natural planetary satellites, space debris, etc.) to increase (to decrease) ship (probe) speed up to 1000 m/sec (or more) and to achieve any new direction in outer space. The flight possibilities of space ships and probes are increased by a factor of millions.

  1. Spatial variations of 0.2 to 5 MeV protons in the 1-5 AU in-ecliptic region from Ulysses, Voyager 1 and 2, and IMP 8 gradient studies

    NASA Astrophysics Data System (ADS)

    Boufaida, Moncef; Armstrong, Thomas P.

    1997-04-01

    Protons with energies ranging from 0.3 to 2 MeV are nearly always present in the environment of Earth. Solar flare events and interplanetary shock waves can be identified as producing or enhancing these fluxes. However, interplanetary particles are observed even in the absence of solar flares. Explaining the presence of these proton fluxes in the interplanetary medium and accounting for their variations is a major problem in space physics. Observations of interplanetary proton fluxes have been made continuously at 1 AU with the Interplanetary Monitoring Platform (IMP) 8 from 1973 to the present and in the 1-5 AU range by Voyagers 1 and 2 (1977-1978) and Ulysses (1990-1991). Daily averaged proton fluxes of IMP 8, Voyagers 1 and 2, and Ulysses have been carefully interpolated to matching energy passbands so that fluxes in the same passbands at two radial distances could be compared. These daily averaged fluxes were then compared as ratios and were autocorrelated and cross-correlated as functions of time delay. The radial gradient, the energy spectra, and the distribution of these proton fluxes were also examined. The results showed that protons in the 0.3 to 5 MeV energy range using the Voyager 1/IMP 8, Voyager 2/IMP 8, and Ulysses/IMP 8 paired observations in the 1 to 5 AU in-ecliptic region tend to ``decorrelate'' with increasing radial separation and become uncorrelated by about 4 or 5 AU. Higher-energy fluxes decorrelate less rapidly, and lower-energy proton fluxes have more dominantly positive radial gradients than those of higher energy. The radial gradient of 0.3 to 0.5 MeV proton fluxes is dominantly positive for 1-2 AU, while that of 2 to 4 MeV proton fluxes is negative. In contrast, from 2 to 4 AU the radial gradient of 0.3 to 0.5 MeV proton fluxes is weakly negative, and that of 2 to 4 MeV protons is weakly positive. This finding suggests that 0.3 to 0.5 MeV protons are more subject to interplanetary acceleration than are 2 to 4 MeV protons in the 1-2 AU range. The results also showed that radial gradients are robust and persist, even if all heliolongitude coherence is purposely removed by shuffling the time order within 120-day time intervals.

  2. Exo-S: A Probe-scale Space Mission to Directly Image and Spectroscopically Characterize Exoplanetary Systems Using a Starshade and Telescope System

    NASA Astrophysics Data System (ADS)

    Seager, Sara; Cash, Webster C.; Kasdin, N. Jeremy; Sparks, William B.; Turnbull, Margaret C.; Kuchner, Marc J.; Roberge, Aki; Domagal-Goldman, Shawn; Shaklan, Stuart; Thomson, Mark; Lisman, Doug; Martin, Suzanne; Cady, Eric; Webb, David

    2014-06-01

    "Exo-S" is NASA's first directed community study of a starshade and telescope system for space-based discovery and characterization of exoplanets by direct imaging. Under a cost cap of $1B, Exo-S will use a modestly sized starshade (also known as an "external occulter") and a modest aperture space telescope for high contrast observations of exoplanetary systems. The Exo-S will obtain spectra of a subset of its newly discovered exoplanets as well as already known Jupiter-mass exoplanets. Exo-S will be capable of reaching down to the discovery of Earth-size planets in the habitable zones of twenty sun-like stars, with a favorable few accessible for spectral characterization. We present highlights of the science goals, the mission design, and technology milestones already reached. At the study conclusion in 2015, NASA will evaluate the Exo-S concept for potential development at the end of this decade.

  3. Exo-C: a Probe-Scale Space Mission to Directly Image and Spectroscopically Characterize Exoplanetary Systems Using an Internal Coronagraph

    NASA Technical Reports Server (NTRS)

    Stapelfeldt, Karl R.; Brenner, Michael P.; Warfield, Keith R.; Dekens, Frank G.; Belikov, Ruslan; Brugarolas, Paul B.; Bryden, Geoffrey; Cahoy, Kerri L.; Chakrabarti, Supriya; Dubovitsky, Serge; Effinger, Robert T.; Hirsch, Brian; Kissil, Andrew; Krist, John E.; Lang, Jared J.; Marley, Mark S.; McElwain, Michael W.; Meadows, Victoria S.; Nissen, Joel; Oseas, Jeffrey M.; Serabyn, Eugene; Sunada, Eric; Trauger, John T.; Unwin, Stephen C.

    2014-01-01

    "Exo-C" is NASA's first community study of a modest aperture space telescope designed for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discover previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. At the study conclusion in 2015, NASA will evaluate it for potential development at the end of this decade. Keywords: Exoplanets, high contrast imaging, optical astronomy, space mission concepts

  4. A simple method for obtaining a three-dimensional proton distribution function from Voyager plasma data. [on a solar wind experiment

    NASA Technical Reports Server (NTRS)

    Olbert, S.; Jessen, J.; Belcher, J. W.; Lazarus, A.

    1978-01-01

    The main sensor of the Vogager plasma experiment consists of a cluster of three, modulated-grid Faraday cups whose normals are arranged symmetrically about the symmetry axis of the cluster at an angle of 20 degrees to that axis. In interplanetary space, each cup explores the positive ion distribution by accepting particles from contiguous slices in velocity space. The slices are narrow in the direction of the normal to the modulating grid but are broad in planes parallel to that grid. The resulting three sets of measurements can be combined to yield the three-dimensional distribution function in the following way: the distribution function is assumed to be gyrotropic. For each value of speed in a frame of reference moving with the bulk velocity of the solar wind, the variation of the distribution function with angle from the field direction is represented by a series of Legendre polynomials. Effects such as double-streaming and heat flow can be well represented by using only the first three terms of the series which are fully specified by the measurements. Examples of the use of this method in the analysis of Voyager data are shown.

  5. Multi-Point Observations of the Inner Magnetosphere from the Van Allen Probes and Related Missions at NASA's Space Physics Data Facility (SPDF)

    NASA Astrophysics Data System (ADS)

    McGuire, R. E.; Bilitza, D.; Candey, R. M.; Chimiak, R.; Cooper, J. F.; Garcia, L. N.; Harris, B. T.; Johnson, R. C.; Kovalick, T.; Lal, N.; Leckner, H.; Liu, M.; Papitashvili, N. E.; Roberts, D. A.

    2014-12-01

    A wide range of current, public, science-quality particle and field data from the Van Allen Probes and related missions is ingested, archived and served to the international science community by SPDF. As an active heliophysics final archive, SPDF now serves 100+ Level-2 and Level-3 data products that fully span the range of measurements from particles and plasmas (RBSPICE, ECT) through magnetic-electric fields and waves (EMFISIS, EFW). This collection of mission data (in a standard CDF format with standard ISTP/SPDF) is available through SPDF's CDAWeb user interface, through CDAWeb's web services and associated APIs for IDL and Matlab users, and through direct FTP/HTTP download access. These data are supplemented with orbit displays through our SSCWeb and 4D Orbit Viewer services and HDP/VSPO direct links to investigator sites/resources. This range of data in CDAWeb makes comparison of data among instruments and spacecraft much easier, as well as comparisons and analysis of these data with current data from other missions including THEMIS, TWINS, Cluster, ACE, Wind and now >120 ground magnetometer stations. In addition, SPDF supports data from the BARREL Antarctic balloon program and new data from instruments on the NOAA GOES and POES spacecraft. SPDF will add public data from the MMS mission to this collection when launched in 2015.

  6. New Worlds Probe

    NASA Astrophysics Data System (ADS)

    Lo, Amy S.; Glassman, Tiffany; Dailey, Dean; Sterk, Ken; Green, James; Cash, Webster; Soummer, Remi

    2010-07-01

    The New Worlds Observer is a flagship-scale terrestrial planet finding and characterizing mission using an external occulter known as a starshade. The starshade is a separate space vehicle from the observing telescope; the starshade performs all the necessary starlight suppression to enable high contrast imaging of terrestrial exo-planets. While effective as a flagship-scale mission designed to fulfill and exceed the requirements of the Terrestrial Planet Finder (TPF) mission, the starshade architecture is flexible and can accommodate a variety of design and cost categories, including working with an existing telescope. We present in this paper an architecture using a starshade with the James Web Space Telescope (JWST), a mission concept we call New Worlds Probe, which can deliver many of the TPF mission requirements for significantly lower mission cost. We give an overview of the science capabilities, the starshade design and technical maturity, and concepts for starshade-JWST cooperative operation.

  7. The atmosphere of Neptune - Results of radio occultation measurements with the Voyager 2 spacecraft

    NASA Technical Reports Server (NTRS)

    Lindal, G. F.; Lyons, J. R.; Sweetnam, D. N.; Eshleman, V. R.; Hinson, D. P.

    1990-01-01

    This paper presents the vertical temperature and composition profiles of Neptune's troposphere and stratosphere, covering an altitude of 250 km, obtained from radio tracking data that were acquired during Voyager-2's occultation by Neptune, which began near 62 deg N planetographic latitude and ended near 45 deg S latitude. In the computations, the He/H2 abundance ratio 15/85 was adapted, which is consistent with solar abundance estimates and with recent results from Uranus. It was assumed that aerosols and heavier gases such as CH4, NH3, H2S, and H2O have a negligible effect on the microwave refractivity above the 0.5 bar pressure level.

  8. Properties of scatterers in the troposphere and lower stratosphere of Uranus based on Voyager imaging data

    NASA Technical Reports Server (NTRS)

    Rages, Kathy; Pollack, James B.; Tomasko, Martin G.; Doose, Lyn R.

    1991-01-01

    Scalar and vector radiative transfer and microphysical models are presently constructed from photometrically and geometrically corrected Voyager images of Uranus defining spatially-resolved intensities over a range of phase angles for two latitude bands. The methane ice cloud occupying 1.2-1.3 bar is of 0.7 optical depth at 22.5 deg S, rising to 2.4 at 65 deg S; the volume absorption coefficient of the cloud particles is 50 percent greater at the low latitude than at the high, assuming constant mean cloud particle size. The scattering model also includes photochemically-produced stratospheric hydrocarbon ices in the upper troposphere and stratosphere, as well as an optically thick hydrogen sulfide cloud.

  9. Standing hydromagnetic waves in the Io plasma torus - Voyager 1 observations

    NASA Technical Reports Server (NTRS)

    Glassmeier, K.-H.; Neubauer, F. M.; Ness, N. F.; Acuna, M. H.

    1989-01-01

    An attempt to analyze Voyager 1 magnetic field data for the existence of any ultralow-frequency hydromagnetic waves in the Io plasma torus is presented. The coincidence between the increase in wave activity and the entry into the Io plasma torus is in support of treating the torus as a low Alfven velocity region and thus as a hydromagnetic waveguide. A first theoretical treatment of hydromagnetic wave propagation within the torus suggests that decoupling of toroidal and poloidal type oscillations can occur under the condition of axisymmetry of the wave field. Numerical calculations of the fundamental mode toroidal and first harmonic poloidal eigenperiods for a model Jovian magnetosphere give values quite in agreement with the observed periods. Observations of nearly axisymmetric, decoupled toroidal and poloidal mode eigenoscillations of the Io plasma torus suggest a large-scale source mechanism for the detected magnetic field fluctuations.

  10. Strong Temporal Variation Over One Saturnian Year: From Voyager to Cassini

    PubMed Central

    Li, Liming; Achterberg, Richard K.; Conrath, Barney J.; Gierasch, Peter J.; Smith, Mark A.; Simon-Miller, Amy A.; Nixon, Conor A.; Orton, Glenn S.; Flasar, F. Michael; Jiang, Xun; Baines, Kevin H.; Morales-Juberías, Raúl; Ingersoll, Andrew P.; Vasavada, Ashwin R.; Del Genio, Anthony D.; West, Robert A.; Ewald, Shawn P.

    2013-01-01

    Here we report the combined spacecraft observations of Saturn acquired over one Saturnian year (~29.5 Earth years), from the Voyager encounters (1980–81) to the new Cassini reconnaissance (2009–10). The combined observations reveal a strong temporal increase of tropic temperature (~10 Kelvins) around the tropopause of Saturn (i.e., 50?mbar), which is stronger than the seasonal variability (~a few Kelvins). We also provide the first estimate of the zonal winds at 750?mbar, which is close to the zonal winds at 2000?mbar. The quasi-consistency of zonal winds between these two levels provides observational support to a numerical suggestion inferring that the zonal winds at pressures greater than 500?mbar do not vary significantly with depth. Furthermore, the temporal variation of zonal winds decreases its magnitude with depth, implying that the relatively deep zonal winds are stable with time. PMID:23934437

  11. Strong temporal variation over one Saturnian year: from Voyager to Cassini.

    PubMed

    Li, Liming; Achterberg, Richard K; Conrath, Barney J; Gierasch, Peter J; Smith, Mark A; Simon-Miller, Amy A; Nixon, Conor A; Orton, Glenn S; Flasar, F Michael; Jiang, Xun; Baines, Kevin H; Morales-Juberías, Raúl; Ingersoll, Andrew P; Vasavada, Ashwin R; Del Genio, Anthony D; West, Robert A; Ewald, Shawn P

    2013-01-01

    Here we report the combined spacecraft observations of Saturn acquired over one Saturnian year (~29.5 Earth years), from the Voyager encounters (1980-81) to the new Cassini reconnaissance (2009-10). The combined observations reveal a strong temporal increase of tropic temperature (~10 Kelvins) around the tropopause of Saturn (i.e., 50 mbar), which is stronger than the seasonal variability (~a few Kelvins). We also provide the first estimate of the zonal winds at 750 mbar, which is close to the zonal winds at 2000 mbar. The quasi-consistency of zonal winds between these two levels provides observational support to a numerical suggestion inferring that the zonal winds at pressures greater than 500 mbar do not vary significantly with depth. Furthermore, the temporal variation of zonal winds decreases its magnitude with depth, implying that the relatively deep zonal winds are stable with time. PMID:23934437

  12. The magnetic anomaly model of the Jovian magnetosphere - Predictions for Voyager

    NASA Technical Reports Server (NTRS)

    Dessler, A. J.; Vasyliunas, V. M.

    1979-01-01

    The magnetic anomaly model, in which the anomalously weak magnetic field region in the northern hemisphere of Jupiter influences the outer Jovian magnetosphere by one or more plasma interaction processes, has been put forth to account for the various observed Jovian magnetospheric phenomena that show evidence of Jovian longitudinal asymmetry or planetary spin periodicity. From this model, normalized by empirical fitting to Pioneer 10 and 11 flyby data and to ground-based radio data, a series of predictions are made that are subject to test by the forthcoming flybys of Jupiter by Voyagers 1 and 2. These predictions cover: (1) the longitude range and time intervals of enhanced interaction between Io (and possibly Europa) and Jupiter's ionosphere, (2) plasma, energetic particle, and magnetic field periodicities in the outer magnetosphere, and (3) the sub-spacecraft System III longitude and the time, modulo 10 hours, of the first and subsequent magnetopause crossings.

  13. The Occurence Rate, Polarization Character, and Intensity of Broadband Jovian Kilometric Radiation. [Voyager Project

    NASA Technical Reports Server (NTRS)

    Desch, M. D.; Kaiser, M. L.

    1980-01-01

    The major observational features of one new component of Jupiter's radio emission spectrum, the broadband kilometer-wavelenth radiation or bKOM are described. The Voyager planetary radio astronomy experiments reveal that the overall occurrence morphology, total power, and polarization character of bKOM are strong functions of the latitude and/or local time geometry of the observations. The post-encounter data show a decline in the mean occurrence rates and power level of bKOM and, in particular, a depletion in the occurrence rate at those same longitudes where the detection rate is a maximum before encounter. Additionally, the polarization sense undergoes a permanent reversal in sign after encounter, whereas the time-averaged wave axial ratio and degrees of polarization remain relatively unchanged. No evidence of any control by Io is found. The strong dependence of the morphology on local time suggests a source whose beam is nearly fixed relative to the Jupiter-sun line.

  14. Voyager spacecraft attitude control propulsion system post-launch performance requirements changes

    NASA Technical Reports Server (NTRS)

    Groudle, T. A.

    1991-01-01

    A test program aimed at the re-qualification of the 0.2-lbf attitude control thruster of the Voyager 2 spacecraft was carried out while the spacecraft was in flight on an interplanetary trajectory to Uranus. The objective of the program was to determine if the 0.2-lbf thruster could be successfully and repeatedly fired at pulse widths of less than the standard minimum pulse width of 10 milliseconds with no degradation. It was demonstrated that the thruster was qualified for short pulse operation at pulse widths of 4 ms or greater. Pulse widths of 4.0 ms provide an impulse bit of approximately 45 percent of the impulse provided by a 10-ms pulse, and the pulse-to-pulse and unit-to-unit variation is approximately plus or minus 10 percent.

  15. Photometry from Voyager 2 - Initial results from the Uranian atmosphere, satellites, and rings

    NASA Technical Reports Server (NTRS)

    Lane, A. L.; West, R. A.; Nelson, R. M.; Wallis, B. D.; Buratti, B. J.; Horn, L. J.; Hord, C. W.; Esposito, L. W.; Simmons, K. E.; Graps, A. L.

    1986-01-01

    The results of Voyager 2 photopolarimetry (PPS) surveys of Uranus, the ring system, occultation experiments and observations of the Uranian moons are reported. Dual-channel photometry and polarimetry data obtained of the atmosphere at various emission and phase angles are delineated and compared with characteristics of the Saturn and Jupiter atmospheres. The results of temperature, UV absorption and density profile calculations are also discussed. Extensive ring dimensional data, based on two occultation experiments, are provided in tabular form noting that the rings contain no dust. Finally, the geometric albedos of the five major moons and the phase curve of the moon Titania are presented. The latter data indicate that Titanian surface features are not the result of recent events such as volcanism or ice slurry outflows.

  16. Implications of Voyager data for energetic ion erosion of the icy satellites of Saturn

    NASA Technical Reports Server (NTRS)

    Lanzerotti, L. J.; Maclennan, C. G.; Brown, W. L.; Johnson, R. E.; Barton, L. A.; Reimann, C. T.; Garrett, J. W.; Boring, J. W.

    1983-01-01

    The possible production of a neutral-particle torus by magnetosphere-particle sputtering of the icy satellites (Enceladus, Tethys, Dione, Rhea) of Saturn is discussed. Particle spectra from the Voyager low-energy-charged-particle experiment are used together with laboratory-derived erosion rates and velocity distributions for the ejected species. An extended torus region in the inner magnetosphere of Saturn is expected, with H2O escape fluxes in the vicinities of the satellites varying from about 2 to 7 x 10 to the 7th mol/sq cm sec for incident protons and from about 6 to 14 x 10 to the 9th mol/sq cm sec if the incident ions are all oxygen.

  17. Shocks in the solar wind between 1 and 8.5 AU: Voyager 1 observations

    NASA Technical Reports Server (NTRS)

    Gazis, P. R.

    1984-01-01

    A survey was made of all interplanetary shocks detected by the plasma science experiment aboard the Voyager 1 spacecraft between 1.2 and 8.5 AU. Shock normals and shock velocities are determined. The variation of shock frequency and various shock parameters with heliocentric distance is discussed. The results indicate that beyond 1.2 AU, the vast majority of shocks were associated with interaction regions between high and low speed streams; of 95 events, only 1 was clearly associated with a transient event. Forward shocks were more numerous and seemed to form closer to the sun than reverse shocks. Forward shocks were stronger than reverse shocks. The energy balance of three shocks is examined. A close agreement is found between the measured and the predicted pressure ratios across these shocks. The contribution of shocks to the global energy balance is discussed. Shocks are found to have a significant effect in heating the solar wind.

  18. Strong Temporal Variation Over One Saturnian Year: From Voyager to Cassini

    NASA Technical Reports Server (NTRS)

    Li, Liming; Achterberg, Richard K.; Conrath, Barney J.; Gierasch, Peter J.; Smith, Mark A.; Simon-Miller, Amy A.; Nixon, Conor A.; Orton, Glenn S.; Flasar, F. Michael; Jiang, Xun; Baines, Kevin H.; Morales-Juberias, Raul; Ingersoll, Andrew P.; Vasavada, Ashwin R.; DelGenio, Anthony D.; West, Robert A.; Ewald, Shawn P.

    2013-01-01

    Here we report the combined spacecraft observations of Saturn acquired over one Saturnian year (approximately 29.5 Earth years), from the Voyager encounters (1980-81) to the new Cassini reconnaissance (2009-10). The combined observations reveal a strong temporal increase of tropic temperature (approximately 10 Kelvins) around the tropopause of Saturn (i.e., 50 mbar), which is stronger than the seasonal variability (approximately a few Kelvins). We also provide the first estimate of the zonal winds at 750 mbar, which is close to the zonal winds at 2000 mbar. The quasi-consistency of zonal winds between these two levels provides observational support to a numerical suggestion inferring that the zonal winds at pressures greater than 500 mbar do not vary significantly with depth. Furthermore, the temporal variation of zonal winds decreases its magnitude with depth, implying that the relatively deep zonal winds are stable with time.

  19. The albedo, effective temperature, and energy balance of Uranus, as determined from Voyager IRIS data

    NASA Astrophysics Data System (ADS)

    Pearl, J. C.; Conrath, B. J.; Hanel, R. A.; Pirraglia, J. A.

    1990-03-01

    The albedo, T(eff), and energy balance of Uranus are presently derived from Voyager IR Spectrometer and Radiometer data. By obtaining the absolute phase curve of Uranus, it has become possible to evaluate the Bond albedo without making separate determinations of the geometric albedo and phase integral. An orbital mean value for the bolometric Bond albedo of 0.3 + or - 0.049 yields an equilibrium temperature of 58.2 + or - 1.0 K. Thermal spectra from pole-to-pole latitude coverage establish a T(eff) of 59.1 + or - 0.3 K, leading to an energy balance of 1.06 + or - 0.08 for Uranus.

  20. Albedo, internal heat, and energy balance of Jupiter - Preliminary results of the Voyager infrared investigation

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.; Conrath, B. J.; Herath, L. W.; Kunde, V. G.; Pirraglia, J. A.

    1981-01-01

    Full disk measurements recorded by the 0.4-1.7 micron radiometer on Voyager 1 indicate a geometric albedo of 0.274 + or - 0.013. This measurement and the Pioneer-based phase integral of 1.25 yield a Jovian Bond albedo of 0.343 + or - 0.032. Infrared spectra yield a thermal emission of 1.359 + or - 0.014 x .001 W/sq cm, which corresponds to an equivalent blackbody temperature of 124.4 + or - 0.3 K. In addition, the internal heat flux of Jupiter is estimated to be 5.444 + or - 0.425 x .0001 W/sq cm, and the energy balance defined as the ratio of emitted thermal to absorbed solar energy is 1.668 + or - 0.085.

  1. Borescopic Laser Doppler Velocimetry probe

    NASA Astrophysics Data System (ADS)

    O'Brien, Kory T.

    A miniature fiber-optic, single-velocity-component Laser Doppler Velocimetry (LDV) probe for measurement in cramped spaces, where access is very limited, has been designed, constructed, and tested. The probe design allows the main probe dimensions to be small (7mm in diameter). In addition, the proposed back-scatter collection scheme allows the main section to be as long as needed to access remote locations. The laser beams are first collimated by passing them through two separate collimating lenses. The collimated light then passes through 1 mm holes machined into a right angle prism-mirror and are focused to form the measurement probe volume using the focusing lens placed at the end of the probe extension tube. The light scattered by the particles in the flow is collected back by the focusing lens and is collimated. The collimated light then reflects off the right-angle mirror by 90 degrees, passes through the receiving lens, and is focused to the receiving fiber terminator. The receiving fiber-optic cable transmits the collected light to the photo-multiplier tube which then converts the signal into an electrical signal for further processing of the data. The probe working principle was proven in two types of jet flows.

  2. An analysis of Neptune's stratospheric haze using high-phase-angle voyager images.

    NASA Astrophysics Data System (ADS)

    Moses, Julianne I.; Rages, Kathy; Pollack, James B.

    1995-01-01

    We have inverted high-phase-angle Voyager images of Neptune to determine the atmospheric extinction coefficient as a function of altitude and the scattering phase function at a reference altitude. Comparisons between theoretical models and observations help separate the contributions from molecular Rayleigh and aerosol scattering and help determine the variation of the aerosol size, concentration, and scattering properties with altitude. Further comparisons between models and data allow us to place constraints on the location and composition of the hazes, the concentration and downward flux of certain condensible hydrocarbon gases, the eddy diffusion coefficient in the lower stratosphere, and the thermal profile in parts of Neptune's stratosphere. We find that a distinct stratospheric haze layer exists near 12 +1-1 mbar in Neptune's lower stratosphere, most probably due to condensed ethane. The derived stratospheric haze production rate of 1.0 +0.2-0.3 × 10 -15 g cm -2 sec -1 is substantially lower than photochemical model predictions. Evidence for hazes at higher altitudes also exists. Unlike the situation on Uranus, large particles (0.08-0.11 ?m) may be present at high altitudes on Neptune (e.g., near 0.5 mbar), well above the region in which we expect the major hydrocarbon species to condense. Near 28 mbar, the mean particle size is about 0.13 +0.02-0.02 ?m with a concentration of 5 +3-3 particles cm -3. The cumulative haze extinction optical depth above 15 mbar in the clear filter is ˜3 × 10 -3, and much of this extinction is due to scattering rather than absorption; thus, if our limb-scan sites are typical, the hazes cannot account for the stratospheric temperature inversion on Neptune and may not contribute significantly to atmospheric heating. We compare the imaging results with the results from other observations, including those of the Voyager Photopolarimeter Subsystem, and discuss differences between Neptune and Uranus.

  3. Mortality of live export cattle on long-haul voyages: pathologic changes and pathogens.

    PubMed

    Moore, S Jo; O'Dea, Mark A; Perkins, Nigel; Barnes, Anne; O'Hara, Amanda J

    2014-03-01

    The cause of death in 215 cattle on 20 long-haul live export voyages from Australia to the Middle East, Russia, and China was investigated between 2010 and 2012 using gross, histologic, and/or molecular pathology techniques. A quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay was used to detect nucleic acids from viruses and bacteria known to be associated with respiratory disease in cattle: Bovine coronavirus (Betacoronavirus 1), Bovine herpesvirus 1, Bovine viral diarrhea virus 1 and 2, Bovine respiratory syncytial virus, Bovine parainfluenza virus 3, Histophilus somni, Mycoplasma bovis, Mannheimia haemolytica, and Pasteurella multocida. The most commonly diagnosed cause of death was respiratory disease (107/180, 59.4%), followed by lameness (n = 22, 12.2%), ketosis (n = 12, 6.7%), septicemia (n = 11, 6.1%), and enteric disease (n = 10, 5.6%). Two thirds (130/195) of animals from which lung samples were collected had histologic changes and/or positive qRT-PCR results indicative of infectious lung disease: 93 out of 130 (72%) had evidence of bacterial infection, 4 (3%) had viral infection, and 29 (22%) had mixed bacterial and viral infections, and for 4 (3%) the causative organism could not be identified. Bovine coronavirus was detected in up to 13% of cattle tested, and this finding is likely to have important implications for the management and treatment of respiratory disease in live export cattle. Results from the current study indicate that although overall mortality during live export voyages is low, further research into risk factors for developing respiratory disease is required. PMID:24518275

  4. Grant Proposal for the Continuation of the Voyager Interstellar Mission: LECP Investigation

    NASA Technical Reports Server (NTRS)

    Krimigis, Stamatios M.; Armstrong, Thomas P.; Lanzerotti, Louis J.; Ip, Wing-H.; Decker, Robert B.; Keath, Edwin P.; Mauk, Barry H.; McNutt, Ralph L., Jr.; Gloeckler, George; Hamilton, Douglas C.

    1996-01-01

    This proposal documents the plans of the Low Energy Charged Particle (LECP) investigation team for participation in NASA's Voyager Interstellar Mission (VIM) as the Voyager 1 and 2 spacecraft explore the outer reaches of the heliosphere and search for the termination shock and the heliopause. The proposal covers the four year period from 1 January 1997 to 31 December 2000. The LECP instruments on Voyager 1 and 2 measure in situ intensities of charged particles with energies from about 30 keV to 100 MeV for ions, and about 20 keV to greater than 10 MeV for electrons. The instruments provide detailed spectral, angular, and compositional information about the particles. Composition is available for greater than 200 keV/nuc using multi-parameter measurements. Angular information is obtained by a mechanically scanned platform that rotates at various commanded rates. Measurements of low energy ion and electron intensities versus time and spatial location within the heliosphere contain an abundance of information regarding various transport and acceleration processes on both local (approx. 1 hr, approx. 0.01 AU) and global (approx. 11 yrs, approx. 100 AU) scales. The LECP instruments provide unique observations of such dynamical processes, and we anticipate that it will return critical information regarding the boundaries of the heliosphere. Several recent and exciting discoveries based on LECP measurements emphasize the important role that low energy charged particle distributions play in physical processes in the interplanetary medium. Yet, at the same time, these discoveries also underscore the fact that our understanding of processes in the outer heliosphere is, in most cases, incomplete, and in others, only rudimentary at best. Among the discoveries referred to above are the following: (1) Shocks: Examination of greater than 30 keV ion intensities have revealed: (a) a total absence of acceleration beyond only -100-200 keV at a strong transient shock in May 1991 at 35 AU, despite an enhanced level of seed particles; (b) a large transient shock in September 1991 of global scale, with intensities of shock-accelerated ions greater than or equal to 30 keV to approx. 30 MeV showing complex, highly energy-dependent spatial evolution, and small-scale (approx. few gyroradii), often anisotropic, micro-structures; (c) recurrent intensity increases in greater than or equal to 30 keV to -few MeV ions, with structures that, in some cases, show no correlation with the associated corotating shock. (2) Superthermal ion pressure: A global merged interaction region with a leading shock, downstream of which the superthermal ion (greater than or equal to 30 keV to approx. 4 MeV) pressure is comparable to that of the thermal plasma, and the total particle pressure yields a plasma beta of order unity. (3) Pickup ions: Measurements of the C/O ratio within transient structures at 35-45 AU showing the first clear evidence that transient shocks can pre-accelerate interstellar pickup ions from approx. 1 keV/nuc to at least 1 MeV/nuc. (4) Seed particles: Injection of ions for acceleration to high energies at the termination shock is unlikely to be a problem, since interplanetary transient and recurrent shocks are continually accelerating ions, of solar wind or interstellar origin, to highly superthermal energies. (5) Precursor electrons: Ambient solar electrons (greater than or equal to few tens of keV) that exist in the outer heliosphere ca form a broad precursor, several days wide, that is upstream of the termination shock and potentially observable a few months prior to the shock crossing. (6) Solar wind velocity at Voyager 1: We can use LECP ion data to obtain the solar wind velocity at Voyager 1, enabling us to provide critical measurement of the plasma flow as we approach and encounter the termination shock and other regions (necessary due to the partial failure of the Voyager 1 PLS experiment). The work of the LECP investigator team during the VIM will include: (1) Continuing operations with regard to the receipt, processing, verification, cata

  5. Cassini Saturn Probe Undergoes Preflight Testing

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The newly assembled Cassini Saturn probe undergoes vibration and thermal testing at the JPL facilities in Pasadena, California. Subjected to weeks of 'shake and bake' tests that imitate the forces and extreme temperatures the spacecraft will experience during launch and spaceflight. Cassini's mission is to orbit Saturn for four years and study the planet, its rings and moons in detail. The large moon Titan is a principal target for exploration, and Cassini will carry the Huygens probe, (gold-mylar circular object seen here mounted on the front of the spacecraft) to be released to enter Titan's thick atmosphere and descend to the surface via parachute. The Huygens probe is provided by the European Space Agency (ESA) and the radio antenna at top was provided by the Italian Space Agency (ASI). The project is a joint endeavor of NASA, the European Space Agency and the Italian Space Agency. JPL manages the program for NASA's Office of Space Science, Washington, DC.

  6. THE FUTURE DEVELOPMENT OF ENERGETIC THIN-FILM PROCESSES FOR SPACED BASED DEPOSITIONS

    Microsoft Academic Search

    Michael L. Fulton

    NASA's Lunar-Mars proposal (January 14, 2004) plans to use the Moon as an outpost for future voyages to Mars and beyond. The ability to deposit high performance thin-film coatings in the vacuum of lunar-space will be extremely valuable for executing many aspects of this new mission. Space-based thin-film depositions will enable the future development of flexible large- area space antennae

  7. Radioisotope space power generators: Design concepts

    NASA Astrophysics Data System (ADS)

    Forsman, Tina; Simion, George

    The use of radioisotope power systems for space applications was a key part of some of the most ambitious astronautical undertakings of the United States. Nuclear power sources have provided the electrical energy for the NASA Pioneer, Viking, and Voyager missions as well as earlier earth orbital and Apollo missions. Recently developed, radioisotope thermoelectric generators (RTGs) will be used in future space missions, such as the Galileo Project (Jupiter study) and the International Solar Polar Mission. Present design concepts of RTGs and related dynamic isotope power systems (DIPS) are surveyed.

  8. Space-Based Photometry of Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Southworth, John

    2012-04-01

    I briefly review the history and prospects for the study of eclipsing binary star systems from space-based observatories. The benefits of shifting to space satellites lie in the high precision and cadence achievable, as well as the ability to access wavelength regions which are unattainable from the ground. Whilst small amounts of data on eclipsing binaries were obtained by the Voyager, IUE, OAO-II, Hipparcos and MOST, the more recent CoRoT and Kepler missions were the first to provide extensive data on large numbers of systems. The future holds the prospect of the PLATO satellite, which will go bigger, better and brighter.

  9. Voyager observations of Saturn's rings. 1: The eccentric rings at 1.29, 1.45, 1.95 and 227 RS

    NASA Astrophysics Data System (ADS)

    Porco, C. C.

    1983-08-01

    Five major eccentric features in the rings of Saturn are studied. These are the outer A and B ring edges at 1.95 and 2.27 R(subs) and three narrow ringlets at 1.29, 1.45, and 1.95 R(sub). Data acquired by four Voyager experiments-imaging Science (SS), Radio Science (RSS), Ultraviolet Spectrometer (UVS), and Photopolarimeter (PPS) were used in this investigation. The discovery of a periodic variation in spoke activity in Saturn's rings from the analysis of Voyager images is reported. A Fourier power spectrum was computed using a data set generated by quantifying spoke activity observed on the morning (western) half of the rings in Voyager images spanning approximately 12 Saturn rotations and in Voyager 2 images spanning approximately 90 Saturn rotations.

  10. Radial Evolution of the Solar Wind from IMP 8 to Voyager 2 John D. Richardson, Karolen I. Paularena, Alan J. Lazarus, and John W. Belcher

    E-print Network

    Richardson, John

    measurements . T using modulated-grid Faraday cups manufactured at MIT he Voyager 2 plasma experiment has plasma experiment on IMP 8 is a single s p Faraday cup with a split collector plate which measure rotons

  11. PROBING THE GC-LMXB CONNECTION IN NGC 1399: A WIDE-FIELD STUDY WITH THE HUBBLE SPACE TELESCOPE AND CHANDRA

    SciTech Connect

    Paolillo, Maurizio [Department of Physical Sciences, University of Napoli Federico II, 80126 Napoli (Italy); Puzia, Thomas H. [Herzberg Institute of Astrophysics, Victoria, BC V9E 2E7 (Canada); Goudfrooij, Paul [Space Telescope Science Institute, Baltimore, MD 21218 (United States); Zepf, Stephen E. [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States); Maccarone, Thomas J. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Kundu, Arunav [Eureka Scientific, Oakland, CA 94602 (United States); Fabbiano, Giuseppina [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Angelini, Lorella, E-mail: paolillo@na.infn.it [Laboratory for High Energy Astrophysics, NASA Goddard Space Flight Center, Code 660, Greenbelt, MD 20771 (United States)

    2011-08-01

    We present a wide-field study of the globular cluster (GC)/low-mass X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The large field of view of the Advanced Camera for Surveys/WFC, combined with Hubble Space Telescope and Chandra high resolution, allow us to constrain the LMXB formation scenarios in elliptical galaxies. We confirm that NGC 1399 has the highest LMXB fraction in GCs of all nearby elliptical galaxies studied so far, even though the exact value depends on galactocentric distance due to the interplay of a differential GC versus galaxy light distribution and the GC color dependence. In fact, LMXBs are preferentially hosted by bright, red GCs out to >5 R{sub eff} of the galaxy light. The finding that GCs hosting LMXBs follow the radial distribution of their parent GC population argues against the hypothesis that the external dynamical influence of the galaxy affects the LMXB formation in GCs. On the other hand, field-LMXBs closely match the host galaxy light, thus indicating that they are originally formed in situ and not inside GCs. We measure GC structural parameters, finding that the LMXB formation likelihood is influenced independently by mass, metallicity, and GC structural parameters. In particular, the GC central density plays a major role in predicting which GCs host accreting binaries. Finally, our analysis shows that LMXBs in GCs are marginally brighter than those in the field, and in particular the only color-confirmed GC with L{sub X} > 10{sup 39} erg s{sup -1} shows no variability, which may indicate a superposition of multiple LMXBs in these systems.

  12. Hubble space telescope/cosmic origins spectrograph observations of the quasar Q0302–003: Probing the He II reionization epoch and QSO proximity effects

    SciTech Connect

    Syphers, David; Shull, J. Michael, E-mail: David.Syphers@colorado.edu [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, Boulder, CO 80309 (United States)

    2014-03-20

    Q0302–003 (z = 3.2860 ± 0.0005) was the first quasar discovered that showed a He II Gunn-Peterson trough, a sign of incomplete helium reionization at z ? 2.9. We present its Hubble Space Telescope/Cosmic Origins Spectrograph far-UV medium-resolution spectrum, which resolves many spectral features for the first time, allowing study of the quasar itself, the intergalactic medium, and quasar proximity effects. Q0302–003 has a harder intrinsic extreme-UV spectral index than previously claimed, as determined from both a direct fit to the spectrum (yielding ?{sub ?} ? –0.8) and the helium-to-hydrogen ion ratio in the quasar's line-of-sight proximity zone. Intergalactic absorption along this sightline shows that the helium Gunn-Peterson trough is largely black in the range 2.87 < z < 3.20, apart from ionization due to local sources, indicating that helium reionization has not completed at these redshifts. However, we tentatively report a detection of nonzero flux in the high-redshift trough when looking at low-density regions, but zero flux in higher-density regions. This constrains the He II fraction to be about 1% in the low-density intergalactic medium (IGM) and possibly a factor of a few higher in the IGM as a whole, suggesting helium reionization has progressed substantially by z ? 3.1. The Gunn-Peterson trough recovers to a He II Ly? forest at z < 2.87. We confirm a transmission feature due to the ionization zone around a z = 3.05 quasar just off the sightline, and resolve the feature for the first time. We discover a similar such feature possibly caused by a luminous z = 3.23 quasar further from the sightline, which suggests that this quasar has been luminous for >34 Myr.

  13. Magnetic drifts at Io - Depletion of 10-MeV electrons at Voyager 1 encounter due to a forbidden zone

    NASA Technical Reports Server (NTRS)

    Goldstein, B. E.; Ip, W.-H.

    1983-01-01

    A model for magnetic field lines is used to track the Voyager spacecraft trajectory past Io back to the equatorial plane in order to determine the cause of an observed depletion of 10 MeV electrons in Io's orbit. The field lines are in the vicinity of an Alfven wing, a noncompressive field perturbation. It is suggested that the Jovian magnetospheric drift features influence the behavior of particles around Io, which also has a zone of reduced convection velocity. An analytical model is developed that demonstrates that a forbidden zone may exist around Io due to the gradient drifts and reduced convection velocity, and projections of particles convecting to the Io surface agree well with the Voyager data for particle concentrations. Discrepancies in the measured 9 MeV fluxes with respect to Pioneer data indicate that a possible change in the Io conductance in the interval between the passages of the two spacecraft.

  14. NASA Smart Surgical Probe Project

    NASA Technical Reports Server (NTRS)

    Mah, Robert W.; Andrews, Russell J.; Jeffrey, Stefanie S.; Guerrero, Michael; Papasin, Richard; Koga, Dennis (Technical Monitor)

    2002-01-01

    Information Technologies being developed by NASA to assist astronaut-physician in responding to medical emergencies during long space flights are being employed for the improvement of women's health in the form of "smart surgical probe". This technology, initially developed for neurosurgery applications, not only has enormous potential for the diagnosis and treatment of breast cancer, but broad applicability to a wide range of medical challenges. For the breast cancer application, the smart surgical probe is being designed to "see" a suspicious lump, determine by its features if it is cancerous, and ultimately predict how the disease may progress. A revolutionary early breast cancer detection tool based on this technology has been developed by a commercial company and is being tested in human clinical trials at the University of California at Davis, School of Medicine. The smart surgical probe technology makes use of adaptive intelligent software (hybrid neural networks/fuzzy logic algorithms) with the most advanced physiologic sensors to provide real-time in vivo tissue characterization for the detection, diagnosis and treatment of tumors, including determination of tumor microenvironment and evaluation of tumor margins. The software solutions and tools from these medical applications will lead to the development of better real-time minimally-invasive smart surgical probes for emergency medical care and treatment of astronauts on long space flights.

  15. Test of the Pioneer anomaly with the Voyager 2 radio-ranging distance measurements to Uranus and Neptune

    Microsoft Academic Search

    Lorenzo Iorio

    2006-01-01

    In this paper we test the hypothesis that the Pioneer anomaly can be of gravitational origin by comparing the predicted model-independent shifts Delta a\\/a for the semimajor axis of Uranus and Neptune with the Voyager 2 radio-technical distance measurements performed at JPL-NASA. As in the case of other tests based on different methods and data sets (secular perihelion advance, right

  16. The 3-D effects in the long-term solar wind speed rise observed by Voyager 2 in early 1994

    Microsoft Academic Search

    V. J. Pizzo; K. I. Paularena; J. D. Richardson; A. J. Lazarus; J. W. Belcher

    1995-01-01

    In early 1994, Voyager 2 at 42-43 AU near heliolatitude 10 deg S observed over a period of approximately 100 days a remarkable sequence of quasi-recurrent stream fronts, wherein the background (ambient) speed rose steadily from approximately 450 to approximately 550 km\\/s while the mean period of the streams decreased from the usual 25 days down to approximately 20 days.

  17. Probes Measure Slots

    NASA Technical Reports Server (NTRS)

    Maslakowski, John E.; Gilbert, Jeffrey L.

    1995-01-01

    Contact probes devised for measuring depths and widths of slots. Configured in conical or wedge shapes, depending on specific applications. Conical or wedge surface of probe centers probe in slot, while two thin probe rods made to protrude from cone or wedge until their tips simultaneously make contact with outer surface and bottom of slot.

  18. Captain Cook's beer: the antiscorbutic use of malt and beer in late 18th century sea voyages.

    PubMed

    Stubbs, Brett J

    2003-01-01

    The custom of allowing British seamen the regular use of fermented liquor is an old one. Ale was a standard article of the sea ration as early as the fourteenth century. By the late eighteenth century, beer was considered to be at once a food (a staple beverage and essential part of the sea diet), a luxury (helping to ameliorate the hardship and irregularity of sea life) and a medicine (conducive to health at sea). In particular, beer and its precursors, wort and malt, were administered with the aim of preventing and curing scurvy. This paper examines the use of malt and beer during late eighteenth century British sea voyages, particularly their use as antiscorbutic agents, focusing on James Cook's three voyages during the period 1768-1780. Cook administered sweet wort (an infusion of malt), beer (prepared from an experimental, concentrated malt extract), and spruce beer (prepared mainly from molasses), among many other items, in his attempts to prevent and to cure scurvy. Despite the inconclusive nature of his own experiments, he reported favourably after his second voyage (1772-1775) on the use of wort as an antiscorbutic sea medicine (for which purpose it is now known to be useless). Cook thereby lent credibility to erroneous medical theories about scurvy, helping to perpetuate the use of ineffective treatments and to delay the discovery of a cure for the disorder. PMID:12810402

  19. The Solar-Sail Launched Interstellar Probe: Pre-Perihelion Trajectories and Application of Holography

    NASA Technical Reports Server (NTRS)

    Matloff, Gregory L.

    2002-01-01

    Design of missions beyond our solar system presents many challenges. Here, we consider certain aspects of the solar-sail launched interstellar probe (ISP), a spacecraft slated for launch in the 2010 time period that is planned to reach the heliopause, at 200 Astronomical Units (AU) from the Sun after a flight of about 20-years duration. The baseline mission under consideration by NASA / JPL has a sail radius of 200 m, a science payload of 25 kg, a spacecraft areal mass thickness of about two grams per square meter and is accelerated out of the solar system at about 14 AU per year after performing a perihelion pass of about 0.25 AU. In current plans, the sail is to be dropped near Jupiter's orbit (5.2 AU from the Sun) on the outbound trajectory leg. One aspect of this study is application of a realistic model of sail thermo-optics to sail kinematics that includes diffuse / specular reflectance and sail roughness. The effects of solar-wind degradation of sail material, based on recent measurements at the NASA MSFC (Marshall Space Flight Center) Space Environment Facility were incorporated in the kinematical model. After setting initial and final conditions for the spacecraft, trajectory was optimized using the provision of variable sail aspect angle. The second phase of the study included consideration of rainbow holography as a medium for a message plaque that would be carried aboard the ISP in the spirit of the message plaques aboard Pioneer 10 /11 and Voyager 1 /2. A prototype holographic message plaque was designed and created by artist C. Bangs with the assistance of Ana Maria Nicholson and Dan Schweitzer of the Center for Holographic Arts in Long Island City, NY. The piece was framed by Simon Liu Inc. of Brooklyn, NY. Concurrent to the creation of the prototype message plaque, we explored the potential of this medium to transmit large amounts of visual information to any extraterrestrial civilization that might detect and intercept ISP. It was also necessary to investigate possible degradation of holograms by the space environment. We developed a new way of characterizing the optical quality of holograms.

  20. Leadership in Space: Selected Speeches of NASA Administrator Michael Griffin, May 2005 - October 2008

    NASA Technical Reports Server (NTRS)

    Griffin, Michael

    2008-01-01

    Speech topics include: Leadership in Space; Space Exploration: Real and Acceptable Reasons; Why Explore Space?; Space Exploration: Filling up the Canvas; Continuing the Voyage: The Spirit of Endeavour; Incorporating Space into Our Economic Sphere of Influence; The Role of Space Exploration in the Global Economy; Partnership in Space Activities; International Space Cooperation; National Strategy and the Civil Space Program; What the Hubble Space Telescope Teaches Us about Ourselves; The Rocket Team; NASA's Direction; Science and NASA; Science Priorities and Program Management; NASA and the Commercial Space Industry; NASA and the Business of Space; American Competitiveness: NASA's Role & Everyone's Responsibility; Space Exploration: A Frontier for American Collaboration; The Next Generation of Engineers; System Engineering and the "Two Cultures" of Engineering; Generalship of Engineering; NASA and Engineering Integrity; The Constellation Architecture; Then and Now: Fifty Years in Space; The Reality of Tomorrow; and Human Space Exploration: The Next 50 Years.

  1. Generation and Scattering of Radiation Observed by Voyager in the Outer Heliosphere

    NASA Technical Reports Server (NTRS)

    Spangler, Steven R.; Cairns, Iver H.

    2003-01-01

    Excellent progress was made under this grant on the generation and scattering of the 2-3 kHz radio emissions observed by the Voyager spacecraft in the outer heliosphere. These are the most powerful radio emissions produced in our solar system, surpassing even those of Jupiter and the Sun. The widely-held hypothesis pursued is that the radiation is generated near the electron plasma frequency f(sub p) or near 2f(sub p) as a shock wave traverses the heliosheath regions and/or heliopause predicted in the interaction region between the solar wind and the local interstellar medium. (Note that f (sup 2) (sub p) is proportional to the plasma density.) The traveling shock wave is plausibly associated with a global merged interaction region (GMIR). Accordingly, this so-called GMIR model is strongly analogous to the common interpretation of type II solar radio bursts and to radio emissions associated with Earth's bow shock, with coronal mass ejections (CMEs) and Earth's magnetosphere playing the role of a GMIR, respectively. Accordingly, Dr Cairns work on type II bursts, Earth's foreshock, and stochastic growth theory (not described in detail) strongly aided and complemented the research progress on the 2-3 kHz emissions described.

  2. Detailed analysis of low energy plasma data under the Voyager Uranus data analysis program

    NASA Technical Reports Server (NTRS)

    Mcnutt, Ralph L., Jr.; Belcher, John W.; Bagenal, Frances; Richardson, John D.

    1992-01-01

    Research effort included the PLS data analysis program where modifications to the data fitting procedure and elimination of possible noise and electron contamination were made. The analysis code corrections were used in checking the Neptune data gathered during the Voyager 2 encounter and for analyzing selected plasma spectra from the warm Io torus. A major task accomplished was the summary of Uranus-related research in the U.S. National Report to the International Union of Geodesy and Geophysics for the 1987 - 1990 quadrennium. A limited amount of work was accomplished on assessing the Pedersen conductivity of the ionosphere and comparing it with inferred values from shielding by the Uranian ring current. Under this grant there has been a great deal of effort expended on identifying and classifying plasma waves and oscillations in the magnetosheath and solar wind downstream from Uranus. Large amplitude oscillations in plasma parameters are found in the magnetosheath, with density changes of up to a factor of ten occurring on times scales of minutes. New algorithms developed for analyzing the inbound bow shock crossing of Neptune will probably be applied to a more detailed analysis of the Uranus shock in the near future.

  3. Particle size distributions in Saturn's rings from Voyager 1 radio occultation

    NASA Technical Reports Server (NTRS)

    Marouf, E. A.; Tyler, G. L.; Zebker, H. A.; Simpson, R. A.; Eshleman, V. R.

    1983-01-01

    Information on Saturn ring particle sizes obtained with the Voyager 1 ring occultation experiment is discussed. The theory underlying the determination of the particle size distribution is presented, including differential extinction and inversion of the scattered signal. Experimental observations and results for the observed spectra, differential cross sections, suprameter and sub- to suprameter size distributions are presented. The size and mass distributions both cut off sharply at about 4-5 m; the mass distribution peaks over the 3-4 m size range for four ring system features at 1.35, 1.51, 2.01, and 2.12 Saturn radii. A power-law type model is consistent with the data over a limited size range of 0.01 to 1 m. The fractional contribution of the suprameter particles to the microwave opacity for the four features appears to be about 1/3, 1/3, 2/3, and 1, respectively, and their cumulative surface mass per unit area are about 11, 16, 41, and 132 g/sq cm if the particles are solid water ice.

  4. The D/H ratio in Saturn's atmosphere from Voyager IRIS spectra

    NASA Technical Reports Server (NTRS)

    Courtin, R.; Gautier, D.; Marten, A.; Bezard, B.; Hanel, R.

    1985-01-01

    A selection of 1656 spectra recorded between 180 and 2300 mm in the 20 to 40 N latitude range by the Voyager interferometer IRIS were analyzed. The CH3D/H2 and CH4/H2 ratios are determined from a best fit of the radiances measured in the nu6 and nu4 fundamental bands, respectively centered at 1161 and 1304 mm. Results are CH3D/H2 = 3.9 + or - 2.5 times 10 to the minus 7th power and CH4/H2 = 4.5 + 2.4, -1.9 x 0.001. The uncertainty includes random errors due to instrumental noise and possible systematic errors in the assumed temperature profile and spectroscopic parameters. The D/H isotopic ratio is determined from abundance ratios from the expression D/H = 1/4f (CH3D/H2)/(CH4/H2) where f accounts for equilibrium deuterium fractionation between the molecular hydrogen and methane phases. Beer and Taylor (1973, 1978) estimated f = 1.37 + or - 0.07 for Jupiter assuming a wide range of convective velocities and neglecting catalytic effects from dust particles. The same value was adopted for Saturn and yields D/H = 1.6 +1.3, -1.2 times 10 to the minus 5th power.

  5. Multispectral and geomorphic studies of processed Voyager 2 images of Europa

    NASA Technical Reports Server (NTRS)

    Meier, T. A.

    1984-01-01

    High resolution images of Europa taken by the Voyager 2 spacecraft were used to study a portion of Europa's dark lineations and the major white line feature Agenor Linea. Initial image processing of images 1195J2-001 (violet filter), 1198J2-001 (blue filter), 1201J2-001 (orange filter), and 1204J2-001 (ultraviolet filter) was performed at the U.S.G.S. Branch of Astrogeology in Flagstaff, Arizona. Processing was completed through the stages of image registration and color ratio image construction. Pixel printouts were used in a new technique of linear feature profiling to compensate for image misregistration through the mapping of features on the printouts. In all, 193 dark lineation segments were mapped and profiled. The more accurate multispectral data derived by this method was plotted using a new application of the ternary diagram, with orange, blue, and violet relative spectral reflectances serving as end members. Statistical techniques were then applied to the ternary diagram plots. The image products generated at LPI were used mainly to cross-check and verify the results of the ternary diagram analysis.

  6. Survey of the plasma electron environment of Jupiter: A view from Voyager

    NASA Technical Reports Server (NTRS)

    Scudder, J. D.; Sittler, E. C., Jr.; Bridge, H. S.

    1980-01-01

    The plasma environment within Jupiter's bow shock is considered in terms of the in situ, calibrated electron plasma measurements made between 10 eV and 5.95 keV by the Voyager plasma science experiment (PLS). Measurements were analyzed and corrected for spacecraft potential variations; the data were reduced to nearly model independent macroscopic parameters of the local electron density and temperature. It is tentatively concluded that the radial temperature profile within the plasma sheet is caused by the intermixing of two different electron populations that probably have different temporal histories and spatial paths to their local observation. The cool plasma source of the plasma sheet and spikes is probably the Io plasma torus and arrives in the plasma sheet as a result of flux tube interchange motions or other generalized transport which can be accomplished without diverting the plasma from the centrifugal equator. The hot suprathermal populations in the plasma sheet have most recently come from the sparse, hot mid-latitude "bath" of electrons which were directly observed juxtaposed to the plasma sheet.

  7. Heliospheric magnetic field strength out to 66 AU: Voyager 1, 1978-1996

    NASA Astrophysics Data System (ADS)

    Burlaga, L. F.; Ness, N. F.; Wang, Y.-M.; Sheeley, N. R.

    1998-10-01

    We discuss Voyager 1 (V1) observations of the heliospheric magnetic field strength from 1978 through 1996. During this period the distance of V1 from the Sun increased from ~3 AU to 66 AU and its heliographic latitude increased from ~5°S to 33°N. The magnetic field strength profile observed by V1 is consistent with Parker's spiral field model when one considers (1) the solar cycle variation of the observed magnetic field strength at 1 AU, B1(t) (which is a measure of the source field strength) and (2) the latitudinal and solar cycle variations of the solar wind speed, V(t,?). Both B1(t) and V(t,?) make significant contributions to the variation of the magnetic field strength variations observed by V1. There is no evidence for a ``magnetic flux deficit'' increasing with distance from the Sun. There is a solar cycle variation of the magnetic field strength in the outer heliosphere, which will affect the modulation of cosmic rays.

  8. The 3-D Moons: The Voyager stereo atlas of the outer solar system

    NASA Technical Reports Server (NTRS)

    Schenk, P.; Moore, J. M.

    1993-01-01

    Comprehension and analysis of geologic features on any planet is enhanced manyfold by a clear perception between albedo and topography. On many of the icy satellites significant albedo contrasts due to mixtures of dark rocky and bright icy materials can be associated with topographic features. Subtle topographic features can be masked by albedo variation and under high solar illumination albedo and topography can be difficult to separate. To this end we are compiling an atlas of stereo image pairs of the outer solar system based on Voyager imaging for the investigation of various geologic problems and for general use. For the icy satellites, general perceptions of topography are usually gleaned from shape-from-shading information in the images processed by the human brain (i.e. visual inspection). With few exceptions, actual topography has been measured on a spot-by-spot basis using shadow heights or photoclinometry, or along limb profiles (where geographic context may be unavailable). Shadow heights are limited to regions within approximately 10 deg of the terminator and images with resolution better than approximately 1 km/pixel. Photoclinometric scans can be used more widely but are subject to a variety of errors, primarily uncertain assumptions of uniform scene albedo or poorly understood photometry. Stereoscopic analysis, where available, has the potential for greatly expanding topographic perception.

  9. Engine spectrometer probe and method of use

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis (Inventor); Kittinger, Scott A. (Inventor)

    2006-01-01

    The engine spectrometer probe and method of using the same of the present invention provides a simple engine spectrometer probe which is both lightweight and rugged, allowing an exhaust plume monitoring system to be attached to a vehicle, such as the space shuttle. The engine spectrometer probe can be mounted to limit exposure to the heat and debris of the exhaust plume. The spectrometer probe 50 comprises a housing 52 having an aperture 55 and a fiber optic cable 60 having a fiber optic tip 65. The fiber optic tip 65 has an acceptance angle 87 and is coupled to the aperture 55 so that the acceptance angle 87 intersects the exhaust plume 30. The spectrometer probe can generate a spectrum signal from light in the acceptance angle 506 and the spectrum signal can be provided to a spectrometer 508.

  10. A resistively heated CeB6 emissive probe

    NASA Astrophysics Data System (ADS)

    Martin, M. J.; Bonde, J.; Gekelman, W.; Pribyl, P.

    2015-05-01

    The plasma potential, Vp, is a key quantity in experimental plasma physics. Its spatial gradients directly yield the electrostatic field present. Emissive probes operating under space-charge limited emission conditions float close to Vp even under time-varying conditions. Throughout their long history in plasma physics, they have mostly been constructed with resistively heated tungsten wire filaments. In high density plasmas (>1012 cm-3), hexaboride emitters are required because tungsten filaments cannot be heated to sufficient emission without component failure. A resistively heated emissive probe with a cerium hexaboride, CeB6, emitter has been developed to work in plasma densities up to 1013 cm-3. To show functionality, three spatial profiles of Vp are compared using the emissive probe, a cold floating probe, and a swept probe inside a plasma containing regions with and without current. The swept probe and emissive probe agree well across the profile while the floating cold probe fails in the current carrying region.

  11. Slingshot Dynamics for Self Replicating Probes and the Effect on Exploration Timescales

    E-print Network

    Nicholson, Arwen

    2013-01-01

    Interstellar probes can carry out slingshot manoeuvres around the stars they visit, gaining a boost in velocity by extracting energy from the star's motion around the Galactic Centre. These maneouvres carry little to no extra energy cost, and in previous work it has been shown that a single Voyager-like probe exploring the galaxy does so 100 times faster when carrying out these slingshots than when navigating purely by powered flight (Forgan et al. 2012). We expand on these results by repeating the experiment with self-replicating probes. The probes explore a box of stars representative of the local Solar neighbourhood, to investigate how self-replication affects exploration timescales when compared with a single non-replicating probe. We explore three different scenarios of probe behaviour: i) standard powered flight to the nearest unvisited star (no slingshot techniques used), ii) flight to the nearest unvisited star using slingshot techniques, and iii) flight to the next unvisited star that will give the m...

  12. Health physics innovations developed during Cassini for future space applications

    SciTech Connect

    Nickell, Rod [Health Physics Office (United States); Rutherford, Theresa [Health Physics Office, BOC-022, Kennedy Space Center, Florida 32899 (United States); Marmaro, George [NASA Radiation Protection Officer, JJ-C, Kennedy Space Center, Florida 32899 (United States)

    1999-01-22

    There has been a long history of space missions involving Space Nuclear Auxiliary Power (SNAP) devices starting with the Transit 4A Spacecraft (1961), on through the Apollo, Pioneer, Viking, Voyager, Galileo, Ulysses, Mars Pathfinder, and most recently, Cassini (1997). All of these Major Radiological Source (MRS) missions were processed at the Kennedy Space Center/Cape Canaveral Air Station (KSC/CCAS) Launch Site in full compliance with program and regulatory requirements. The cumulative experience gained supporting these past missions has led to significant innovations which will be useful for bench-marking future MRS ground processing.

  13. Health physics innovations developed during Cassini for future space applications

    NASA Astrophysics Data System (ADS)

    Nickell, Rod; Rutherford, Theresa; Marmaro, George

    1999-01-01

    There has been a long history of space missions involving Space Nuclear Auxiliary Power (SNAP) devices starting with the Transit 4A Spacecraft (1961), on through the Apollo, Pioneer, Viking, Voyager, Galileo, Ulysses, Mars Pathfinder, and most recently, Cassini (1997). All of these Major Radiological Source (MRS) missions were processed at the Kennedy Space Center/Cape Canaveral Air Station (KSC/CCAS) Launch Site in full compliance with program and regulatory requirements. The cumulative experience gained supporting these past missions has led to significant innovations which will be useful for bench-marking future MRS ground processing.

  14. Thermoelectric power conversion in space

    NASA Technical Reports Server (NTRS)

    Awaya, Henry I.; Ewell, Richard; Nesmith, Bill; Vandersande, James

    1990-01-01

    A radiatively-heated multicouple for use in the next generation of radioisotope thermoelectric generator (RTG) will employ 20 individual couples within a single cell, so that 40 n- and p-semiconductor legs will be interconnected in series. At the hot end of the RTG, the legs will be electrically interconnected using silicon molybdenum; on the cold side, the legs are interconnected by tungsten. The entire cell is then mechanically attached to a radiator, which conducts heat away and radiates it into space. Deep-space applications will use RTGs developed for vacuum operation; thermoelectric converter power systems using a unicouple configuration have flown on such missions as Pioneers 10 and 11, which used lead telluride thermoelectric converters, and Voyagers I and II, which used silicon germanium-based thermoelectrics.

  15. Gravitational redshift space-probe experiment

    NASA Technical Reports Server (NTRS)

    Vessot, R. F. C.; Levine, M. W.

    1979-01-01

    A Scout D rocket was launched from Wallops Island, Virginia, carrying an atomic hydrogen maser oscillator system as the payload. The frequency of signals from the oscillator was monitored on the ground at Merritt Island, Florida, by using two hydrogen masers as comparison oscillators. The first-order Doppler shift in the signals was eliminated by a go-return transponder link to the payload, and the resulting data, representing the relativistic shifts, were recovered and recorded. The objective was to measure directly the effect of gravitational potential on the frequency of an atomic hydrogen maser assuming it to be a 'proper' clock. A gravitational effect amounting to some 4.5 parts in 10 to the 10th power was measured with an oscillator having a stability better than 1 part in 10 to the 14th power. Therefore, to make the best possible use of the oscillator, all frequency shifts at the 2 to 5 X 10 to the -15 power level in delta f/f in the system must be accounted for. This includes all the phase variations that can cause such a shift to appear. The experiment, the data available and the manner in which they were processed, and the results are described.

  16. Theory of a cylindrical probe in a collisionless magnetoplasma

    NASA Technical Reports Server (NTRS)

    Laframboise, J. G.; Rubinstein, J.

    1976-01-01

    A theory is presented for a cylindrical electrostatic probe in a collisionless plasma in the case where the probe axis is inclined at an angle to a uniform magnetic field. The theory is applicable to electron collection, and under more restrictive conditions, to ion collection. For a probe at space potential, the theory is exact in the limit where probe radius is much less than Debye length. At attracting probe potentials, the theory yields an upper bound and an adiabatic limit for current collection. At repelling probe potentials, it provides a lower bound. The theory is valid if the ratios of probe radius to Debye length and probe radius to mean gyroradius are not simultaneously large enough to produce extrema in the probe sheath potential. The numerical current calculations are based on the approximation that particle orbits are helices near the probe, together with the use of kinetic theory to relate velocity distributions near the probe to those far from it. Probe characteristics are presented for inclination angles from 0 to 90 deg and for probe-radius mean-gyroradius ratios from 0.1 to infinity. For an angle of 0 deg, the end-effect current is calculated separately.

  17. The Heliosphere in Space

    NASA Astrophysics Data System (ADS)

    Frisch, P. C.; Hanson, A. J.; Fu, P. C.

    2008-12-01

    A scientifically accurate visualization of the Journey of the Sun through deep space has been created in order to share the excitement of heliospheric physics and scientific discovery with the non-expert. The MHD heliosphere model of Linde (1998) displays the interaction of the solar wind with the interstellar medium for a supersonic heliosphere traveling through a low density magnetized interstellar medium. The camera viewpoint follows the solar motion through a virtual space of the Milky Way Galaxy. This space is constructed from real data placed in the three-dimensional solar neighborhood, and populated with Hipparcos stars in front of a precisely aligned image of the Milky Way itself. The celestial audio track of this three minute movie includes the music of the heliosphere, heard by the two Voyager satellites as 3 kHz emissions from the edge of the heliosphere. This short heliosphere visualization can be downloaded from http://www.cs.indiana.edu/~soljourn/pub/AstroBioScene7Sound.mov, and the full scientific data visualization of the Solar Journey is available commercially.

  18. Abundances of Jupiter's Trace Hydrocarbons from Voyager and Cassini. Data Tables: Cassini CIRS Observations Planetary and Space Science, Forthcoming 2010

    NASA Technical Reports Server (NTRS)

    Nixon, C. A.; Achterberg, R. K.; Romani, P. N.; Allen, M.; Zhang, X.; Teanby, N. A.; Irwin, P. G. J.; Flasar, F. M.

    2010-01-01

    The following six tables give the retrieved temperatures and volume mixing ratios of C2H2 and C2H6 and the formal errors on these results from the retrieval, as described in the manuscript. These are in the form of two-dimensional tables, specified on a latitudinal and vertical grid. The first column is the pressure in bar, and the second column gives the altitude in kilometers calculated from hydrostatic equilibrium, and applies to the equatorial profile only. The top row of the table specifies the planetographic latitude.

  19. Voyager radio occultation by the Uranian rings: Structure, dynamics, and particle sizes. Ph.D. Thesis Final Technical Report

    NASA Technical Reports Server (NTRS)

    Gresh, Donna Leigh

    1990-01-01

    Diffraction of Voyager 2's 3.6 and 13 cm wavelength microwaves by the Uranian rings is removed through an inverse Fresnel transform filtering procedure that accommodates the significant eccentricity of the rings. Resulting 50 m resolution profiles at two observation longitudes: (1) reveal remarkably detailed and longitudinally varying structure, (2) provide eccentricity gradient profiles of Rings alpha, beta, and epsilon which bring into question current theoretical models for observed rigid precession, and (3) suggest that two possible unseen satellites may confine some of the very sharp edges observed via resonant interactions.

  20. An analysis of the Voyager 2 Ultraviolet Spectrometer occultation data at Uranus - Inferring heat sources and model atmospheres

    NASA Technical Reports Server (NTRS)

    Stevens, Michael H.; Strobel, Darrell F.; Herbert, Floyd

    1993-01-01

    Heat source information is derived here from the Voyager 2 Ultraviolet Spectrometer occultation data of Uranus. Analytic functions for the local heat dependence on altitude are used to obtain a temperature profile by solving the heat equation. The stellar entrance and exit occultation and a solar occultation are used to infer the thermal and density structure of the atmosphere. The least squares fit solution to the solar occultation data gives one source located at 1.8 x 10 exp -5 microbar with a strength of 0.056 +/- 0.01 erg/sq cm/s. Latitudinal temperature gradients are obtained.

  1. Particle sizes of the Uranus delta ring's inner diffuse companion through comparison of RSS and PPS Voyager occultation data

    NASA Technical Reports Server (NTRS)

    Hui, John; Horn, Linda J.; Lane, Arthur L.

    1991-01-01

    In January, 1976, Voyager 2's photopolarimeter and UV spectrometer observed Delta Sagitarii and Beta Persei during their occultation by the Uranian delta ring. An inner diffuse companion of this ring was detected and found to have an average width of 12 km. By comparing the widths and equivalent depths of the two sets of data, it is established that the particles making the greatest contribution to the integrated opacities of the companion are of greater-than-several-cm sizes. The particles appear to be located away from the photopolarimetry edges, where there may be particles smaller than those observed elsewhere.

  2. Large-scale interplanetary magnetic fields: Voyager 1 and 2 observations between 1 AU and 9.5 AU

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Klein, L. W.; Lepping, R. P.; Behannon, K. W.

    1984-01-01

    The large-scale radial and temporal variations of the interplanetary magnetic field strength B observed by Voyagers 1 and 2 are discussed. Two components of the magnetic field strength were considered: (1) an average component, B sub zero, based on solar rotation averages, and (2) a fluctuation component, delta B, expressed by 10- or 24-hour averages of B normalized by the best-fit average field for the corresponding time and distance. Observations of the sector structure, interfaces, and shocks are presented to further describe magnetic field strength.

  3. Inferences about the solar wind dynamics from observed distributions of electrons and ions. [Voyager and Helios observations

    NASA Technical Reports Server (NTRS)

    Olbert, S.

    1981-01-01

    Recent measurements, mostly from Helios and Voyager, were reviewed. The observational material was compiled into a series of radial profiles for various macroscopic plasma parameters. Several examples for experimentally determined three-dimensional distribution functions of protons are shown. The physical properties of the solar wind electrons were surveyed. The still unresolved question of the driving mechanism of the solar wind is considered. The problem of the energy balance in pure, high velocity streams emanating from solar coronal holes was outlined. It is suggested that the suprathermal electrons may play an important role in driving the wind. Numerical estimates, referring to the lower corona, are offered in support of this hypothesis.

  4. External control of the Saturn kilometric radiation by the solar wind - Comparison between Voyager 1 and 2 observations

    NASA Astrophysics Data System (ADS)

    Rucker, H. O.; Rabl, G. K. F.; Desch, M. D.

    1989-08-01

    The long-term modulation of Saturn's nonthermal radio emission in the kilometric wavelength range has been studied based upon data obtained by Voyagers 1 and 2. A comparison of the ballistic and hydrodynamic propagation of solar wind features from the spacecraft to Saturn allows the uncertainty inherent in the projection to be determined. The results confirm the previous suggestion that momentum, ram pressure, and kinetic energy flux are the primary solar wind parameters that drive the nonthermal radio emission. It is suggested that, under certain conditions and for limited periods of time, the magnetic properties and time derivatives of the solar wind have increased importance.

  5. Test of the Pioneer anomaly with the Voyager 2 radio-ranging distance measurements to Uranus and Neptune

    E-print Network

    Lorenzo Iorio

    2006-08-29

    In this paper we test the hypothesis that the Pioneer anomaly can be of gravitational origin by comparing the predicted model-independent shifts Delta a/a for the semimajor axis of Uranus and Neptune with the Voyager 2 radio-technical distance measurements performed at JPL-NASA. As in the case of other tests based on different methods and data sets (secular perihelion advance, right ascension/declination residuals over about one century), the orbits of the investigated planets are not affected by any anomalous acceleration like that experienced by the Pioneer 10/11 spacecraft.

  6. Using data from automatic planetary stations for solving problems in astronomy and space physics

    NASA Astrophysics Data System (ADS)

    Stoeva, Penka; Stoev, Alexey; Bojurova, Eva

    The specific nature of the Astronomy and Space Physics problems promote students' interest in the relevant sciences and provoke their creativity. It is illustrated by numerous examples of positive response from the participants in the Astronomy Olympiad to extraordinary moments in problems, especially those related to space flight and scientific data and photographs from satellites and automatic interplanetary stations (AIS). Jupiter's satellite Io is one of the satellites with the highest volcano activity in the solar system. So far, the volcanoes of Io were photographed for a short time only by the interplanetary stations Voyager 1 and Galileo - sent by NASA, and New Horizons of ESA. By monitoring these often erupting volcanoes, however, one can quickly gather detailed information and establish methods for prediction of eruptions, including the Earth's volcanoes. This could push forward research on volcanism in the Solar system. Therefore, this issue was used for creation conditions for problems in astronomy. The report shows how through measurements on images of Io taken with AIS heights of the jets emitted by volcanoes are defined. Knowing the mass and radius of the satellite initial speed of the emitted particles is evaluated. Similarly, the initial rate of discharge of earth volcanoes and ice geysers on Saturn's satellite Enceladus are also evaluated. An attempt is made to explain the rings of ejection around the volcanoes on Io. The ratio of the diameter of the dispersion of the substance to the height of the stream is studied. Actually, maximum speed of the particles is evaluated as the boundaries of the volcanic "fountain" are determined by the fast moving particles reaching maximal height. The observed ratio is compared with the theoretical one derived by the students. The results show that although the volcanoes of Io , Earth's volcanoes and even ice geysers of Enceladus operate under very different conditions and arise from different causes, the initial rate of substance ejection are of the same order. Consequently, at least some of the conclusions of the study of space volcanoes can also apply to terrestrial volcanoes. In conclusion, an idea of studying the volcanoes on Io by two space probes in orbit around it to get stereo images is suggested. A series of interesting scientific tasks to be performed by the probe is suggested.

  7. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, Shimon (El Cerrito, CA); Chemla, Daniel S. (Kensington, CA); Ogletree, D. Frank (El Cerrito, CA); Botkin, David (San Francisco, CA)

    1995-01-01

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  8. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  9. Probing five-dimensional black holes with D-branes

    Microsoft Academic Search

    Michael Douglas; Joseph Polchinski; Andrew Strominger

    1997-01-01

    We consider a one-brane probe in the presence of a five-dimensional black hole in the classical limit. The velocity-dependent force on a slowly-moving probe is characterized by a metric on the probe moduli space. This metric is computed for large black holes using low-energy supergravity, and for small black holes using D-brane gauge theory. The results are compared.

  10. Spacecraft Health Automated Reasoning Prototype (SHARP): The fiscal year 1989 SHARP portability evaluations task for NASA Solar System Exploration Division's Voyager project

    NASA Technical Reports Server (NTRS)

    Atkinson, David J.; Doyle, Richard J.; James, Mark L.; Kaufman, Tim; Martin, R. Gaius

    1990-01-01

    A Spacecraft Health Automated Reasoning Prototype (SHARP) portability study is presented. Some specific progress is described on the portability studies, plans for technology transfer, and potential applications of SHARP and related artificial intelligence technology to telescience operations. The application of SHARP to Voyager telecommunications was a proof-of-capability demonstration of artificial intelligence as applied to the problem of real time monitoring functions in planetary mission operations. An overview of the design and functional description of the SHARP system is also presented as it was applied to Voyager.

  11. A review of "The Third Voyage Journals: Writing and Performance in the London East India Company, 1607-10" by Richmond Barbour

    E-print Network

    Hayworth, Gene

    2012-01-01

    crew of thirty men. #14;e Consent never reunited with the rest of the #12;eet; it returned to England in 1608. #14;e Red Dragon returned to England in 1609, the Hector in 1610. #14;e authors of these journals were committed to providing the details... to be owned by the East India Company, and summarizes an account of the previous two voyages, in 1601 and 1604, which had established a trading compound in Java. #14;e #14;ird Voyage, as Barbour notes, was ?charged to open factories in the Red Sea...

  12. Mapping of Titan's tropopause and surface temperatures from Voyager IRIS spectra

    NASA Astrophysics Data System (ADS)

    Courtin, R.; Kim, S. J.

    2002-03-01

    We have derived temperatures at the tropopause and near the surface of Titan from a set of radiance measurements made by the Voyager IRIS instrument at 300 and 510 cm-1 (33.3 and 19.6 ?m). At 510 cm-1, Titan's atmosphere is relatively transparent and the surface contribution to the measured radiance is approximately 60%. On the other hand, the 300 cm-1 radiance is mostly sensitive to the tropopause temperature, as well as to the degree of methane supersaturation in the upper troposphere. The retrievals are based on a simple inversion scheme of the radiative transfer equation and rely on a model of the atmospheric opacity derived by Courtin et al. (Icarus 114 (1995) 144). Although the longitude-latitude coverage afforded by the IRIS dataset is severely limited, as is also the surface area covered by the IRIS footprints (˜22%), we were able to extract longitudinal and latitudinal profiles of the tropopause and near-surface (brightness) temperatures. We find that the zonal distributions of the tropopause and near-surface temperatures are fairly homogenous. The meridional distribution of the tropopause temperature shows only a slight increase ( ˜1 K) from -60° to 60°. On the other hand, the surface brightness temperature varies significantly and symmetrically from equator to pole (2.5- 3.2 K). Less then one-third of this decrease can potentially be attributed to meridional variations of the stratospheric thermal structure. This confirms earlier results obtained from more limited selections of the IRIS data, both in terms of symmetry and amplitude. The role that could be played by meridional variations of the supersaturated distribution of methane is explored, although no definite answer can be derived in this respect. A significant variation of the bulk temperature gradient between the surface and the tropopause is suggested, the troposphere at high latitudes appearing more stable with respect to moist convection than in the equatorial regions. Finally, a very tentative result concerns an area where the near-surface (brightness) temperature shows a significant differential with respect to the extrapolation of the latitudinal distribution of surface temperatures. Possible interpretations of this differential include: a low emissivity surface feature with 25% contrast, an actual surface cold spot (with a temperature contrast of ˜3 K), a transient tropospheric cloud of optical thickness ?˜1, or an elevated area of height ˜5 km. Further high spatial resolution data, especially those that will be collected by the Cassini orbital mission, will be necessary to discriminate between the various possibilities.

  13. Estimation of Plasma Flow Speeds in the Heliosheath using Voyager-1/LECP

    NASA Astrophysics Data System (ADS)

    Roelof, E. C.; Decker, R. B.

    2005-12-01

    We have developed and validated an improved algorithm for extracting plasma flow (ExB) velocities from the scan-plane anisotropies measured by the Low Energy Charged Particle Experiment (LECP) on Voyager-1. We found that the beam-like anisotropies upstream of the termination shock were usually well fit by a Fourier expansion up to and including the second harmonic. Contrary to a common misconception, the second harmonic is not always a "bi-directional" anisotropy. If it is in phase with (rather than out of phase with) the first harmonic, it produces a unidirectional (or beam) anisotropy that is stronger than a simple sinusoidal function. We therefore assume that the ion anisotropy in the plasma frame is described by a second-degree expansion in Legendre polynomials of the pitch cosine with velocity-dependent coefficients. This distribution is then Lorentz-transformed into the spacecraft frame and convolved with the angular response function for the LECP. The resulting equations that relate the count rates in the eight LECP angular sectors can be solved in a least-squares sense for the spherical harmonic coefficients, a procedure that takes into account that one of the eight LECP sectors is blocked. These coefficients are non-linear functions of the plasma flow velocity (V), the velocity (v) of the ions in a given LECP energy channel, and the direction angles of the magnetic field. However, if we assume that the dependence on (V/v) is quadratic, and we make use of the magnetic field directions provided by the VGR-1 magnetometer team, we can then develop an analytic expression for the flow velocity in terms of the LECP sector rates. This is the method utilized by Krimigis et al. (Science, 2005) in their estimates of the heliosheath plasma flow beyond the heliospheric termination shock. We report here on the validation of this technique using computer simulations of the LECP sector response to a gyrotropic ion distribution advected by the plasma flow. For a specified set of spherical harmonic coefficients in the plasma frame (including their velocity dependence), we calculated the seven LECP sector rates. Then, using these as input "data" to our algorithm, we extracted the flow velocity by the procedure described above. We found that the extracted flow velocity agreed with the input velocity to better than 10% for flow velocities of 200 km/s or less. Since the observed downstream anisotropies were weak (well-described by a two-harmonic expansion), and the heliosheath velocities actually extracted were <200 km/s, we consider that our technique produces valid estimates of the plasma flow (ExB) velocity.

  14. Mapping Io's Surface Topography Using Voyager and Galileo Stereo Images and Photoclinometry

    NASA Astrophysics Data System (ADS)

    White, O. L.; Schenk, P.

    2011-12-01

    O.L. White and P.M. Schenk Lunar and Planetary Institute, 3600 Bay Area Boulevard, Houston, Texas, 77058 No instrumentation specifically designed to measure the topography of a planetary surface has ever been deployed to any of the Galilean satellites. Available methods that exist to perform such a task in the absence of the relevant instrumentation include photoclinometry, shadow length measurement, and stereo imaging. Stereo imaging is generally the most accurate of these methods, but is subject to limitations. Io is a challenging subject for stereo imaging given that much of its surface is comprised of volcanic plains, smooth at the resolution of many of the available global images. Radiation noise in Galileo images can also complicate mapping. Paterae, mountains and a few tall shield volcanoes, the only features of any considerable relief, exist as isolated features within these plains; previous research concerning topography measurement on Io using stereo imaging has focused on these features, and has been localized in its scope [Schenk et al., 2001; Schenk et al., 2004]. With customized ISIS software developed at LPI, it is the ultimate intention of our research to use stereo and photoclinometry processing of Voyager and Galileo images to create a global topographic map of Io that will constrain the shapes of local- and regional-scale features on this volcanic moon, and which will be tied to the global shape model of Thomas et al. [1998]. Applications of these data include investigation of how global heat flow varies across the moon and its relation to mantle convection and tidal heating [Tackley et al., 2001], as well as its correlation with local geology. Initial stereo mapping has focused on the Ra Patera/Euboea Montes/Acala Fluctus area, while initial photoclinometry mapping has focused on several paterae and calderas across Io. The results of both stereo and photoclinometry mapping have indicated that distinct topographic areas may correlate with surface geology. To date we have obtained diameter and depth measurements for ten calderas using these DEMs, and we look forward to studying regional and latitudinal variation in caldera depth. References Schenk, P.M., et al. (2001) J. Geophys. Res., 106, pp. 33,201-33,222. Schenk, P.M., et al. (2004) Icarus, 169, pp. 98-110. Tackley, P.J., et al. (2001) Icarus, 149, pp. 79-93. Thomas, P., et al. (1998) Icarus, 135, pp. 175-180. The authors acknowledge the support of the NASA Outer Planet Research and the Planetary Geology and Geophysics research programs.

  15. SATURN PROBES: Why, Where, How? Sushil K. Atreya

    E-print Network

    Atreya, Sushil

    SATURN PROBES: Why, Where, How? Sushil K. Atreya Department of Atmospheric, Oceanic, and Space results on other key heavy elements, no such possibility currently exists for Saturn. At the same time), as an alternative to deep atmospheric probes for composition measurements at Saturn. This paper builds on, updates

  16. Instrument Technologies for the Detection of Extraterrestrial Interstellar Robotic Probes

    Microsoft Academic Search

    Scot L. Stride

    2001-01-01

    In the continuing endeavor to detect evidence of ETI (Extraterrestrial Intelligence) in the solar neighborhood, instrument technologies now exist that allow the formation of a scientific method to carry out a search for interstellar robotic probes of possible extraterrestrial origin. The range of currently observable probe features\\/manifestations will be shown and how they influence search space, instrument selection and deployment.

  17. The abundance and distribution of water vapor in the Jovian troposphere as inferred from Voyager IRIS observations

    NASA Technical Reports Server (NTRS)

    Carlson, Barbara E.; Lacis, Andrew A.; Rossow, William B.

    1992-01-01

    The Voyager IRIS spectra of the Jovian North Equatorial Belt (NEB) hot spots are reanalyzed using a radiative transfer model which includes the full effects of anisotropic multiple scattering by clouds. The atmospheric model includes the three thermochemically predicted cloud layers, NH3, NH4SH, and H2O. Spectrally dependent cloud extinction is modeled using Mie theory and the refractive indices of NH3 ice, NH4SH ice, water, and H2O ice. The upper tropospheric temperature profile, gas abundances, height-dependent parahydrogen profile, and vertical distribution of NH3 cloud opacity are retrieved from an analysis of the far-infrared (180-1200/cm) IRIS observations. With these properties constrained, the 5-micron (1800-2300/cm) observations are analyzed to determine the atmospheric and cloud structure of the deeper atmosphere (P of greater than 1.5 bars). The results show that the abundance of water is at least 1.5 times solar with 2 times solar (0.00276 mixing ratio relative to H2) providing the best-fit to the Voyager IRIS hot spot observations.

  18. The masses of Uranus and its major satellites from Voyager tracking data and earth-based Uranian satellite data

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.; Campbell, J. K.; Taylor, A. H.; Synnott, S. P.

    1992-01-01

    Improved values for the masses of the Uranian system and the satellites Ariel, Umbriel, Titania, Oberon, and Miranda are obtained on the basis of an analysis of the Doppler-tracking data and star-satellite imaging from the Voyager 2 spacecraft combined with earth-based astrometric satellite observations. Masses are expressed as the product, the universal gravitational constant times the mass of the body, in units of (cu km/sq s). The satellite masses are (4.4 +/- 0.5) for Miranda, (90.3 +/- 8.0) for Ariel, (78.2 +/- 9.0) for Umbriel, (235.3 +/- 6.0) for Titania, and (201.1 +/- 5.0) for Oberon. Quoted errors are standard errors and are the present assessment of the true rather than the formal errors. The Uranus rotational pole orientation angles and gravity harmonic coefficients were fixed at the values determined by French et al. (1988) from stellar occultations of the Uranian rings observed from both the earth and Voyager 2 and from the occultation of the spacecraft radio signal.

  19. Metagenomic sequencing reveals altered metabolic pathways in the oral microbiota of sailors during a long sea voyage

    PubMed Central

    Zheng, Weiwei; Zhang, Ze; Liu, Cuihua; Qiao, Yuanyuan; Zhou, Dianrong; Qu, Jia; An, Huaijie; Xiong, Ming; Zhu, Zhiming; Zhao, Xiaohang

    2015-01-01

    Seafaring is a difficult occupation, and sailors face higher health risks than individuals on land. Commensal microbiota participates in the host immune system and metabolism, reflecting the host's health condition. However, the interaction mechanisms between the microbiota and the host's health condition remain unclear. This study reports the influence of long sea voyages on human health by utilising a metagenomic analysis of variation in the microbiota of the buccal mucosa. Paired samples collected before and after a sea-voyage were analysed. After more than 120 days of ocean sailing, the oral microbial diversity of sailors was reduced by approximately 5 fold, and the levels of several pathogens (e.g., Streptococcus pneumonia) increased. Moreover, 69.46% of the identified microbial sequences were unclassified microbiota. Notably, several metabolic pathways were dramatically decreased, including folate biosynthesis, carbohydrate, lipid and amino acid pathways. Clinical examination of the hosts confirmed the identified metabolic changes, as demonstrated by decreased serum levels of haemoglobin and folic acid, a decreased neutrophil-to-lymphocyte ratio, and increased levels of triglycerides, cholesterol and homocysteine, which are consistent with the observed microbial variation. Our study suggests that oral mucosal bacteria may reflect host health conditions and could provide approaches for improving the health of sailors.

  20. Micron-Sized Dust Particles Detected in the Outer Solar System by the Voyager 1 and 2 Plasma Wave Instruments

    NASA Technical Reports Server (NTRS)

    Gurnett, D. A.; Ansher, J. A.; Kurth, W. S.; Granroth, L. J.

    1997-01-01

    During the Voyager 1 and 2 flybys of the outer planets it has been demonstrated that the plasma wave instrument can detect small dust particles striking the spacecraft. In this paper, we examine the Voyager plasma wave data for dust impacts in the interplanetary medium at heliocentric radial distances ranging from 6 to 60 astronomical units (AU). The results show that a small but persistent level of dust impacts exists out to at least 30 to 50 AU. The average number density of these particles is about 2 x 10(exp -8)/cu m, and the average mass of the impacting particles is believed to be a few times 10(exp -11) g, which corresponds to particle diameters in the micron range. Possible sources of these particles are planets, moons, asteroids, comets, and the interstellar medium. Of these, comets appear to be the most likely source. The number densities are only weakly dependent on ecliptic latitude, which indicates that the particles probably do not originate from planets, moons, or asteroids. Comparisons with interstellar dust fluxes measured in the inner regions of the solar system by the Ulysses spacecraft indicate that the particles are not of interstellar origin.

  1. The Supernova \\/ Acceleration Probe (SNAP) Mission

    Microsoft Academic Search

    C. Akerlof; G. Aldering; W. Althouse; R. Amanullah; P. Astier; E. Barrelet; C. Bebek; L. Bergström; J. Bercovitz; G. Bernstein; M. Bester; R. Blandford; E. Bloom; A. Bonissent; C. Bower; W. Carithers; P. Chen; E. Commins; W. Craig; C. Day; S. Deustua; R. DiGennaro; A. Ealet; R. Ellis; M. Eriksson; A. Fruchter; J. F. Genat; G. Goldhaber; A. Goobar; D. Groom; S. Harris; P. Harvey; H. Heetderks; S. Holland; M. Huffer; D. Huterer; S. Kahn; A. Karcher; A. Kim; W. Kolbe; B. Krieger; R. Lafever; J. Lamoureux; M. Lampton; M. Levi; D. Levin; A. Linde; E. Linder; S. Loken; R. Malina; P. Marshall; R. Massey; T. McKay; S. McKee; R. Miquel; E. Mörtsell; N. Mostek; S. Mufson; J. Musser; P. Nugent; H. Oluseyi; R. Pain; N. Palaio; D. Pankow; S. Perlmutter; R. Pratt; E. Prieto; A. Refregier; J. Rhodes; K. Robinson; N. Roe; M. Schubnell; M. Sholl; G. Smadja; G. Smoot; A. Spadafora; G. Tarlé; A. Tomasch; H. von der Lippe; D. Vincent; G. Wang

    2003-01-01

    The Supernova \\/ Acceleration Probe (SNAP) is a proposed space-based experiment designed to measure the expansion history of the Universe, motivated by the discovery that the expansion is accelerating. It will study both the dark energy and the dark matter, through mapping the distance- redshift relation of Type Ia supernovae and through a wide-area weak gravitational lensing survey. A 2-m

  2. National Aeronautics and Space Administration

    E-print Network

    35812NASAFacts Gravity Probe B Testing Einstein's Universe Albert EinsteinTM HUJ, Represented by The Roger Richman Agency, Inc., http://www.albert-einstein.net NASA's Marshall Space Flight Center and Stanford University have developed a sophisticated experi- ment, Gravity Probe B (GP-B), to test Einstein

  3. The Vision for Space Exploration

    NASA Astrophysics Data System (ADS)

    Griffin, M.

    2005-12-01

    The Vision, announced by President Bush in January 2004, will extend humanity's presence across the solar system, starting with a return to the moon by the end of the next decade, followed by journeys to Mars and beyond. Building on the best of Apollo and shuttle technology, NASA's 21st century exploration system will be affordable, reliable, versatile and safe. The exploratory voyages of the next few decades have the potential, in this lifetime, to answer age-old questions about how life begins, whether life exists elsewhere, and how the inevitable discoveries along the way will help better our lives here on Earth. Over the next century, the Vision for Space Exploration will set in motion activities to improve our understanding of age-old questions, and inspire new generations to pursue math and science. We'll see new industries and technologies evolve and discoveries that will benefit all.

  4. Scanning probe metrology

    NASA Astrophysics Data System (ADS)

    Grigg, David A.; Griffith, Joseph E.; Kochanski, G. P.; Vasile, Michael J.; Russell, Phillip E.

    1992-06-01

    The design of a scanning probe microscope suitable for metrology applications must include solutions to several problems. Actuator errors can be large because of their nonlinear behavior, but this can be solved by independently monitoring the actuator's motion. The probe must be shaped properly for a given measurement, and it must be characterized to allow interpretation of the measurement. We have studied the effects of interaction forces and probe shape with emphasis on surface roughness measurements.

  5. 33 CFR 151.2037 - If my vessel cannot conduct ballast water management practices because of its voyage and/or...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false If my vessel cannot conduct ballast water management practices because of its voyage...be prohibited from discharging ballast water? 151.2037 Section 151.2037...

  6. 33 CFR 151.2037 - If my vessel cannot conduct ballast water management practices because of its voyage and/or...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false If my vessel cannot conduct ballast water management practices because of its voyage...be prohibited from discharging ballast water? 151.2037 Section 151.2037...

  7. 33 CFR 151.2036 - If my voyage does not take me into waters 200 nautical miles or greater from any shore, must I...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false If my voyage does not take me into waters 200 nautical miles or greater from any shore, must I divert to conduct a ballast water exchange? 151.2036 Section...

  8. 33 CFR 151.2036 - If my voyage does not take me into waters 200 nautical miles or greater from any shore, must I...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false If my voyage does not take me into waters 200 nautical miles or greater from any shore, must I divert to conduct a ballast water exchange? 151.2036 Section...

  9. Phoenix Conductivity Probe with Shadow and Toothmark

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander inserted the four needles of its thermal and conductivity probe into Martian soil during the 98th Martian day, or sol, of the mission and left it in place until Sol 99 (Sept. 4, 2008).

    The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99 after the probe was lifted away from the soil. The imprint left by the insertion is visible below the probe, and a shadow showing the probe's four needles is cast on a rock to the left.

    The thermal and conductivity probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The probe is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  10. Determination of the thickness and dielectric constant of a dielectric slab backed by free-space or a conductor through inversion of the reflection coefficient of a rectangular waveguide probe

    Microsoft Academic Search

    Jcssc Lai; D. Hughes; Eric Gallaher; Reza Zoughi

    2004-01-01

    Evaluation of thickness and material properties of coatings and dielectric slabs is an important practical issue. Microwave nondestructive testing techniques, using open-ended rectangular waveguide and coaxial probes have shown great potential for this purpose. However, to evaluate one parameter requires that the other be known a priori. This paper discusses the use of a relatively efficient method for evaluating both

  11. Magnetically driven filament probe

    SciTech Connect

    Schmid, A.; Herrmann, A.; Rohde, V.; Maraschek, M.; Mueller, H. W. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, Boltzmannstr. 2, D-85748 Garching (Germany)

    2007-05-15

    A radially movable probe has been developed for studies of filamentary transport in ASDEX Upgrade during edge localized modes (ELMs) by means of Langmuir tips and magnetic pickup coils. The probe is permanently installed at the low field side in the ASDEX Upgrade vacuum vessel and is not subject to limitations in probe size, as, for example, probes on a shared manipulator are. The probe is moved by a magnetic drive, which allows for easy installation in the vessel, and has moderate machine requirements, as it will only require an electric feedthrough and an external power supply. The drive gives a linear motion with a radial range of 5 cm within 50 ms, where range and velocity can be largely scaled according to experimental requirements. The probe has been installed in the outer midplane of the ASDEX Upgrade vessel, where ELM filaments are expected to have their maximum amplitude. Filaments are coherent substructures within an ELM, carrying a fraction of the ELM released energy towards the wall. The new probe allows to measure the structure of these filaments, in particular, parameters such as filament rotation (by time delay measurements) and size (by peak width analysis). Activating the drive moves the probe from a safe position behind the limiter to a position in front of the limiters, i.e., exposes the Langmuir pins to the scrape-off layer plasma.

  12. Formative Assessment Probes

    ERIC Educational Resources Information Center

    Eberle, Francis; Keeley, Page

    2008-01-01

    Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

  13. Galileo probe battery system

    Microsoft Academic Search

    B. P. Dagarin; R. K. Taenaka; E. J. Stofel

    1996-01-01

    NASA's pair of Galileo spacecraft arrived at Jupiter on 7 December 1995. The Probe descended into the upper Jovian atmosphere, performing its planned sequence of scientific measurements of the properties of that medium for about an hour. This Probe has been the most ambitious planetary entry vehicle to date. It evolved over several years of planning and construction, its launch

  14. Continuous measurement with traveling wave probes

    E-print Network

    Andrew Silberfarb; Ivan H. Deutsch

    2003-08-01

    We consider the use of a traveling wave probe to continuously measure the quantum state of an atom in free space. Unlike the more familiar cavity QED geometry, the traveling wave is intrinsically a multimode problem. Using an appropriate modal decomposition we determine the effective measurement strength for different atom-field interactions and different initial states of the field. These include the interaction of a coherent-state pulse with an atom, the interaction of a Fock-state pulse with an atom, and the use of Faraday rotation of a polarized laser probe to perform a QND measurement on an atomic spin.

  15. Drop Zone! Design and Test a Probe

    NSDL National Science Digital Library

    This is a lesson about spacecraft design. Learners will use the information learned in previous lessons, combined with their own creativity and problem-solving skills, to design and test a parachuting probe that will withstand a fall from a high point, land intact, be able to descend slowly, float in liquid, and cost the least to launch into space. Extensions provide an option if the teacher has limited time, and invite the students to simulate other experiments that will be carried out by the Huygens probe. This is lesson 9 of 12 in the Mission to Saturn Educators Guide, Reading Writing Rings, for grades 3-4.

  16. The microwave opacity of Saturn's rings at wavelengths of 3.6 and 13 cm from Voyager 1 radio occultation

    NASA Technical Reports Server (NTRS)

    Tyler, G. L.; Marouf, E. A.; Simpson, R. A.; Zebker, H. A.; Eshleman, V. R.

    1983-01-01

    Information obtained about Saturn's rings through radio occultation observations with Voyager 1 is discussed. The experimental aspects are addressed, including the positional relationships and relative motions of the spacecraft, rings, and earth, the radio system, observables, microwave opacity, and diffraction. The data characteristics, reduction procedures, calibrations, and corrections are described, and results are presented for the opacity, complex extinction, and diffraction. Ring C is found to exhibit a gently undulating structure of normal opacity, except for several narrow imbedded ringlets. The normalized differential opacity indicates a substantial fraction of centimeter-size particles. In the Cassini division, the opacity appears to be nearly independent of wavelength. Ring A appears to be nearly homogeneous over much of its width, but with considerable thickening near its inner boundary with the Cassini division.

  17. Titan's atmosphere from Voyager infrared observations. III - Vertical contributions of hydrocarbons and nitriles near Titan's north pole

    NASA Astrophysics Data System (ADS)

    Coustenis, A.; Bezard, B.; Gautier, D.; Marten, A.; Samuelson, R.

    1991-01-01

    Voyager 1 IR spectra have been used to infer the Titan north polar region minor stratospheric constituents' temperature structure and vertical distribution. The mixing ratios of the species C4H2, C2H6, C3H4, HCN, HC3N, and C2N2 increase with altitude, implying upper stratosphere (and higher) formation regions. When compared with abundances obtained near the equator, it is found that the HC3N and C2N2 nitriles, together with such hydrocarbons as C2H4, C3H4, and C4H2, are substantially enhanced over the north polar region. A factor-of-2 (minimum) depletion of CO2 relative to the equator is noted; it is judged that current photochemical models are inadequate bases for interpretation of these observations.

  18. Aikane: accounts of Hawaiian same-sex relationships in the journals of Captain Cook's Third Voyage (1776-80).

    PubMed

    Morris, R J

    1990-01-01

    The journals recorded by Captain James Cook and his associates on Cook's Third Voyage of discovery (1776-1780) include extensive eyewitness accounts and analyses of the Hawaiian people and their culture-the first to be made by Europeans and Americans. Among these are several reports of young men called aikane, who were attached to the court or train of the ali'i (chiefs), and whose functions were sexual, social, and political. Among these aikane were several who acted as intermediaries between the sailors and the Hawaiians, and whose influence and conduct profoundly affected the course of events at Kealakekua Bay, where Cook was killed in February, 1779. The information contained in these materials suggests that such Hawaiian same-sex relationships are more important than currently accounted for in accepted theories of Hawaiian ethnohistory. PMID:2230108

  19. Voyager's Eleventh Discovery of a Satellite of Uranus and Photometry and the First Size Measurements of Nine Satellites

    NASA Astrophysics Data System (ADS)

    Karkoschka, Erich

    2001-05-01

    The discovery of S/1986 U 10 is presented including photometry and orbital elements. The new satellite orbits only 1200 km outside Belinda's orbit and very close to the 44:43 eccentric resonance with Belinda. Its radius of about 15 km is much smaller than that expected from the trend seen for the other 15 regular uranian satellites. The 10 uranian satellites previously discovered by Voyager 2 are about 20% brighter than determined previously. One of these satellites, Puck, had a measured size which was slightly revised to 81±2 km. The first size measurements for the other nine satellites yielded sizes 40% larger on average and up to 60% larger than previously estimated. Most of these satellites are nonspherical. Juliet and Belinda may be the most oblong satellites in the Solar System among satellites with measured shapes.

  20. What did we learn about the 3D Global Structure of the Heliosphere with Voyager and IBEX

    NASA Astrophysics Data System (ADS)

    Opher, Merav; Provornikova, Elena; Toth, Gabor; Drake, James; Swisdak, Marc; Izmodenov, Vladislav

    2012-07-01

    In this talk I will review what we have learned in the past couple of years about the global structure of the heliosphere. The recent measurements in-situ by the Voyager spacecrafts, combined with the all-sky images of the heliospheric boundaries by the Interstellar Boundary Explorer (IBEX) mission have transformed radically our knowledge of the boundaries of the heliosphere. Concepts that resisted decades are being revisited due to their puzzling measurements. In this talk, I will cover some of these puzzles and what are learning regarding the dynamic nature of the heliosphere and heliosheath. When uncovering the structure of the heliosheath it is crucial to separate spatial from temporal variations. We were fortunate that the extended solar minima conditions minimized temporal effects in the heliosphere and allowed us to uncover the spatial variations. With the increased solar activity becomes a challenge to incorporate temporal effects. I will review some of the puzzled observations of by Voyager spacecraft in the heliosheath indicating that the presence of the heliospheric current sheet might play a crucial role on organizing the heliosheath; affecting both the flows and transport of energetic particles. I will review as well our attempts to estimate the temporal effects that Corotating Interacting Regions have in the heliosheath. Finally, I will address how knowledge gained from missions such as Ulysses and future out of the ecliptic mission concepts as well as theoretical analysis of physical parameters that may be observed from the solar polar orbit will allow us a better understanding of the global structure of the heliosphere, in particular with its interaction with the interstellar medium.

  1. Carbon nanotube based electromechanical probes

    E-print Network

    Yaglioglu, Onnik, 1976-

    2007-01-01

    Electromechanical probing applications continuously require smaller pitches, faster manufacturing and lower electrical resistance. Conventional techniques, such as MEMS based cantilever probes have their shortcomings in ...

  2. A silicon PET probe

    NASA Astrophysics Data System (ADS)

    Studen, A.; Chesi, E.; Cindro, V.; Clinthorne, N. H.; Cochran, E.; Groši?ar, B.; Honscheid, K.; Kagan, H.; Lacasta, C.; Llosa, G.; Linhart, V.; Mikuž, M.; Stankova, V.; Weilhammer, P.; Žontar, D.

    2011-08-01

    PET scanners with high spatial resolution offer a great potential in improving diagnosis, therapy monitoring and treatment validation for several severe diseases. One way to improve resolution of a PET scanner is to extend a conventional PET ring with a small probe with excellent spatial resolution. The probe is intended to be placed close to the area of interest. The coincidences of interactions within the probe and the external ring provide a subset of data which combined with data from external ring, greatly improve resolution in the area viewed by the probe.Our collaboration is developing a prototype of a PET probe, composed of high-resolution silicon pad detectors. The detectors are 1 mm thick, measuring 40 by 26 mm2, and several such sensors are envisaged to either compensate for low stopping power of silicon or increase the area covered by the probe. The sensors are segmented into 1 mm3 cubic voxels, giving 1040 readout pads per sensor. A module is composed of two sensors placed in a back-to-back configuration, allowing for stacking fraction of up to 70% within a module. The pads are coupled to a set of 16 ASICs (VaTaGP7.1 by IDEAS) per module and read out through a custom designed data acquisition board, allowing for trigger and data interfacing with the external ring.This paper presents an overview of probe requirements and expected performance parameters. It will focus on the characteristics of the silicon modules and their impact on overall probe performance, including spatial resolution, energy resolution and timing resolution. We will show that 1 mm3 voxels will significantly extend the spatial resolution of conventional PET rings, and that broadening of timing resolution related to varying depth of photon interactions can be compensated to match the timing resolution of the external ring. The initial test results of the probe will also be presented.

  3. Focus: DNA probes

    SciTech Connect

    Not Available

    1986-11-01

    Progress in the development of DNA probes for the identification and quantitation of specific genetic sequences in biological samples is reviewed. Current research efforts in the development of DNA probes for the diagnosis of a wide variety of bacterial, viral, and other infectious diseases, such as herpes simplex and cytomegalovirus, and inherited genetic diseases such as cystic fibrosis and sickle cell anemia are discussed. Progress in development of DNA probe assays for cancer diagnosis, detection of Salmonella food poisoning, tissue typing (detection of histocompatibility antigens), mutagen screening, and animal diseases, among other applications is included.

  4. Logic Probe Troubleshooting

    NSDL National Science Digital Library

    Bartelt, Terry L. M.

    This brief interactive activity, by Electromechanical Digital Library and Wisconsin Technical College System faculty member Terry Bartelt, introduces Logic Probe Troubleshooting. The resource begins with an overview, the logic components in an integrated circuit, input/outputs leads to which circuit tracks are connected, how to use a logic probe to determine if proper voltage and signals are present, and a demonstration of how the probe measures circuit operation. There is also a defective integrated circuit example and a troubleshooting problem for students to answer. This is an excellent resource, as are the others in this digital library, for reviewing fundamental concepts for electromechanical devices, systems, and applications.

  5. Chemical sensing flow probe

    DOEpatents

    Laguna, G.R.; Peter, F.J.; Butler, M.A.

    1999-02-16

    A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir. 7 figs.

  6. Chemical sensing flow probe

    DOEpatents

    Laguna, George R. (Albuquerque, NM); Peter, Frank J. (Albuquerque, NM); Butler, Michael A. (Albuquerque, NM)

    1999-01-01

    A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir.

  7. The abundances of constituents of Titan's atmosphere from the GCMS instrument on the Huygens probe.

    PubMed

    Niemann, H B; Atreya, S K; Bauer, S J; Carignan, G R; Demick, J E; Frost, R L; Gautier, D; Haberman, J A; Harpold, D N; Hunten, D M; Israel, G; Lunine, J I; Kasprzak, W T; Owen, T C; Paulkovich, M; Raulin, F; Raaen, E; Way, S H

    2005-12-01

    Saturn's largest moon, Titan, remains an enigma, explored only by remote sensing from Earth, and by the Voyager and Cassini spacecraft. The most puzzling aspects include the origin of the molecular nitrogen and methane in its atmosphere, and the mechanism(s) by which methane is maintained in the face of rapid destruction by photolysis. The Huygens probe, launched from the Cassini spacecraft, has made the first direct observations of the satellite's surface and lower atmosphere. Here we report direct atmospheric measurements from the Gas Chromatograph Mass Spectrometer (GCMS), including altitude profiles of the constituents, isotopic ratios and trace species (including organic compounds). The primary constituents were confirmed to be nitrogen and methane. Noble gases other than argon were not detected. The argon includes primordial 36Ar, and the radiogenic isotope 40Ar, providing an important constraint on the outgassing history of Titan. Trace organic species, including cyanogen and ethane, were found in surface measurements. PMID:16319830

  8. The gridded electromagnet probe

    E-print Network

    Shadman, K. (Khashayar), 1972-

    2003-01-01

    We attempted to measure the anisotropy in the electron distribution function in magnetized plasma by exploiting the adiabatic invariance of the electron's magnetic moment with a probe comprising a grid, a collector, and ...

  9. An Ultrasonographic Periodontal Probe

    NASA Astrophysics Data System (ADS)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  10. Gravity Probe B

    NSDL National Science Digital Library

    This broadcast reports on Gravity Probe B, a satellite designed to test the frame dragging prediction of Einstein's theory of general relativity, where a spinning object such as the Earth will push spacetime in front of it. Gravity Probe B uses gyroscopes which will shift direction while orbiting the Earth (if general relativity is correct). The broadcast contains comments from a scientist who has worked on the Gravity Probe B mission for over 44 years. There is a brief explanation of the difference between the behavior of gravity in Newtonian physics and general relativity. The broadcast also discusses why it took so long to build the satellite (a dozen technologies had to be invented first), the cost involved, and whether the plug would be pulled on the mission; however, Gravity Probe B was finally launched on April 20, 2004. The broadcast is 30 minutes in length.

  11. A vertical microfluidic probe.

    PubMed

    Kaigala, G V; Lovchik, R D; Drechsler, U; Delamarche, E

    2011-05-01

    Performing localized chemical events on surfaces is critical for numerous applications. We earlier invented the microfluidic probe (MFP), which circumvented the need to process samples in closed microchannels by hydrodynamically confining liquids that performed chemistries on surfaces (Juncker et al. Nat. Mater. 2005, 4, 622-628). Here we present a new and versatile probe, the vertical MFP (vMFP), which operates in the scanning mode while overcoming earlier challenges that limited the practical implementation of the MFP technology. The key component of the vMFP is the head, a microfluidic device (?1 cm(2) in area) consisting of glass and Si and having microfluidic features fabricated in-plane in the Si layer. The base configuration of the head has two micrometer-size channels that inject/aspirate liquids and terminate at the apex which is ?1 mm(2). In scanning mode, the head is oriented vertically with the apex parallel to the surface with typical spacing of 1-30 ?m. Such length scales and using flow rates from nanoliters/second to microliters/second allow chemical events to be performed on surfaces with tens of picoliter quantities of reagents. Before scanning, the head is clipped on a holder for leak-free, low dead volume interface assembly, providing a simple world-to-chip interface. Surfaces are scanned by mounting the holder on a computer-controlled stage having ?0.1 ?m resolution in positioning. We present detailed steps to fabricate vMFP heads having channels with dimensions from 1 ?m × 1 ?m to 50 ?m × 50 ?m for liquid localization over areas of 10-10,000 ?m(2). Additionally, advanced design strategies are described to achieve high yield in fabrication and to support a broad range of applications. These include particulate filters, redundant aperture architectures, inclined flow-paths that service apertures, and multiple channels to enable symmetric flow confinement. We also present a method to characterize flow confinement and estimate the distance between the head and the surface by monitoring the evolution of a solution of fluorescently labeled antibody on an activated glass surface. This flow characterization reveals regimes of operation suitable for different surface topographies. We further integrate the dispensing of immersion liquid to the vMFP head for processing surfaces for extended periods of time (?60 min). The versatility of the vMFP is exemplified by patterning fluorescently labeled proteins, inactivation of cells using sodium hypochlorite, and staining living NIH fibroblasts with Cellomics. These applications are enabled by the compact design of the head, which provides easy access to the surface, simplifies alignment, and enables processing surfaces having dimensions from the micrometer to the centimeter scale and with large topographical variations. We therefore believe that ease-of-operation, reconfigurability, and conservative use of chemicals by the vMFP will lead to its widespread use by microtechnologists and the chemical and biomedical communities. PMID:21476506

  12. Inherit Space

    NASA Technical Reports Server (NTRS)

    Giarratano, Joseph C.; Jenks, K. C.

    1997-01-01

    The objective of the proposed research was to begin development of a unique educational tool targeted at educating and inspiring young people 12-16 years old about NASA and the Space Program. Since these young people are the future engineers, scientists and space pioneers, the nurturing of their enthusiasm and interest is of critical importance to the Nation. This summer the basic infrastructure of the tool was developed in the context of an educational game paradigm. The game paradigm has achieved remarkable success in maintaining the interest of young people in a self-paced, student-directed learning environment. This type of environment encourages student exploration and curiosity which are exactly the traits that future space pioneers need to develop to prepare for the unexpected. The Inherit Space Educational Tool is an open-ended learning environment consisting of a finite-state machine classic adventure game paradigm. As the young person explores this world, different obstacles must be overcome. Rewards will be offered such as using the flight simulator to fly around and explore Titan. This simulator was modeled on conventional Earth flight simulators but has been considerably enhanced to add texture mapping of Titan's atmosphere utilizing the latest information from the NASA Galileo Space Probe. Additional scenery was added to provide color VGA graphics of a futuristic research station on Titan as well as an interesting story to keep the youngster's attention. This summer the game infrastructure has been developed as well as the Titan Flight Simulator. A number of other enhancements are planned.

  13. Atomic Resolution Imaging with a sub-50 pm Electron Probe

    SciTech Connect

    Erni, Rolf P.; Rossell, Marta D.; Kisielowski, Christian; Dahmen, Ulrich

    2009-03-02

    Using a highly coherent focused electron probe in a 5th order aberration-corrected transmission electron microscope, we report on resolving a crystal spacing less than 50 pm. Based on the geometrical source size and residual coherent and incoherent axial lens aberrations, an electron probe is calculated, which is theoretically capable of resolving an ideal 47 pm spacing with 29percent contrast. Our experimental data show the 47 pm spacing of a Ge 114 crystal imaged with 11-18percent contrast at a 60-95percent confidence level, providing the first direct evidence for sub 50-pm resolution in ADF STEM imaging.

  14. Dual Active Surface Heat Flux Gage Probe

    NASA Technical Reports Server (NTRS)

    Liebert, Curt H.; Kolodziej, Paul

    1995-01-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  15. Voyager 2 Observations of Helium Abundance Enhancements from 1-60 AU

    E-print Network

    Richardson, John

    in the Mariner 2 solar wind energy-per-charge spectra by assuming that they traveled at the same speed Center for Space Research, Massachusetts Institute of Technology, Cambridge Short title: SOLAR WIND-term variation of HAEs is related to the solar cycle. HAEs occur in all solar wind regimes but occur more

  16. Model for resonant plasma probe.

    SciTech Connect

    Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

    2007-04-01

    This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

  17. The Gravity Probe B Experiment

    NASA Technical Reports Server (NTRS)

    Kolodziejczak, Jeffrey

    2008-01-01

    This presentation briefly describes the Gravity Probe B (GP-B) Experiment which is designed to measure parts of Einstein's general theory of relativity by monitoring gyroscope orientation relative to a distant guide star. To measure the miniscule angles predicted by Einstein's theory, it was necessary to build near-perfect gyroscopes that were approximately 50 million times more precise than the best navigational gyroscopes. A telescope mounted along the central axis of the dewar and spacecraft provided the experiment's pointing reference to a guide star. The telescope's image divide precisely split the star's beam into x-axis and y-axis components whose brightness could be compared. GP-B's 650-gallon dewar, kept the science instrument inside the probe at a cryogenic temperature for 17.3 months and also provided the thruster propellant for precision attitude and translation control. Built around the dewar, the GP-B spacecraft was a total-integrated system, comprising both the space vehicle and payload, dedicated as a single entity to experimentally testing predictions of Einstein's theory.

  18. Cometary Plasma Probed by Rosetta

    NASA Astrophysics Data System (ADS)

    Galand, Marina; Vigren, Erik; Raghuram, Susarla; Schwartz, Steve; Eriksson, Anders; Edberg, Niklas; Lebreton, Jean-Pierre; Henri, Pierre; Burch, Jim; Fuselier, Stephen; Haessig, Myrtha; Mandt, Kathy; Altwegg, Kathrin; Tzou, Chia-You

    2015-04-01

    In Fall 2014, comet 67P/Churyumov-Gerasimenko, the main target of the Rosetta mission, was at 3 AU from the Sun. Its outgassing rate was only of the order of 5×1025 s-1 based on Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA) / Cometary Pressure Sensor (COPS). Despite such a thin coma, a plasma of cometary origin has been detected by Rosetta Plasma Consortium (RPC) sensors and ROSINA/ Double Focusing Mass Spectrometer (DFMS). Close to the comet they have revealed the presence of a cometary ionosphere, with a hot electron population, consistent with the deposition of Extreme UltraViolet (EUV) solar radiation. We will present a comparison between RPC sensors and an energy deposition model in terms of suprathermal electron intensities [RPC/ Ion and Electron Sensor (IES)] and electron temperature and density [RPC/ LAngmuir Probe (LAP) and RPC/ Mutual Impedance Probe (MIP)]. We will also compare ion composition among the main species, between our ionospheric model and ROSINA/DFMS. We will discuss effects of the space environment on the cometary plasma. Finally, we will highlight any evolution in the cometary plasma as the comet is getting closer to perihelion.

  19. Review of Gravity Probe B

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In response to a request by the NASA Administrator, the National Research Council (NRC) has conducted an accelerated scientific review of NASA's Gravity Probe B (GP-B) mission. The review was carried out by the Task Group on Gravity Probe B, under the auspices of the NRC's Space Studies Board and Board on Physics and Astronomy. The specific charge to the task group was to review the GP-B mission with respect to the following terms of reference: (1) scientific importance - including a current assessment of the value of the project in the context of recent progress in gravitational physics and relevant technology; (2) technical feasibility - the technical approach will be evaluated for likelihood of success, both in terms of achievement of flight mission objectives but also in terms of scientific conclusiveness of the various possible outcomes for the measurements to be made; and (3) competitive value - if possible, GP-B science will be assessed qualitatively against the objectives and accomplishments of one or more fundamental physics projects of similar cost (e.g., the Cosmic Background Explorer, COBE).

  20. Identification of when a Langmuir probe is in the sheath of a spacecraft: The effects of secondary electron emission from the probe

    NASA Astrophysics Data System (ADS)

    Wang, X.; Hsu, H.-W.; Horányi, M.

    2015-04-01

    Langmuir probes on spacecraft have been used for characterizing the ambient plasma parameters in space. When their boom is short compared to the Debye length, the probes remain immersed in the spacecraft sheath, causing the current-voltage (I-V) characteristics to deviate from that of a probe far away from the spacecraft. We present identification of when a Langmuir probe is in a sheath, based on the secondary electron (SE) emission from the probe itself. The I-V characteristics of a spherical probe are investigated in a plasma sheath above a conducting plate. Plasmas with cold and hot electrons (1 eV and 10 eV), as well as monoenergetic electrons (50-100 eV), are created. The derivative (dI/dV) of the probe I-V curves shows that in addition to a "knee" at a potential more positive than the plasma potential, an additional knee appears at a sheath potential at the probe location. This additional knee is created due to the SE emission from the probe and is identified as an indication of the probe being immersed in the sheath. Our experimental results reproduced the aspects of the Cassini Langmuir probe I-V characteristics, suggesting that at times, the probe may have been immersed in the sheath of the spacecraft in Saturn's magnetosphere, and SE emission from the probe itself may have significantly altered its I-V characteristics.

  1. Excitation of Low-frequency Waves in the Solar Wind by Newborn Interstellar Pickup Ions H+ and He+ as Seen by Voyager at 4.5 AU

    NASA Astrophysics Data System (ADS)

    Joyce, Colin J.; Smith, Charles W.; Isenberg, Philip A.; Murphy, Neil; Schwadron, Nathan A.

    2010-12-01

    We report the observation of a spectral enhancement in the magnetic field fluctuations measured by the MAG instrument on the Voyager 2 spacecraft during 4.5 hr on DOY 7, 1979 at a heliocentric radial position of 4.5 AU. This time period is contained within a solar wind rarefaction when the large-scale interplanetary magnetic field was nearly radial. The frequency range and polarization of the enhanced fluctuations are consistent with waves generated by newly ionized interstellar H+ and He+. We show sunward propagation of the waves via a cross-helicity analysis. We compare the observation with a theoretical model and find reasonable agreement given the model assumptions. This event is the first indication of pickup ion-generated waves seen at Voyager. It is also the first identification of pickup He+ waves by any spacecraft.

  2. Micron-sized-particle impacts detected near Uranus by the Voyager 2 plasma-wave instrument. Progress report for period ending 1986

    Microsoft Academic Search

    D. A. Gurnett; W. S. Kurth; F. L. Scarf; J. A. Burns; J. N. Cuzzi

    1986-01-01

    During the Voyager 2 flyby of Uranus, the plasma-wave and radio-astronomy instruments detected a region of impulsive noise near the equatorial plane just inside the orbit of Miranda, at a radial distance of 4.51 RU. This noise is believed to be caused by micrometer-sized particles hitting the spacecraft. Analysis of various coupling mechanisms shows that when a dust particle is

  3. Drop Zone! Design and Test a Probe

    NSDL National Science Digital Library

    2012-12-27

    This is a set of four activities about spacecraft design. Learners will use the information learned in previous lessons, combined with their own creativity and problem-solving skills, to design and test a parachuting probe that will withstand a fall from a high point, land intact, be able to descend slowly, float in liquid, and cost the least to launch into space. Includes a glossary, information for families, and guidance for deepening the science. This is lesson 7 of 8 in the Jewel of the Solar System: From Out-of-School to Outer Space an adaptation for afterschool programs of the Cassini-Huygens educational product Reading, Writing, and Rings.

  4. The International Space Station: A National Science Laboratory

    NASA Technical Reports Server (NTRS)

    Giblin, Timothy W.

    2011-01-01

    After more than a decade of assembly missions and on the heels of the final voyage of Space Shuttle Discovery, the International Space Station (ISS) has reached assembly completion. With visiting spacecraft now docking with the ISS on a regular basis, the Station now serves as a National Laboratory to scientists back on Earth. ISS strengthens relationships among NASA, other Federal entities, higher educational institutions, and the private sector in the pursuit of national priorities for the advancement of science, technology, engineering, and mathematics. In this lecture we will explore the various areas of research onboard ISS to promote this advancement: (1) Human Research, (2) Biology & Biotechnology, (3) Physical & Material Sciences, (4) Technology, and (5) Earth & Space Science. The ISS National Laboratory will also open new paths for the exploration and economic development of space.

  5. From micro- to nanoscale scanning four-point probes

    Microsoft Academic Search

    Peter Bøggild; Torben M. Hansen; Oliver Kuhn; Francois Grey

    2000-01-01

    We have developed a scanning four-point measurement technique which enables us to locally probe the conductivity with sub-micron spatial resolution. Inherently, the technique is particularly sensitive to conduction channels close to the surface. Our scanning four-point probes with inter-electrode spacing of 60 mum to 1.5 mum are currently used to investigate the electronic properties of atomically flat Si-terraces in ultra-high

  6. A vector network analyzer integrated into coplanar-waveguide probes

    Microsoft Academic Search

    J. V. Bellantoni; R. C. Compton

    1990-01-01

    A novel type of vector network analyzer integrated with two coplanar-waveguide (CPW) probe tips for making on-wafer measurements is presented. The CPW configuration is capable of large bandwidths and allows measurements to be made directly at the device under test. The analyzer consists of detector diodes spaced logarithmically along two CPW probe tips to sample the signal and uses six-port

  7. Integrated Optical Voltage Probe

    NASA Astrophysics Data System (ADS)

    Cordero-Iannarella, R. F.; Yao, S. K.; Thaniyavarn, S.; Findakly, T.; Hayward, G.; Chen, B.

    1983-11-01

    We have designed and tested a guided wave optical modulator for applications as an integrated optical voltage probe. This voltage probe consists of an injection laser diode (ILD) connected to a stress-induced polarization preserving fiber, an electro-optic coupled-channel waveguide modulator, a graded-index multimode fiber for the return optical signal, and an electronics box containing the necessary electronics for the driving of the ILD source and the detection of the return signal. The electronics box can be physically separated from the ILD source and the fiber-modulator assemblies for ease of installation in the field. The ILD and modulator assemblies are ruggedized and the fibers are cabled. This probe has been tested in the frequency range 10 kHz-200 MHz and at a dynamic range of 40 dB at 200 MHz bandwidth.

  8. Analysis of emissive probe techniques for measurements of plasma potential

    NASA Astrophysics Data System (ADS)

    Ruiz, Daniel Edward; Griswold, Martin; Raitses, Yevgeny

    2011-10-01

    We compare the accuracy of several emissive probe techniques for measurements of the plasma potential, including various inflection point methods, saturated floating potential, and separation point. Uncertainties due to voltage drop across the hot filament wire, space-charge effects, secondary electron emission (SEE) and orbital motion effects are studied both theoretically and experimentally. In particular, it is shown that the probe dc heating can cause a non-uniform electron emission and collection across the filament wire. This can reduce the accuracy of probe measurements. Work supported by the US DOE.

  9. The Harp probe - An in situ Bragg scattering sensor

    NASA Technical Reports Server (NTRS)

    Mollo-Christensen, E.; Huang, N. E.; Long, S. R.; Bliven, L. F.

    1984-01-01

    A wave sensor, consisting of parallel, evenly spaced capacitance wires, whose output is the sum of the water surface deflections at the wires, has been built and tested in a wave tank. The probe output simulates Bragg scattering of electromagnetic waves from a water surface with waves; it can be used to simulate electromagnetic probing of the sea surface by radar. The study establishes that the wave probe, called the 'Harp' for short, will simulate Bragg scattering and that it can also be used to study nonlinear wave processes.

  10. Space Flight Plasma Data Analysis

    NASA Technical Reports Server (NTRS)

    Wright, Kenneth H.; Minow, Joseph I.

    2009-01-01

    This slide presentation reviews a method to analyze the plasma data that is reported on board the International Space station (ISS). The Floating Potential Measurement Unit (FPMU), the role of which is to obtain floating potential and ionosphere plasma measurements for validation of the ISS charging model, assess photo voltaic array variability and interpreting IRI predictions, is composed of four probes: Floating Potential Probe (FPP), Wide-sweep Langmuir Probe (WLP), Narrow-sweep Langmuir Probe (NLP) and the Plasma Impedance Probe (PIP). This gives redundant measurements of each parameter. There are also many 'boxes' that the data must pass through before being captured by the ground station, which leads to telemetry noise. Methods of analysis for the various signals from the different sets are reviewed. There is also a brief discussion of LP analysis of Low Earth Orbit plasma simulation source.

  11. A new approach for estimating Titan's electron conductivity based on data from relaxation probe sensors on the Huygens experiment

    E-print Network

    Groth, Clinton P. T.

    A new approach for estimating Titan's electron conductivity based on data from relaxation probe Available online 29 September 2010 Keywords: Titan Relaxation probe Atmospheric electron conductivity Space instrumentation a b s t r a c t The Huygens Probe measured the electrical conductivity of Titan atmosphere from

  12. Macular Bioaccelerometers on Earth and in Space

    NASA Technical Reports Server (NTRS)

    Ross, M. D.; Cutler, L.; Meyer, G.; Vazin, P.; Lam, T.

    1991-01-01

    Space flight offers the opportunity to study linear bioaccelerometers (vestibular maculas) in the virtual absence of a primary stimulus, gravitational acceleration. Macular research in space is particularly important to NASA because the bioaccelerometers are proving to be weighted neural networks in which information is distributed for parallel processing. Neural networks are plastic and highly adaptive to new environments. Combined morphological-physiological studies of maculas fixed in space and following flight should reveal macular adaptive responses to microgravity, and their time-course. Ground-based research, already begun, using computer-assisted, 3-dimensional reconstruction of macular terminal fields will lead to development of computer models of functioning maculas. This research should continue in conjunction with physiological studies, including work with multichannel electrodes. The results of such a combined effort could usher in a new era in understanding vestibular function on Earth and in space. They can also provide a rational basis for counter-measures to space motion sickness, which may prove troublesome as space voyager encounter new gravitational fields on planets, or must re-adapt to 1 g upon return to earth.

  13. Three-dimensional broadband intensity probe for measuring acoustical parameters

    NASA Astrophysics Data System (ADS)

    Miah, Khalid Hossain

    Measuring different acoustical properties have been the key in reducing noise and improving the sound quality from various sources. In this report, a broadband (200 Hz -- 6.5 kHz) three-dimensional seven-microphone intensity probe system is developed to measure the sound intensity, and total energy density in different acoustical environments. Limitations of most commercial intensity probes in measuring the three-dimensional intensity for a broadband sound field was the main motivation in developing this probe. The finite-difference error and the phase mismatch error which are the two main errors associated with the intensity measurements are addressed in this report. As for the physical design, seven microphones were arranged in a two-concentric arrays with one microphone located at the center of the probe. The outer array is for low-frequencies (200 Hz -- 1.0 kHz), and the inner one is for high-frequencies (1.0 kHz -- 6.5 kHz). The screw adjustable center microphone is used for the microphone calibration, and as the reference microphone of the probe. The simultaneous calibrations of all the microphones in the probe were done in the anechoic room. Theories for the intensity and the energy densities calculations for the probe were derived from the existing four-microphone probe configuration. Reflection and diffraction effects on the intensity measurements due to the presence of the microphones, and the supporting structures were also investigated in this report. Directivity patterns of the calculated intensity showed the omnidirectional nature of the probe. The intensity, and total energy density were calculated and compared with the ideal values in the anechoic room environment. Characterization of sound fields in a reverberant enclosed space, and sound source identification are some applications that were investigated using this probe. Results of different measurements showed effectiveness of the probe as a tool to measure key acoustical properties in many practical environments.

  14. A resistively heated CeB6 emissive probe.

    PubMed

    Martin, M J; Bonde, J; Gekelman, W; Pribyl, P

    2015-05-01

    The plasma potential, Vp, is a key quantity in experimental plasma physics. Its spatial gradients directly yield the electrostatic field present. Emissive probes operating under space-charge limited emission conditions float close to Vp even under time-varying conditions. Throughout their long history in plasma physics, they have mostly been constructed with resistively heated tungsten wire filaments. In high density plasmas (>10(12) cm(-3)), hexaboride emitters are required because tungsten filaments cannot be heated to sufficient emission without component failure. A resistively heated emissive probe with a cerium hexaboride, CeB6, emitter has been developed to work in plasma densities up to 10(13) cm(-3). To show functionality, three spatial profiles of Vp are compared using the emissive probe, a cold floating probe, and a swept probe inside a plasma containing regions with and without current. The swept probe and emissive probe agree well across the profile while the floating cold probe fails in the current carrying region. PMID:26026525

  15. Dual-probe spectroscopic fingerprints of defects in graphene

    NASA Astrophysics Data System (ADS)

    Settnes, Mikkel; Power, Stephen R.; Petersen, Dirch H.; Jauho, Antti-Pekka

    2014-07-01

    Recent advances in experimental techniques emphasize the usefulness of multiple scanning probe techniques when analyzing nanoscale samples. Here, we analyze theoretically dual-probe setups with probe separations in the nanometer range, i.e., in a regime where quantum coherence effects can be observed at low temperatures. In a dual-probe setup the electrons are injected at one probe and collected at the other. The measured conductance reflects the local transport properties on the nanoscale, thereby yielding information complementary to that obtained with a standard one-probe setup (the local density of states). In this work we develop a real-space Green's function method to compute the conductance. This requires an extension of the standard calculation schemes, which typically address a finite sample between the probes. In contrast, the developed method makes no assumption of the sample size (e.g., an extended graphene sheet). Applying this method, we study the transport anisotropies in pristine graphene sheets, and analyze the spectroscopic fingerprints arising from quantum interference around single-site defects, such as vacancies and adatoms. Furthermore, we demonstrate that the dual-probe setup is a useful tool for characterizing the electronic transport properties of extended defects or designed nanostructures. In particular, we show that nanoscale perforations, or antidots, in a graphene sheet display Fano-type resonances with a strong dependence on the edge geometry of the perforation.

  16. Chemistry & Biology Fluorogenic Probe

    E-print Network

    Raines, Ronald T.

    on signal transduction pathways that can mal- function in cancer patients (Hanahan and Weinberg, 2011 options. For example, pancreatic-type ribonucleases (ptRNases) have emerged as putative cancer esterases activate the tri- methyl lock. Using this probe, we found that human breast cancer cells undergo

  17. Endocavity Ultrasound Probe Manipulators.

    PubMed

    Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

    2013-06-01

    We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure. PMID:24795525

  18. Galileo Probe Mass Spectrometer

    NASA Technical Reports Server (NTRS)

    Owen, Tobias C.

    1998-01-01

    During the past year, the Principal Investigator's research carried out under this contract has focused on an analysis of the implications of Galileo Probe Mass Spectrometer (GPMS) results for the origin of Jupiter's atmosphere and the origin of the ice and other possible volatiles on the Galilean satellites.

  19. Data catalog series for space science and applications flight missions. Volume 6: Master index volume

    NASA Technical Reports Server (NTRS)

    Horowitz, Richard; Ross, Patricia A.; King, Joseph H.

    1989-01-01

    The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA, and other U.S. government agencies. This volume contains the Master Index. The following spacecraft are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided.

  20. Phoenix Conductivity Probe Inserted in Martian Soil

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This series of six images from the Robotic Arm Camera on NASA's Phoenix Mars Lander records the first time that the four spikes of the lander's thermal and electrical conductivity probe were inserted into Martian soil.

    The images were taken on July 8, 2008, during the Phoenix mission's 43rd Martian day, or sol, since landing. The insertion visible from the shadows cast on the ground on that sol was a validation test of the procedure. The spikes on the probe are about 1.5 centimeters or half an inch long.

    The science team will use the probe tool to assess how easily heat and electricity move through the soil from one spike to another. Such measurements can provide information about frozen or unfrozen water in the soil. The probe is mounted on the 'knuckle' of Phoenix's Robotic Arm. It has already been used for assessing water vapor in the atmosphere when it is held above the ground.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.