Science.gov

Sample records for voyager space probes

  1. Voyager 1 encounters new region of space

    NASA Astrophysics Data System (ADS)

    Zielinski, Sarah

    2006-10-01

    Voyager 1, which left Earth in 1977 and is now about 10 billion miles away, has entered a region of space with strange anomalies, according to project scientist Ed Stone, former director of the Jet Propulsion Laboratory. The spacecraft has encountered magnetic potholes and bumps-areas where the magnetic field of the heliosheath either nearly vanishes or doubles, respectively. It also has encountered `anomalous cosmic rays' that are less energetic, and thus less dangerous, than galactic cosmic rays. In addition, the solar wind in the heliosheath has been slower than scientists had expected, only about 54,700 kilometers per hour compared with the predicted 322,000-483,000 kilometers per hour. Voyager 1 is expected to reach the edge of the heliosheath in about 10 years.

  2. Voyager.

    ERIC Educational Resources Information Center

    Education Commission of the States, Denver, CO.

    This paper provides an overview of the Voyager Expanded Learning programs. Initially begun with hands-on, activity-based learning experiences centered around academic themes designed to pique children's interest and motivate them to learn, Voyager has expanded from elementary after- and summer-school programs to include K-8 programs designed for…

  3. 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...

  4. Space Probe Launch

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Managed by Marshall Space Flight Center, the Space Tug was a reusable multipurpose space vehicle designed to transport payloads to different orbital inclinations. Utilizing mission-specific combinations of its three primary modules (crew, propulsion, and cargo) and a variety of supplementary kits, the Space Tug was capable of numerous space applications. This 1970 artist's concept depicts the Tug's propulsion module launching a space probe into lunar orbit.

  5. Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time

    NASA Astrophysics Data System (ADS)

    Shapiro Key, Joey; Yunes, Nico; Grimberg, Irene

    2015-01-01

    Einstein's Symphony: A Gravitational Wave Voyage Through Space and Time is a gravitational wave astronomy planetarium show in production by a collaboration of scientists, filmmakers, and artisits from the Center for Gravitational Wave Astonomy (CGWA) at the University of Texas at Brownsville (UTB) and Montana State University (MSU). The project builds on the success of the interdisciplinary Celebrating Einstein collaboration. The artists and scientists who created the A Shout Across Time original film and the Black (W)hole immersive art installation for Celebrating Einstein are teaming with the Museum of the Rockies Taylor Planetarium staff and students to create a new full dome Digistar planetarium show that will be freely and widely distributed to planetaria in the US and abroad. The show uses images and animations filmed and collected for A Shout Across Time and for Black (W)hole as well as new images and animations and a new soundtrack composed and produced by the MSU School of Music to use the full capability of planetarium sound systems. The planetarium show will be narrated with ideas drawn from the Celebrating Einstein danced lecture on gravitational waves that the collaboration produced. The combination of products, resources, and team members assembled for this project allows us to create an original planetarium show for a fraction of the cost of a typical show. In addition, STEM education materials for G6-12 students and teachers will be provided to complement and support the show. This project is supported by the Texas Space Grant Consortium (TSGC), Montana Space Grant Consortium (MSGC), and the American Physical Society (APS).

  6. Future studies of planetary rings by space probes

    NASA Technical Reports Server (NTRS)

    Stone, E. C.

    1984-01-01

    Recent space probe observations of the rings of Jupiter and Saturn have furnished a substantial enhancement of the current understanding of the outer planets' rings. Voyager 2 offers further opportunities for the study of the Neptune and Uranus ring systems. The Galileo mission to Jupiter furnishes the first opportunity for long term space probe studies of a planetary ring system. It is suggested that an appropriately instrumented Saturn orbiter would not only provide a similar opportunity for the study of the Saturn rings, but may also be the only means by which to adequately address the nature of the diverse phenomena displayed by this prototypical planetary ring system.

  7. The navigation of space probes

    NASA Technical Reports Server (NTRS)

    Fliegel, H. F.; Ohandley, D. A.; Zielenbach, J. W.

    1974-01-01

    A new navigational method combining electronic measurement procedures and celestial mechanics makes it possible to conduct a space probe very close to a desired point in the neighborhood of a remote planet. Approaches for the determination of the position of the space probe in space are discussed, giving attention to the effects of errors in the employed data. The application of the navigational methods in a number of space missions is also considered.

  8. 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)

  9. Nick Sagan Reflects on Voyager 1 and the Golden Record

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2013-10-01

    When scientists confirmed on 12 September that NASA's Voyager 1 spacecraft had entered interstellar space (Eos, 94(39), 339, doi:10.1002/2013EO390003), the probe was acknowledged as the first human-made object to travel into that realm. The probe and its twin, Voyager 2, each carry a 12-inch gold-plated copper disk, known as the Golden Record.

  10. PROBING THE NATURE OF THE HELIOSHEATH WITH THE NEUTRAL ATOM SPECTRA MEASURED BY IBEX IN THE VOYAGER 1 DIRECTION

    SciTech Connect

    Opher, M.; Prested, C.; McComas, D. J.; Schwadron, N. A.; Drake, J. F.

    2013-10-20

    We are able to show by comparing modeled energetic neutral atoms (ENAs) spectra to those measured by Interstellar Boundary Explorer (IBEX) that the models along the Voyager 1 (V1) trajectory that best agree with the low energy IBEX data include extra heating due to ram and magnetic energy in the quasi-stagnation region or a kappa ion distribution (with κ = 2.0) in the outer heliosheath. The model explored is the multi-ion, multi-fluid (MI-MF) which treats the pick-up ions and the thermal ion fluids with separate Maxwellian distributions. These effects are included ad hoc in the modeled ENA since they are not present in the model. These results indicate that the low energy spectra of ENAs as measured by IBEX is sensitive to the physical nature of the heliosheath and to effects not traditionally present in current global models. Therefore, by comparing the low energy ENA spectra to models, we can potentially probe the heliosheath in locations beyond those probed by V1 and Voyager 2 (V2)

  11. Voyages Guided by the Skies: Ancient Concepts of Exploring and Domesticating Time and Space across Cultures

    NASA Astrophysics Data System (ADS)

    Rappenglück, Michael A.

    2015-05-01

    Persistence and change are necessary for the stability and development of both the human individual and the human society, since the beginnings of human history. Man needs a static framework which, related to his self-awareness, defines a topocentric system of perception, evaluation, order, and meaning. He also requires a dynamic impetus, which allows exceeding the limits of special world views, shifting of perspectives and transformations of individual as well as social approaches to life. Travelling especially helped to broaden man's horizon and mind. Across cultures voyages guided by the skies are linked with practical concepts of exploring and domesticating time and space, but also figuratively with the life's journey and with other worlds, being expressed by mythic, ritual and later scientific language.

  12. Cryogenic temperature control by means of energy storage materials. [for long space voyages

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Picklesimer, E. A.; Connor, L. E.

    1977-01-01

    An investigation was conducted to study the concept of thermal control by means of physical or chemical reaction heats for applications involving the storage of cryogens during long-term space voyages. The investigation included some preliminary experimental tests of energy storage material (ESM) effectiveness. The materials considered can store and liberate large amounts of thermal energy by means of mechanisms such as sensible heat, heat of fusion, and physical or chemical reaction heat. A differential thermal analysis was utilized in the laboratory tests. Attention is given to the evaluation of cryogenic ESM thermal control concepts, the experimental determination of phase change materials characteristics, and adsorption ESMs. It is found that an ESM shield surrounded by multiple layer insulation provides the best protection for a cryogen store.

  13. Gravity Probe B Space Vehicle

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The space vehicle for Gravity Probe B (GP-B) arrives at the launch site at Vandenburg Air Force Base. GP-B is the relativity experiment being developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. The experiment will measure, very precisely, the expected tiny changes in the direction of the spin axes of four gyroscopes contained in an Earth-orbiting satellite at a 400-mile altitude. So free are the gyroscopes from disturbance that they will provide an almost perfect space-time reference system. They will measure how space and time are very slightly warped by the presence of the Earth, and, more profoundly, how the Earth's rotation very slightly drags space-time around with it. These effects, though small for the Earth, have far-reaching implications for the nature of matter and the structure of the Universe. GP-B is among the most thoroughly researched programs ever undertaken by NASA. This is the story of a scientific quest in which physicists and engineers have collaborated closely over many years. Inspired by their quest, they have invented a whole range of technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by the Marshall Space Flight Center, development of the GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  14. NASA Now: Space Science: Voyager’s Grand Tour of the Solar System

    NASA Video Gallery

    Planetary scientist Lou Mayo discusses what we’re learning from the Voyager missions, where the two spacecraft currently are located, and some of the incredible discoveries made on the long journ...

  15. Deep space network radio science system for Voyager Uranus and Galileo missions

    NASA Technical Reports Server (NTRS)

    Peng, T. K.; Donivan, F. F.

    1986-01-01

    An overview is presented of major new requirements, challenges and conceptual designs for the DSN Radio Science System in the 1985 to 1988 period. The Voyager Uranus encounter is being supported with larger combined aperture, higher sample rate, and a centrally controlled network. The Galileo mission will be provided with a high resolution S-Band Faraday rotation detection capability and a high-stability Doppler system with X-Band uplink for gravitational wave search.

  16. Probing planetary pollution from space

    NASA Technical Reports Server (NTRS)

    Fishman, Jack

    1991-01-01

    The data sets obtained from instruments that have measured carbon monoxide and tropospheric ozone from space are reviewed. These instruments include a gas cell correlation radiometer named MAPS (Measurement of Air Pollution from Satellites), the Total Ozone Mapping Spectrometer, and the Stratospheric Aerosol and Gas Experiment. Particular attention is given to differential absorption lidar technology which can determine the vertical distribution of aerosols and selected trace gases with considerably more resolution than passive remote sensing techniques. The current plans for monitoring pollution from spaceborne platforms are also discussed.

  17. Encounter with Jupiter. [Pioneer 10 space probe

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Pioneer 10 space probe's encounter with the Jupiter is discussed in detail. Tables are presented which include data on the distances during the encounter, times of crossing satellite orbits, important events in the flight near Jupiter, and time of experiments. Educational study projects are also included.

  18. Compression of Space for Low Visibility Probes

    PubMed Central

    Born, Sabine; Krüger, Hannah M.; Zimmermann, Eckart; Cavanagh, Patrick

    2016-01-01

    Stimuli briefly flashed just before a saccade are perceived closer to the saccade target, a phenomenon known as perisaccadic compression of space (Ross et al., 1997). More recently, we have demonstrated that brief probes are attracted towards a visual reference when followed by a mask, even in the absence of saccades (Zimmermann et al., 2014a). Here, we ask whether spatial compression depends on the transient disruptions of the visual input stream caused by either a mask or a saccade. Both of these degrade the probe visibility but we show that low probe visibility alone causes compression in the absence of any disruption. In a first experiment, we varied the regions of the screen covered by a transient mask, including areas where no stimulus was presented and a condition without masking. In all conditions, we adjusted probe contrast to make the probe equally hard to detect. Compression effects were found in all conditions. To obtain compression without a mask, the probe had to be presented at much lower contrasts than with masking. Comparing mislocalizations at different probe detection rates across masking, saccades and low contrast conditions without mask or saccade, Experiment 2 confirmed this observation and showed a strong influence of probe contrast on compression. Finally, in Experiment 3, we found that compression decreased as probe duration increased both for masks and saccades although here we did find some evidence that factors other than simply visibility as we measured it contribute to compression. Our experiments suggest that compression reflects how the visual system localizes weak targets in the context of highly visible stimuli. PMID:27013989

  19. NASA Facts, Voyager.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC. Educational Programs Div.

    This document is one of a series of publications of the National Aeronautics and Space Administration (NASA) on facts about the exploration of Jupiter and Saturn. This NASA mission consists of two unmanned Voyager spacecrafts launched in August and September of 1977, and due to arrive at Jupiter in 1979. An account of the scientific equipment…

  20. Voyager 2 Jupiter encounter

    NASA Technical Reports Server (NTRS)

    1979-01-01

    A NASA News Release is presented which contains the following: (1) general release; (2) two views of Voyager 2 flight past Jupiter; (3) Voyager mission summary; (4) Voyager 1 science results; (5) Jupiter science objectives; (6) Jupiter the planet and its satellites; (7) Voyager experiments; (8) planet comparison; (9) a list of Voyager science investigators and (10) the Voyager team.

  1. 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

  2. Voyager backgrounder

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The Voyager spacecraft and experiments are described. The spacecraft description includes the structure and configuration, communications systems, power supplies, computer command subsystems, and the science platform. The experiments discussed are investigations of cosmic rays, low-energy charged particles, magnetic fields, and plasma waves, along with studies in radio astronomy photopolarimetry. The tracking and data acquisition procedures for the missions are presented.

  3. Galileo Space Probe News Conference. Part 1

    NASA Technical Reports Server (NTRS)

    1996-01-01

    This NASA Kennedy Space Center (KSC) video release presents Part 1 of a press conference regarding the successful entry of the Galileo Space Probe into Jupiter's atmosphere. The press conference panel is comprised of twelve principal investigators and project scientists that oversee the Galileo mission. Among these panelists, William J. O'Neil (Jet Propulsion Lab.) begins the video praising all of the scientists that worked on the orbiter mission. He then presents a visual overview of Galileo's overall mission trajectory and schedule. Marcie Smith (NASA Ames Research Center) then describes the Galileo Probe mission and the overall engineering and data acquisition aspects of the Probe's Jupiter atmospheric entry. Dr. Richard Young (NASA Ames Research Center) follows with a brief scientific overview, describing the measurements of the atmospheric composition as well as the instruments that were used to gather the data. Atmospheric pressure, temperature, density, and radiation levels of Jupiter were among the most important parameters measured. It is explained that these measurements would be helpful in determining among other things, the overall dynamic meteorology of Jupiter. A question and answer period follows the individual presentations. Atmospheric thermal structure, water abundances, wind profiles, radiation, cloud structure, chemical composition, and electricity are among the topics discussed. Parts 2 and 3 of the press conference can be found in document numbers NONP-NASA-VT-2000001074, and NONP-NASA-VT-2000001075.

  4. 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.

  5. NASA Now Minute: Space Science: Voyager’s Grand Tour of the Solar System

    NASA Video Gallery

    Planetary scientist Lou Mayo discusses what we’re learning from theVoyager missions, where the two spacecraft are currently located andsome of the incredible discoveries made on the long journe...

  6. Voyager picture of Jupiter

    NASA Technical Reports Server (NTRS)

    1998-01-01

    NASA's Voyager 1 took this picture of the planet Jupiter on Saturday, Jan. 6, the first in its three-month-long, close-up investigation of the largest planet. The spacecraft, flying toward a March 5 closest approach, was 35.8 million miles (57.6 million kilometers) from Jupiter and 371.7 million miles (598.2 million kilometers) from Earth when the picture was taken. As the Voyager cameras begin their meteorological surveillance of Jupiter, they reveal a dynamic atmosphere with more convective structure than had previously been thought. While the smallest atmospheric features seen in this picture are still as large as 600 miles (1,000 kilometers) across, Voyager will be able to detect individual storm systems as small as 3 miles (5 kilometers) at closest approach. The Great Red Spot can be seen near the limb at the far right. Most of the other features are too small to be seen in terrestrial telescopes. This picture was transmitted to the Jet Propulsion Laboratory through the Deep Space Network's tracking station at Madrid, Spain. The Voyager Project is managed for NASA by Caltech's Jet Propulsion Laboratory.

  7. Thermodynamic considerations in the support of life for long space voyages

    NASA Technical Reports Server (NTRS)

    Iberall, A. S.; Cardon, S. Z.

    1979-01-01

    The essential requirements for the maintenance of life, particularly human life, on isolated space missions of long duration were investigated through the study of extended irreversible thermodynamics. The characterization of a four trophic level system was developed. Questions of stability are discussed.

  8. What do space voyagers value? a thematic analysis of the narratives of spaceflight veterans

    NASA Astrophysics Data System (ADS)

    Suedfeld, Peter

    Values are desired outcomes, differing in importance, that guide people's lives. Considerable anecdotal evidence suggests that astronauts and cosmonauts experience changes in values as a consequence of their experiences in space. Among the most frequently mentioned changes are a greater appreciation of the unity of Earth and humanity, and an increase in self-confidence. Two preliminary studies by the author have confirmed significant changes in values among (a) four Apollo-era American astronauts and (b) ten male astronauts from the Apollo, Mercury, and Gemini programs, three female veterans of the Shuttle-Mir, and two male high-ranking NASA administrators. The current study expanded the database to 104 space veterans from the US, Russia, and other nations, whose narratives (memoirs, media interviews, and oral histories) were subjected to thematic content analysis for references to Schwartz's well-established value categories. Significant pre-flight differences were found related to nationality, space age era (through vs. later than 1975), and longest flight duration. Comparing references from the pre-flight period with those to the time of the mission and then to post-return from space, we found a U-shaped curve for the values of Achievement, Power, and Self-Direction, and steady increases across periods for Enjoyment and Universalism. Compared to multicultural norms, astronauts showed higher values placed on Achievement, Enjoyment (their two primary values), and Power (after the mission only), and lower values on Security, Self-Direction (after the mission), Universalism, and Tradition.

  9. 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.

  10. 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

  11. NASA Facts: Voyager

    NASA Technical Reports Server (NTRS)

    1977-01-01

    A news release on NASA's Voyager project is presented. The spacecraft, science instrumentation, experiments and a mission profile are described. A drawing identifying Voyager's major components and instrumentation was included along with diagrams showing the path of Voyager 1 (JST trajectory) past Jupiter, and the path of Voyager 2 (JXT trajectory) during its encounter with Jupiter. An exercise for student involvement was also provided.

  12. Voyager's decade of wonder

    SciTech Connect

    Mclaughlin, W.I. )

    1989-07-01

    The development and implementation of the Voyager missions are reviewed. The interplanetary missions preceding Voyager are discussed, focusing on the technological development leading up to the Voyager spacecraft. The main results from Voyager observations of Jupiter, Saturn, and Uranus are outlined. Also, consideration is given to the prospects for observations of Neptune.

  13. 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.

  14. The Voyager Interstellar Mission.

    PubMed

    Rudd, R P; Hall, J C; Spradlin, G L

    1997-01-01

    The Voyager Interstellar Mission began on January 1, 1990, with the primary objective being to characterize the interplanetary medium beyond Neptune and to search for the transition region between the interplanetary medium and the interstellar medium. At the start of this mission, the two Voyager spacecraft had already been in flight for over twelve years, having successfully returned a wealth of scientific information about the planetary systems of Jupiter, Saturn, Uranus, and Neptune, and the interplanetary medium between Earth and Neptune. The two spacecraft have the potential to continue returning science data until around the year 2020. With this extended operating lifetime, there is a high likelihood of one of the two spacecraft penetrating the termination shock and possibly the heliopause boundary, and entering interstellar space before that time. This paper describes the Voyager Interstellar Mission--the mission objectives, the spacecraft and science payload, the mission operations system used to support operations, and the mission operations strategy being used to maximize science data return even in the event of certain potential spacecraft subsystem failures. The implementation of automated analysis tools to offset and enable reduced flight team staffing levels is also discussed. PMID:11540770

  15. Huygens space probe ready to leave Europe

    NASA Astrophysics Data System (ADS)

    1997-03-01

    Over the past year, the Huygens probe has been integrated and extensively tested at the facilities of Daimler Benz Aerospace Dornier Satellitensysteme in Ottobrunn near Munich. It was designed and developed for ESA by a European industrial consortium led by Aerospatiale (F) as prime contractor. The European activities have been successfully completed and this is to be formalised by the Flight Acceptance Review which will release the probe for shipment to the USA. To mark this important milestone a press briefing is scheduled for Wednesday, 26 March at 10.00 hours at Daimler-Benz Aerospace Dornier Satellitensysteme in Ottobrunn. The detailed programme of the press briefing is attached. If you wish to attend the press briefing, please complete the attached accreditation form and return it, preferably by fax, to : Daimler Benz Aerospace Dornier Satellitensysteme Mr. Mathias Pikelj, Fax. + 49 7545 8 5589, Tel. + 49 7545 8 9123 NOTE FOR THE EDITORS: Background facts about the Cassini Huygens mission Huygens is a medium-sized mission of ESA's Horizons 2000 programme for space science, and a contribution to the joint NASA ESA Cassini mission. Christiaan Huygens discovered Saturn s moon Titan in 1655, and the mission named after him aims to land a 343 kilogram probe on Titan carrying a package of scientific instruments through the atmosphere. Six sets of instruments will analyse the chemical composition of the atmosphere, observe the weather and topography of Titan, and examine the nature of its surface. Titan is larger than the planet Mercury, and its unique atmosphere, rich in nitrogen and hydrocarbons, may resemble the atmosphere of the primitive Earth, before life began. Nominal dates for the Huygens mission are as follows: * launch, 6 October 1997 * arrival at Saturn, 1 July 2004 * release of Huygens, 6 November 2004 * entry into Titan's atmosphere, 27 November 2004. The Saturn Orbiter, the other element in the Cassini mission, will relay the signals from Huygens to

  16. "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…

  17. Voyager - Humanity's Farthest Journey

    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...

  18. Voyager - 35 Years Later

    NASA Video Gallery

    This video drops in on mission control for NASA's Voyager spacecraft asVoyager 1 sends back data from the far reaches of our solar system.Credit: NASA/JPL-Caltech    › Voyager's mission site

  19. 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.

  20. Space-charge limits of ion sensitive probes

    NASA Astrophysics Data System (ADS)

    Brunner, D.; LaBombard, B.; Ochoukov, R.; Sullivan, R.; Whyte, D.

    2013-12-01

    Ion sensitive probes (ISPs) are used to measure ion temperature and plasma potential in magnetized plasmas. Their operation relies on the difference in electron and ion Larmor radii to preferentially collect the ion species on a recessed electrode. Because of their simple two-electrode construction and optimal geometry for heat flux handling they are an attractive probe to use in the high heat flux boundary of magnetic confinement fusion experiments. However, the integrity of its measurements is rarely, if ever, checked under such conditions. Recent measurements with an ISP in the Alcator C-Mod tokamak have shown that its ion current is space-charge limited and thus its current-voltage (I-V) response does not contain information on the ion temperature. We numerically solve a 1D Vlasov-Poisson model of ion collection to determine how much bias is needed to overcome space-charge effects and regain the classic I-V characteristic with an exponential decay. Prompted by the observations of space charge in C-Mod, we have performed a survey of ISP measurements reported in the literature. Evidence of space-charge limited current collection is found on many probes, with few authors noting its presence. Some probes are able to apparently exceed the classic 1D space-charge limit because electrons can E × B drift into the probe volume, partially reducing the net ion charge; it is argued that this does not, however, change the basic problem that space charge compromises the measurement of ion temperature. Guidance is given for design of ISPs to minimize the effects of space charge.

  1. 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.

  2. Voyager-Jupiter radio science data papers

    NASA Technical Reports Server (NTRS)

    Levy, G. S.; Wood, G. E.

    1980-01-01

    The reduction and interpretation of the radio science data from the Voyager 1 and 2 encounters of the planet Jupiter and its satellites resulted in the preparation of several papers for publication in the special Voyager-Jupiter issue of the Journal of Geophysical Research. The radio science and tracking systems of the Deep Space Network provide the data which makes this research possible. This article lists submitted papers by title, with their authors and with abstracts of their contents.

  3. Voyage of Discovery

    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...

  4. 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.

  5. The Evolving Space Weather System—Van Allen Probes Contribution

    NASA Astrophysics Data System (ADS)

    Zanetti, L. J.; Mauk, B. H.; Fox, N. J.; Barnes, R. J.; Weiss, M.; Sotirelis, T. S.; Raouafi, N.-E.; Kessel, R. L.; Becker, H. N.

    2014-10-01

    The overarching goal and purpose of the study of space weather is clear—to understand and address the issues caused by solar disturbances on humans and technological systems. Space weather has evolved in the past few decades from a collection of concerned agencies and researchers to a critical function of the National Weather Service of NOAA. The general effects have also evolved from the well-known telegraph disruptions of the mid-1800s to modern day disturbances of the electric power grid, communications and navigation, human spaceflight and spacecraft systems. The last two items in this list, and specifically the effects of penetrating radiation, were the impetus for the space weather broadcast implemented on NASA's Van Allen Probes' twin pair of satellites, launched in August of 2012 and orbiting directly through Earth's severe radiation belts. The Van Allen Probes mission, formerly the Radiation Belt Storm Probes (RBSP), was renamed soon after launch to honor the discoverer of Earth's radiation belts at the beginning of the space age, the late James Van Allen (the spacecraft themselves are still referred to as RBSP-A and RBSP-B). The Van Allen Probes are one part of NASA's Living With a Star program formulated to advance the scientific understanding of the connection between solar disturbances, the resulting heliospheric conditions, and their effects on the geospace and Earth environment.

  6. Mission to Jupiter. [Pioneer 10 and 11 space probes

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The Pioneer 10 and Pioneer 11 space probes and their missions to Jupiter are discussed along with the experiments and investigations which will be conducted onboard. Jupiter's atmosphere, its magnetic fields, radiation belts, the spacecraft instruments, and the Jovian system will be investigated. Educational study projects are also included.

  7. Features of the Gravity Probe B Space Vehicle

    NASA Astrophysics Data System (ADS)

    Reeve, William; Green, Gaylord

    2007-04-01

    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 autonomous operations and safemode protection. Features of the Gravity Probe B Space Vehicle mechanisms include: 1) sixteen helium micro-thrusters, the first proportional thrusters flown in space, and large-orifice thruster isolation valves, 2) seven precision and high-authority mass trim mechanisms, 3) four non-pyrotechnic, highly reliable solar array deployment and release mechanism sets. Early incremental prototyping was used extensively to reduce spacecraft development risk. All spacecraft systems were redundant and provided multiple failure tolerance in critical systems. Lockheed Martin performed the spacecraft design, systems engineering, hardware and software integration, environmental testing and launch base operations, as well as on-orbit operations support for the Gravity Probe B space science experiment.

  8. 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.

  9. Voyage to Jupiter.

    ERIC Educational Resources Information Center

    Morrison, David; Samz, Jane

    This publication illustrates the features of Jupiter and its family of satellites pictured by the Pioneer and the Voyager missions. Chapters included are: (1) "The Jovian System" (describing the history of astronomy); (2) "Pioneers to Jupiter" (outlining the Pioneer Mission); (3) "The Voyager Mission"; (4) "Science and Scientsts" (listing 11…

  10. The Voyager flights to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The results of the mini-Grand Tour to Jupiter and Saturn by the Voyager 1 and 2 spacecraft are highlighted. Features of the spacecraft are depicted including the 11 instruments designed to probe the planets and their magnetic environments, the rings of Saturn, the fleets of satellites escorting the planets, and the interplanetary medium. Major scientific discoveries relating to these phenomena are summarized.

  11. Voyager at Neptune: 1989

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The Voyager mission has taken advantage of a rare planetary alignment that occurs at intervals of about 175 years and affords an extraordinary opportunity: a grand tour by a single spacecraft of the outer planets Jupiter, Saturn, Uranus, and Neptune. Voyager 2 will fly past Nepture and its large moon Triton on August 24, 1989. The discovery of Neptune, along with its current history is discussed. The imaging challenges, tracking and data acquisition, and the Voyager spacecraft are explained. Data will be gathered on the ring arcs of Neptune, the atmosphere and surface of Neptune, Triton, and Nereid (the smaller moon).

  12. 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.

  13. Voyager 1 Image of Ganymede

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Voyager 1 took this picture of Ganymede from a distance of 1.6 million miles. Ganymede is Jupiter's largest satellite with a radius of approximately 2600 kilometers, about 1.5 times that of Earth's Moon. Ganymede is the seventh and largest of Jupiter's known satellites and is the third of the Galilean moons. Discovered in 1610 by Galileo and Marius, Ganymede is the largest satellite in the Solar System. It was named after the Greek mythical character, Ganymede, a handsome Trojan boy that Zeus took to Olympus to be a cupbearer for the gods (one of the only humans in Greek mythology who became immortal). Ganymede is larger than Mercury but has only half Mercury's mass. It has a bulk density of only two grams per cubic centimeter, almost half that of Earth's Moon. Ganymede is most likely composed of a mixture of rock and ice. The long white filaments resemble rays associated with impacts on the lunar surface. The various colors of different regions probably represent differing surface materials. Several dots of a single color (blue, green, and orange) on the picture are the result of markings on the camera used for pointing determinations and are not physical markings. Voyager scientists discovered that Ganymede has its own magnetosphere embedded inside Jupiter's large one. JPL manages and controls the Voyager Project for NASA's Office of Space Science.

  14. Voyager 1 View of Callisto

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Voyager 1 took this picture of Callisto during Voyager's approach to Jupiter's outer large satellite in 1979. Both Galileo and Marius discovered Callisto in 1610. In Greek mythology, Callisto was a nymph loved by Zeus and thus hated by Hera. Hera turned her into a bear, which Zeus placed in the heavens as the constellation Ursa Major. Voyager was 350,000 kilometers from Callisto and took this picture that shows features about seven kilometers wide across the surface. Callisto is a little smaller than Ganymede (Callisto is about the size of Mercury) and it seems that it is composed of a mixture of ice and rock (about 40 percent ice and 60 percent rock and iron). The darker color of Callisto (about half as reflective as Ganymede but still twice as bright as the Moon) implies that the upper surface is 'dirty ice' or water- rich rock frozen on Callisto's cold surface (approximately -243 Fahrenheit degrees at the equator). Callisto's atmosphere is mostly carbon dioxide. Far more craters appear on the surface of Callisto than on the surface of Ganymede, leading scientists to believe that Callisto is the oldest of the Galilean satellites. Callisto could date back as far as four billion years ago and has remained relatively unchanged in the history of space.

  15. Pu-powered space probes face uncertain future

    SciTech Connect

    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.

  16. Voyage to Uranus

    NASA Technical Reports Server (NTRS)

    Dalrymple, M.

    1985-01-01

    Preparations being made for the Voyager 2's encounter with the seventh planet, Uranus are discussed. Research activities involved with the methane in Uranus' atmosphere and its absorption of photons of sunlight are discussed.

  17. The Voyager magnetometer boom

    NASA Technical Reports Server (NTRS)

    Miller, D. C.

    1979-01-01

    The Voyager spacecraft magnetometer experiment utilizes two sensors on a deployable boom. The boom is an Astromast. The implementation of the Astromast into the Voyager design is described along with the hardware used to hold, latch, and deploy the mast and the tests to demonstrate damping, deployment, and alignments. Several problems encountered are discussed and their solutions are given. Flight deployment and preliminary alignment results are presented. Finally, the design is evaluated in retrospect.

  18. Voyages to Saturn

    NASA Technical Reports Server (NTRS)

    Morrison, D.

    1982-01-01

    The Voyager mission to Saturn is explained in detail. A history of Saturn observations from ancient times to the present is given. The Voyager spacecraft and their instruments are described. An overview of planetary astronomy is presented. The text is supplemented by numerous black and white and color photographs. The Saturn satellites are discussed in detail, and preliminary pictorial maps of the satellites are given.

  19. 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.

  20. Future exploration of the asteroids. [by space probes

    NASA Technical Reports Server (NTRS)

    Morrison, D.; Niehoff, J.

    1979-01-01

    Future possibilities for the further study of the asteroids are reviewed, with particular attention paid to space missions for their direct exploration. The role of traditional ground-based and earth orbiting techniques is examined briefly, and it is concluded that although astronomical techniques are presently at their peak, and despite the opportunities provided by the Infrared Astronomical satellite, the Space Telescope and Spacelab Infrared Telescope Facility, the next major step will require direct exploration by space probes to obtain information on asteroid surface chemistry, geology and bulk properties. Various mission modes and propulsion systems for a first multi-target asteroid mission are discussed, including flyby, rendezvous, landing and sample return, and ion-drive propulsion systems. Science payloads for a basic rendezvous mission are considered, and target selection for multi-asteroid flyby tours and rendezvous tours is discussed. Consideration is also given to sample return missions for the evaluation of the asteroid as potential resources.

  1. Deep Space Network Capabilities for Receiving Weak Probe Signals

    NASA Technical Reports Server (NTRS)

    Asmar, Sami; Johnston, Doug; Preston, Robert

    2005-01-01

    Planetary probes can encounter mission scenarios where communication is not favorable during critical maneuvers or emergencies. Launch, initial acquisition, landing, trajectory corrections, safing. Communication challenges due to sub-optimum antenna pointing or transmitted power, amplitude/frequency dynamics, etc. Prevent lock-up on signal and extraction of telemetry. Examples: loss of Mars Observer, nutation of Ulysses, Galileo antenna, Mars Pathfinder and Mars Exploration Rovers Entry, Descent, and Landing, and the Cassini Saturn Orbit Insertion. A Deep Space Network capability to handle such cases has been used successfully to receive signals to characterize the scenario. This paper will describe the capability and highlight the cases of the critical communications for the Mars rovers and Saturn Orbit Insertion and preparation radio tracking of the Huygens probe at (non-DSN) radio telescopes.

  2. Welded Titanium Case for Space-Probe Rocket Motor

    NASA Technical Reports Server (NTRS)

    Brothers, A. J.; Boundy, R. A.; Martens, H. E.; Jaffe, L. D.

    1959-01-01

    The high strength-to-weight ratio of titanium alloys suggests their use for solid-propellant rocket-motor cases for high-performance orbiting or space-probe vehicles. The paper describes the fabrication of a 6-in.-diam., 0.025-in.-wall rocket-motor from the 6A1-4V titanium alloy. The rocket-motor case, used in the fourth stage of a successful JPL-NASA lunar-probe flight, was constructed using a design previously proven satisfactory for Type 410 stainless steel. The nature and scope of the problems peculiar to the use of the titanium alloy, which effected an average weight saving of 34%, are described.

  3. Space Science Education by Mathematica Demonstrations: Interactive Design of Moving Space Probe Elements Mechanics by Foldable and Extendable Structures for Space Applications

    NASA Astrophysics Data System (ADS)

    Kabai, S.; Bérczi, Sz.

    2010-03-01

    By the interactive Mathematica Demonstrations of the Wolfram Research several mechanics for space probe operation and motion simulations were studied as space robotics and science educational program.

  4. Role of space charge in scanned probe oxidation

    NASA Astrophysics Data System (ADS)

    Dagata, J. A.; Inoue, T.; Itoh, J.; Matsumoto, K.; Yokoyama, H.

    1998-12-01

    The growth rate and electrical character of nanostructures produced by scanned probe oxidation are investigated by integrating an in situ electrical force characterization technique, scanning Maxwell-stress microscopy, into the fabrication process. Simultaneous topographical, capacitance, and surface potential data are obtained for oxide features patterned on n- and p-type silicon and titanium thin-film substrates. The electric field established by an applied voltage pulse between the probe tip and substrate depends upon reactant and product ion concentrations associated with the water meniscus at the tip-substrate junction and within the growing oxide film. Space-charge effects are consistent with the rapid decline of high initial growth rates, account for observed doping and voltage-pulse dependencies, and provide a basis for understanding local density variations within oxide features. An obvious method for avoiding the buildup of space charge is to employ voltage modulation and other dynamic pulse-shaping techniques during the oxidation pulse. Voltage modulation leads to a significant enhancement of the growth rate and to improvements in the aspect ratio compared with static voltage pulses.

  5. IEC Thrusters for Space Probe Applications and Propulsion

    NASA Astrophysics Data System (ADS)

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

    2009-03-01

    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 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.

  6. IEC Thrusters for Space Probe Applications and Propulsion

    SciTech Connect

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

    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.

  7. Voyager 1 May Have Crossed Termination Shock

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    NASA's intrepid Voyager 1, launched in 1977, may have recently become the first spacecraft to at least temporarily cross the termination shock of the solar system and enter into the heliosheath. Or maybe not. Different teams of scientists recently published conflicting papers about whether the spacecraft has entered this realm. Either way, the scientists agree that Voyager 1 is crossing through unexplored territory and likely will become the first human'made object to cross the termination shock and enter the heliosheath on its way toward the heliopause and interstellar space.

  8. 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.

  9. Voyager 2 Observes Energetic Electrons

    NASA Video Gallery

    This animation shows the Voyager 2 observations of energetic electrons. Voyager 2 detected a dramatic drop of the flux of electrons as it left the sector region. The intense flux came back as soon ...

  10. Probing Asteroid Families for Evidence of Ultraviolet Space Weathering Effects

    NASA Astrophysics Data System (ADS)

    Vilas, Faith

    2005-07-01

    We propose six HST orbits to obtain UV reflectance spectra covering 200-460 nm of two Vesta asteroid family members, asteroid 832 Karin, and two Karin family members. These observations extend work done under a Cycle 13 AR grant, where we analyzed all of the existing IUE and HST S-class asteroids in the MAST database to investigate the effects of space weathering at UV wavelengths. Our hypothesis is that the manifestation of space weathering at UV wavelengths is a spectral bluing, in contrast with a spectral reddening at visible-NIR wavelengths, and that UV wavelengths can be more sensitive to relatively small amounts of weathering than longer wavelengths. The proposed observations will address two objectives: {1} Measure the UV-visible spectra of 832 Karin and two members of the young Karin family {absolute age of 5.8 My}, in order to determine whether intermediate space weathering is observable in objects likely pristine when they originated from the interior of Karin's pa rent body. {2} Measure the UV-visible spectra of two members of the Vesta family to compare with our analysis of IUE Vesta spectra. These observations will probe Vesta's interior, and test our hypothesis by contrasting the apparent amount of alteration on the surfaces of Vestoids with excavated material on Vesta.

  11. Two Voyagers to Saturn

    NASA Astrophysics Data System (ADS)

    1981-08-01

    The pages which follow may be taken as a celebration of the impending encounter of Voyager 2 with Saturn and are a pointer to the richness of data likely to be gathered in the next few days and weeks. Although there may be some to whom the work of these two remarkable spacecraft will be proof of how even more remarkable would have been the Grand Tour of the Solar System planned in the 1960s but executed only in the form of the two Voyagers, to most people the encounters with Jupiter and Saturn will seem exciting enough for the time being. Yet there are Uranus and Neptune to come. This group of scientific articles includes some of the first detailed attempts to make sense of last year's Voyager 1 observations of Saturn-and Nature acknowledges its debt to Dr G. E. Hunt of University College, London for having helped to recruit these articles and to give shape to the ground they cover. The scope is necessarily restricted, for there is hardly a branch of planetary astronomy which has not been changed in some way by the data from Voyager 1-and which is not about to be changed again.

  12. Voyager Outreach Compilation

    NASA Technical Reports Server (NTRS)

    1998-01-01

    This NASA JPL (Jet Propulsion Laboratory) video presents a collection of the best videos that have been published of the Voyager mission. Computer animation/simulations comprise the largest portion of the video and include outer planetary magnetic fields, outer planetary lunar surfaces, and the Voyager spacecraft trajectory. Voyager visited the four outer planets: Jupiter, Saturn, Uranus, and Neptune. The video contains some live shots of Jupiter (actual), the Earth's moon (from orbit), Saturn (actual), Neptune (actual) and Uranus (actual), but is mainly comprised of computer animations of these planets and their moons. Some of the individual short videos that are compiled are entitled: The Solar System; Voyage to the Outer Planets; A Tour of the Solar System; and the Neptune Encounter. Computerized simulations of Viewing Neptune from Triton, Diving over Neptune to Meet Triton, and Catching Triton in its Retrograde Orbit are included. Several animations of Neptune's atmosphere, rotation and weather features as well as significant discussion of the planet's natural satellites are also presented.

  13. Electric Field Double Probe Measurements for Ionospheric Space Plasma Experiments

    NASA Technical Reports Server (NTRS)

    Pfaff, R.

    1999-01-01

    Double probes represent a well-proven technique for gathering high quality DC and AC electric field measurements in a variety of space plasma regimes including the magnetosphere, ionosphere, and mesosphere. Such experiments have been successfully flown on a variety of spacecraft including sounding rockets and satellites. Typical instrument designs involve a series of trades, depending on the science objectives, type of platform (e.g., spinning or 3-axis stabilized), expected plasma regime where the measurements will be made, available telemetry, budget, etc. In general, ionospheric DC electric field instruments that achieve accuracies of 0.1 mV/m or better, place spherical sensors at large distances (10m or more) from the spacecraft body in order to extend well beyond the spacecraft wake and sheath and to achieve large signal-to-noise ratios for DC and long wavelength measurements. Additional sets of sensors inboard of the primary, outermost sensors provide useful additional information, both for diagnostics of the plasma contact potentials, which particularly enhance the DC electric field measurements on non-spinning spacecraft, and for wavelength and phase velocity measurements that use the spaced receiver or "interferometer" technique. Accurate attitude knowledge enables B times V contributions to be subtracted from the measured potentials, and permits the measured components to be rotated into meaningful geophysical reference frames. We review the measurement technique for both DC and wave electric field measurements in the ionosphere discussing recent advances involving high resolution burst memories, multiple baseline double probes, new sensor surface materials, biasing techniques, and other considerations.

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

    SciTech Connect

    Murthy, Jayant; Henry, Richard Conn; Holberg, Jay B.

    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.

  15. Triton - Voyager's finale

    NASA Technical Reports Server (NTRS)

    Brown, R. H.

    1992-01-01

    The investigation of the Neptunian satellite Triton by the Voyager 2 is described with interpretations of the object's nature and composition. The orbit, seasonal cycle, and southern-hemisphere solstice are described, and the composition of the satellite is discussed. Triton's mass and radius are known, and the objects is made up of about 70 percent rock and organics and 30 percent ice by mass. Triton's interior is warm and geologically active considering its distance from the sun, and large amounts of frozen methane and nitrogen are theorized to contribute to the object's high reflectivity. Also noted in the Voyager color images are creeping ice, cryogenic lava, and dark streaks on the south polar cap from nitrogen gas leaks driven by a type of greenhouse effect. Triton represents a class of satellite that has not been observed previously: a moon-sized body in a retrograde inclined orbit from the class of objects that coalesced to form Neptune.

  16. Voyager 1 'Blue Movie'

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This is the original Voyager 'Blue Movie' (so named because it was built from Blue filter images). It records the approach of Voyager 1 during a period of over 60 Jupiter days. Notice the difference in speed and direction of the various zones of the atmosphere. The interaction of the atmospheric clouds and storms shows how dynamic the Jovian atmosphere is.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 66 images taken once every Jupiter rotation period (about 10 hours). This time-lapse movie uses images taken every time Jupiter longitude 68W passed under the spacecraft. These images were acquired in the Blue filter from Jan. 6 to Feb. 3 1979. The spacecraft flew from 58 million kilometers to 31 million kilometers from Jupiter during that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  17. Aspects of Voyager photogrammetry

    NASA Technical Reports Server (NTRS)

    Wu, Sherman S. C.; Schafer, Francis J.; Jordan, Raymond; Howington, Annie-Elpis

    1987-01-01

    In January 1986, Voyager 2 took a series of pictures of Uranus and its satellites with the Imaging Science System (ISS) on board the spacecraft. Based on six stereo images from the ISS narrow-angle camera, a topographic map was compiled of the Southern Hemisphere of Miranda, one of Uranus' moons. Assuming a spherical figure, a 20-km surface relief is shown on the map. With three additional images from the ISS wide-angle camera, a control network of Miranda's Southern Hemisphere was established by analytical photogrammetry, producing 88 ground points for the control of multiple-model compilation on the AS-11AM analytical stereoplotter. Digital terrain data from the topographic map of Miranda have also been produced. By combining these data and the image data from the Voyager 2 mission, perspective views or even a movie of the mapped area can be made. The application of these newly developed techniques to Voyager 1 imagery, which includes a few overlapping pictures of Io and Ganymede, permits the compilation of contour maps or topographic profiles of these bodies on the analytical stereoplotters.

  18. Floating Potential Probe Deployed on the International Space Station

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.

    2001-01-01

    In the spring and summer of 2000, at the request of the International Space Station (ISS) Program Office, a Plasma Contactor Unit Tiger Team was set up to investigate the threat of the ISS arcing in the event of a plasma contactor outage. Modeling and ground tests done under that effort showed that it is possible for the external structure of the ISS to become electrically charged to as much as -160 V under some conditions. Much of this work was done in anticipation of the deployment of the first large ISS solar array in November 2000. It was recognized that, with this deployment, the power system would be energized to its full voltage and that the predicted charging would pose an immediate threat to crewmembers involved in extravehicular activities (EVA's), as well as long-term damage to the station structure, were the ISS plasma contactors to be turned off or stop functioning. The Floating Potential Probe was conceived, designed, built, and deployed in record time by a crack team of scientists and engineers led by the NASA Glenn Research Center in response to ISS concerns about crew safety.

  19. Preliminary Results from the Space Probe Pioneer V

    NASA Technical Reports Server (NTRS)

    Fan, C. Y.; Meyer, P.; Simpson, J. A.

    1960-01-01

    The space probe Pioneer V was launched March 11, 1960, into an orbit around the sun and inside the orbit of earth. The scientific apparatus included instruments identical with the University of Chicago apparatus used on Explorer VI [Fan, Meyer, and Simpson, 1960b], namely, energetic particle detectors which measure fluxes of protons with energies greater than 75 Mev, electrons with energies greater than 15 Mev, and the bremsstrahlung from electrons and y rays of lower energy. Simultaneously with the measurements in Pioneer V a series of four neutron monitor piles were recording the changes in cosmic radiation intensity at the earth. We report here on some preliminary results obtained from the Chicago experiments during the time within which Pioneer V traveled to a distance of approximately 8 x 10 km from earth. Beginning on March 20, solar activity rapidly increased with many solar flares, radio noise bursts, etc., over a period of 10 days. Most of our results relate to this period. The preliminary data are given in Figures 1 and 2.

  20. Planning the Voyager spacecraft's mission to Uranus

    NASA Technical Reports Server (NTRS)

    Plagemann, Stephen H.

    1987-01-01

    The application of the systems engineering process to the planning of the Voyager spacecraft mission is described. The Mission Planning Office prepared guidelines that controlled the use of the project and multimission resources and spacecraft consumables in order to obtain valuable scientific data at an acceptable risk level. Examples of mission planning which are concerned with the design of the Deep Space Network antenna, the uplink window for transmitting computer command subsystem loads, and the contingency and risk assessment functions are presented.

  1. Outer planet probe navigation. [considering Pioneer space missions

    NASA Technical Reports Server (NTRS)

    Friedman, L.

    1974-01-01

    A series of navigation studies in conjunction with outer planet Pioneer missions are reformed to determine navigation requirements and measurement systems in order to target probes. Some particular cases are established where optical navigation is important and some cases where radio alone navigation is suffucient. Considered are a direct Saturn mission, a Saturn Uranus mission, a Jupiter Uranus mission, and a Titan probe mission.

  2. 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.

  3. Erratum: Voyager Color Photometry of Saturn's Main Rings

    NASA Technical Reports Server (NTRS)

    Estrada, Paul R.; Cuzzi, Jeffrey N.; Showalter, Mark R.; DeVincenzi, Donald (Technical Monitor)

    2002-01-01

    We correct a calibration error in our earlier analysis of Voyager color observations of Saturn's main rings at 14 deg phase angle and present thoroughly revised and reanalyzed radial profiles of the brightness of the main rings in Voyager G, V, and UV filters, and ratios of these brightnesses. These results are consistent with more recent HST results at 6 deg phase angle, once allowance is made for plausible phase reddening of the rings. Unfortunately, the Voyager camera calibration factors are simply not sufficiently well known for a combination of the Voyager and HST data to be used to constrain the phase reddening quantitatively. However, some interesting radial variations in reddening between 6-14 deg phase angles are hinted at. We update a ring-and-satellite color vs. albedo plot from Cuzzi and Estrada in several ways. The A and B rings are still found to be in a significantly redder part of color-albedo space than Saturn's icy satellites.

  4. 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.

  5. Deep Space Network capabilities for receiving weak probe signals

    NASA Technical Reports Server (NTRS)

    Asmar, Sami; Johnston, Doug; Preston, Robert

    2004-01-01

    This paper will describe the capability and highlight the cases of the critical communications for the Mars rovers and Saturn Orbit Insertion and preparation radio tracking of the Huygens probe at (non-DSN) radio telescopes.

  6. Probing Critical Surfaces in Momentum Space Using Real-Space Entanglement Entropy: Bose versus Fermi

    NASA Astrophysics Data System (ADS)

    Yang, Kun; Lai, Hsin-Hua

    A co-dimension one critical surface in the momentum space can be either a familiar Fermi surface, which separates occupied states from empty ones in the non-interacting fermion case, or a novel Bose surface, where gapless bosonic excitations are anchored. Their presence gives rise to logarithmic violation of entanglement entropy area law. When they are convex, we show that the shape of these critical surfaces can be determined by inspecting the leading logarithmic term of real space entanglement entropy. The fundamental difference between a Fermi surface and a Bose surface is revealed by the fact that the logarithmic terms in entanglement entropies differ by a factor of two: SlogBose = 2SlogFermi , even when they have identical geometry. Our method has remarkable similarity with determining Fermi surface shape using quantum oscillation. We also discuss possible probes of concave critical surfaces in momentum space. HHL and KY acknowledge the National Science Foundation through Grants No. DMR-1004545, DMR-1157490, No. DMR-1442366, and State of Florida. HHL is also partially supported by NSF Grant No. DMR-1309531, and the Smalley Postdoctoral Fellowship in Quantum Ma.

  7. Positioning Reduction of Deep Space Probes Based on VLBI Tracking

    NASA Astrophysics Data System (ADS)

    Qiao, S. B.

    2011-11-01

    ) Investigate the application of Kalman filter to the positioning reduction of deep space probes and develop related software systems. In summary, the progress in this dissertation is made in the positioning reduction of deep space probes tracked by VLBI concerning the algorithm study, software development, real observation processing and so on, while a further study is still urgent and arduous.

  8. Early Results from the Floating Potential Probe on the International Space Station

    NASA Technical Reports Server (NTRS)

    Morton, Thomas L.; Ferguson, Dale C.

    2001-01-01

    This viewgraph presentation provides information on the Floating Potential Probe (FPP) on the International Space Station (ISS). The FPP measures the body voltage (electric potential) of the, and the measurements are then transmitted to Earth.

  9. Amalthea. [Voyager observations

    NASA Technical Reports Server (NTRS)

    Thomas, P.; Veverka, J.

    1982-01-01

    Voyager images have revealed Amalthea to be an irregular object 270 x 165 x 150 km in size. The spin period is probably synchronous with the orbital period of 11.9 hr, with the long axis pointing toward Jupiter. The satellite's surface is heavily scarred by impact craters, the largest of which has a diameter of 90 km (comparable to the mean radius of the satellite). Amalthea is very dark (reflectance about 5-6%) and very red, but isolated bright spots (reflectance up to 20%) occur. The spectrum of these bright spots is less red and may show an absorption feature near 0.6 micron. It is likely that the surface of Amalthea has been severely altered by its environment and by contamination from Io (especially by sulfur). It may, therefore, be very difficult to obtain definitive information on the composition of the intrinsic Amalthea material from remote sensing measurements.

  10. Amalthea - Voyager imaging results

    NASA Technical Reports Server (NTRS)

    Veverka, J.; Thomas, P.; Davies, M.; Morrison, D.

    1981-01-01

    Voyager images of Amalthea are presented, which reveal an irregular satellite in synchronous rotation relative to Jupiter with dimensions of 270 x 165 x 150 km. The surface appears scarred by large craters and sharp ridges to indicate a history of cosmic battering. Amalthea'a normal surface reflectance is 5-6% with a very red color and a mean opposition angle magnitude of +14. The phase coefficient between phase angles of 0.8 and 42 deg of 0.042 + or - 0.004 mag/deg indicates that the phase integral does not exceed 0.3 and the Bond Albedo is less than 0.02. Several prominent bright spots of 10-50 km across occur on local slopes and ridges, have albedos several times higher than the background, and have a greenish color where the spectrum bends down beyond 0.56 microns.

  11. Voyager photometry of Europa

    NASA Technical Reports Server (NTRS)

    Buratti, B.; Veverka, J.

    1983-01-01

    The photometric properties of Europa are derived through an analysis of 90 Voyager images with 3-143 deg phase angles in the spectral range from 0.34 to 0.58 microns. It is noted that, at small phase angles, the disk-integrated phase curve shows almost no evidence of an opposition effect. The scattering properties of Europa in general, and of the bright plain and dark mottled terrain types, cannot be represented by a lunar-like photometric law, although an equation which is a linear superposition of a lunar-like scattering law and a Lambert component provides an adequate and simple representation of scattering properties. The plains are photometrically more homogeneous than the mottled terrain, and these two terrain types exhibit an average normal reflectance of 0.71 on both leading and trailing hemispheres and of 0.60 on leading and 0.48 on trailing hemispheres, respectively.

  12. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 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... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  13. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 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... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  14. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 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... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  15. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 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... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  16. 46 CFR Sec. 2 - Voyage numbers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 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... General Agent shall affix his abbreviated designation and initial voyage numbers, as NSA-13/XYZ-1....

  17. Voyager EUV and FUV observations

    SciTech Connect

    Holberg, J.B.

    1984-11-01

    The Voyager 1 and 2 ultraviolet spectrometers are sensitive over the wavelength range 500 to 1700 A. In the extreme ultraviolet (EUV), at wavelengths shortward of the Lyman limit (912 A), Voyager observations detected emission from three out of a sample of 11 nearly hot DA white dwarfs. These observations imply very low HI column densities in the directions of the three stars detected. In the far ultraviolet (FUV), at wavelengths between 912 and 1200 A, Voyager observations of O and B stars can be used to study interstellar reddening at the shortest wavelengths and to provide useful estimates of interstellar H2 column densities.

  18. Jupiter and the Voyager mission

    USGS Publications Warehouse

    Soderblom, L.

    1980-01-01

    In 1977, the United States launched two unmanned Voyager spacecraft that were to take part in an extensive reconnaissance of the outer planets over a 12-year period visiting the environs of Jupiter, Saturn, Uranus, and Neptune. Their first encounter was with the complex Jupiter planetary system 400 million miles away. Sweeping by Jupiter and its five moons in 1979, the two spacecraft have sent back to Earth an enormous amount of data that will prove to be vital in understanding our solar system. Voyager 1 is scheduled to fly past Saturn on November 13 of this year; Voyager 2, in August of the following year. 

  19. Data link relay design. [space probe with entry at Uranus

    NASA Technical Reports Server (NTRS)

    Parsons, P.

    1974-01-01

    The data link for the Ames baseline probe as applied to the MJU spacecraft specifically with an entry at Uranus is analyzed. A frequency analysis, a trajectory analysis, and a discussion of the effects on the spacecraft design by the data link are presented. The possibilities of a two-way link are considered.

  20. Ganymede - Comparison of Voyager and Galileo Resolution

    NASA Technical Reports Server (NTRS)

    1996-01-01

    These images demonstrate the dramatic improvement in the resolution of pictures that NASA's Galileo spacecraft is returning compared to previous images of the Jupiter system. The frame at left was taken by the Voyager 2 spacecraft when it flew by in 1979, with a resolution of about 1.3 kilometers (0.8 mile) per pixel. The frame at right showing the same area was captured by Galileo during its first flyby of Ganymede on June 27, 1996; it has a resolution of about 74 meters (243 feet) per pixel, more than 17 times better than that of the Voyager image. In the Voyager frame, line-like bright and dark bands can be seen but their detailed structure and origin are not clear. In the Galileo image, each band is now seen to be composed of many smaller ridges. The structure and shape of the ridges permit scientists to determine their origin and their relation to other terrains, helping to unravel the complex history of the planet-sized moon. In each of these frames, north is to the top, and the sun illuminates the surface from the lower left nearly overhead (about 77 degrees above the horizon). The area shown, at latitude 10 degrees north, 167 degrees west, is about 35 by 55 kilometers (25 by 34 miles). The image was taken June 27 when Galileo was 7,448 kilometers (4.628 miles) away from Ganymede. The Jet Propulsion Laboratory manages the Galileo mission for NASA's Office of Space Science.

  1. 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.

  2. Voyager Encounters Saturn: Scientific Highlights

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Observations generated by Voyager 1's encounter with Saturn are disclosed. Atmospheric conditions, the rings, new moons and the five inner moons are described. Titan, Hyperion and Iapetus are discussed in detail, as is Saturn's magnetosphere.

  3. The Voyager 2 Neptune encounter

    SciTech Connect

    Tsurutani, B.T. )

    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.

  4. Voyager to the Seventh Planet.

    ERIC Educational Resources Information Center

    Gold, Michael

    1986-01-01

    Presents recent findings obtained by the Voyager 2 mission on Uranus. Updates information on the planet's moons, rings, atmosphere, and magnetic field. Illustrations and diagrams of selected aspects of Uranus are included. (ML)

  5. 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.

  6. MARINER 9 SPACE PROBE UNDERGOES FINAL CHECKS PRIOR TO ENCAPSULATION

    NASA Technical Reports Server (NTRS)

    1971-01-01

    A technician checks the Mariner I spacecraft prior to its encapsulation for launch to Mars. An Atlas-Centaur rocket successfully launched the mars-bound spacecraft from Cape Kennedy at 6:23 p.m. EDT, May 30, 1971. Designated Mariner 9 following launch, the probe will arrive at Mars in mid-November. It will transmit scientific data about that planet's surface and atmosphere.

  7. Triumph of the Voyager mission

    USGS Publications Warehouse

    Kerr, R. A.

    1989-01-01

    It had been a long, productive trip. Launched in 1977, the two Voyager spacecraft had visited three giant planets, a dozen major Moons, three ring systems with thousands of rings composed of a myriad of tiny Moonlets. The spacecraft had returned 5 trillion bits of data and over 100,000 photographs. The last encounter in our Solar System by Voyager 2 with Neptune was to be a spectacular finale to the 12-year drama. 

  8. Wilkinson Microwave Anisotropy Probe data and the curvature of space

    NASA Astrophysics Data System (ADS)

    Uzan, Jean-Philippe; Kirchner, Ulrich; Ellis, George F. R.

    2003-10-01

    Inter alia, the high-precision Wilkinson Microwave Anisotropy Probe (WMAP) data on cosmic background radiation marginally indicate that the Universe has positively curved (and hence spherical) spatial sections. In this Letter, we take this data seriously and consider some of the consequences for the background dynamics. In particular, we show that this implies a limit to the number of e-foldings that could have taken place in the inflationary epoch; however, this limit is consistent with some inflationary models that solve all the usual cosmological problems and that are consistent with standard structure formation theory.

  9. European Space Agency studies of the solar probe

    NASA Technical Reports Server (NTRS)

    Roxburgh, I. W.

    1978-01-01

    The feasibility and scientific objectives of a solar probe were studied by a Mission Definition Group in 1975 and 1976. The orbit analysis program was developed and an extended study of the orbit analysis was done in 1977. The results of these studies are in the Report of the Mission Definition Study (1976) and an E.S.O.C. report (1978), and the reader is referred to these sources for greater details. In this report, only brief discussion on mission concept and objectives, satellite design, orbit, orbit analysis, are presented.

  10. Voyager encounters Saturn

    NASA Astrophysics Data System (ADS)

    1981-05-01

    Scientific discoveries and observations of the November 11-13, 1980 Voyager 1 Saturn flyby and the resulting theories are presented. The basic appearance of the Saturn atmosphere is similar to that of Jupiter, but its features are made less clear by a much thicker haze layer above the visible clouds. The greatest wind speeds (more than 1600 km per hour) occur at the equator. Temperatures near the cloud tops range from -305 to -294 F, with the coolest temperature near the center of the equatorial zone. Auroral emissions were observed near the poles, and auroral-type emissions in the ultraviolet were also seen near the illuminated limbs of the planet. Radio emissions indicate that the body of the planet and its magnetosphere rotate every 10 hours 39 minutes 26 seconds. A, B, and C rings were observed to consist of hundreds of ringlets, a few of which are elliptical in shape, and a further explanation of the D, E, and F rings is given. Each of the recently discovered moons was photographed, but only S-10 and S-11 had large enough diameters in the images to permit their shapes to be determined. Data on Saturn's inner and outer moons are presented, and special attention is given to Titan. Saturn's magnetosphere extends nearly a million miles inward from the planet toward the sun, and its charged particles are dragged along by the magnetic field and circle Saturn once every 10 hours 39 minutes.

  11. 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.

  12. Probing scalar tensor theories for gravity in redshift space

    NASA Astrophysics Data System (ADS)

    Sabiu, Cristiano G.; Mota, David F.; Llinares, Claudio; Park, Changbom

    2016-07-01

    We present measurements of the spatial clustering statistics in redshift space of various scalar field modified gravity simulations. We utilise the two-point and three-point correlation functions to quantify the spatial distribution of dark matter halos within these simulations and thus discriminate between the models. We compare Λ cold dark matter (ΛCDM) simulations to various modified gravity scenarios and find consistency with previous work in terms of two-point statistics in real and redshift space. However, using higher-order statistics such as the three-point correlation function in redshift space we find significant deviations from ΛCDM hinting that higher-order statistics may prove to be a useful tool in the hunt for deviations from General Relativity.

  13. Probing chemical space with alkaloid-inspired libraries.

    PubMed

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

    2014-02-01

    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 because of their structural complexity and sp(3)-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 sp(3) content, comparable to a basis set of representative natural products and were highly rule-of-five compliant. PMID:24451589

  14. Probing chemical space with alkaloid-inspired libraries

    NASA Astrophysics Data System (ADS)

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

    2014-02-01

    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 because of 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.

  15. Probing Planckian physics in de Sitter space with quantum correlations

    SciTech Connect

    Feng, Jun; Zhang, Yao-Zhong; Gould, Mark D.; Fan, Heng; Sun, Cheng-Yi; Yang, Wen-Li

    2014-12-15

    We study the quantum correlation and quantum communication channel of both free scalar and fermionic fields in de Sitter space, while the Planckian modification presented by the choice of a particular α-vacuum has been considered. We show the occurrence of degradation of quantum entanglement between field modes for an inertial observer in curved space, due to the radiation associated with its cosmological horizon. Comparing with standard Bunch–Davies choice, the possible Planckian physics causes some extra decrement on the quantum correlation, which may provide the means to detect quantum gravitational effects via quantum information methodology in future. Beyond single-mode approximation, we construct proper Unruh modes admitting general α-vacua, and find a convergent feature of both bosonic and fermionic entanglements. In particular, we show that the convergent points of fermionic entanglement negativity are dependent on the choice of α. Moreover, an one-to-one correspondence between convergent points H{sub c} of negativity and zeros of quantum capacity of quantum channels in de Sitter space has been proved. - Highlights: • Quantum correlation and quantum channel in de Sitter space are studied. • Gibbons–Hawking effect causes entanglement degradation for static observer. • Planckian physics causes extra decrement on quantum correlation. • Convergent feature of negativity relies on the choice of alpha-vacua. • Link between negativity convergence and quantum channel capacity is given.

  16. Voyager at Saturn, Act II

    NASA Astrophysics Data System (ADS)

    Beatty, J. K.

    1981-11-01

    Preliminary results of the Voyager 2 encounter with Saturn are discussed. Following a review of the Voyager 2 mission, noting the jamming of the scan platform carrying most of the instruments just prior to encounter, attention is given to observations of ring structures including ringlets, spokes, kinks, Cassini's division and satellite resonance effects. Changes in the atmosphere of Saturn allowing cloud structures to be observed with greater contrast and clarity than during the Voyager 1 encounter are noted, and differences between the observed meteorology on Saturn and that on Jupiter are pointed out. Observations of the Saturn magnetic field, including an internal anomaly responsible for a radio pulse and plasma and neutral hydrogen toruses within the magnetosphere are presented along with detections of electromagnetic disturbances near the ring system. Consideration is finally given to Voyager 2 images and measurements of the Saturn satellites, which revealed a dense, orange-colored atmosphere attributed to an aerosol haze around Titan, the ancient cratered surface with an enormous rift on Tethys, evidence of at least five distinct evolutionary episodes on Enceladus, and the configuration of the highly contrasting forward and rear-facing sides of Iapetus. The potential for discoveries in the Voyager 2 encounter with Uranus to take place four years hence is also indicated.

  17. Space Weather data processing and Science Gateway for the Van Allen Probes

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    A near real-time data processing pipeline for the Space Weather broadcast data from the Van Allen Probes is presented. The Van Allen Probes broadcasts a sub-set of the science data in real-time when not downlinking the principal science data. This broadcast is received by several ground stations and relayed to APL in near real time to be ingested into the space weather processing pipeline. This pipeline processes the available level zero space weather data into higher level science data products. These products are made available to the public via the Van Allen Probes Science Gateway website (http://athena.jhuapl.edu). The website acts as pivotal point though which all other instrument SOC's can be accessed. Several other data products (e.g KP/DST indices) and tools (e.g orbit calculator) are made also available to the general public.

  18. 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.

  19. Probing Planckian physics in de Sitter space with quantum correlations

    NASA Astrophysics Data System (ADS)

    Feng, Jun; Zhang, Yao-Zhong; Gould, Mark D.; Fan, Heng; Sun, Cheng-Yi; Yang, Wen-Li

    2014-12-01

    We study the quantum correlation and quantum communication channel of both free scalar and fermionic fields in de Sitter space, while the Planckian modification presented by the choice of a particular α-vacuum has been considered. We show the occurrence of degradation of quantum entanglement between field modes for an inertial observer in curved space, due to the radiation associated with its cosmological horizon. Comparing with standard Bunch-Davies choice, the possible Planckian physics causes some extra decrement on the quantum correlation, which may provide the means to detect quantum gravitational effects via quantum information methodology in future. Beyond single-mode approximation, we construct proper Unruh modes admitting general α-vacua, and find a convergent feature of both bosonic and fermionic entanglements. In particular, we show that the convergent points of fermionic entanglement negativity are dependent on the choice of α. Moreover, an one-to-one correspondence between convergent points Hc of negativity and zeros of quantum capacity of quantum channels in de Sitter space has been proved.

  20. Mass spectrometer experiments for the European space probe Giotto

    NASA Astrophysics Data System (ADS)

    Neumann, G.

    The Particulate Impact Analyzer (PIA) and Neutral Mass Spectrometer (NMS) experiments to be carried on board the Giotto cometary probe are presented. The NMS is designed to determine the chemical composition of gases and ions in the coma of Halley's Comet based on the ue of two spectrometers: an electrostatic parallel-plate analyzer, and a similar analyzer coupled with a magnetic analyzer with double-focusing geometry. The sensor structure consists of a monolithic multi-rib milled body with integral fixation points, with provisions for electromagnetic and thermal isolation, and dust protection. The PIA is intended for the measurement of the physical and chemical characteristics of cometary dust particles. It is based on an instrument comprising an entrance baffle and shutter unit, a target unit at which the dust is ionized, a light flash detector marking the flash of ionization, an acceleration grid sending the ions into the time-of-flight unit, and a multiplier unit for recording the time of flight spectrum. A microprocessor-based electronics system housed in a separate case next to the sensor performs tasks of power supply, signal processing, data processing and flow control.

  1. MARINER 8 SPACE PROBE'S SOLAR ARRAYS ARE INSTALLED

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Technicians prepare to install a solar panel on the Mariner H spacecraft in preparation for its launch to Mars, no earlier than May 7, 1971. The spacecraft will be launched aboard an Atlas Centaur space vehicle from Cape Kennedy's Complex 36A, and will go into orbit around Mars at the completion of a seven-month journey from Earth. It is designed to operate 90 days and return data about the planet's atmospheric and surface characteristics. Following launch, the spacecraft will be designated Mariner 8. A second Mariner Mars spacecraft is scheduled to be launched 10 days later.

  2. Space probe/satellite ejection apparatus for spacecraft

    NASA Technical Reports Server (NTRS)

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

    1985-01-01

    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.

  3. MARINER 8 SPACE PROBE UNDERGOES INSTALLATION OF SOLAR ARRAYS

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Technicians install solar panels aboard the mariner H spacecraft in a cleanroom facility at Cape Kennedy. The spacecraft will orbit Mars following a seven-month journey from Earth. Designed to function 90 days, the spacecraft, which will be designated Mariner 8 following launch, will provide data about the Red Planet's atmospheric and surface characteristics. Mariner Mars H will be launched aboard an Atlas-Centaur space vehicle no earlier than May 7, 1971, from Cape Kennedy's Launch Complex 36A. A second Mariner Mars spacecraft will be launched 10 days later.

  4. Space probe/satellite ejection apparatus for spacecraft

    NASA Technical Reports Server (NTRS)

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

    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.

  5. Probing the shape of atoms in real space

    NASA Astrophysics Data System (ADS)

    Herz, M.; Giessibl, F. J.; Mannhart, J.

    2003-07-01

    The structure of single atoms in real space is investigated by scanning tunneling microscopy. Very high resolution can be obtained by a dramatic reduction of the tip-sample distance. The instabilities which are normally encountered while using small tip-sample distances are avoided by oscillating the tip of the scanning tunneling microscope vertically with respect to the sample. The surface atoms of Si(111)-(7×7) with their well-known electronic configuration are used to image individual samarium, cobalt, iron, and silicon atoms. The resulting images resemble the charge density corresponding to 4f, 3d, and 3p atomic orbitals.

  6. The Jovian magnetosphere - A post-Voyager view

    NASA Astrophysics Data System (ADS)

    Hill, T. W.

    1981-01-01

    Results of observational and theoretical work presented at the Rice University Conference on the Physics of the Jovian Magnetosphere (February 27-29, 1980) are summarized and used to elucidate the post-Voyager status of the understanding of Jovian magnetosphere dynamics. Works considered treat earth-based and Voyager observations of the Io torus, decametric and kilometric radio emissions, corotation of magnetospheric plasma with the magnetic field, and theoretical studies of mechanisms of particle acceleration, diffusion and loss in the magnetosphere and interplanetary space. Issues remaining to be resolved by future research are also indicated, particularly questions of the discrepancy between plasma flow measurements obtained on the two plasma experiments on each Voyager spacecraft, and the localization of the source of torus plasma.

  7. Astrometric Gravitation Probe: a space mission concept for fundamental physics

    NASA Astrophysics Data System (ADS)

    Vecchiato, Alberto; Fienga, Agnes; Gai, Mario; Lattanzi, Mario G.; Riva, Alberto; Busonero, Deborah

    2015-08-01

    Modern technological developments have pushed the accuracy of astrometric measurements in the visible band down to the micro-arcsec level. This allows to test theories of gravity in the weak field limit to unprecedented level, with possible consequences spanning from the validity of fundamental physics principles, to tests of theories describing cosmological and galactic dynamics without resorting to Dark Matter and Dark Energy.This is the main goal of Astrometric Gravitation Probe (AGP) mission, which will be achieved by highly accurate astrometric determination of light deflection (as a modern rendition of the Dyson, Eddington, and Robertson eclipse experiment of 1919), aberration, and of the orbits of selected Solar System objects, with specific reference to the excess shift of the pericentre effect.The AGP concept was recently proposed for the recent call for ESA M4 missions as a collaboration among several scientists coming from many different European and US institutions. Its payload is based on a 1.15 m diameter telescope fed through a coronagraphic system by four fields, two set in symmetric positions around the Sun, and two in the opposite direction, all imaged on a CCD detector. Large parts of the instrument are common mode to all fields. The baseline operation mode is the scan of the ±1.13 deg Ecliptic strip, repeated for a minimum of 3 years and up to an optimal duration of 5 years. Operations and calibrations are simultaneous, defined in order to ensure common mode instrumental effects, identified and removed in data reduction. The astrometric and coronagraphic technologies build on the heritage of Gaia and Solar Orbiter.We review the mission concept and its science case, and discuss how this measurement concepts can be scaled to different mission implementations.

  8. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 3 2013-10-01 2013-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping COAST GUARD... REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means: A voyage on any body of water seaward of the low water mark such as an ocean or arm thereof, other major bodies of water such...

  9. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 3 2011-10-01 2011-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping COAST GUARD... REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means: A voyage on any body of water seaward of the low water mark such as an ocean or arm thereof, other major bodies of water such...

  10. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 3 2014-10-01 2014-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping COAST GUARD... REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means: A voyage on any body of water seaward of the low water mark such as an ocean or arm thereof, other major bodies of water such...

  11. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping COAST GUARD... REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means: A voyage on any body of water seaward of the low water mark such as an ocean or arm thereof, other major bodies of water such...

  12. 46 CFR 80.15 - Ocean voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Ocean voyage. 80.15 Section 80.15 Shipping COAST GUARD... REGISTRY § 80.15 Ocean voyage. An ocean voyage for the purposes of this part means: A voyage on any body of water seaward of the low water mark such as an ocean or arm thereof, other major bodies of water such...

  13. Improved downlink frequency calculations for Voyager 2

    NASA Technical Reports Server (NTRS)

    Ricardo, A. L.

    1982-01-01

    Voyager 2 and her sister Voyager 1 were launched, respectively, in August and September 1977. The object of these spacecraft was to conduct exploratory investigations of the Jupiter and Saturn planetary systems and the interplanetary medium between Earth and Saturn. In April 1978 the Voyager 2 redundant receiver and the loop capacitor in the prime spacecraft receiver failed, leaving the Voyager Project with a major problem: how to communicate with the spacecraft and get the data back.

  14. Welded Titanium Case for Space-Probe Rocket Motor

    NASA Technical Reports Server (NTRS)

    Brothers, A. J.; Boundy, R. A.; Martens, H. E.; Jaffe, L. D.

    1959-01-01

    Early in 1958, the Jet Propulsion Laboratory of the California Institute of Technology was requested to participate in a lunar-probe mission code-named Juno II which would place a 15-lb Instrumented payload (Pioneer IV) in the vicinity of the moon. The vehicle was to use the same high-speed upper-stage assembly as flown on the successful Jupiter-C configuration; however, the first-stage booster was to be a Jupiter rather than a Redstone. An analysis of the intended flight and payload configuration Indicated that the feasibility of accomplishing the mission was questionable and that additional performance would have to be obtained if the mission was to be feasible. Since the most efficient way of Increasing the performance of a staged vehicle is to increase the performance of the last stage, a study of possible ways of doing this was made.. Because of the time schedule placed on this effort It was decided to reduce the weight of the fourth-stage rocket-motor case by substituting the annealed 6Al--4V titanium alloy for the Type 410 stainless steel. Although this introduced an unfamiliar material, It reduced the changes in design and fabrication techniques. This particular titanium alloy was chosen on the basis of previous tests which proved the suitability of the alloy as a pressure-vessel material when used at an annealed yield strength of about 120, 000 psi. The titanium-case fourth stage of Juno U is shown with the payload and on the missile in Fig. 1; the stainless-steel motor cases used in the Jupiter-C vehicle are shown in Fig. 2. The fourth-stage motor case has a diameter of 6 in., a length of approximately 38 in. center dot and a nominal cylindrical wall thickness of 0.025 in. As shown in Fig. 1, the case serves as the structural support of the payload and is aligned to the upper stage assembly through an alignment ring. The nozzle is threaded into the end of the motor case, and is of the ceramic-coated steel design. Figure 3 shows a comparison of the

  15. View of Callisto from Voyager and Galileo

    NASA Technical Reports Server (NTRS)

    1996-01-01

    View of Callisto, most distant of the four large moons of Jupiter. This mosaic was prepared from images obtained by three spacecraft: Voyager 1 (left side), Galileo (middle), and Voyager 2 data (right side). The Voyager data were taken in 1979 but left a 'gap' centered at longitude 290 degrees in the trailing hemisphere of Callisto. The Galileo Solid-State Imaging system photographed this area on its second orbit around Jupiter on 9 September, 1996 Universal Time. The resolution of the Galileo data is 4.3 kilometers/pixel (2.7 miles), meaning that the smallest visible feature is about 12 kilometers (7 miles) across. North is to the top of the picture.

    Features of interest in the new Galileo data include a dark, smooth area in the northern latitudes (upper third) which appears to mantle older terrain. This could be dark ejecta from a small impact crater. Also visible is a fresh, sharp-rimmed crater some 90 km (56 miles) across named Igaluk (center left third of picture), and a bright zone in the south polar area (bottom of image) which could be an impact scar.

    The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  16. 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

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

    SciTech Connect

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

    2012-05-15

    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.

  18. 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.

  19. Voyager to Jupiter and Saturn

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The NASA Voyager mission to explore planets of the outer solar system is summarized. The mission schedule and profiles for encounters with Jupiter and Saturn, and possibly with Uranus and Pluto are included along with a description of the spacecraft and its trajectories. Scientific investigations to be made and the instruments carried are also discussed.

  20. The Voyage of the MIMI.

    ERIC Educational Resources Information Center

    Gibbon, Sam; Hooper, Kristina

    1986-01-01

    The Voyage of MIMI is a major educational project housed at Bank Street College (New York) which is directed toward the development of extensive television, computer software, videodisc, and print materials for use in science and mathematics education in grades 5-7. The first series has been completed, and includes a 13-part dramatic television…

  1. Voyager - a mission for life

    NASA Astrophysics Data System (ADS)

    Williamson, Mark

    2012-12-01

    There may be no such thing as a "job for life" these days, but NASA's Voyager mission to Jupiter, Saturn and beyond has kept hundreds of scientists busy for as much as 35 years. Mark Williamson reveals how researchers stay motivated and scientifically productive during such a long-term project.

  2. The heliosphere neutrals composition: from Voyager UVS to IMAPS

    NASA Astrophysics Data System (ADS)

    Ben-Jaffel, L.

    2015-12-01

    For the last 35 years, the Voyagers (V) 1 and 2 ultraviolet spectrometers (UVS) data harvest has covered heliosphere sky-background in-situ measurements, stellar spectrophotometry, and outer planets encounters. Their long and ongoing operation period overlaps with many current and past ultraviolet missions, offering unique opportunities for cross-calibration with other spectrometers. Here we revisit the Voyager UVS calibration to assess the intriguing 243% (V1) and 156% (V2) sensitivity enhancements recently proposed. Using the Saturn Lyman-α airglow, observed in-situ by both Voyagers, and remotely by IUE, we match the Voyager values to IUE, taking into account the shape of the Saturn and sky-background Lyman-α lines observed with the Goddard High Resolution Spectrograph onboard the Hubble Space Telescope. For all known ranges of the interplanetary H I density, we show that the V1 and V2 UVS sensitivities at the Lyman-α channels cannot be enhanced by the amounts thus far proposed. Our prescription is to keep the original calibration of the Voyager UVS with an uncertainty that should not exceed 30%, making both instruments some of the most stable EUV/FUV spectrographs of the history of space exploration. This rich heritage from past and current space missions confirms that UV observations of the sky-background are a powerful lever for constraining the neutral composition and large structure of the heliosphere. It also points to the need in the future for fine Doppler-shift measurements and faint emissions detection in order to directly access the microphysical processes that drive the instant shape and composition of the heliosphere that is forced by the magnetized plasmas from solar wind and the local interstellar medium. Future deep space missions should thus include UV capabilities that make use of sensitive, high-resolution technology that allows achieving the highest throughput for extended light sources.

  3. Endeavour's Final Voyage

    NASA Video Gallery

    After nearly two decades of achievements in space, Endeavour makes one last reach for the stars on its 25th and final mission, STS-134. This webcast examines the mission to come and explores the st...

  4. 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).

  5. Has Voyager 1 really crossed the heliopause?

    NASA Astrophysics Data System (ADS)

    Gloeckler, G.; Fisk, L. A.

    2015-01-01

    The Voyager 1 spacecraft is currently in the vicinity of the heliopause, which separates the heliosphere from the local interstellar medium. There has been a precipitous decrease in particles accelerated in the heliosphere, and a substantial increase in galactic cosmic rays (GCRs). The evidence is unclear, however, as to whether Voyager 1 has crossed the heliopause into the local interstellar medium, or remains within the heliosheath. In this paper we propose a test that will determine whether Voyager 1 has crossed the heliopause: If Voyager 1 remains in the heliosheath, the high plasma densities must be due to compressed solar wind, with the consequence that Voyager 1 will encounter another current sheet, where the polarity of the magnetic field reverses. Voyager 1 observations can be used to predict that the next current sheet crossing is likely to occur during 2015. A prediction is also provided as to what the Voyager 2 plasma detector will measure in the next few years.

  6. 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. This work supported by the Naval Research Laboratory Base Program.

  7. 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.

  8. Ariel at Voyager Closest Approach

    NASA Technical Reports Server (NTRS)

    1986-01-01

    This picture is part of the highest-resolution Voyager 2 imaging sequence of Ariel, a moon of Uranus about 1,300 kilometers (800 miles) in diameter. The clear-filter, narrow-angle image was taken Jan. 24, 1986, from a distance of 130,000 km (80,000 mi). The complexity of Ariel's surface indicates that a variety of geologic processes have occurred. The numerous craters, for example, are indications of an old surface bombarded by meteoroids over a long period. Also conspicuous at this resolution, about 2.4 km (1.5 mi), are linear grooves (evidence of tectonic activity that has broken up the surface) and smooth patches (indicative of deposition of material). The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

  9. The Voyager program at APL

    NASA Technical Reports Server (NTRS)

    Mauk, Barry H.; Keath, Edwin P.; Krimigis, Stamatios M.

    1990-01-01

    An overview is presented of the structure and function of the Applied Physics Laboratory's low-energy charged particle (LECP) instrument used in NASA's Voyager program. The LECP experiment was designed to measure the intensity, energy spectra, composition, angular distributions, and spatial and temporal characteristics of ions and electrons that are encountered by the spacecraft. Scientific findings of previous planetary encounters are noted, and color energy-time spectrograms that summarize the LECP results at each planet are presented and analyzed. Some details of the encounter by Voyager 2 of Neptune are provided, noting that the characteristics of the trajectory that was used provided for close observation of Triton, observations of particle structures, and exploration of Neptune's polar cap. A schematic of Neptune's magnetosphere is provided and analyzed.

  10. Voyager 1: Encounter with Saturn

    NASA Technical Reports Server (NTRS)

    Panagakos, N.

    1980-01-01

    The history of the Voyager Project is reviewed as well as known facts about Saturn and its satellites. Important results of encounters with Jupiter are summarized. Scientific objectives of the flyby of Saturn involve the planet's atmosphere, rings, and magnetic field interactions with the solar wind and satellites. The search for additional satellites, and various aspects of Titan, Rhea, Dione, Mimas, Iapetus, Hyperion, and Enceladas are also of interest. The instruments developed to obtain these goals are described.

  11. Take a Voyage of Discovery

    ERIC Educational Resources Information Center

    Texley, Juliana

    2008-01-01

    On December 27, 1831, the "H.M.S. Beagle" left Plymouth Harbor for a round-the-world voyage. On board was would-be botanist Charles Darwin, the best tour guide biology has ever known. In 2009, we will celebrate Darwin's 200th birthday and the 150th anniversary of "The Origin of Species" publication. What better way to prepare for this celebration…

  12. The Jovian nebula - A post-Voyager perspective

    NASA Technical Reports Server (NTRS)

    Trauger, J. T.

    1984-01-01

    Voyager 1 carried a diverse collection of magnetospheric probes through the inner Jovian magnetosphere in March 1979. The ensuing data analysis and theoretical investigation provided a comprehensive description of the Jovian nebula, a luminous torus populated with newly released heavy ions drawn from Io's surface. Recent refinements in earth-based imaging instrumentation are used to extend the Voyager in situ picture in temporal and spatial coverage. An analysis of S III and S II forbidden-line optical emissions observed during the Jovian apparitions of 1981 through 1983 reveals three distinct torus components. Regularities have been identified in the ion partitioning and ion densities in the hot outer and inner tori, sharply defined radial structure is found in the plasma near Io, and the relative permanence of the cool inner torus is inferred. An extended cloud of neutral material is required as a source of fresh ions in the nebula.

  13. VOYAGER 1 NEAR THE HELIOPAUSE

    SciTech Connect

    Borovikov, S. N.; Pogorelov, N. V.

    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.

  14. Investigation of interplanetary dust from out-of-ecliptic space probes. [astronomical models of interplanetary dust

    NASA Technical Reports Server (NTRS)

    Fechtig, H.; Giese, R. H.; Hanner, M. S.; Zook, H. A.

    1976-01-01

    Measurements of interplanetary dust via zodiacal light observations and direct detection are discussed for an out-of-ecliptic space probe. Particle fluxes and zodiacal light brightnesses were predicted for three models of the dust distribution. These models predict that most of the information will be obtained at space probe distances less than 1 A.U. from the ecliptic plane. Joint interpretation of the direct particle measurements and the zodiacal light data can yield the best knowledge of the three-dimensional particle dynamics, spatial distribution, and physical characteristics of the interplanetary dust. Such measurements are important for an understanding of the origin and role of the dust in relation to meteoroids, asteroids, and comets, as well as the interaction of the dust with solar forces.

  15. On the detection of a cometary mass distribution. [by perturbations on space probe orbits

    NASA Technical Reports Server (NTRS)

    Boss, A. P.; Peale, S. J.

    1976-01-01

    The problem of detecting a possible cometary distribution on the fringes of the solar system is examined. The acceleration of a space probe due to a hypothetical cometary mass distribution with the surface density rising to a maximum and subsequently falling off with increasing distance from the sun is analyzed. The total minimum detectable cometary mass for the Pioneer and Mariner spacecraft is estimated on the basis of this model to be on the order of 1000 earth masses. Precision tracking of deep space probes is less sensitive by three orders of magnitude for the detection of an unseen cometary mass distribution at the fringes of the solar system than are the secular perturbations of long-period comets.

  16. Changes around Marduk between Voyager, and Galileo's first two orbits

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Detail of changes around Marduk on Jupiter's moon Io as seen by Voyager 1 in 1979 (upper left) and NASA's Galileo spacecraft between June 1996 (lower left) and September 1996 (upper and lower right). The new dark red linear feature extending southeast from Marduk is about 250 kilometers long and may be a volcanic fissure. The flow-like feature at the bottom of the images is distinct in the Voyager data, indistinct in the June Galileo data, but distinct again in the September Galileo data. This may be due to the different lighting conditions rather than volcanic activity. The Voyager 1 image uses the green, blue, and violet filters. The upper right September 1996 image from Galileo uses the violet and green filters of the solid state imaging system aboard the Galileo spacecraft and a synthetic blue to simulate Voyager colors. The lower June and September, 1996 Galileo images use the imaging system's near-infrared (756 nm), green, and violet filters. North is to the top in all frames.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  17. 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.

  18. 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.

  19. Physical limitations in sensors for a drag-free deep space probe

    NASA Technical Reports Server (NTRS)

    Juillerat, R.

    1971-01-01

    The inner perturbing forces acting on sensors were analyzed, taking into account the technological limitations imposed on the proof mass position pickup and proof mass acquisition system. The resulting perturbing accelerations are evaluated as a function of the drag-free sensor parameters. Perturbations included gravitational attraction, electrical action, magnetic action, pressure effects, radiation effects, and action of the position pickup. These data can be used to study the laws of guidance, providing an optimization of the space probe as a whole.

  20. Planetary and Space Science Education by Mathematica Demonstrations: Lunar Probe Planning, Instrumentations and Field Operation Simulations for Hunveyor Model by Studies of Surveyor

    NASA Astrophysics Data System (ADS)

    Kabai, S.; Bérczi, Sz.

    2008-03-01

    By interactive Mathematica Demonstrations of the Wolfram Research instrumentation, mechatronics and field operation simulations of lunar and martian space probes were studied focusing on our Surveyor- type educational space probe model: Hunveyor.

  1. Voyager observations of plasma in the heliosheath

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.

    2012-04-01

    Voyager 2 has been observing plasma in the heliosheath since August 2007. We present the most recent data which shows that the plasma speed has remained fairly constant while the flow direction has turned toward the heliotail, with flows about 60 degrees from the radial direction. The density has increased by a factor of two over the past year, possibly due to solar cycle changes as solar maximum approaches. The heliosheath remains a highly variable environment with changes in plasma parameters occurring on time scales of tens of minutes. These Voyager 2 data will be compared with the Voyager 1 observations, which show a very different speed profile than observed at Voyager 2.

  2. The deep space network. [tracking and communication support for space probes

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The objectives, functions, and organization of the deep space network are summarized. Progress in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations is reported. Interface support for the Mariner Venus Mercury 1973 flight and Pioneer 10 and 11 missions is included.

  3. New developments at Hunveyor and Husar space probe model constructions in Hungarian Universities and Colleges: status report of 2008

    NASA Astrophysics Data System (ADS)

    Hegzi, S.; Bérczi, Sz.; Hudoba, Gy.; Magyar, I.; Lang, A.; Istenes, Z.; Weidinger, T.; Tepliczky, I.; Varga, T.; Hargitai, H.

    2008-09-01

    Introduction Hunveyor and Husar space probe models are the main school robotics program in Hungary in the last decade initiated by our Cosmic Materials Space research Group (CMSRG). As a new form of planetary science education in Hungary students build their lander and rover robots and test them on test tables, carry out simulations, and go with their instruments to field works of planetary geology analog sites. Recently 10 groups work in this program and here is a status report about the new results. Planetary robot construction and simulations steps We summarized in 10 steps the main "constructional and industrial research and technology" description of planetary material studying and collecting by space probes (landers, rovers). We focused on the activity we began and teach to carry out at those steps. (Main planets considered were the Moon and Mars): 1. Reconnaissance and survey of the surface of a planet by orbital space probes (i.e. Lunar Orbiter, MGS, MRO etc.) Our studies: photogeology, geomorphology, preparations to cartography. 2. Mapping of the surface of the selected planet with geographical and stratigraphical methods. We (CMSRG) prepared thematic maps on Moon, Mercury, Mars, Venus [1] and Atlas (3) in the series [2,3]. 3. Identification of various surface materials by albedo, spectroscopic [4], thermal IR, identification and selection of the target sites. (in terrestrial analog sites during field works) 4. Planning the space probe system lander and rover working together (MPF-Sojourner type assembly). Planning of the Hunveyor and Husar models. 5. Construction and manufacturing lander and rover units. All Hunveyor groups built their models [5]. 6. Launching and traveling the space probes to the planetary surface. (No rocket building, we simulate [6] some events during the voyage only). 7. Measuring the planetary surface environment on the surface of target planet [7]. (CMSRG) groups carry out test-table measurements [8] and simulations, and later they

  4. Uruk Sulcus Mosaic - Galileo over Voyager Data

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A mosaic of four Galileo images of the Uruk Sulcus region on Ganymede (Latitude 11 N, Longitude: 170 W) is shown overlayed on the data obtained by the Voyager 2 spacecraft in 1979. North is to the top of the picture, and the sun illuminates the surface from the lower left, nearly overhead. The area shown is about 120 by 110 kilometers (75 by 68 miles) in extent and the smallest features that can be discerned are 74 meters (243 feet) in size in the Galileo images and 1.3 kilometers (0.8 miles) in the Voyager data. The higher resolution Galileo images unveil the details of parallel ridges and troughs that are principal features in the brighter regions of Ganymede. High photometric activity (large light contrast at high spatial frequencies) of this ice-rich surface was such that the Galileo camera's hardware data compressor was pushed into truncating lines. The north-south running gap between the left and right halves of the mosaic is a result of line truncation from the normal 800 samples per line to about 540. The images were taken on 27 June, 1996 Universal Time at a range of 7,448 kilometers (4,628 miles) through the clear filter of the Galileo spacecraft's imaging system.

    Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  5. 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

  6. 46 CFR 185.503 - Voyage plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Voyage plan. 185.503 Section 185.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.503 Voyage plan. (a) The master of the following vessels...

  7. 46 CFR 185.503 - Voyage plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Voyage plan. 185.503 Section 185.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.503 Voyage plan. (a) The master of the following vessels...

  8. 46 CFR 185.503 - Voyage plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Voyage plan. 185.503 Section 185.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.503 Voyage plan. (a) The master of the following vessels...

  9. 46 CFR 185.503 - Voyage plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Voyage plan. 185.503 Section 185.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.503 Voyage plan. (a) The master of the following vessels...

  10. 46 CFR 185.503 - Voyage plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Voyage plan. 185.503 Section 185.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Preparations for Emergencies § 185.503 Voyage plan. (a) The master of the following vessels...

  11. The Columbian Voyages in Historical Perspective.

    ERIC Educational Resources Information Center

    Harlan, Louis R.

    1991-01-01

    Discusses the modern historical view of the Columbian voyages that recognizes both the positive and negative consequences of the contact. Describes the voyages as a boon to scientific knowledge, a key step in the development of world trade, and an ecological disaster. Acknowledges the role of India, Islam, and Iberian Jews. (DK)

  12. Voyager Sails into Market for Reading

    ERIC Educational Resources Information Center

    Manzo, Kathleen Kennedy

    2006-01-01

    This article reports how the Voyager Universal Literacy core program, which is sailing successively into the market for reading programs, has been the target of several speculations over its secrets of success. Use of the Voyager Universal Literacy program has since spread to 1,000 districts throughout the country since its introduction into the…

  13. Voyager Spacecraft During Vibration Testing

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Two Voyager spacecraft were launched in 1977 to explore the outer planets and some of their satellites. A prototype Voyager spacecraft is shown at NASA's Jet Propulsion Laboratory in Pasadena, California, as it successfully passed vibration tests which simulated the expected launch environment. The large parabolic antenna at the top is 3.7 meters in diameter and was used at both S-band and X-band radio frequencies for communicating with Earth over the great distances from the outer planets. The spacecraft received electrical power from three nuclear power sources (lower left). The shiny cylinder on the left side under the antenna contained a folded boom, which extended after launch to hold a magnetometer instrument thirteen meters away from the body of the spacecraft. The truss-like structure on the right side is the stowed instrument boom which supported three science instruments and a scan platform. The scan platform allowed the accurate pointing of two cameras and three other science instruments at Jupiter, Saturn, the rings of Saturn, Jupiter's moons, Saturn's moons, Uranus, moons of Uranus, and Neptune.

  14. Voyager Briefing: Expectations of the Neptune Encounter

    NASA Technical Reports Server (NTRS)

    1989-01-01

    This NASA KSC video release presents a news briefing held Aug. 4, 1989 at NASA Headquarters three weeks after Voyager 2's official "encounter" with Neptune began. The video is comprised of two slide presentations followed by a short question and answer period. The press conference is moderated by Charles Redmond, (NASA Public Affairs), includes an introduction by Dr. Geoffrey A Briggs (Dir., Solar System Exploration Div.), and features Norman R. Haynes (Voyager Project Manager, JPL) and Dr. Edward C. Stone (Voyager Project Scientist, Cal Tech). Mr. Haynes' presentation centers on Voyager's history, engineering changes, and spacecraft trajectories while Dr. Stone presents the scientific aspects of Voyager, including the 11 scientific investigations planned for the mission, instruments used, and imaging techniques.

  15. Voyager Briefing: Expectations of the Neptune Encounter

    NASA Astrophysics Data System (ADS)

    1989-08-01

    This NASA KSC video release presents a news briefing held Aug. 4, 1989 at NASA Headquarters three weeks after Voyager 2's official "encounter" with Neptune began. The video is comprised of two slide presentations followed by a short question and answer period. The press conference is moderated by Charles Redmond, (NASA Public Affairs), includes an introduction by Dr. Geoffrey A Briggs (Dir., Solar System Exploration Div.), and features Norman R. Haynes (Voyager Project Manager, JPL) and Dr. Edward C. Stone (Voyager Project Scientist, Cal Tech). Mr. Haynes' presentation centers on Voyager's history, engineering changes, and spacecraft trajectories while Dr. Stone presents the scientific aspects of Voyager, including the 11 scientific investigations planned for the mission, instruments used, and imaging techniques.

  16. Voyager radio science observations of Neptune and Triton

    NASA Astrophysics Data System (ADS)

    Tyler, G. L.; Sweetnam, D. N.; Anderson, J. D.; Borutzki, S. E.; Campbell, J. K.; Kursinski, E. R.; Levy, G. S.; Lindal, G. F.; Lyons, J. R.; Wood, G. E.

    1989-12-01

    Voyager 2 undertook radio science investigations of the Neptune and Triton masses and densities, as well as of their atmospheric and ionospheric vertical structures, the atmospheric composition and low-order gravitational harmonics of Neptune, and ring material characteristics. Upon probing the atmosphere of Neptune to a pressure level of about 500,000 Pa, the effects of a methane cloud region and of ammonia absorption below the cloud have become apparent. The tenuous neutral atmosphere of Triton produced distinct signatures in the occultation data; it is inferred that the Triton atmosphere is controlled by water-pressure equilibrium with surface ices.

  17. Titan. [Voyager IRIS observation of satellite atmosphere

    NASA Technical Reports Server (NTRS)

    Lunine, Jonathan I.

    1990-01-01

    Saturn's satellite Titan is the second-largest in the solar system. Its dense atmosphere is mostly molecular nitrogen with an admixture of methane, a surface pressure of 1.5 bars and a surface temperature of 94K. The fundamental driving force in the long-term evolution of Titan's atmosphere is the photolysis of methane in the stratosphere to form higher hydrocarbons and aerosols. The current rate of photolysis and undersaturation of methane in the lower troposphere suggests the presence of a massive ethane-methane-nitrogen ocean. The ocean evolves to a more ethane-rich state over geologic time, driving changes in the atmospheric thermal structure. An outstanding issue concerning Titan's earliest history is the origin of atmospheric nitrogen: was it introduced into Titan as molecular nitrogen or ammonia? Measurement of the argon-to-nitrogen ratio in the present atmosphere provides a diagnostic test of these competing hypotheses. Many of the questions raised by the Voyager encounters about Titan and its atmosphere can be adequately addressed only by an entry probe, such as that planned for the Cassini mission.

  18. Voyager II Encounter with Neptune: Voyager/Neptune Briefing

    NASA Technical Reports Server (NTRS)

    1989-01-01

    The main focus of this lecture is to discuss the relative size of the planets, the formation of the solar system, details of atmospheric motion (atmospheric dynamics), the aspects of the magnetic fields, different ring systems, and the Triton satellite. The study evolves around the planets of Jupiter, Saturn, Uranus, and Neptune. Their temperature and absorption properties of the ice are discussed. Two of the chemicals being absorbed by the ice are ammonia and methane. Also discussed are the belt and zonal circulation models, jet streams, plumes and clouds, magnetic fields, planetary rings, the pressure on Triton, the atmosphere of Titan, Callisto, Aria, Ganymede, Ariel, Miranda, Io, Europa, Amalthea, Rhea, Dione, Tethys, Enceladus, Mimas, Hyperion, Oberon, Titania, and Umbriel. The lecture also contained some computerized simulation and various images from Voyager.

  19. The Context for IMAP: Voyager and INCA Observations of the Heliosheath at E > 5 keV

    NASA Astrophysics Data System (ADS)

    Krimigis, Stamatios M.

    2016-04-01

    The basic premise of the proposed Interstellar Mapping and Acceleration Probe (IMAP) is detailed scientific understanding of the Heliosheath (HS) and beyond, a region of space explored in situ by Voyager 1 (V1) since 2004, Voyager 2 (V2) since 2007, and remotely via energetic neutral atoms (ENA) by the Cassini/INCA (Ion and Neutral CAmera) since 2003 and IBEX since 2009. The IMAP instrumentation proposed for this purpose combines and extends the IBEX and INCA ENA energy ranges (0.3- 20 keV and 3-200 keV, for low and high energy, respectively). All three missions-Voyagers, Cassini/INCA, and IBEX- have made discovery-class measurements in the HS, the Voyagers providing in situ ion intensities at E > 30 keV, while INCA images ENA in the range 5 < E < 55 keV, and IBEX 0.3 < E < 6 keV. The partial overlap in energy coverage between Voyager ions and INCA ENA allows for the possibility of observing the intensity and time evolution of ions in the HS, thought to give rise to the ENAs via charge-exchange, and the resultant ENA images in the inner heliosphere and their spatial and/or temporal variability. Unfortunately, no such "ground truth" ion measurements are possible at Voyager in the ENA energy range imaged by IBEX. Some of the key findings from the Voyager and Cassini/INCA measurements are as follows: (1) The HS contains a hot plasma population that carries a substantial part (30-50 %) of the total pressure at E > 5 keV, the rest residing below that range, resulting in a beta (particle/magnetic pressure) always > 1, typically >10. (2) The width of the HS in the direction of V1 is ~ 30 AU, but is thought to be larger (40-70 AU) in the southern ecliptic where V2 currently travels.. (3) The ENA intensities at E > 5 keV exhibit a correlation with the solar cycle (SC) over the period 2003 to 2015, with minimum intensities in the anti-nose direction observed ~ 1.5 yrs after solar minimum followed by a recovery thereafter. (4) The in situ ion measurements at V2 within the HS

  20. 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

  1. In situ temperature measurements of reaction spaces under microwave irradiation using photoluminescent probes.

    PubMed

    Ano, Taishi; Kishimoto, Fuminao; Sasaki, Ryo; Tsubaki, Shuntaro; Maitani, Masato M; Suzuki, Eiichi; Wada, Yuji

    2016-05-11

    We demonstrate two novel methods for the measurement of the temperatures of reaction spaces locally heated by microwaves, which have been applied here to two example systems, i.e., BaTiO3 particles covered with a SiO2 shell (BaTiO3-SiO2) and layered tungstate particles. Photoluminescent (PL) probes showing the temperature-sensitivity in their PL lifetimes are located in the nanospaces of the above systems. In the case of BaTiO3-SiO2 core-shell particles, rhodamine B is loaded into the mesopores of the SiO2 shell covering the BaTiO3 core, which generates the heat through the dielectric loss of microwaves. The inner nanospace temperature of the SiO2 shell is determined to be 28 °C higher than the bulk temperature under microwave irradiation at 24 W. On the other hand, Eu(3+) is immobilized in the interlayer space of layered tungstate as the PL probe, showing that the nanospace temperature of the interlayer is only 4 °C higher than the bulk temperature. This method for temperature-measurement is powerful for controlling microwave heating and elucidates the ambiguous mechanisms of microwave special effects often observed in chemical reactions, contributing greatly to the practical application of microwaves in chemistry and materials sciences. PMID:27136754

  2. Voyager observations of Zeta Tau

    NASA Technical Reports Server (NTRS)

    Carone, T. E.; Polidan, R. S.

    1987-01-01

    Two Voyager observations of Zeta Tau, a well-known Be/shell star of spectral type B1 IVe and vsin(i) = 220 km/s, separated by 503 days are presented and discussed. The observations show that in the spectral region shortward of Lyman-alpha, the 950-1150 A flux increased by about 40 percent, while in the region longward of 1300 A the flux increased by about 30 percent. Changes in features at 975 A and at 1020 A also appear. The observed change in the continuum flux is probably associated with a change in the effective temperature of the underlying B star, though change in the ubiquitous Fe II lines cannot be ruled out as the cause. The line variations are consistent with IUE spectra of Zeta Tau taken during the same time period.

  3. Voyager 1 Red Spot Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie shows the portion of Jupiter around the Great Red Spot as it swirls through more than 60 Jupiter days. Notice the difference in speed and direction of the various zones of the atmosphere. The interaction of the atmospheric clouds and storm shows how dynamic the Jovian atmosphere is.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 66 images taken once every Jupiter rotation period (about 10 hours). This time-lapse movie uses images taken every time Jupiter longitude 68W passed under the spacecraft. These images were acquired in the Blue filter from Jan. 6 to Feb. 3 1979. The spacecraft flew from 58 million kilometers to 31 million kilometers from Jupiter during that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  4. Voyager 2 Jupiter Eruption Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie records an eruptive event in the southern hemisphere of Jupiter over a period of 8 Jupiter days. Prior to the event, an undistinguished oval cloud mass cruised through the turbulent atmosphere. The eruption occurs over avery short time at the very center of the cloud. The white eruptive material is swirled about by the internal wind patterns of the cloud. As a result of the eruption, the cloud then becomes a type of feature seen elsewhere on Jupiter known as 'spaghetti bowls'.

    As Voyager 2 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 8 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Violet filter around May 6, 1979. The spacecraft was about 50 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  5. The Argonne Voyager multimedia server

    SciTech Connect

    Disz, T.; Judson, I.; Olson, R.; Stevens, R.

    1997-07-01

    With the growing presence of multimedia-enabled systems, one will see an integration of collaborative computing concepts into the everyday environments of future scientific and technical workplaces. Desktop teleconferencing is in common use today, while more complex desktop teleconferencing technology that relies on the availability of multipoint (greater than two nodes) enabled tools is now starting to become available on PCs. A critical problem when using these collaboration tools is the inability to easily archive multistream, multipoint meetings and make the content available to others. Ideally one would like the ability to capture, record, playback, index, annotate and distribute multimedia stream data as easily as one currently handles text or still image data. While the ultimate goal is still some years away, the Argonne Voyager project is aimed at exploring and developing media server technology needed to provide a flexible virtual multipoint recording/playback capability. In this article the authors describe the motivating requirements, architecture implementation, operation, performance, and related work.

  6. Radio science experiment of Voyager-2 spacecraft occultation by Neptune

    NASA Technical Reports Server (NTRS)

    Hayashi, T.; Nishimura, T.; Takano, T.; Yamamoto, Z.; Yamada, M.; Shuto, K.; Saito, H.; Ichikawa, T.; Kawashima, N.; Mizuno, E.

    1990-01-01

    NASA-JPL and Japan's Institute of Space and Astronautical Science collaborated at the Usuda Deep Space Center in the Voyager-2 Neptune occultation experiment. Phase information is extracted from the recorded data by means of a digital filter that can track the carrier frequency and narrow the filter bandwidth by up to 3 mHz. The results thus obtained can verify the phase-stability of the receiving system as a whole. Problems experienced by low-noise amplifiers were solved through the use of system redundancies.

  7. Radio science experiment of Voyager-2 spacecraft occultation by Neptune

    NASA Astrophysics Data System (ADS)

    Hayashi, T.; Nishimura, T.; Takano, T.; Yamamoto, Z.; Yamada, M.; Shuto, K.; Saito, H.; Ichikawa, T.; Kawashima, N.; Mizuno, E.

    NASA-JPL and Japan's Institute of Space and Astronautical Science collaborated at the Usuda Deep Space Center in the Voyager-2 Neptune occultation experiment. Phase information is extracted from the recorded data by means of a digital filter that can track the carrier frequency and narrow the filter bandwidth by up to 3 mHz. The results thus obtained can verify the phase-stability of the receiving system as a whole. Problems experienced by low-noise amplifiers were solved through the use of system redundancies.

  8. 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

  9. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false International voyage. 42.05-45 Section 42.05-45 Shipping... Definition of Terms Used in This Subchapter § 42.05-45 International voyage. (a) The term international voyage as used in this part shall have the same meaning as the term international voyage in Article...

  10. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 2 2014-10-01 2014-10-01 false International voyage. 42.05-45 Section 42.05-45 Shipping... Definition of Terms Used in This Subchapter § 42.05-45 International voyage. (a) The term international voyage as used in this part shall have the same meaning as the term international voyage in Article...

  11. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 2 2012-10-01 2012-10-01 false International voyage. 42.05-45 Section 42.05-45 Shipping... Definition of Terms Used in This Subchapter § 42.05-45 International voyage. (a) The term international voyage as used in this part shall have the same meaning as the term international voyage in Article...

  12. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 2 2013-10-01 2013-10-01 false International voyage. 42.05-45 Section 42.05-45 Shipping... Definition of Terms Used in This Subchapter § 42.05-45 International voyage. (a) The term international voyage as used in this part shall have the same meaning as the term international voyage in Article...

  13. 46 CFR 42.05-45 - International voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false International voyage. 42.05-45 Section 42.05-45 Shipping... Definition of Terms Used in This Subchapter § 42.05-45 International voyage. (a) The term international voyage as used in this part shall have the same meaning as the term international voyage in Article...

  14. Voyager 2 to make closest encounter with Saturn in August

    NASA Technical Reports Server (NTRS)

    1981-01-01

    The planned Voyager 2 Saturn mission is described. Information about Saturn obtained from the Voyager 1 encounter is summarized. Data on the satellites and rings of Saturn are tabulated. The video programming schedule for the Voyager 2 Saturn encounter is given. The Voyager science team is listed.

  15. Interstellar Mapping and Acceleration Probe (IMAP) - Its Time Has Come!

    NASA Astrophysics Data System (ADS)

    Schwadron, N.; Kasper, J. C.; Mewaldt, R. A.; Moebius, E.; Opher, M.; Spence, H. E.; Zurbuchen, T.

    2014-12-01

    Our piece of cosmic real-estate, the heliosphere, is the domain of all human existence -- an astrophysical case-history of the successful evolution of life in a habitable system. By exploring our global heliosphere and its myriad interactions, we develop key physical knowledge of the interstellar interactions that influence exoplanetary habitability as well as the distant history and destiny of our solar system and world. IBEX was the first mission to explore the global heliosphere and in concert with Voyager 1 and Voyager 2 is discovering a fundamentally new and uncharted physical domain of the outer heliosphere. The enigmatic IBEX ribbon is an unanticipated discovery demonstrating that much of what we know or think we understand about the outer heliosphere needs to be revised. The next quantum leap enabled by IMAP will open new windows on the frontier of Heliophysics at a time when the space environment is rapidly evolving. IMAP with 100 times the combined resolution and sensitivity of IBEX will discover the substructure of the IBEX ribbon and will reveal in unprecedented resolution global maps of our heliosphere. The remarkable synergy between IMAP, Voyager 1 and Voyager 2 will remain for at least the next decade as Voyager 1 pushes further into the interstellar domain and Voyager 2 moves through the heliosheath. Voyager 2 moves outward in the vicinity of the IBEX ribbon and its plasma measurements will create singular opportunities for discovery in the context of IMAP's global measurements. IMAP, like ACE before it, will be a keystone of the Heliophysics System Observatory by providing comprehensive cosmic ray, energetic particle, pickup ion, suprathermal ion, neutral atom, solar wind, solar wind heavy ion, and magnetic field observations to diagnose the changing space environment and understand the fundamental origins of particle acceleration. Thus, IMAP is a mission whose time has come. IMAP is the highest ranked next Solar Terrestrial Probe in the Decadal

  16. 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

  17. 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.

  18. Voyager 1 Explores the "Magnetic Highway"

    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...

  19. Wall current probe: A non-invasive in situ plasma diagnostic for space and time resolved current density distribution measurement

    SciTech Connect

    Baude, R.; Gaboriau, F.; Hagelaar, G. J. M.

    2013-08-15

    In the context of low temperature plasma research, we propose a wall current probe to determine the local charged particle fluxes flowing to the chamber walls. This non-intrusive planar probe consists of an array of electrode elements which can be individually biased and for which the current can be measured separately. We detail the probe properties and present the ability of the diagnostic to be used as a space and time resolved measurement of the ion and electron current density at the chamber walls. This diagnostic will be relevant to study the electron transport in magnetized low-pressure plasmas.

  20. Voyager 2 and the Uranian rings

    SciTech Connect

    Porco, C.C.

    1986-12-01

    Voyager 2 data on the Uranian disk system are presented and examined. The disk system consists of nine narrow rings, ranging in width from a few km to about 100 km. The Uranian rings are eccentric, inclined to the planet's equatorial plane, and precessing. The Uranian ring characteristics detected in the Voyager data are described and compared with those of the Saturn rings. The origin and maintenance of the rings are discussed, and the particle distribution in the ring system is studied.

  1. 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.

  2. Probing theories of gravity with phase space-inferred potentials of galaxy clusters

    NASA Astrophysics Data System (ADS)

    Stark, Alejo; Miller, Christopher J.; Kern, Nicholas; Gifford, Daniel; Zhao, Gong-Bo; Li, Baojiu; Koyama, Kazuya; Nichol, Robert C.

    2016-04-01

    Modified theories of gravity provide us with a unique opportunity to generate innovative tests of gravity. In Chameleon f (R ) gravity, the gravitational potential differs from the weak-field limit of general relativity (GR) in a mass dependent way. We develop a probe of gravity which compares high mass clusters, where Chameleon effects are weak, to low mass clusters, where the effects can be strong. We utilize the escape velocity edges in the radius/velocity phase space to infer the gravitational potential profiles on scales of 0.3-1 virial radii. We show that the escape edges of low mass clusters are enhanced compared to GR, where the magnitude of the difference depends on the background field value |fR 0 ¯ | . We validate our probe using N-body simulations and simulated light cone galaxy data. For a Dark Energy Spectroscopic Instrument Bright Galaxy Sample, including observational systematics, projection effects, and cosmic variance, our test can differentiate between GR and Chameleon f (R ) gravity models, |fR 0 ¯ |=4 ×10-6 (2 ×10-6) at >5 σ (>2 σ ), more than an order of magnitude better than current cluster-scale constraints.

  3. Probing Real-Space and Time-Resolved Correlation Functions with Many-Body Ramsey Interferometry

    NASA Astrophysics Data System (ADS)

    Knap, Michael; Kantian, Adrian; Giamarchi, Thierry; Bloch, Immanuel; Lukin, Mikhail D.; Demler, Eugene

    2013-10-01

    We propose to use Ramsey interferometry and single-site addressability, available in synthetic matter such as cold atoms or trapped ions, to measure real-space and time-resolved spin correlation functions. These correlation functions directly probe the excitations of the system, which makes it possible to characterize the underlying many-body states. Moreover, they contain valuable information about phase transitions where they exhibit scale invariance. We also discuss experimental imperfections and show that a spin-echo protocol can be used to cancel slow fluctuations in the magnetic field. We explicitly consider examples of the two-dimensional, antiferromagnetic Heisenberg model and the one-dimensional, long-range transverse field Ising model to illustrate the technique.

  4. Scalar field probes of power-law space-time singularities

    NASA Astrophysics Data System (ADS)

    Blau, Matthias; Frank, Denis; Weiss, Sebastian

    2006-08-01

    We analyse the effective potential of the scalar wave equation near generic space-time singularities of power-law type (Szekeres-Iyer metrics) and show that the effective potential exhibits a universal and scale invariant leading inverse square behaviour ~ x-2 in the ``tortoise coordinate'' x provided that the metrics satisfy the strict Dominant Energy Condition (DEC). This result parallels that obtained in [1] for probes consisting of families of massless particles (null geodesic deviation, a.k.a. the Penrose Limit). The detailed properties of the scalar wave operator depend sensitively on the numerical coefficient of the x-2-term, and as one application we show that timelike singularities satisfying the DEC are quantum mechanically singular in the sense of the Horowitz-Marolf (essential self-adjointness) criterion. We also comment on some related issues like the near-singularity behaviour of the scalar fields permitted by the Friedrichs extension.

  5. Real-space measurement of potential distribution in PECVD ONO electrets by Kelvin probe force microscopy

    NASA Astrophysics Data System (ADS)

    Emmerich, F.; Thielemann, C.

    2016-05-01

    Multilayers of silicon oxide/silicon nitride/silicon oxide (ONO) are known for their good electret properties due to deep energy traps near the material interfaces, facilitating charge storage. However, measurement of the space charge distribution in such multilayers is a challenge for conventional methods if layer thickness dimensions shrink below 1 μm. In this paper, we propose an atomic force microscope based method to determine charge distributions in ONO layers with spatial resolution below 100 nm. By applying Kelvin probe force microscopy (KPFM) on freshly cleaved, corona-charged multilayers, the surface potential is measured directly along the z-axis and across the interfaces. This new method gives insights into charge distribution and charge movement in inorganic electrets with a high spatial resolution.

  6. Real-space measurement of potential distribution in PECVD ONO electrets by Kelvin probe force microscopy.

    PubMed

    Emmerich, F; Thielemann, C

    2016-05-20

    Multilayers of silicon oxide/silicon nitride/silicon oxide (ONO) are known for their good electret properties due to deep energy traps near the material interfaces, facilitating charge storage. However, measurement of the space charge distribution in such multilayers is a challenge for conventional methods if layer thickness dimensions shrink below 1 μm. In this paper, we propose an atomic force microscope based method to determine charge distributions in ONO layers with spatial resolution below 100 nm. By applying Kelvin probe force microscopy (KPFM) on freshly cleaved, corona-charged multilayers, the surface potential is measured directly along the z-axis and across the interfaces. This new method gives insights into charge distribution and charge movement in inorganic electrets with a high spatial resolution. PMID:27053633

  7. Light as a probe of the structure of space-time

    NASA Astrophysics Data System (ADS)

    Tartaglia, Angelo

    2016-05-01

    Light is an intrinsically relativistic probe and when used in an adequately sized array of ring lasers it is sensible to the curvature and to the chirality of space-time. On this basis the GINGER experiment is being implemented at the underground National Laboratories at Gran Sasso. The experiment, whose objective is the measurement of the terrestrial frame dragging effect or deviations from it, will be presented and discussed in its foundation. Furthermore, at a bigger scale, the possibilities given by the under way GAIA mission and the proposed AGP, will be analyzed with a special attention paied to the possibility of extracting information concerning the angular momenta of the sun and the main bodies of the solar system.

  8. Comparison of Galileo Probe and Earth-Based Translation Rates of Jupiter's Equatorial Clouds

    PubMed

    Beebe; Simon; Huber

    1996-05-10

    The Doppler wind speeds derived from Galileo probe data are comparable with the maximum translation speeds observed in the equatorial zone by Voyager 1 and the Hubble Space Telescope. Slower published values of east-west winds are based on measurements of larger features and should be interpreted as translation rates of large weather systems interacting with the wind. The nature of the hot-spot region that the Galileo probe entered is compatible with a high-speed jet at 6 degrees north. The hot spot is associated with an equatorial weather system that spans 5 degrees of latitude and translates at 103 meters per second. PMID:8662572

  9. Voyages Through Time: Everything Evolves

    NASA Astrophysics Data System (ADS)

    Fisher, Jane; Tarter, Jill; Devore, Edna; Pendleton, Yvonne; O'Sullivan, Kathleen; Burke, Meg

    2004-06-01

    The SETI Institute, the California Academy of Sciences, NASA Ames Research Center, and San Francisco State University have developed standards-based curriculum materials for a one-year high school integrated science course centered on the unifying theme of evolution. Scientists, teachers, curriculum writers, and media specialists are currently finalizing six modules that integrate astronomical, geological, and biological sciences as well as the history of science and technology. The sequence of lessons in each module is designed to promote students' understanding and skills as defined by the National Science Education Standards and Benchmarks for Science Literacy. The modules cover: Cosmic Evolution, Planetary Evolution, Origin of Life, Evolution of Life, Hominid Evolution, and the Evolution of Technology. The core lessons for all six modules are provided via CD-ROM, including instructional guidelines, science background information, and additional resources (print, audiovisual, software, WWW sites, and databases). These products will be published as a complete set for use as a yearlong science course and will also be available as individual modules for use in discipline-based courses. Evolutionary change is a powerful framework for studying our world and our place therein. It is a story of epic size, capable of inspiring awe and of expanding our sense of time and place. This story is the basis of Voyages Through Time.

  10. 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

  11. Application of high stability oscillators to radio science experiments using deep space probes

    NASA Technical Reports Server (NTRS)

    Kursinski, Emil R.

    1990-01-01

    The microwave telecommunication links between the earth and deep space probes have long been used to conduct radio science experiments which take advantage of the phase coherency and stability of these links. These experiments measure changes in the phase delay of the signals to infer electrical, magnetic and gravitational properties of the solar system environment and beyond through which the spacecraft and radio signals pass. The precision oscillators, from which the phase of the microwave signals are derived, play a key role in the stability of these links and therefore the sensitivity of these measurements. These experiments have become a driving force behind recent and future improvements in the Deep Space Network and spacecraft oscillators and frequency and time distribution systems. Three such experiments which are key to these improvements are briefly discussed and relationship between their sensitivity and the signal phase stability is described. The first is the remote sensing of planetary atmospheres by occultation in which the radio signal passes through the atmosphere and is refracted causing the signal pathlength to change from which the pressure and the temperature of the atmosphere can be derived. The second experiment is determination of the opacity of planetary rings by passage of the radio signals through the rings. The third experiment is the research for very low frequency gravitational radiation. The fractional frequency variation of the signal is comparable to the spatial strain amplitude the system is capable of detecting. A summary of past results and future possibilities for these experiments are presented.

  12. Probing the bioactivity-relevant chemical space of robust reactions and common molecular building blocks.

    PubMed

    Hartenfeller, Markus; Eberle, Martin; Meier, Peter; Nieto-Oberhuber, Cristina; Altmann, Karl-Heinz; Schneider, Gisbert; Jacoby, Edgar; Renner, Steffen

    2012-05-25

    In the search for new bioactive compounds, there is a trend toward increasingly complex compound libraries aiming to target the demanding targets of the future. In contrast, medicinal chemistry and traditional library design rely mainly on a small set of highly established and robust reactions. Here, we probe a set of 58 such reactions for their ability to sample the chemical space of known bioactive molecules, and the potential to create new scaffolds. Combined with ~26,000 common available building blocks, the reactions retrieve around 9% of a scaffold-diverse set of compounds active on human target proteins covering all major pharmaceutical target classes. Almost 80% of generated scaffolds from virtual one-step synthesis products are not present in a large set of known bioactive molecules for human targets, indicating potential for new discoveries. The results suggest that established synthesis resources are well suited to cover the known bioactivity-relevant chemical space and that there are plenty of unexplored regions accessible by these reactions, possibly providing valuable "low-hanging fruit" for hit discovery. PMID:22512717

  13. 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.

  14. Telecommunications and data acquisition systems support for Voyager missions to Jupiter and Saturn, 1972-1981, prelaunch through Saturn encounter

    NASA Technical Reports Server (NTRS)

    Traxler, M. R.; Beauchamp, D. F.

    1983-01-01

    The Deep Space Network has supported the Voyager Project for approximately nine years, during which time implementation, testing, and operational support was provided. Four years of this time involved testing prior to launch; the final five years included network operations support and additional network implementation. Intensive and critical support intervals included launch and four planetary encounters. The telecommunications and data acquisition support for the Voyager Missions to Jupiter and Saturn are summarized.

  15. DC Langmuir Probe for Measurement of Space Plasma: A Brief Review

    NASA Astrophysics Data System (ADS)

    Oyama, Koichiro

    2015-09-01

    Herein, we discuss the in situ measurement of the electron temperature in the ionosphere/plasmasphere by means of DC Langmuir probes. Major instruments which have been reported are a conventional DC Langmuir probe, whose probe voltage is swept; a pulsed probe, which uses pulsed bias voltage; a rectification probe, which uses sinusoidal signal; and a resonance cone probe, which uses radio wave propagation. The content reviews past observations made with the instruments above. We also discuss technical factors that should be taken into account for reliable measurement, such as problems related to the contamination of electrodes and the satellite surface. Finally, we discuss research topics to be studied in the near future.

  16. Voyager planetary radio astronomy studies

    NASA Technical Reports Server (NTRS)

    Staelin, David H.; Eikenberry, Stephen S.

    1993-01-01

    Analysis of nonthermal radio emission data obtained by the Planetary Radio Astronomy (PRA) spectrometers on the Voyager 1 and 2 spacecraft was performed. This PRA data provided unique insights into the radio emission characteristics of the outer planets because of PRA's unique spectral response below the terrestrial ionospheric plasma frequency and its unprecedented proximity to the source. Of those results which were documented or published, this final report surveys only the highlights and cites references for more complete discussions. Unpublished results for Uranus, Neptune, and theoretical Ionian current distributions are presented at greater length. The most important conclusion to be drawn from these observations is that banded spectral emission is common to the radio emission below 1-2 MHz observed from all four Jovian planets. In every case multiple spectral features evolve on time scales of seconds to minutes. To the extent these features drift in frequency, they appear never to cross one another. The Neptunian spectral features appear to drift little or not at all, their evolution consisting principally of waxing and waning. Since other evidence strongly suggests that most or all of this radio emission is occurring near the local magnetospheric electron cyclotron frequency, this implies that this emission preferentially occurs at certain continually changing planetary radii. It remains unknown why certain radii might be favored, unless radial electric field components or other means serve to differentiate radially the magnetospheric plasma density, particle energy vectors, or particle coherence. Calculation of the spatial distribution and intensity of the Io-generated magnetospheric currents are also presented; these currents may be limited principally by wave impedance and local field strengths.

  17. Miranda as seen by Voyager 2

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Flying by in early 1986, Voyager 2 captured this picture of Miranda, which enabled scientists to study this moon of Uranus in much greater detail than ever before. Discovered in 1948 by Gerard Peter Kuiper, Miranda is named for the daughter of the wily Prospero in Shakespeare's 'The Tempest.' It is the eleventh known satellite of Uranus and the innermost large moon of Uranus It was necessary that Voyager 2 passed by Miranda, not for scientific reasons, but simply for the gravity assist it needed to go on to Neptune. Due to the position of the entire Solar System, Miranda provided the energy to throw Voyager 2 to Neptune. Before Voyager, Miranda was largely ignored as it is not the largest moon and did not seem to have any other outstanding qualities. Fortunately, however, Voyager passed close enough to Miranda to provide scientists with fascinating photographs that captivated astronomers. About half ice and half rock, Miranda's surface has terraced layers that indicate both older and new surfaces coexisting. Since the mixing of ancient and recent surfaces is rare in planetary geology, scientists have postulated two explanations for the different ages of the numerous valleys and cliffs on Miranda. One theory is that Miranda could have shattered as many as five times and was then reassembled. Another hypothesis is that partly melted ice upwells forced new surfaces to emerge.

  18. Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities

    SciTech Connect

    Demidov, V. I.; Koepke, M. E.; Raitses, Y.

    2010-10-15

    By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an electron-temperature-dependent offset, i.e., the case with an equal-collection-area probe. This design goal is achieved by combining an ambient magnetic field in the plasma with baffles, or shields, on the probe, resulting in species-selective magnetic insulation of the probe collection area. This permits the elimination of electron current to the probe by further adjustment of magnetic insulation which results in an ion-temperature-dependent offset when the probe is electrically floating. Subtracting the floating potential of two magnetically insulated baffled probes, each with a different degree of magnetic insulation, enables the electron or ion temperature to be measured in real time.

  19. A Model Space Mission to probe Einstein's Equivalence Principle - The STE-QUEST Study

    NASA Astrophysics Data System (ADS)

    Heske, Astrid; Cacciapuoti, Luigi; Gehler, Martin

    Understanding General Relativity at all scales requires, in particular, understanding gravity at quantum level. To attempt this, tests of the most prominent aspect of General Relativity, the Einstein Equivalence Principle, can be performed with the next generation of atomic quantum sensors to significantly improved accuracy. To exploit the ultimate limits of atomic sensors a dedicated space platform is needed; the advantages space offers are, among others, unperturbed free-fall conditions, longer interaction times per measurement and large variations in velocity and gravitational field. In the frame of the third medium class launch opportunity of ESA's Cosmic Vision 2015 - 2025 programme a study was conducted - STE-QUEST (Space-Time Explorer and QUantum Equivalence principle Test), one of the candidates for a medium class mission - and the feasibility of such a mission assessed. The spacecraft would carry two instruments probing the different aspects of the Einstein Equivalence Principle: begin{enumerate} A dual species ( (87) Rb and (85) Rb) atom interferometer to probe the universality of propagation of matter waves. A high-performance time and frequency link dedicated to comparison of atomic clocks on ground. The specific primary science objectives for STE-QUEST are: begin{enumerate} Universality of propagation of matter waves test begin{itemize} Test of the universality of free fall of matter waves to an uncertainty of the Eötvös ratio lower than 2*10 (-15) . Gravitational redshift tests begin{itemize} Sun gravitational red-shift measurement to a fractional uncertainty of 2*10 (-6) , with an ultimate goal of 5*10 (-7) . Moon gravitational red-shift measurement to a fractional uncertainty of 4*10 (-4) , with an ultimate goal of 9*10 (-5) . Such a measurement has never been attempted before. The availability of an atomic clock on-board the spacecraft (optional) would additionally allow testing the Earth gravitational red-shift measurement to a fractional

  20. Voyager Plasma Observations in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.

    2012-12-01

    The Voyager spacecraft are both more than 20 AU past the termination shock. The plasma experiment on Voyager 2 measures the plasma velocity, density, and temperature. This paper discusses the recent observations. The density increased in 2011 by a factor of 2 and in 2012 has remained at the higher level. The speed had been roughly constant since the TS but recently has started to decrease; the speed profile is very different from that at Voyager 1. The plasma at V2 continues to turn tailward. The V1 and V2 data will be compared, and we will discuss the magnetic flux which is conserved at V2 but not at V1.

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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 around voids identified with a watershed algorithm in redshift space and compare the results with the expectation from general relativity and the ΛCDM model. We find linear theory to work remarkably well in describing the dynamics of voids. Adopting a Bayesian inference framework, we explore the full posterior of our model parameters and forecast the achievable accuracy on measurements of the growth rate of structure and the geometric distortion through the Alcock-Paczyński effect. Systematic errors in the latter are reduced from ~15% to ~5% when peculiar velocities are taken into account. The relative parameter uncertainties in galaxy surveys with number densities comparable to the SDSS MAIN (CMASS) sample probing a volume of 1h-3Gpc3 yield σf/b/(f/b).~2% (20%) and σDAH/DAH~0.2% (2%), respectively. At this level of precision the linear-theory model becomes systematics dominated, with parameter biases that fall beyond these values. Nevertheless, the presented method is highly model independent; its viability lies in the underlying assumption of statistical isotropy of the Universe.

  2. 15 CFR 970.2502 - Post voyage report.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2502 Post voyage report. Within 30 days of the conclusion of each exploration voyage, the United...

  3. 15 CFR 970.2502 - Post voyage report.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ENVIRONMENTAL DATA SERVICE DEEP SEABED MINING REGULATIONS FOR EXPLORATION LICENSES Pre-license Exploration § 970.2502 Post voyage report. Within 30 days of the conclusion of each exploration voyage, the United...

  4. 46 CFR 185.280 - Official Logbook for foreign voyages.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... wages due to a seaman who dies during the voyage and the gross amount of all deductions to be made from the wages; (ii) The sale of the property of a seaman who dies during the voyage, including a...

  5. 46 CFR 185.280 - Official Logbook for foreign voyages.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... wages due to a seaman who dies during the voyage and the gross amount of all deductions to be made from the wages; (ii) The sale of the property of a seaman who dies during the voyage, including a...

  6. 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.

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20 Shipping... VESSELS Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States port or place on the Great Lakes to another United States port or place on...

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

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 2 2011-10-01 2011-10-01 false Great Lakes voyage. 46.05-20 Section 46.05-20 Shipping... VESSELS Definitions Used in This Part § 46.05-20 Great Lakes voyage. A Great Lakes voyage is any voyage from a United States port or place on the Great Lakes to another United States port or place on...

  9. Limiting vibration in space lattices

    SciTech Connect

    Midturi, S.

    1997-12-01

    Using finite-element analysis and other methods, engineers are evaluating ways to control the vibrations and extend the use of flexible, deployable structures in space. The exploration of the universe by the United States has led to many technological innovations for space travel. Among them are lightweight lattice structures and booms, which have been used on the Voyager probes to the outer planets, the Hubble space telescope,m and many other missions. Typical applications of lattice structures in space include instrument booms, antennae, and solar-array deployers and supports. Booms are designed for automatic deployment to a controlled length and retraction into a very compact stowage volume. Deployable solar booms are often subjected to severe vibration while in orbit, and vibration must be limited or completely eliminated for safe and satisfactory performance.

  10. 46 CFR 46.05-10 - Foreign voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Foreign voyage. 46.05-10 Section 46.05-10 Shipping COAST... VESSELS Definitions Used in This Part § 46.05-10 Foreign voyage. (a) A foreign voyage for the purpose of... jurisdiction of the United States and a port of a foreign country, its colonies, territories, or...

  11. 46 CFR 175.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Vessels on an international voyage. 175.120 Section 175... 100 GROSS TONS) GENERAL PROVISIONS § 175.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with...

  12. 46 CFR 175.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Vessels on an international voyage. 175.120 Section 175... 100 GROSS TONS) GENERAL PROVISIONS § 175.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with...

  13. 46 CFR 175.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Vessels on an international voyage. 175.120 Section 175... 100 GROSS TONS) GENERAL PROVISIONS § 175.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with...

  14. 46 CFR 188.10-35 - International voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false International voyage. 188.10-35 Section 188.10-35... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-35 International voyage. (a) This section describes those voyages which are considered to be “international voyages” for the purposes of...

  15. 46 CFR 175.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Vessels on an international voyage. 175.120 Section 175... 100 GROSS TONS) GENERAL PROVISIONS § 175.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with...

  16. 46 CFR 188.10-35 - International voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false International voyage. 188.10-35 Section 188.10-35... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-35 International voyage. (a) This section describes those voyages which are considered to be “international voyages” for the purposes of...

  17. 46 CFR 188.10-35 - International voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false International voyage. 188.10-35 Section 188.10-35... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-35 International voyage. (a) This section describes those voyages which are considered to be “international voyages” for the purposes of...

  18. 46 CFR 114.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Vessels on an international voyage. 114.120 Section 114... PROVISIONS § 114.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with the applicable requirements of SOLAS...

  19. 46 CFR 114.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Vessels on an international voyage. 114.120 Section 114... PROVISIONS § 114.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with the applicable requirements of SOLAS...

  20. 46 CFR 188.10-35 - International voyage.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false International voyage. 188.10-35 Section 188.10-35... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-35 International voyage. (a) This section describes those voyages which are considered to be “international voyages” for the purposes of...

  1. 46 CFR 175.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Vessels on an international voyage. 175.120 Section 175... 100 GROSS TONS) GENERAL PROVISIONS § 175.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with...

  2. 46 CFR 188.10-35 - International voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false International voyage. 188.10-35 Section 188.10-35... PROVISIONS Definition of Terms Used in This Subchapter § 188.10-35 International voyage. (a) This section describes those voyages which are considered to be “international voyages” for the purposes of...

  3. 46 CFR 114.120 - Vessels on an international voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Vessels on an international voyage. 114.120 Section 114... PROVISIONS § 114.120 Vessels on an international voyage. A mechanically propelled vessel that carries more than 12 passengers on an international voyage must comply with the applicable requirements of SOLAS...

  4. Enhancing Resilience in Youth through a 10-Day Developmental Voyage

    ERIC Educational Resources Information Center

    Hayhurst, Jill; Hunter, John A.; Kafka, Sarah; Boyes, Mike

    2015-01-01

    The present study sought to examine the potential for resilience to be enhanced in a group of youth participating in a developmental voyage, and to identify the factors that contribute to increased resilience following the voyage. Two studies are reported. Study 1 revealed that voyage participants experienced increased resilience over the course…

  5. 15 CFR 970.2502 - Post voyage report.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 15 Commerce and Foreign Trade 3 2014-01-01 2014-01-01 false Post voyage report. 970.2502 Section 970.2502 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued....2502 Post voyage report. Within 30 days of the conclusion of each exploration voyage, the United...

  6. Voyager Reading Programs. What Works Clearinghouse Intervention Report

    ERIC Educational Resources Information Center

    What Works Clearinghouse, 2010

    2010-01-01

    "Voyager Passport"[TM] is a supplemental reading intervention system for students in grades K-5. "Voyager Passport Reading Journeys"[TM] is a reading intervention program designed for adolescents who struggle with reading. The "Voyager Universal Literacy System"[R] is a K-3 reading program that includes a core reading curriculum; a progress…

  7. Data Announcement Bulletin: Voyager 1 and Voyager 2 Jupiter Encounter Data

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Available data on imaging, infrared spectroscopy and radiometry, triaxial fluxgate magnetometers, the multifilter photopolarimeter, planetary radio astronomy, and radio science is described. The Voyager experiments are listed, and it is indicated on which experiments data is available.

  8. 46 CFR 122.503 - Voyage plan.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Voyage plan. 122.503 Section 122.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS OPERATIONS Preparations...

  9. 46 CFR 122.503 - Voyage plan.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Voyage plan. 122.503 Section 122.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS OPERATIONS Preparations...

  10. 46 CFR 122.503 - Voyage plan.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Voyage plan. 122.503 Section 122.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS OPERATIONS Preparations...

  11. 46 CFR 122.503 - Voyage plan.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Voyage plan. 122.503 Section 122.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS OPERATIONS Preparations...

  12. 46 CFR 122.503 - Voyage plan.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Voyage plan. 122.503 Section 122.503 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS CARRYING MORE THAN 150 PASSENGERS OR WITH OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS OPERATIONS Preparations...

  13. Voyager 2's encounter with Neptune

    NASA Technical Reports Server (NTRS)

    Mclaughlin, William I.

    1990-01-01

    The results of Voyager 2 observations of Neptune are reviewed. Observations of Neptune's Great Dark Spot, rotation atmosphere, magnetic field, rings, and satellites are discussed. Also, observations of Triton are considered, noting the presence of geyser activity on the satellite. Several photographs of features on both Neptune and Triton are presented.

  14. The Second Voyage of the Mimi.

    ERIC Educational Resources Information Center

    Bank Street Coll. of Education, New York, NY.

    This book includes 12 units that have been adapted from the television series "Voyage of the Mimi." Each unit includes the episode, an activity, and an expedition. The episodes introduce and accompany each episode of the television series. The activity is an extension of that episode which can be done in the classroom. Mapping skills, foreign…

  15. The Hemispheric Roots of the Columbian Voyages.

    ERIC Educational Resources Information Center

    Shaffer, Lynda N.

    1991-01-01

    Urges that the search for origins of European exploration extend to Africa and East Asia and their international trade. Cites contributions of India and the Arabs, Chinese, and Malaysians. Emphasizes the importance of mathematics, navigation, and sailing technology. Argues that without these contributions the European voyages would not have been…

  16. Group-galaxy correlations in redshift space as a probe of the growth of structure

    NASA Astrophysics Data System (ADS)

    Mohammad, F. G.; de la Torre, S.; Bianchi, D.; Guzzo, L.; Peacock, J. A.

    2016-05-01

    We investigate the use of the cross-correlation between galaxies and galaxy groups to measure redshift-space distortions (RSD) and thus probe the growth rate of cosmological structure. This is compared to the classical approach based on using galaxy auto-correlation. We make use of realistic simulated galaxy catalogues that have been constructed by populating simulated dark matter haloes with galaxies through halo occupation prescriptions. We adapt the classical RSD dispersion model to the case of the group-galaxy cross-correlation function and estimate the RSD parameter β by fitting both the full anisotropic correlation function ξs(rp, π) and its multipole moments. In addition, we define a modified version of the latter statistics by truncating the multipole moments to exclude strongly non-linear distortions at small transverse scales. We fit these three observable quantities in our set of simulated galaxy catalogues and estimate statistical and systematic errors on β for the case of galaxy-galaxy, group-group, and group-galaxy correlation functions. When ignoring off-diagonal elements of the covariance matrix in the fitting, the truncated multipole moments of the group-galaxy cross-correlation function provide the most accurate estimate, with systematic errors below 3 per cent when fitting transverse scales larger than 10 h-1 Mpc. Including the full data covariance enlarges statistical errors but keep unchanged the level of systematic error. Although statistical errors are generally larger for groups, the use of group-galaxy cross-correlation can potentially allow the reduction of systematics while using simple linear or dispersion models.

  17. Spectrophotometric probe

    DOEpatents

    Prather, W.S.; O'Rourke, P.E.

    1994-08-02

    A support structure is described 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. 3 figs.

  18. Spectrophotometric probe

    DOEpatents

    Prather, William S.; O'Rourke, Patrick E.

    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.

  19. Rossi and Space Physics

    NASA Astrophysics Data System (ADS)

    Stone, Edward

    2012-03-01

    The beginning of the Space Age opened a new realm of exploration and Bruno Rossi immediately focused on devising an instrument for studying the interplanetary environment. The modulated Faraday cup that he and his colleagues developed was launched on Explorer X on March 21, 1961. Although the lifetime of the battery-powered spacecraft was only 60 hours, that was long enough for the MIT plasma probe to reveal a hot, supersonic solar wind flowing along the flank of the Earth's magnetosphere. The legacy of that first short flight now extends outward on a 34-year journey to 98 AU where the plasma probe on Voyager 2 measures the deflection of the subsonic wind as it approaches the outer frontier of the heliosphere and contact with the interstellar plasma outside. Over the coming decade that legacy will extend inward to within 0.05 AU of the Sun as the plasma probe on Solar Probe Plus explores the region near the inner frontier and the source of the supersonic solar wind. The exploration of the solar wind from near its beginning outward to its end will be a lasting tribute to Bruno Rossi's contributions to Space Physics.

  20. Planetary radio astronomy observations from Voyager 2 near Jupiter

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Pearce, J. B.; Riddle, A. C.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Thieman, J. R.; Carr, T. D.; Gulkis, S.; Boischot, A.

    1979-01-01

    The Voyager 2 Planetary Radio Astronomy experiment to Jupiter has confirmed and extended to higher zenomagnetic latitudes results from the identical experiment carried by Voyager 1. The kilometric emissions discovered by Voyager 1 often extended to 1 megahertz or higher on Voyager 2 and often consisted of negatively, or less frequently, positively drifting narrowband bursts. On the basis of tentative identification of plasma wave emissions similar to those detected by Voyager 1, the plasma torus associated with Io appeared somewhat denser to Voyager 2 than it did to Voyager 1. The paper reports on quasi-periodic sinusoidal or impulsive bursts in the broadcast band range of wavelengths (800 to 1800 kHz). A Faraday effect appears at decametric frequencies, which probably results from propagation of the radiation near its sources on Jupiter. Finally, the occurrence of decametric emission in homologous arc families is discussed.

  1. Magnetic field studies at jupiter by voyager 2: preliminary results.

    PubMed

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

    1979-11-23

    Data from the Goddard Space Flight Center magnetometers on Voyager 2 have yielded on inbound trajectory observations of multiple crossings of the bow shock and magnetosphere near the Jupiter-sun line at radial distances of 99 to 66 Jupiter radii (RJ) and 72 to 62 RJ, respectively. While outbound at a local hour angle of 0300, these distances increase appreciably so that at the time of writing only the magnetopause has been observed between 160 and 185 RJ. These results and the magnetic field geometry confirm the earlier conclusion from Voyager I studies that Jupiter has an enormous magnetic tail, approximately 300 to 400 RJ in diameter, trailing behind the planet with respect to the supersonic flow of the solar wind. Addi- tional observations of the distortion of the inner magnetosphere by a concentrated plasma show a spatial merging of the equatorial magnetodisk current with the cur- rent sheet in the magnetic tail. The spacecraft passed within 62,000 kilometers of Ganymede (radius = 2,635 kilometers) and observed characteristic fluctuations in- terpreted tentatively as being due to disturbances arising from the interaction of the Jovian magnetosphere with Ganymede. PMID:17733916

  2. Antenna arraying of Voyager telemetry signals by symbol stream combining

    NASA Astrophysics Data System (ADS)

    Hurd, W. J.; Rabkin, J.; Russell, M. D.; Siev, B.; Cooper, H. W.; Anderson, T. O.; Winter, P. U.

    1986-08-01

    Telemetry signals received from the Voyager 2 spacecraft at Deep Space Stations at Parkes and Canberra, Australia, on February 6, 1986, were combined by the method of symbol stream combining. This second demonstration of symbol stream combining followed the International Cometary Explorer (ICE) demonstration at Giacobini-Zinner encounter in September 1985. The Voyager demonstration was at a symbol rate of 43.2 ksymb/s, compared to 2 ksymb/s for ICE. Recording, playback, and combining at this higher rate were demonstrated. The average symbol signal-to-noise ratio (SNR) of the combined data was 2.84 dB, or 0.23 dB less than the sum of the SNRs of the two imput symbol streams. This 0.23 loss from ideal combining was due to use of 4-bit quantization of the input symbol stream and imperfect scaling. A practical implementation with 8-bit quantization could achieve combining losses of under 0.05 dB over a wide dynamic range of input signal levels.

  3. Vision and Voyages: Lessons Learned from the Planetary Decadal Survey

    NASA Astrophysics Data System (ADS)

    Squyres, S. W.

    2015-12-01

    The most recent planetary decadal survey, entitled Vision and Voyages for Planetary Science in the Decade 2013-2022, provided a detailed set of priorities for solar system exploration. Those priorities drew on broad input from the U.S. and international planetary science community. Using white papers, town hall meetings, and open meetings of the decadal committees, community views were solicited and a consensus began to emerge. The final report summarized that consensus. Like many past decadal reports, the centerpiece of Vision and Voyages was a set of priorities for future space flight projects. Two things distinguished this report from some previous decadals. First, conservative and independent cost estimates were obtained for all of the projects that were considered. These independent cost estimates, rather than estimates generated by project advocates, were used to judge each project's expected science return per dollar. Second, rather than simply accepting NASA's ten-year projection of expected funding for planetary exploration, decision rules were provided to guide program adjustments if actual funding did not follow projections. To date, NASA has closely followed decadal recommendations. In particular, the two highest priority "flagship" missions, a Mars rover to collect samples for return to Earth and a mission to investigate a possible ocean on Europa, are both underway. The talk will describe the planetary decadal process in detail, and provide a more comprehensive assessment of NASA's response to it.

  4. Galileo Regio Mosaic - Galileo over Voyager Data

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A mosaic of four Galileo images of the Galileo Regio region on Ganymede (Latitude 18 N, Longitude: 149 W) is shown overlayed on the data obtained by the Voyager 2 spacecraft in 1979. North is to the top of the picture, and the sun illuminates the surface from the lower left, about 58 degrees above the horizon. The smallest features that can be discerned are about 80 meters (262 feet) in size in the Galileo images. These Galileo images show fine details of the dark terrain that makes up about half of the surface of the planet-sized moon. Ancient impact craters of various sizes and states of degradation testify to the great age of the terrain, dating back several billion years. The images reveal distinctive variations in albedo from the brighter rims, knobs, and furrow walls to a possible accumulation of dark material on the lower slopes, and crater floors. High photometric activity (large light contrast at high spatial frequencies) of this ice-rich surface was such that the Galileo camera's hardware data compressor was pushed into truncating lines. The north-south running gap between the left and right halves of the mosaic is a result of line truncation from the normal 800 samples per line to about 540. The images were taken on 27 June, 1996 Universal Time at a range of 7,580 kilometers (4,738 miles) through the clear filter of the Galileo spacecraft's imaging system. Launched in October 1989, Galileo entered orbit around Jupiter on December 7, 1995. The spacecraft's mission is to conduct detailed studies of the giant planet, its largest moons and the Jovian magnetic environment. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC.

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  5. Space and time-resolved probing of heterogeneous catalysis reactions using lab-on-a-chip

    NASA Astrophysics Data System (ADS)

    Navin, Chelliah V.; Krishna, Katla Sai; Theegala, Chandra S.; Kumar, Challa S. S. R.

    2016-03-01

    Probing catalytic reactions on a catalyst surface in real time is a major challenge. Herein, we demonstrate the utility of a continuous flow millifluidic chip reactor coated with a nanostructured gold catalyst as an effective platform for in situ investigation of the kinetics of catalytic reactions by taking 5-(hydroxymethyl)furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) conversion as a model reaction. The idea conceptualized in this paper can not only dramatically change the ability to probe the time-resolved kinetics of heterogeneous catalysis reactions but also used for investigating other chemical and biological catalytic processes, thereby making this a broad platform for probing reactions as they occur within continuous flow reactors.Probing catalytic reactions on a catalyst surface in real time is a major challenge. Herein, we demonstrate the utility of a continuous flow millifluidic chip reactor coated with a nanostructured gold catalyst as an effective platform for in situ investigation of the kinetics of catalytic reactions by taking 5-(hydroxymethyl)furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) conversion as a model reaction. The idea conceptualized in this paper can not only dramatically change the ability to probe the time-resolved kinetics of heterogeneous catalysis reactions but also used for investigating other chemical and biological catalytic processes, thereby making this a broad platform for probing reactions as they occur within continuous flow reactors. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr06752a

  6. Investigating Global Ion and Neutral Atom Populations with IBEX and Voyager

    NASA Technical Reports Server (NTRS)

    Florinski, Vladimir

    2016-01-01

    The main objective of this project was to investigate pickup ion (PUI) production in the solar wind and heliosheath (the region between the termination shock and the heliopause) and compute the distributed energetic neutral atom fluxes throughout the helioshpere. The simulations were constrained by comparing the model output against observations from Ulysses, New Horizons, Voyager 1 and 2, and IBEX space probes. As evidenced by the number of peer reviewed journal publications resulting from the project (13 plus three submitted) and their citation rate (156 citations over three years), the project has made a lasting contribution to the field. The outcome is a significant improvement of our understanding of the pickup ion production and distribution in the distant heliosphere. The team has accomplished the entire set of tasks A-H set forth in the proposal. Namely, the transport modeling framework has been augmented with two populations of pickup ions (PUIs), the boundary conditions for the plasma and interstellar neutral hydrogen were verified against Ulysses and New Horizons PUI and an optimal set of velocity diffusion parameters established. The multi-component fluxes of PUIs were computed and isotropic velocity distributions generated for each cell in the computer simulation that covered the heliosphere from 1.5 AU to the heliopause. The distributions were carefully compared with in situ measurements at 3 AU (Ulysses), 12 AU (New Horizons), and 80-90 AU (Voyager 1 and 2) as well as those inferred from ENA fluxes measured by Cassini and IBEX (Wu et al., 2016). Some examples of modeldata comparison are shown in Figure 1. We have used coupled MHD-plasma and kinetic-neutral code to investigate the likely range of plasma and magnetic field parameters in the local interstellar medium (LISM), based on the assumption that the shape of the IBEX ribbon could be used to determine the orientation of the interstellar magnetic field. While the magnetic field is believed to be

  7. New method for probing Kerr space-time based on imaging observation of in-falling gas blob

    NASA Astrophysics Data System (ADS)

    Moriyama, Kotaro; Mineshige, Shin

    2016-06-01

    We propose a new observational method to probe the black hole space-time described by Einstein's theory. We consider a gas blob with an arc shape falling from the marginally stable orbit onto a black hole, carrying a finite amount of angular momentum. Previously, we proposed measuring the black hole spin from the flux variation data of the in-falling blob, assuming the Kerr space-time. We demonstrate here that we can independently measure the black hole spin solely by using the imaging data of the in-falling blob. We then introduce a Kerr-like hole (with one additional parameter which describes a stronger or weaker frame-dragging effect than that of the Kerr hole) and apply the two different methods of spin measurement: one based on the flux variation data and the other based on the imaging data. We obtain different spin values by the different methods for the Kerr-like hole. This is because these methods are sensitive to different components of the metric. We can in this way probe the black hole space-time through the comparison of the estimated spin values; that is, if the black hole space-time is described by the Kerr metric, all of them should coincide.

  8. On whether or not voyager 1 has crossed the heliopause

    SciTech Connect

    Fisk, L. A.; Gloeckler, G.

    2014-07-01

    The Voyager 1 spacecraft is currently in the vicinity of the heliopause, which separates the heliosphere from the local interstellar medium. There has been a precipitous decrease in particles accelerated in the heliosphere, and a substantial increase in galactic cosmic rays (GCRs), suggesting easy escape of the former across the heliopause, and entry of the latter. The question is, has Voyager 1 actually crossed the heliopause and is it now in the interstellar medium? We contend that the evidence is inconclusive. The direction of the magnetic field observed by Voyager 1 is unchanged from the direction of the heliospheric magnetic field, and different from the expected direction of the interstellar magnetic field. However, the plasma density, which is measured from observations of plasma waves, is similar to the expected interstellar density and much larger than the solar wind plasma density observed by Voyager 2 (which has a working plasma detector) at smaller heliocentric distances than Voyager 1. In this paper, an analytic model is presented that is based upon and is consistent with all Voyager observations, and in which the higher plasma densities measured by Voyager 1 are due simply to compressed solar wind. Thus both the magnetic field and the plasma density observations are consistent with Voyager 1 still remaining well within the heliosheath. The model has a simple test: Voyager 1 should encounter a magnetic sector boundary crossing, where the behavior of particles accelerated in the heliosphere and the GCRs will be different from what Voyager 1 is now observing.

  9. New Access and Analysis Tools for Voyager LECP Data

    NASA Astrophysics Data System (ADS)

    Brown, L. E.; Hill, M. E.; Decker, R. B.; Cooper, J. F.; Krimigis, S. M.; Vandegriff, J. D.

    2008-12-01

    The Low Energy Charged Particle (LECP) instruments on the Voyager 1 and 2 spacecraft have been returning unique scientific measurements since launching in 1977, most notably observations from the historic tour of the giant planets. As these spacecraft continue on their exit trajectories from the Solar system they have become an interstellar mission and have begun to probe the boundary between the heliosphere and the interstellar cloud and continue to make exciting discoveries. As the mission changed from one focused on discrete encounters to an open ended search for heliospheric boundaries and transitory disturbances, the positions and timing of which are not known, the data processing needs have changed. Open data policies and the push to draw data under the umbrella of emerging Virtual Observatories have added a data sharing component that was not a part of the original mission plans. We present our work in utilizing new, reusable software analysis tools to access legacy data in a way that leverages pre-existing data analysis techniques. We took an existing Applied Physics Laboratory application, Mission Independent Data Layer (MIDL) -- developed originally under a NASA Applied Information Research Program (AISRP) and subsequently used with data from Geotail, Cassini, IMP-8, ACE, Messenger, and New Horizons -- and applied it to Voyager data. We use the MIDL codebase to automatically generate standard data products such as daily summary plots and associated tabulated data that increase our ability to monitor the heliospheric environment on a regular basis. These data products will be publicly available and updated automatically and can be analyzed by the community using the ultra portable MIDL software launched from the data distribution website. The currently available LECP data will also be described with SPASE metadata and incorporated into the emerging Virtual Energetic Particle Observatory (VEPO).

  10. 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.

  11. Fourier spectroscopy on planetary missions including Voyager

    NASA Technical Reports Server (NTRS)

    Hanel, R. A.

    1981-01-01

    In the last dozen years spaceborne Fourier transform spectrometers have obtained infrared emission spectra of Earth, Mars, Jupiter, Saturn and Titan as well as of the Galilean and other Saturnian satellites and Saturn's rings. Intercomparisons of the properties of planetary atmospheres and of the characteristics of solid surfaces are now feasible. The principles of remotely sensing the environment on a planetary body are dicussed. Special consideration is given to the most recent results obtained by the Voyager infrared investigation on the Saturn system.

  12. Jupiter's Plasmasheet: Voyager and Galileo Observations

    NASA Astrophysics Data System (ADS)

    Bagenal, F.; Wilson, R. J.; Richardson, J. D.; Paterson, W. R.

    2011-12-01

    We have collated and, in some cases, re-analyzed the plasma data obtained by the Voyager 1 & 2 and Galileo spacecraft in the magnetosphere of Jupiter. We present the derived spatial and temporal variations in plasma density, temperature and velocity throughout the plasmasheet. We also use a simple model for density distribution with latitude to produce 3-D maps of plasmasheet properties and derive the flow of mass and energy in the magnetosphere.

  13. Calibration of the Voyager Ultraviolet Spectrometers and the Composition of the Heliosphere Neutrals: Reassessment

    NASA Astrophysics Data System (ADS)

    Ben-Jaffel, Lotfi; Holberg, J. B.

    2016-06-01

    The data harvest from the Voyagers’ (V 1 and V 2) Ultraviolet Spectrometers (UVS) covers encounters with the outer planets, measurements of the heliosphere sky-background, and stellar spectrophotometry. Because their period of operation overlaps with many ultraviolet missions, the calibration of V1 and V2 UVS with other spectrometers is invaluable. Here we revisit the UVS calibration to assess the intriguing sensitivity enhancements of 243% (V1) and 156% (V2) proposed recently. Using the Lyα airglow from Saturn, observed in situ by both Voyagers, and remotely by International Ultraviolet Explorer (IUE), we match the Voyager values to IUE, taking into account the shape of the Saturn Lyα line observed with the Goddard High Resolution Spectrograph on board the Hubble Space Telescope. For all known ranges of the interplanetary hydrogen density, we show that the V1 and V2 UVS sensitivities cannot be enhanced by the amounts thus far proposed. The same diagnostic holds for distinct channels covering the diffuse He i 58.4 nm emission. Our prescription is to keep the original calibration of the Voyager UVS with a maximum uncertainty of 30%, making both instruments some of the most stable EUV/FUV spectrographs in the history of space exploration. In that frame, we reassess the excess Lyα emission detected by Voyager UVS deep in the heliosphere, to show its consistency with a heliospheric but not galactic origin. Our finding confirms results obtained nearly two decades ago—namely, the UVS discovery of the distortion of the heliosphere and the corresponding obliquity of the local interstellar magnetic field (˜ 40^\\circ from upwind) in the solar system neighborhood—without requiring any revision of the Voyager UVS calibration.

  14. Calibration of the Voyager Ultraviolet Spectrometers and the Composition of the Heliosphere Neutrals: Reassessment

    NASA Astrophysics Data System (ADS)

    Ben-Jaffel, Lotfi; Holberg, J. B.

    2016-06-01

    The data harvest from the Voyagers’ (V 1 and V 2) Ultraviolet Spectrometers (UVS) covers encounters with the outer planets, measurements of the heliosphere sky-background, and stellar spectrophotometry. Because their period of operation overlaps with many ultraviolet missions, the calibration of V1 and V2 UVS with other spectrometers is invaluable. Here we revisit the UVS calibration to assess the intriguing sensitivity enhancements of 243% (V1) and 156% (V2) proposed recently. Using the Lyα airglow from Saturn, observed in situ by both Voyagers, and remotely by International Ultraviolet Explorer (IUE), we match the Voyager values to IUE, taking into account the shape of the Saturn Lyα line observed with the Goddard High Resolution Spectrograph on board the Hubble Space Telescope. For all known ranges of the interplanetary hydrogen density, we show that the V1 and V2 UVS sensitivities cannot be enhanced by the amounts thus far proposed. The same diagnostic holds for distinct channels covering the diffuse He i 58.4 nm emission. Our prescription is to keep the original calibration of the Voyager UVS with a maximum uncertainty of 30%, making both instruments some of the most stable EUV/FUV spectrographs in the history of space exploration. In that frame, we reassess the excess Lyα emission detected by Voyager UVS deep in the heliosphere, to show its consistency with a heliospheric but not galactic origin. Our finding confirms results obtained nearly two decades ago—namely, the UVS discovery of the distortion of the heliosphere and the corresponding obliquity of the local interstellar magnetic field (∼ 40^\\circ from upwind) in the solar system neighborhood—without requiring any revision of the Voyager UVS calibration.

  15. On the accuracy of the relativistic parameters beta, gamma, and the solar oblateness coefficient J2, as deduced from ranging data of a drag-free space probe

    NASA Technical Reports Server (NTRS)

    Roth, E. A.

    1971-01-01

    Motion in the general gravity field is described mathematically. A covariance analysis, based on two simple models, is presented. Two drag-free space probes were considered, for which the orbital elements are given.

  16. Chemistry Experiments — For Comparative Analyses for Demonstrating Environmental Differences on Venus, Earth, Mars and Titan, — Built on Educational Space Probes Hunveyor and Husar

    NASA Astrophysics Data System (ADS)

    Bérczi, Sz.; Róka, A.; Nyíri, Z.; Varga, T.; Fabriczy, A. Sz.; Peták, Cs.; Hudoba, Gy.; Hegyi, S.; Lang, A.; Gyollai, I.; Gucsik, A.

    2014-11-01

    We compared chemical environments of Venus, Earth, Mars and Titan by experiments planned for selection to realize them on educational space probe landers and rovers (Hunveyor and Husar) built by Hungarian universities and high schools.

  17. 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.

  18. Space and time-resolved probing of heterogeneous catalysis reactions using lab-on-a-chip.

    PubMed

    Navin, Chelliah V; Krishna, Katla Sai; Theegala, Chandra S; Kumar, Challa S S R

    2016-03-01

    Probing catalytic reactions on a catalyst surface in real time is a major challenge. Herein, we demonstrate the utility of a continuous flow millifluidic chip reactor coated with a nanostructured gold catalyst as an effective platform for in situ investigation of the kinetics of catalytic reactions by taking 5-(hydroxymethyl)furfural (HMF) to 2,5-furandicarboxylic acid (FDCA) conversion as a model reaction. The idea conceptualized in this paper can not only dramatically change the ability to probe the time-resolved kinetics of heterogeneous catalysis reactions but also used for investigating other chemical and biological catalytic processes, thereby making this a broad platform for probing reactions as they occur within continuous flow reactors. PMID:26888331

  19. Voyager 2 Movie of Saturn's Moon: Phoebe

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Voyager 2 took this photo sequence of Saturn's outer satellite, Phoebe, on Sept. 4, 1981, from 2.2 million kilometers (1.36 million miles) away. The top image is the normal version and the bottom is an enhanced version to increase resolution. This sequence lasts 23.4 hours and contains 35 images. The early images were taken about 43 minutes apart, while the later ones are about 29 minutes apart. There are two significant gaps in the sequence: images 7 and 8 are separated by 2.3 hours and images 19 and 20 are separated by 2.8 hours.

    Because the sunlight is coming from the left, mountains and ridges can best be seen as they reflect the sunlight near the terminator (right side of Phoebe). Other intrinsically bright spots can be seen rotating across the whole disk. In this time-lapse sequence, Phoebe appears to be a lumpy spheroid with possible large mountains sometimes showing on the limb (left side of Phoebe). The photos show that Phoebe is about 220 kilometers (132 miles) in diameter. Its rotation period (length of day) was determined from this set of images to be 9.4 hours (see Thomas, P., et al, 'Phoebe: Voyager 2 Observations', Journal of Geophysical Research, vol. 88, p. 8736, 1 November 1983).

    These images were processed by the Multimission Image Processing Laboratory of the Jet Propulsion Laboratory. The Voyager Project is managed for NASA by the Jet Propulsion Laboratory.

  20. Studies of the interplanetary magnetic field: IMP's to Voyager

    NASA Technical Reports Server (NTRS)

    Ness, Norman F.

    1987-01-01

    During the last two decades, spacecraft projects and individual experiments for which Frank McDonald was a leader have contributed very significantly to the current understanding of the structure of interplanetary space and the correlation between solar and interplanetary disturbances. Studies on the IMP, HELIOS, and Pioneer spin-stabilized spacecraft and the larger attitude-stabilized Voyager spacecraft have provided data sets from which the modern view of the heliosphere has evolved. That concept in which the inner solar system is shown to be dominated by individual streams associated with specific source regions on the Sun is illustrated. As these high-speed streams overtake the preexisting solar plasma, they coalesce and modify the characteristics so that at larger heliocentric distances, these disturbances appear as radially propagating concentric shells of compressed magnetic fields and enhanced fluctuations

  1. New local interstellar spectra for protons, helium and carbon derived from PAMELA and Voyager 1 observations

    NASA Astrophysics Data System (ADS)

    Bisschoff, D.; Potgieter, M. S.

    2016-02-01

    With the cosmic ray observations made by the Voyager 1 spacecraft outside the dominant modulating influence of the heliosphere, the comparison of computed galactic spectra with experimental data at lower energies is finally possible. Spectra for specifically protons, helium and carbon nuclei, computed by galactic propagation models, can now be compared with observations at low energies from Voyager 1 and at high energies from the PAMELA space detector at Earth. We set out to reproduce the Voyager 1 observations in the energy range of 6 MeV/nuc to 60 MeV/nuc, and the PAMELA spectrum above 50 GeV/nuc, using the GALPROP code, similarly to our previous study for Voyager 1 electrons. By varying the galactic diffusion parameters in the GALPROP plain diffusion model, specifically the rigidity dependence of spatial diffusion, and then including reacceleration, we compute spectra simultaneously for galactic protons, helium and carbon. We present new local interstellar spectra, with expressions for the energy range of 3 MeV/nuc to 100 GeV/nuc, which should be of value for solar modulation modeling.

  2. 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…

  3. Nano-optical scan probes: Opening doors to previously-inaccessible parameter spaces

    SciTech Connect

    Schuck, James

    2014-06-08

    I will discuss recent progress on new near-field probe geometries, including the “campanile” geometry, which has been used in recent hyperspectral imaging experiments, providing nanoscale spectral information distinct from what is obtained with other methods. Article not available.

  4. 1958 NASA/USAF Space Probes (ABLE-1). Volume 3; Vehicles, Trajectories, and Flight Histories

    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.

  5. 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.

  6. Magnetic reconnection physics in the solar wind with Voyager 2

    NASA Astrophysics Data System (ADS)

    Stevens, Michael L.

    2009-08-01

    Magnetic reconnection is the process by which the magnetic topology evolves in collisionless plasmas. This phenomenon is fundamental to a broad range of astrophysical processes such as stellar flares, magnetospheric substorms, and plasma accretion, yet it is poorly understood and difficult to observe in situ . In this thesis, the solar wind plasma permeating interplanetary space is treated as a laboratory for reconnection physics. I present an exhaustive statistical approach to the identification of reconnection outflow jets in turbulent plasma and magnetic field time series data. This approach has been automated and characterized so that the resulting reconnection survey can be put in context with other related studies. The algorithm is shown to perform similarly to ad hoc studies in the inner heliosphere. Based on this technique, I present a survey of 138 outflow jets for the Voyager 2 spacecraft mission, including the most distant in situ evidence of reconnection discovered to date. Reconnection in the solar wind is shown to be strongly correlated with stream interactions and with solar activity. The solar wind magnetic field is found to be reconnecting via large, quasi-steady slow- mode magnetohydrodynamic structures as far out as the orbit of Neptune. The role of slow-mode shocks is explored and, in one instance, a well-developed reconnection structure is shown to be in good agreement with the Petschek theory for fast reconnection. This is the first reported example of a reconnection exhaust that satisfies the full jump conditions for a stationary slow-mode shock pair. A complete investigation into corotating stream interactions over the Voyager 2 mission has revealed that detectable reconnection structure occurs in about 23% of forced, global-scale current sheets. Contrary to previous studies, I find that signatures of this kind are most likely to be observed for current sheets where the magnetic field shear and the plasma-b are high. Evidence has been found

  7. Selecting and implementing scientific objectives. [for Voyager 1 and 2 planetary encounters

    NASA Technical Reports Server (NTRS)

    Miner, E. D.; Stembridge, C. H.; Doms, P. E.

    1985-01-01

    The procedures used to select and implement scientific objectives for the Voyager 1 and 2 planetary encounters are described. Attention is given to the scientific tradeoffs and engineering considerations must be addressed at various stages in the mission planning process, including: the limitations of ground and spacecraft communications systems, ageing of instruments in flight, and instrument calibration over long distances. The contribution of planetary science workshops to the definition of scientific objectives for deep space missions is emphasized.

  8. The Use of Langmuir Probes in Non-Maxwellian Space Plasmas

    NASA Technical Reports Server (NTRS)

    Hoegy, Walter R.; Brace, Larry H.

    1998-01-01

    Disturbance of the Maxwellian plasma may occur in the vicinity of a spacecraft due to photoemission, interactions between the spacecraft and thermospheric gases, or electron emissions from other devices on the spacecraft. Significant non-maxwellian plasma distributions may also occur in nature as a mixture of ionospheric and magnetospheric plasmas or secondaries produced by photoionization in the thermosphere or auroral precipitation. The general formulas for current collection (volt-ampere curves) by planar, cylindrical, and spherical Langmuir probes in isotropic and anisotropic non-maxwellian plasmas are examined. Examples are given of how one may identify and remove the non-maxwellian components in the Langmuir probe current to permit the ionospheric parameters to be determined. Theoretical volt-ampere curves presented for typical examples of non-maxwellian distributions include: two-temperature plasmas and a thermal plasma with an energetic electron beam. If the non-ionospheric electrons are Maxwellian at a temperature distinct from that of the ionosphere electrons, the volt-ampere curves can be fitted directly to obtain the temperatures and densities of both electron components without resorting to differenting the current. For an arbitrary isotropic distribution, the current for retarded particles is shown to be identical for the three geometries. For anisotropic distributions, the three probe geometries are not equally suited for measuring the ionospheric electron temperature and density or for determining the distribution function in the presence of non-maxwellian back-round electrons.

  9. 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).

  10. 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.

  11. The Global Positioning System constellation as a space weather monitor: Comparison of electron measurements with Van Allen Probes data

    NASA Astrophysics Data System (ADS)

    Morley, Steven K.; Sullivan, John P.; Henderson, Michael G.; Blake, J. Bernard; Baker, Daniel N.

    2016-02-01

    Energetic electron observations in Earth's radiation belts are typically sparse, and multipoint studies often rely on serendipitous conjunctions. This paper establishes the scientific utility of the Combined X-ray Dosimeter (CXD), currently flown on 19 satellites in the Global Positioning System (GPS) constellation, by cross-calibrating energetic electron measurements against data from the Van Allen Probes. By breaking our cross calibration into two parts—one that removes any spectral assumptions from the CXD flux calculation and one that compares the energy spectra—we first validate the modeled instrument response functions, then the calculated electron fluxes. Unlike previous forward modeling of energetic electron spectra, we use a combination of four distributions that together capture a wide range of observed spectral shapes. Our two-step approach allowed us to identify, and correct for, small systematic offsets between block IIR and IIF satellites. Using the Magnetic Electron Ion Spectrometer and Relativistic Electron-Proton Telescope on Van Allen Probes as a "gold standard," we demonstrate that the CXD instruments are well understood. A robust statistical analysis shows that CXD and Van Allen Probes fluxes are similar and the measured fluxes from CXD are typically within a factor of 2 of Van Allen Probes at energies ≲4 MeV. We present data from 17 CXD-equipped GPS satellites covering the 2015 "St. Patrick's Day" geomagnetic storm to illustrate the scientific applications of such a high data density satellite constellation and therefore demonstrate that the GPS constellation is positioned to enable new insights in inner magnetospheric physics and space weather forecasting.

  12. The Global Positioning System constellation as a space weather monitor. Comparison of electron measurements with Van Allen Probes data

    DOE PAGESBeta

    Morley, Steven K.; Sullivan, John P.; Henderson, Michael G.; Blake, J. Bernard; Baker, Daniel N.

    2016-02-06

    Energetic electron observations in Earth's radiation belts are typically sparse, and multipoint studies often rely on serendipitous conjunctions. This paper establishes the scientific utility of the Combined X-ray Dosimeter (CXD), currently flown on 19 satellites in the Global Positioning System (GPS) constellation, by cross-calibrating energetic electron measurements against data from the Van Allen Probes. By breaking our cross calibration into two parts—one that removes any spectral assumptions from the CXD flux calculation and one that compares the energy spectra—we first validate the modeled instrument response functions, then the calculated electron fluxes. Unlike previous forward modeling of energetic electron spectra, wemore » use a combination of four distributions that together capture a wide range of observed spectral shapes. Moreover, our two-step approach allowed us to identify, and correct for, small systematic offsets between block IIR and IIF satellites. Using the Magnetic Electron Ion Spectrometer and Relativistic Electron-Proton Telescope on Van Allen Probes as a “gold standard,” here we demonstrate that the CXD instruments are well understood. A robust statistical analysis shows that CXD and Van Allen Probes fluxes are similar and the measured fluxes from CXD are typically within a factor of 2 of Van Allen Probes at energies inline image4 MeV. Our team present data from 17 CXD-equipped GPS satellites covering the 2015 “St. Patrick's Day” geomagnetic storm to illustrate the scientific applications of such a high data density satellite constellation and therefore demonstrate that the GPS constellation is positioned to enable new insights in inner magnetospheric physics and space weather forecasting.« less

  13. 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.

  14. Spectrophotometry of Io - Preliminary Voyager 1 results

    NASA Technical Reports Server (NTRS)

    Soderblom, L.; Johnson, T.; Kupferman, P.; Pieri, D.; Morrison, D.; Danielson, E.; Smith, B.; Veverka, J.; Sagan, C.; Cook, A.

    1980-01-01

    Multispectral images of Io acquired with the Voyager 1 narrow-angle camera agree with earth-based spectrophotometry to better than 10%. Although the surface materials have general spectral properties similar to various allotropes of sulfur, their ultraviolet (UV) reflectances are much higher. It is likely that varying amounts of SO2 frost mixed with or absorbed on sulfur-rich materials raises the UV reflectance. The possible association with large amounts of SO2 with low temperature forms of sulfur in the white patches on Io is consistent with Io surface models in which SO2 and S exist in thermally stable stratified zones.

  15. Sequencing Voyager II for the Uranus encounter

    NASA Technical Reports Server (NTRS)

    Morris, R. B.

    1986-01-01

    The process of developing the programmed sequence of events necessary for the Voyager 2 spacecraft to return desired data from its Uranus encounter is discussed. The major steps in the sequence process are reviewed, and the elements of the Mission Sequence Software are described. The design phase and the implementation phase of the sequence process are discussed, and the Computer Command Subsystem architecture is examined in detail. The software's role in constructing the sequences and converting them into onboard programs is elucidated, and the problems unique to the Uranus encounter sequences are considered.

  16. Satellite ephemerides for the Voyager Neptune encounter

    NASA Technical Reports Server (NTRS)

    Jacobson, Robert A.

    1988-01-01

    This paper presents the results of the latest fits of both analytical theory and numerically integrated Neptunian satellite orbits to Earth-based astrometric observations. Ephemerides based on the integrated orbits will be used by the Voyager project for pre-encounter planning and analysis until late 1988 when the final pre-encounter ephemerides will be produced. As a by-product of the orbit fits, new estimates of the Neptune mass, the second zonal harmonic of Neptune, and the pole orientation of Neptune are obtained. The theory and integrated orbits are compared with each other and with orbits obtained by previous investigators.

  17. 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.

  18. Summary of whistlers observed by Voyager 1 at Jupiter. Progress report

    SciTech Connect

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

    1983-12-20

    We summarize the Voyager 1 observations of whistlers at Jupiter in order to provide a basis for further analyses of the density profile of the Io plasma torus as well as to support studies of atmospheric lightning at Jupiter. All the whistlers detected by Voyager 1 fell into three general regions in the torus at radial distances ranging between 5 and 6 R sub J. An analysis of the broadband wave amplitudes measured by the Voyager 1 plasma wave instrument and estimates of the peak whistler amplitudes imply the grouping of whistlers was due to variations in the sensitivity of the receiver to whistlers and not to variations in the source or propagation paths of the whistlers. The whistler dispersions are presented in statistical form for each of the three groups of events and analyzed in view of the structure of the Io plasma torus as determined by plasma probe measurements. The results of these analyses give source locations for the whistlers at the foot of the magnetic field lines threading the torus in both hemispheres and over a range of longitudes.

  19. Examination of the Voyager 2 Plasma Observations in the Vicinity of the Termination Shock

    NASA Astrophysics Data System (ADS)

    Intriligator, D. S.; Intriligator, J.; Webber, W. R.

    2008-12-01

    We examine the plasma distributions obtained by the MIT plasma probe on Voyager 2 in 2007. These are the first plasma data obtained in the vicinity of the termination shock. The Voyager 2 plasma observations (Richardson et al., Nature, 454, July 2008,doi:10.10338, p.63) were somewhat surprising. Richardson et al. reported that following the termination shock crossing the solar wind flow did not become subsonic as expected. Rather Richardson et al. reported the solar wind flow slowed, but still remained supersonic. We examine some of the details of the MIT plasma data. We compare the plasma data with other in-situ spacecraft measurements. The results also are evaluated in terms of theoretical expectations. Our detailed analyses show that the time periods around the reported termination shock crossings are more complex and revealing than earlier believed. This work is sponsored by NASA Grant NNX08AE40G and by Carmel Research Center. We are grateful to John Richardson for providing the Voyager 2 MIT plasma data.

  20. Modeling gradual diffusion changes in radiation belt electron phase space density for the March 2013 Van Allen Probes case study

    NASA Astrophysics Data System (ADS)

    Li, Zhao; Hudson, Mary; Jaynes, Allison; Boyd, Alexander; Malaspina, David; Thaller, Scott; Wygant, John; Henderson, Michael

    2014-10-01

    March 2013 provided the first equinoctial period when all of the instruments on the Van Allen Probes spacecraft were fully operational. This interval was characterized by disturbances of outer zone electrons with two time scales of variation, diffusive and rapid dropout and restoration. A radial diffusion model was applied to the monthlong interval to confirm that electron phase space density is well described by radial diffusion for the whole month at low first invariant ≤ 400 MeV/G but peaks in phase space density observed by the Energetic Particle, Composition, and Thermal Plasma (ECT) instrument suite at higher first invariant are not reproduced by radial transport from a source at higher L. The model does well for much of the monthlong interval, capturing three of four enhancements in phase space density which emerge from the outer boundary, while the strong enhancement following dropout on 17-18 March requires local acceleration at higher first invariant (M=1000 MeV/G versus 200 MeV/G) not included in our model. We have incorporated phase space density from ECT measurement at the outer boundary and plasmapause determination from the Electric Field and Waves (EFW) instrument to separate hiss and chorus loss models.

  1. 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.

  2. 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.

  3. Amateur Radio Communications with a Deep Space Probe (Yes, It's Possible)

    NASA Astrophysics Data System (ADS)

    Cudnik, Brian; Rahman, Mahmudur; Saganti, Seth; Erickson, Gary M.; Saganti, Premkumar

    2015-05-01

    Prairie View A&M University through the collaboration with NASA-Johnson Space Center has partnered with the Kyushu Institute of Technology (KIT), Japan and developed a payload for the Shinen-2 spacecraft that was launched from Japan on December 3, 2014 as part of the Hayabusa2 mission. The main purpose of the Shinen-2 spacecraft is deep space communication experiment to test the feasibility of deep-space radio communications from the spacecraft to Earth without the need of the Deep Space Network (DSN) of NASA. This presents an opportunity to the wider community of amateur astronomers, ham radio operators, and other research personnel in that they will have the opportunity to work with deep space communication such as Shinen-2 spacecraft. It should be possible to detect a signal as an increased strength from Shinen-2 spacecraft at a rest frequency of 437.385 MHz, using commercially available equipment procured at low-cost, when the spacecraft approaches to within 3,000,000 km of the Earth during December 2015.

  4. On Determining Wood Thermal Diffusivity and Probe Spacing for Sap Flow Measurements using In-Situ Heat Response Curves

    NASA Astrophysics Data System (ADS)

    Chen, X.; Miller, G.; Baldocchi, D.; Rubin, Y.

    2008-12-01

    The heat pulse method is widely used to measure water flux in plants and soil; it works by inferring the velocity of water in a porous medium from the speed at which a heat pulse is propagated through the system. No systematic, non-destructive calibration procedure exists to determine the site-specific parameters necessary for calculating sap velocity: wood thermal diffusivity and probe spacing. Such parameter calibration is crucial to obtaining the correct transpiration amount from the sap flow measurements at the plant scale and consequently to the up-scaling of water flux to a larger scale and to the water cycle modeling along the soil-vegetation-atmosphere continuum. The purpose of this study is to present a statistical framework to simultaneously estimate these parameters from in-situ heat response curves collected by the implanted probes of heat ratio apparatus. Conditioned on the heat response data, the parameters are inferred using a Bayesian inversion technique with Markov chain Monte Carlo sampling method. The primary advantage of the proposed methodology is that, unlike most of the existing work, it does not require known probe spacing or any further intrusive sampling of sapwood. The Bayesian framework also enables direct quantification of uncertainty in estimated sap flow velocity. Experiments using synthetic data show that multiple tests on the same apparatus are essential to obtain reliable, accurate solutions. When applied to field conditions, these tests are conducted during different seasons and automated using the existing data logging system. The seasonality of wood thermal diffusivity is obtained as a by-product of the parameter estimation process, and it shows consistency with the seasonal change of tree diameters monitored using tree dendrometer. An empirical factor is adopted to account for flow deformation caused by the implanted probes, and it is also estimated in this study. The proposed methodology is ready to be applied to calibrate

  5. Idealized Voyager Jovian magnetosphere shape and field

    SciTech Connect

    Engle, I.M. )

    1991-05-01

    A magnetic field arising from the Jovian equatorial sheet current deduced from Voyager 1 and 2 observations has been added to a planetary dipole field to provide a model of magnetic field inside the magnetopause. This internal field was used to calculate the magnetopause surface in a cyclic process. During each cycle, the surface was calculated, and the resulting field due to currents on the magnetopause was calculated for inclusion in the total field used to calculate the next-order surface. The resulting magnetopause is, as anticipated, flatter in shape than one resulting primarily from a dipole internal field source, but not dissimilar in overall height-to-width configuration to that of the magnetopause calculated for the larger inflated magnetopause observed by Pioneer 10. An array of magnetic field values for locations internal and external to the magnetopause due to currents on the surface has been computed by integrating over the entire magnetopause. A model for the total magnetospheric field of this semi-inflated magnetosphere has been constructed by adding this latter contribution to the internal source fields to obtain a global model of a semi-inflated Jovianlike magnetospheric field. The magnitude of the contribution of the surface currents to the total magnetic field in the region of the orbits of the Galilean satellites is calculated to be considerably larger for this Voyager model than for the Pioneer model.

  6. BrainVoyager--past, present, future.

    PubMed

    Goebel, Rainer

    2012-08-15

    BrainVoyager started as a simple fMRI analysis tool in the mid 1990s; the software was primarily created to fulfill the needs of its author and his colleagues to analyze anatomical and functional MRI data in a way that would be most appropriate for their research questions in visual and auditory perception. More specifically, the software was designed with three major goals in mind. First, it should allow analyses that would exploit optimally the high-resolution information available in fMRI data. Second, it should integrate volume-based analysis and cortex-based analysis including the possibility to visualize topographic activation data on flattened cortex representations. Third, it should combine hypothesis testing with data-driven analysis including interactive visualization tools that would make it as easy as possible to look at and explore data. A fourth guiding principle was to develop a software package that fulfilled the author's preference for elegant user interfaces, beautiful visualizations and high-performance computing. These major guiding principles from the beginning of BrainVoyager development are still noticeable in the most recent incarnations of the software that has grown from a small fMRI analysis tool on the Windows platform to a comprehensive cross-platform multi-modal software package integrating (real-time) fMRI, DWI/DTI, (i)EEG, MEG, TMS and fNIRS analyses. PMID:22289803

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

    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. FIB-SEM Tomography Probes the Mesoscale Pore Space of an Individual Catalytic Cracking Particle

    PubMed Central

    2016-01-01

    The overall performance of a catalyst particle strongly depends on the ability of mass transport through its pore space. Characterizing the three-dimensional structure of the macro- and mesopore space of a catalyst particle and establishing a correlation with transport efficiency is an essential step toward designing highly effective catalyst particles. In this work, a generally applicable workflow is presented to characterize the transport efficiency of individual catalyst particles. The developed workflow involves a multiscale characterization approach making use of a focused ion beam-scanning electron microscope (FIB-SEM). SEM imaging is performed on cross sections of 10.000 μm2, visualizing a set of catalyst particles, while FIB-SEM tomography visualized the pore space of a large number of 8 μm3 cubes (subvolumes) of individual catalyst particles. Geometrical parameters (porosity, pore connectivity, and heterogeneity) of the material were used to generate large numbers of virtual 3D volumes resembling the sample’s pore space characteristics, while being suitable for computationally demanding transport simulations. The transport ability, defined as the ratio of unhindered flow over hindered flow, is then determined via transport simulations through the virtual volumes. The simulation results are used as input for an upscaling routine based on an analogy with electrical networks, taking into account the spatial heterogeneity of the pore space over greater length scales. This novel approach is demonstrated for two distinct types of industrially manufactured fluid catalytic cracking (FCC) particles with zeolite Y as the active cracking component. Differences in physicochemical and catalytic properties were found to relate to differences in heterogeneities in the spatial porosity distribution. In addition to the characterization of existing FCC particles, our method of correlating pore space with transport efficiency does also allow for an up-front evaluation of

  9. 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.

  10. Probing the interstellar medium in early-type galaxies with Infrared Space Oberservatory observations

    NASA Technical Reports Server (NTRS)

    Malhotra, S.; Hollenbach, D.; Helou, D.; Silbermann, N.; Valjavec, E.; Rubin, R.; Dale, D.; Hunter, D.; Lu, N.; Lord, S.; Dinerstein, H.; Thronson, H.

    2000-01-01

    Four IRAS-detected early-type galaxies were observed with the Infrared Space Observatory (ISO). With the exception of the 15 mu m image of NGC 1052, the mid-IR images of NGC 1052, NGC 1155, NGC 5866, and NGC 6958 at 4.5, 7, and 15 mu m show extended emission.

  11. Voyager 1 observes low-energy galactic cosmic rays in a region depleted of heliospheric ions.

    PubMed

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

    2013-07-12

    On 25 August 2012, Voyager 1 was at 122 astronomical units when the steady intensity of low-energy ions it had observed for the previous 6 years suddenly dropped for a third time and soon completely disappeared as the ions streamed away into interstellar space. Although the magnetic field observations indicate that Voyager 1 remained inside the heliosphere, the intensity of cosmic ray nuclei from outside the heliosphere abruptly increased. We report the spectra of galactic cosmic rays down to ~3 × 10(6) electron volts per nucleon, revealing H and He energy spectra with broad peaks from 10 × 10(6) to 40 × 10(6) electron volts per nucleon and an increasing galactic cosmic-ray electron intensity down to ~10 × 10(6) electron volts. PMID:23811227

  12. The near real time image navigation of pictures returned by Voyager 2 at Neptune

    NASA Technical Reports Server (NTRS)

    Underwood, Ian M.; Bachman, Nathaniel J.; Taber, William L.; Wang, Tseng-Chan; Acton, Charles H.

    1990-01-01

    The development of a process for performing image navigation in near real time is described. The process was used to accurately determine the camera pointing for pictures returned by the Voyager 2 spacecraft at Neptune Encounter. Image navigation improves knowledge of the pointing of an imaging instrument at a particular epoch by correlating the spacecraft-relative locations of target bodies in inertial space with the locations of their images in a picture taken at that epoch. More than 8,500 pictures returned by Voyager 2 at Neptune were processed in near real time. The results were used in several applications, including improving pointing knowledge for nonimaging instruments ('C-smithing'), making 'Neptune, the Movie', and providing immediate access to geometrical quantities similar to those traditionally supplied in the Supplementary Experiment Data Record.

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

    SciTech Connect

    Yang, Qiguang; Williams, Frances; Zhao, Xin; Reece, Charles E.; Krishnan, Mahadevan

    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 surfaces 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.

  14. Probing space charge and resolving overlimiting current mechanisms at the microchannel-nanochannel interface

    NASA Astrophysics Data System (ADS)

    Schiffbauer, Jarrod; Liel, Uri; Leibowitz, Neta; Park, Sinwook; Yossifon, Gilad

    2015-07-01

    We present results demonstrating the space charge-mediated transition between classical, diffusion-limited current and surface-conduction dominant over-limiting current in a shallow microchannel-nanochannel device. The extended space charge layer develops at the depleted microchannel-nanochannel entrance at high current and is correlated with a distinctive maximum in the dc resistance. Experimental results for a shallow surface-conduction dominated system are compared with theoretical models, allowing estimates of the effective surface charge at high voltage to be obtained. In comparison to an equilibrium estimate of the surface charge obtained from electrochemical impedance spectroscopy, it is further observed that the effective surface charge appears to change under applied voltage.

  15. Probing phase-space noncommutativity through quantum beating, missing information, and the thermodynamic limit

    NASA Astrophysics Data System (ADS)

    Bernardini, A. E.; Bertolami, O.

    2013-07-01

    In this work we examine the effect of phase-space noncommutativity on some typically quantum properties such as quantum beating, quantum information, and decoherence. To exemplify these issues we consider the two-dimensional noncommutative quantum harmonic oscillator whose component behavior we monitor in time. This procedure allows us to determine how the noncommutative parameters are related to the missing information quantified by the linear quantum entropy and by the mutual information between the relevant Hilbert space coordinates. Particular questions concerning the thermodynamic limit of some relevant properties are also discussed in order to evidence the effects of noncommutativity. Finally, through an analogy with the Zeeman effect, we identify how some aspects of the axial symmetry of the problem suggest the possibility of decoupling the noncommutative quantum perturbations from unperturbed commutative well-known solutions.

  16. Debris Disk Science Enabled by a Probe-scale Space Coronagraph Mission

    NASA Astrophysics Data System (ADS)

    Stapelfeldt, Karl R.; Trauger, J. T.; Krist, J. E.

    2010-01-01

    Debris disks are the signposts of planetary systems: collisions between rocky/icy parent bodies maintain debris dust around main sequence stars against losses to radiation pressure and P-R drag. Debris disk structures show the location of asteroid/Kuiper belts around nearby stars, and reflect dynamical interactions with local extrasolar planets. Only 17 debris disks with high optical depth have been spatially resolved to date in scattered light images made with the Hubble Space Telescope and ground-based adaptive optics. Hundreds more with lower optical depth have been identified among nearby stars through far-IR photometry with the Spitzer Space Telescope, and more should follow in the next few years from Herschel. The most capable means for imaging this larger disk population is a next-generation coronagraphic instrument on a 1.5m class optical space telescope. Utilizing high-contrasat imaging simulations validated by laboratory demonstrations on the JPL High Contrast Imaging Testbed, we show that such a mission will be capable of imaging Kuiper disk structures down to the 10 zodi level, and exozodiacal dust down to the 1 zodi level, around a major sample of nearby stars. This performance goes well beyond what is about to be achieved with upcoming extreme adaptive optics systems or the ALMA array, and thus provides the best path for imaging exploration of planetary systems in the solar neighborhood.

  17. Probing the Allende meteorite with a miniature laser-ablation mass analyser for space application

    NASA Astrophysics Data System (ADS)

    Neuland, M. B.; Meyer, S.; Mezger, K.; Riedo, A.; Tulej, M.; Wurz, P.

    2014-10-01

    We measured the elemental composition on a sample of Allende meteorite with a miniature laser ablation mass spectrometer. This laser mass spectrometer (LMS) has been designed and built at the University of Bern in the Department of Space Research and Planetary Sciences with the objective of using such an instrument on a space mission. Utilising the meteorite Allende as the test sample in this study, it is demonstrated that the instrument allows the in situ determination of the elemental composition and thus mineralogy and petrology of untreated rocky samples, particularly on planetary surfaces. In total, 138 measurements of elemental compositions have been carried out on an Allende sample. The mass spectrometric data are evaluated and correlated with an optical image. It is demonstrated that by illustrating the measured elements in the form of mineralogical maps, LMS can serve as an element imaging instrument with a very high spatial resolution of μm scale. The detailed analysis also includes a mineralogical evaluation and an investigation of the volatile element content of Allende. All findings are in good agreement with published data and underline the high sensitivity, accuracy and capability of LMS as a mass analyser for space exploration.

  18. Angular distribution of cosmological parameters as a probe of space-time inhomogeneities

    NASA Astrophysics Data System (ADS)

    Carvalho, C. Sofia; Marques, Katrine

    2016-08-01

    We develop a method based on the angular distribution on the sky of cosmological parameters to probe the inhomogeneity of large-scale structure and cosmic acceleration. We demonstrate this method on the largest type Ia supernova (SN) data set available to date, as compiled by the Joint Light-curve Analysis (JLA) collaboration and, hence, consider the cosmological parameters that affect the luminosity distance. We divide the SN sample into equal surface area pixels and estimate the cosmological parameters that minimize the chi-square of the fit to the distance modulus in each pixel, hence producing maps of the cosmological parameters {ΩM,ΩΛ,H0} . In poorly sampled pixels, the measured fluctuations are mostly due to an inhomogeneous coverage of the sky by the SN surveys; in contrast, in well-sampled pixels, the measurements are robust enough to suggest a real fluctuation. We also measure the anisotropy of the parameters by computing the power spectrum of the corresponding maps of the parameters up to ℓ = 3. For an analytical toy model of an inhomogeneous ensemble of homogeneous pixels, we derive the backreaction term in the deceleration parameter due to the fluctuations of H0 across the sky and measure it to be of order 10-3 times the corresponding average over the pixels in the absence of backreaction. We conclude that, for the toy model considered, backreaction is not a viable dynamical mechanism to emulate cosmic acceleration.

  19. Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space

    PubMed Central

    Collins, Liam; Belianinov, Alex; Somnath, Suhas; Balke, Nina; Kalinin, Sergei V.; Jesse, Stephen

    2016-01-01

    Kelvin probe force microscopy (KPFM) has provided deep insights into the local electronic, ionic and electrochemical functionalities in a broad range of materials and devices. In classical KPFM, which utilizes heterodyne detection and closed loop bias feedback, the cantilever response is down-sampled to a single measurement of the contact potential difference (CPD) per pixel. This level of detail, however, is insufficient for materials and devices involving bias and time dependent electrochemical events; or at solid-liquid interfaces, where non-linear or lossy dielectrics are present. Here, we demonstrate direct recovery of the bias dependence of the electrostatic force at high temporal resolution using General acquisition Mode (G-Mode) KPFM. G-Mode KPFM utilizes high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates. We show how G-Mode KPFM can be used to capture nanoscale CPD and capacitance information with a temporal resolution much faster than the cantilever bandwidth, determined by the modulation frequency of the AC voltage. In this way, G-Mode KPFM offers a new paradigm to study dynamic electric phenomena in electroactive interfaces as well as a promising route to extend KPFM to the solid-liquid interface. PMID:27514987

  20. Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space.

    PubMed

    Collins, Liam; Belianinov, Alex; Somnath, Suhas; Balke, Nina; Kalinin, Sergei V; Jesse, Stephen

    2016-01-01

    Kelvin probe force microscopy (KPFM) has provided deep insights into the local electronic, ionic and electrochemical functionalities in a broad range of materials and devices. In classical KPFM, which utilizes heterodyne detection and closed loop bias feedback, the cantilever response is down-sampled to a single measurement of the contact potential difference (CPD) per pixel. This level of detail, however, is insufficient for materials and devices involving bias and time dependent electrochemical events; or at solid-liquid interfaces, where non-linear or lossy dielectrics are present. Here, we demonstrate direct recovery of the bias dependence of the electrostatic force at high temporal resolution using General acquisition Mode (G-Mode) KPFM. G-Mode KPFM utilizes high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates. We show how G-Mode KPFM can be used to capture nanoscale CPD and capacitance information with a temporal resolution much faster than the cantilever bandwidth, determined by the modulation frequency of the AC voltage. In this way, G-Mode KPFM offers a new paradigm to study dynamic electric phenomena in electroactive interfaces as well as a promising route to extend KPFM to the solid-liquid interface. PMID:27514987

  1. Voyager absolute far-ultraviolet spectrophotometry of hot stars

    NASA Technical Reports Server (NTRS)

    Holberg, J. B.; Forrester, W. T.; Shemansky, D. E.; Barry, D. C.

    1982-01-01

    Voyager observations in the 912-1200 A spectral region are used to indirectly intercompare absolute stellar spectrophotometry from previous experiments. Measurements of hot stars obtained by the Voyager 1 and 2 ultraviolet spectrometers show considerably higher 912-1200 A continuum fluxes than the recent observations of Brune et al. (1979) and Carruthers et al. (1981). The intercomparisons show all observations in basic agreement near 1200 A. The Carruthers et al. flux measurements are preferred down to 1050 A at which point the Voyager and Brune et al. values are respectively 60% higher and 60% lower. Below 1050 A the diasgreement among the observations becomes very large and the fluxes predicted by model atmospheres have been adopted. The pure hydrogen line-blanketed model atmosphere calculations of Wesemael et al. 1980) in comparison with Voyager observations of HZ 43 are used to adjust the Voyager calibration below 1050 A. This adjusted Voyager calibration, which is in good agreement with current model atmosphere fluxes for both early-type stars and DA white dwarfs, will be used for Voyager astronomical observations.

  2. Availability of feature-oriented scanning probe microscopy for remote-controlled measurements on board a space laboratory or planet exploration Rover.

    PubMed

    Lapshin, Rostislav V

    2009-06-01

    Prospects for a feature-oriented scanning (FOS) approach to investigations of sample surfaces, at the micrometer and nanometer scales, with the use of scanning probe microscopy under space laboratory or planet exploration rover conditions, are examined. The problems discussed include decreasing sensitivity of the onboard scanning probe microscope (SPM) to temperature variations, providing autonomous operation, implementing the capabilities for remote control, self-checking, self-adjustment, and self-calibration. A number of topical problems of SPM measurements in outer space or on board a planet exploration rover may be solved via the application of recently proposed FOS methods. PMID:19566423

  3. Voyager 1 Jupiter Southern Hemisphere Movie

    NASA Technical Reports Server (NTRS)

    2000-01-01

    This movie shows a portion of Jupiter in the southern hemisphere over 17Jupiter days. Above the white belt, notice the series of atmospheric vortices headed west. Even these early approach frames show wild dynamics in the roiling environment south of the white belt. Notice the small tumbling white cloud near the center.

    As Voyager 1 approached Jupiter in 1979, it took images of the planet at regular intervals. This sequence is made from 17 images taken once every Jupiter rotation period (about 10 hours). These images were acquired in the Blue filter around Feb. 1, 1979. The spacecraft was about 37 million kilometers from Jupiter at that time.

    This time-lapse movie was produced at JPL by the Image Processing Laboratory in 1979.

  4. 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.

  5. Voyager disk-integrated photometry of Triton

    NASA Technical Reports Server (NTRS)

    Hillier, J.; Helfenstein, P.; Verbiscer, A.; Veverka, J.; Brown, R. H.; Goguen, J.; Johnson, T. V.

    1990-01-01

    Hapke's (1981) photometric model has been combined with a plane-parallel thin atmospheric haze model to describe Voyager whole-disk observations of Triton, in the violet, blue, and green wavelength bands, in order to obtain estimates of Triton's geometric albedo, phase integral, and Bond albedo. Phase angle coverage in these filters ranging from about 12 to 159 deg was obtained by combining narrow- and wide-angle camera images. An upturn in the data at the highest phase angles observed can be explained by including scattering in a thin atmospheric haze layer with optical depths systematically decreasing with wavelength from about 0.06 in the violet to 0.03 for the green filter data.

  6. 1958 NASA/USAF Space Probes (Able-1). Volume 1; Summary

    NASA Technical Reports Server (NTRS)

    1959-01-01

    Early in calendar year 1958 Space Technology Laboratories, Inc. (STL) (then Space Technology Laboratories, a division of the Ramo-Wooldridge Corp.) developed for the Air Force Ballistic Missile Division (AFBMD) an Advanced Re-entry Test Vehicle (ARTV) for the purpose of testing ballistic missile nose cones at the full range of 5500 nautical miles. The two-stage ARTV utilized the Thor ballistic missile and the second stage propulsion system developed for the Vanguard program. In late 1957 and early 1958, STL/AFBMD prepared studies of various missile combinations which could be utilized for space testing. The Thor, in combination with the Vanguard second and third stages, was one of the vehicles considered which offered a very early capability of placing a reasonable payload in a lunar orbit. These STL/AFBMD studies were presented to various appropriate groups including the Killian, Millikan, H. J . Stewart Committees; Headquarters, Air Research and Development Command, and ARDC Centers. Subsequently the Advanced Research Projects Agency (ARPA) contacted STL relative to the availability of hardware for an early lunar shot. By utilizing existing spares already purchased for the ARTV, and by making use of the ARTV contractors already in being, it appeared feasible to launch by the third quarter of calendar year 1958 a payload which would be captured by the moon's gravitational force. On 27 March 1958, ARPA directed STL to proceed with a program of three lunar shots. As much as possible, these shots were to utilize existing ARTV spare hardware and impose no interference with the ballistic missile programs. In September this program was transferred to the direction of the National Aeronautics and Space Administration (NASA). On 17 August 1958 the first launching of the Able-1 vehicle was attempted, but the flight was terminated by a propulsion failure of the first stage. Subsequent launchings were attempted on 13 October and 8 November 1958. Of these launchirigs the

  7. A voyage to Mars: A challenge to collaboration between man and machines

    NASA Technical Reports Server (NTRS)

    Statler, Irving C.

    1991-01-01

    A speech addressing the design of man machine systems for exploration of space beyond Earth orbit from the human factors perspective is presented. Concerns relative to the design of automated and intelligent systems for the NASA Space Exploration Initiative (SEI) missions are largely based on experiences with integrating humans and comparable systems in aviation. The history, present status, and future prospect, of human factors in machine design are discussed in relation to a manned voyage to Mars. Three different cases for design philosophy are presented. The use of simulation is discussed. Recommendations for required research are given.

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

    NASA Astrophysics Data System (ADS)

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

    1989-05-01

    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.

  9. 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.

  10. Full data acquisition in Kelvin Probe Force Microscopy: Mapping dynamic electric phenomena in real space

    DOE PAGESBeta

    Balke, Nina; Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam; Belianinov, Alex; Somnath, Suhas

    2016-08-12

    Kelvin probe force microscopy (KPFM) has provided deep insights into the role local electronic, ionic and electrochemical processes play on the global functionality of materials and devices, even down to the atomic scale. Conventional KPFM utilizes heterodyne detection and bias feedback to measure the contact potential difference (CPD) between tip and sample. This measurement paradigm, however, permits only partial recovery of the information encoded in bias- and time-dependent electrostatic interactions between the tip and sample and effectively down-samples the cantilever response to a single measurement of CPD per pixel. This level of detail is insufficient for electroactive materials, devices, ormore » solid-liquid interfaces, where non-linear dielectrics are present or spurious electrostatic events are possible. Here, we simulate and experimentally validate a novel approach for spatially resolved KPFM capable of a full information transfer of the dynamic electric processes occurring between tip and sample. General acquisition mode, or G-Mode, adopts a big data approach utilising high speed detection, compression, and storage of the raw cantilever deflection signal in its entirety at high sampling rates (> 4 MHz), providing a permanent record of the tip trajectory. We develop a range of methodologies for analysing the resultant large multidimensional datasets involving classical, physics-based and information-based approaches. Physics-based analysis of G-Mode KPFM data recovers the parabolic bias dependence of the electrostatic force for each cycle of the excitation voltage, leading to a multidimensional dataset containing spatial and temporal dependence of the CPD and capacitance channels. We use multivariate statistical methods to reduce data volume and separate the complex multidimensional data sets into statistically significant components that can then be mapped onto separate physical mechanisms. Overall, G-Mode KPFM offers a new paradigm to study

  11. Probing the Depths of Space Weathering: A Cross-sectional View of Lunar Rock 76015

    NASA Technical Reports Server (NTRS)

    Noble, Sarah K.; Keller, L. P.; Stroud, Rhonda

    2007-01-01

    The term "space weathering" refers to the cumulative effects of several processes operating at the surface of any solar system body not protected by a thick atmosphere. These processes include cosmic and solar ray irradiation, solar wind implantation and sputtering, as well as melting and vaporization due to micrometeorite bombardment. Space weathering discussions have generally centered around soils but exposed rocks will also incur the effects of weathering. Rocks have much longer surface lifetimes than an individual soil grain and thus record a longer history of exposure. By studying the weathering products which have built up on a rock surface, we can gain a deeper perspective on the weathering process and better assess the relative importance of various weathering components. The weathered coating, or patina, of the lunar rock 76015 has been previously studied using SEM and TEM. It is a noritic breccia with both "glazed" (smooth glassy) and "classic" (microcratered and pancake-bearing) patina coatings. Previous TEM work on 76015 relied on ultramicrotomy to prepare cross sections of the patina coating, but these sections were limited by the "chatter" and loss of material in these brittle samples. Here we have used a focused ion beam (FIB) instrument to prepare cross sections in which the delicate stratigraphy of the patina coating is beautifully preserved.

  12. Electron distributions in the inner Jovian magnetosphere: Voyager 1 observations

    NASA Technical Reports Server (NTRS)

    Ye, G.; Armstrong, T. P.

    1993-01-01

    Using several improvements in the analysis of the observations of the Low Energy Charged Particle (LECP) experiment on Voyager 1, electron phase space densities in the inner Jovian magnetosphere (5 - 10 R(sub J) were first calculated at constant first and second invariants (represented by mu and K, respectively), based on the LECP measurements. The calculated electron phase space density profiles show that in the inner Jovian magnetosphere there exist evident time and longitude variations, energetic electron injections, and present radial transport and distributed losses. To study the radial and pitch angle diffusions of Jovian electrons, we have calculated the phase space densities in the K-L space. It is found that the electron population in the inner Jovian magnetosphere seems to consist of two components: electrons radially diffusing from a main external source and electrons generated from local sources. The radially diffusing electrons have a relatively time stationary and isotropic distribution, while the locally created electrons mainly concentrate around the equatorial plane and have relatively lower energies, in comparison with the inward diffusing electrons. Consequently, the sources of precipitation losses to the ionosphere must be primarily electrons transported from outer sources, and the major precipitations occur in the inner magnetosphere (L less than 7.5 R(sub J). In the inner Jovian magnetosphere (L = 5 to approximately 10 R(sub J)) it is estimated that for electrons with magnetic moment mu = 300 MeV/G, the diffusion coefficient D is roughly 10(exp -8) to approximately 10(exp -6) R(exp 2)(sub J)/s, and the lifetime against the diffusion losses is of the order of 10(exp 4) to approximately 10(exp 6) s.

  13. The Atmospheric Circulation of a Nine-hot-Jupiter Sample: Probing Circulation and Chemistry over a Wide Phase Space

    NASA Astrophysics Data System (ADS)

    Kataria, Tiffany; Sing, David K.; Lewis, Nikole K.; Visscher, Channon; Showman, Adam P.; Fortney, Jonathan J.; Marley, Mark S.

    2016-04-01

    We present results from an atmospheric circulation study of nine hot Jupiters that compose a large transmission spectral survey using the Hubble and Spitzer Space Telescopes. These observations exhibit a range of spectral behavior over optical and infrared wavelengths, suggesting diverse cloud and haze properties in their atmospheres. By utilizing the specific system parameters for each planet, we naturally probe a wide phase space in planet radius, gravity, orbital period, and equilibrium temperature. First, we show that our model “grid” recovers trends shown in traditional parametric studies of hot Jupiters, particularly equatorial superrotation and increased day–night temperature contrast with increasing equilibrium temperature. We show how spatial temperature variations, particularly between the dayside and nightside and west and east terminators, can vary by hundreds of kelvin, which could imply large variations in Na, K, CO and {{{CH}}}4 abundances in those regions. These chemical variations can be large enough to be observed in transmission with high-resolution spectrographs, such as ESPRESSO on VLT, METIS on the E-ELT, or MIRI and NIRSpec aboard JWST. We also compare theoretical emission spectra generated from our models to available Spitzer eclipse depths for each planet and find that the outputs from our solar-metallicity, cloud-free models generally provide a good match to many of the data sets, even without additional model tuning. Although these models are cloud-free, we can use their results to understand the chemistry and dynamics that drive cloud formation in their atmospheres.

  14. k-space image correlation to probe the intracellular dynamics of gold nanoparticles

    NASA Astrophysics Data System (ADS)

    Bouzin, M.; Sironi, L.; Chirico, G.; D'Alfonso, L.; Inverso, D.; Pallavicini, P.; Collini, M.

    2016-04-01

    The collective action of dynein, kinesin and myosin molecular motors is responsible for the intracellular active transport of cargoes, vesicles and organelles along the semi-flexible oriented filaments of the cytoskeleton. The overall mobility of the cargoes upon binding and unbinding to motor proteins can be modeled as an intermittency between Brownian diffusion in the cell cytoplasm and active ballistic excursions along actin filaments or microtubules. Such an intermittent intracellular active transport, exhibited by star-shaped gold nanoparticles (GNSs, Gold Nanostars) upon internalization in HeLa cancer cells, is investigated here by combining live-cell time-lapse confocal reflectance microscopy and the spatio-temporal correlation, in the reciprocal Fourier space, of the acquired image sequences. At first, the analytical theoretical framework for the investigation of a two-state intermittent dynamics is presented for Fourier-space Image Correlation Spectroscopy (kICS). Then simulated kICS correlation functions are employed to evaluate the influence of, and sensitivity to, all the kinetic and dynamic parameters the model involves (the transition rates between the diffusive and the active transport states, the diffusion coefficient and drift velocity of the imaged particles). The optimal procedure for the analysis of the experimental data is outlined and finally exploited to derive whole-cell maps for the parameters underlying the GNSs super-diffusive dynamics. Applied here to the GNSs subcellular trafficking, the proposed kICS analysis can be adopted for the characterization of the intracellular (super-) diffusive dynamics of any fluorescent or scattering biological macromolecule.

  15. Tone-Based Command of Deep Space Probes using Ground Antennas

    NASA Technical Reports Server (NTRS)

    Bokulic, Robert S.; Jensen, J. Robert

    2008-01-01

    A document discusses a technique for enabling the reception of spacecraft commands at received signal levels as much as three orders of magnitude below those of current deep space systems. Tone-based commanding deals with the reception of commands that are sent in the form of precise frequency offsets using an open-loop receiver. The key elements of this technique are an ultrastable oscillator and open-loop receiver onboard the spacecraft, both of which are part of the existing New Horizons (Pluto flyby) communications system design. This enables possible flight experimentation for tone-based commanding during the long cruise of the spacecraft to Pluto. In this technique, it is also necessary to accurately remove Doppler shift from the uplink signal presented to the spacecraft. A signal processor in the spacecraft performs a discrete Fourier transform on the received signal to determine the frequency of the received signal. Due to the long-term drift in the oscillators and orbit prediction model, the system is likely to be implemented differentially, where changes in the uplink frequency convey the command information.

  16. IS VOYAGER 1 INSIDE AN INTERSTELLAR FLUX TRANSFER EVENT?

    SciTech Connect

    Schwadron, N. A.; McComas, D. J.

    2013-12-01

    Plasma wave observations from Voyager 1 have recently shown large increases in plasma density, to about 0.1 cm{sup –3}, consistent with the density of the local interstellar medium. However, corresponding magnetic field observations continue to show the spiral magnetic field direction observed throughout the inner heliosheath. These apparently contradictory observations may be reconciled if Voyager 1 is inside an interstellar flux transfer event—similar to flux transfer events routinely seen at the Earth's magnetopause. If this were the case, Voyager 1 remains inside the heliopause and based on the Voyager 1 observations we can determine the polarity of the interstellar magnetic field for the first time.

  17. Voyager: Exploratory Analysis via Faceted Browsing of Visualization Recommendations.

    PubMed

    Wongsuphasawat, Kanit; Moritz, Dominik; Anand, Anushka; Mackinlay, Jock; Howe, Bill; Heer, Jeffrey

    2016-01-01

    General visualization tools typically require manual specification of views: analysts must select data variables and then choose which transformations and visual encodings to apply. These decisions often involve both domain and visualization design expertise, and may impose a tedious specification process that impedes exploration. In this paper, we seek to complement manual chart construction with interactive navigation of a gallery of automatically-generated visualizations. We contribute Voyager, a mixed-initiative system that supports faceted browsing of recommended charts chosen according to statistical and perceptual measures. We describe Voyager's architecture, motivating design principles, and methods for generating and interacting with visualization recommendations. In a study comparing Voyager to a manual visualization specification tool, we find that Voyager facilitates exploration of previously unseen data and leads to increased data variable coverage. We then distill design implications for visualization tools, in particular the need to balance rapid exploration and targeted question-answering. PMID:26390469

  18. Saturn radio emission and the solar wind - Voyager-2 studies

    SciTech Connect

    Desch, M.D.; Rucker, H.O.

    1985-01-01

    Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the relationship between parameters of the solar wind/interplanetary medium and the nonthermal Saturn radiation. Solar wind and interplanetary magnetic field properties were combined to form quantities known to be important in controlling terrestrial magnetospheric processes. The Voyager 2 data set used in this investigation consists of 237 days of Saturn preencounter measurements. However, due to the immersion of Saturn and the Voyager 2 spacecraft into the extended Jupiter magnetic tail, substantial periods of the time series were lacking solar wind data. To cope with this problem a superposed epoch method (CHREE analysis) was used. The results indicate the superiority of the quantities containing the solar wind density in stimulating the radio emission of Saturn - a result found earlier using Voyager 1 data - and the minor importance of quantities incorporating the interplanetary magnetic field. 10 references.

  19. 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.

  20. Saturn radio emission and the solar wind - Voyager-2 studies

    NASA Technical Reports Server (NTRS)

    Desch, M. D.; Rucker, H. O.

    1985-01-01

    Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the relationship between parameters of the solar wind/interplanetary medium and the nonthermal Saturn radiation. Solar wind and interplanetary magnetic field properties were combined to form quantities known to be important in controlling terrestrial magnetospheric processes. The Voyager 2 data set used in this investigation consists of 237 days of Saturn preencounter measurements. However, due to the immersion of Saturn and the Voyager 2 spacecraft into the extended Jupiter magnetic tail, substantial periods of the time series were lacking solar wind data. To cope with this problem a superposed epoch method (CHREE analysis) was used. The results indicate the superiority of the quantities containing the solar wind density in stimulating the radio emission of Saturn - a result found earlier using Voyager 1 data - and the minor importance of quantities incorporating the interplanetary magnetic field.

  1. 46 CFR 122.280 - Official logbook for foreign voyages.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... seaman, the following information required by 46 U.S.C. 10702: (i) The wages due to a seaman who dies... the property of a seaman who dies during the voyage, including a statement of each article sold...

  2. Standing Alfven wave current system at Io - Voyager 1 observations

    NASA Astrophysics Data System (ADS)

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

    1981-09-01

    The enigmatic control of the occurrence frequency of Jupiter's decametric emissions by the satellite Io has been 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 Goddard Space Flight Center magnetic field experiment on Voyager 1 on March 5, 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 x 10 to the 6th A. A mass density of 7400-13,600 proton mass units/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 1050-1500/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.

  3. The Voyager Spacecraft. [Jupiter-Saturn mission investigations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The configuration of the Voyager spacecraft is described as well as the subsystems for power, temperature control, attitude control, and propulsion. Major features of Jupiter and Saturn including their atmospheres, surfaces, and natural satellites are discussed. The 13 onboard experiments and their scientific objectives are explained. Other aspects covered include tracking, data acquisition, and the mission control and computing center. Members of the Voyager team and subcontractors are listed.

  4. Triton and Nereid astrographic observations from Voyager 2

    NASA Technical Reports Server (NTRS)

    Jacobson, R. A.

    1991-01-01

    This article describes the reduced astrographic observations of Triton and Nereid derived from Voyager 2 imaging data. The data set contains 496 sets of spacecraft-centered fight ascension and declination observations and includes all of the observations used in Voyager encounter operations. The details of the conversion process from imaging to astrographic observations are given. The effect of using the astrographic rather than imaging form in ephemeris improvement is evaluated.

  5. Interstellar Probe: The Next Step To Flight

    NASA Astrophysics Data System (ADS)

    McNutt, Ralph; Zurbuchen, Thomas H.

    2016-07-01

    In the years following the discovery of the solar wind, the term "heliosphere" was coined and defined as "the region of interplanetary space where the solar wind is flowing supersonically." In June 1971, with the development of the Pioneer probes to Jupiter and beyond well underway, a session of the American Astronautical Society meeting considered scientific exploration reaching beyond the solar system and into the interstellar medium. Despite many discussions, studies, and meetings since, the most recent held under the auspices of the Keck Institute for Space Studies (8-11 September 2014 and 13-15 January 2015), such missions have been relegated to the '"future" due to the large distances and solar system escape speeds contemplated for their execution. In the meantime, the Voyager Interstellar Mission (VIM), consisting of the twin Voyager spacecraft almost 40 years since their respective launches, are making inroads into this region beyond the termination shock of the solar wind, a new region of the solid bodies of the solar system has been opened by the New Horizons flyby of the Pluto system, and the Cassini Ion and Neutral CAmera (INCA) and Interstellar Boundary Explorer (IBEX) have remotely sensed neutral atoms that have provided significant clues to the global structure of the interaction of the solar wind and interstellar medium. It is now time for a dedicated mission to the regime beyond the solar system to explore our galactic environment. A first, near-term implementation can be carried out with the near-current flight system technology. What is also clear is that the high speeds required will limit the spacecraft to a relatively small mass of no more than ~500 kg, regardless of the propulsion details. The recent success of the New Horizons mission at the Pluto system illustrates that with modern technologies, such spacecraft sizes can still accommodate the means to produce paradigm-shifting science, providing for a compelling scientific mission. The

  6. The helium abundance of Jupiter from Voyager

    NASA Technical Reports Server (NTRS)

    Gautier, D.; Conrath, B.; Flasar, F. M.; Hanel, R. A.; Kunde, V. G.; Chedin, A.; Scott, N.

    1980-01-01

    Full disk measurements recorded 31 days before the Voyager 1 encounter with Jupiter by the radiometer of the infrared instrument, IRIS, indicate a geometric albedo of 0.274 + or - 0.013. Combining this measurement with the Pioneer derived phase integral of 1.25 and our error estimate of 0.1 yields a Jovian Bond albedo of 0.343 + or - 0.032. Infrared spectra recorded at the same time by the Michelson interferometer, along with a model extrapolation to low wave numbers not covered by the instrument, yield a thermal emission of (1.359 + or - 0.014) .001 W cm to the (-2) power. As in the case of the albedo measurement, the quoted errors in the emission measurement reflect estimates of systematic effects and are uncertain while the random component is negligible. From these measurements the internal heat flux of Jupiter is estimated to be (5.444 + or - 0.425) .0001 W cm to the (-2) power, and the energy balance defined as the ratio of emitted thermal to absorbed solar energy is 1.668 + or - 0.085.

  7. 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.

  8. Voyager observations of Jovian millisecond radio bursts

    NASA Technical Reports Server (NTRS)

    Alexander, J. K.; Desch, M. D.

    1984-01-01

    Voyager Planetary Radio Astronomy data collected over 30-day intervals centered on the two close encounters with Jupiter were utilized to study the characteristics of millisecond-duration radio bursts (s-bursts) at frequencies between 5 and 15 MHz. In this frequency range, s-bursts are found to occur almost independently of Central Meridian Longitude and to depend entirely on the phase of Io with respect to the observer's planetocentric line of sight. Individual bursts typically cover a total frequency range of about 1.5 to 3 MHz, and they are usually strongly circularly polarized. Most bursts in a particular s-burst storm will exhibit the same polarization sense (either right-hand or left-hand), and there is some evidence for a systematic pattern in which one polarizations sense is preferred over the other as a function of Io phase and Central Meridian Longitude. These data are all suggestive of a radio source that is located along the instantaneous Io flux tube and that extends over a linear dimension of 5000 km along the field lines in both the northern and southern Hemispheres.

  9. 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.

  10. Radioisotope Thermoelectric Power Systems: Enabling Technology for European Space Exploration Missions

    NASA Astrophysics Data System (ADS)

    Williams, H. R.; Ambrosi, R. M.; Bannister, N. P.; Samara-Ratna, P.; Tinsley, T. P.; Rice, T.; Sarsfield, M. J.; Cordingley, L.; Slade, R.; Deacon, T.; Jorden, A.; Johnson, W.; Stephenson, K.

    2012-09-01

    Radioisotope power systems (RPS) have proved critical enablers for many of the most demanding space and planetary science missions. US systems, fuelled by 238Pu, have returned extraordinary science from missions such as the Pioneer and Voyager probes, Galileo (Jupiter) and Cassini (Saturn). At the time of writing, New Horizons and Mars Science Laboratory are en route to Pluto and Mars respectively and are equipped with Radioisotope Thermoelectric Generators (RTG). RPSs can provide electrical power to spacecraft systems independently of solar energy, permitting more capable and productive spacecraft and missions. Europe is focused on developing 241Am powered RPSs.

  11. Parkes radio science system design and testing for Voyager Neptune encounter

    NASA Technical Reports Server (NTRS)

    Rebold, T. A.; Weese, J. F.

    1989-01-01

    The Radio Science System installed at Parkes, Australia for the Voyager Neptune encounter was specified to meet the same stringent requirements that were imposed upon the Deep Space Network Radio Science System. The system design and test methodology employed to meet these requirements at Parkes are described, and data showing the measured performance of the system are presented. The results indicate that the system operates with a comfortable margin on the requirements. There was a minor problem with frequency-dependent spurious signals which could not be fixed before the encounter. Test results characterizing these spurious signals are included.

  12. Voyager investigation of the cosmic diffuse background: Observations of rocket-studied locations with Voyager

    NASA Technical Reports Server (NTRS)

    Henry, Richard C.

    1994-01-01

    Attachments to this final report include 2 papers connected with the Voyager work: 'Voyager Observations of Dust Scattering Near the Coalsack Nebula' and 'Search for the Intergalactic Medium'. An appendix of 12 one-page write-ups prepared in connection with another program, UVISI, is also included. The one-page write-ups are: (1) Sky survey of UV point sources to 600 times fainter than previous (TD-1) survey; (2) Diffuse galactic light: starlight scattered from dust at high galactic latitude; (3) Optical properties of interstellar grains; (4) Fluorescence of molecular hydrogen in the interstellar medium; (5) Line emission from hot interstellar medium and/or hot halo of galaxy; (6) Integrated light of distant galaxies in the ultraviolet; (7) Intergalactic far-ultraviolet radiation field; (8) Radiation from recombining intergalactic medium; (9) Radiation from re-heating of intergalactic medium following recombination; (10) Radiation from radiative decay of dark matter candidates (neutrino, etc.); (11) Reflectivity of the asteroids in the Ultraviolet; and (12) Zodiacal light.

  13. Disturbances observed near Ganymede by Voyager 2

    SciTech Connect

    Burlaga, L.F.; Belcher, J.W.; Ness, N.F.

    1980-01-01

    We investigated disturbances in the field and particle environment observed by Voyager 2 as it passed near the Jovian moon Ganymede in Jupiter's magnetosphere. The plasma analyzer observed at least a dozen sharply bounded depressions in density (cavities). We estimated that they probably extended at least 20 RGAMMA along the ambient magnetic field lines (R/sub G/=2635 km is the radius of Ganymede) and between 2--50 R/sub G/ in the directions transverse to B. Depressions in the magnetic field strength of the order of 5% of the ambient field strength (60nT to 135nT) were observed at the boundaries of the cavities in more than half of the cases; they were probably produced by currents flowing transverse to B on the boundaries. In some cases, the magnetic field strength inside the cavities was a few percent higher than the ambient value. This gives an upper limit on ..beta..=nkT/(B/sup 2//8..pi..) outside the cavities, viz. Beta<0.2; inmost cases ..beta.. was appreciably smaller than this. The flux of >2.5 MeV protons was strongly anti-correlated with the plasma density, the flux being higher inside the cavities than outside. One possible mechanism for the production of these flux enhancements and the cavities themselves is a local, magnetic field-aligned electric field, E. It is possible that Ganymede is responsible for the energetic protons in the cavities, in which case vertical-bar E vertical-barapprox.50 mV/m. Such a localized source implies radial motions of the magnetospheric plasma with speeds of the order of a few hundred km/s. Such motions could be produced by long-wavelength, small-amplitude Alfven waves in Jupiter's magnetosphere.

  14. Voyager 2 at neptune: imaging science results.

    PubMed

    Smith, B A; Soderblom, L A; Banfield, D; Barnet, C; Basilevsky, A T; Beebe, R F; Bollinger, K; Boyce, J M; Brahic, A; Briggs, G A; Brown, R H; Chyba, C; Collins, S A; Colvin, T; Cook, A F; Crisp, D; Croft, S K; Cruikshank, D; Cuzzi, J N; Danielson, G E; Davies, M E; De Jong, E; Dones, L; Godfrey, D; Goguen, J; Grenier, I; Haemmerle, V R; Hammel, H; Hansen, C J; Helfenstein, C P; Howell, C; Hunt, G E; Ingersoll, A P; Johnson, T V; Kargel, J; Kirk, R; Kuehn, D I; Limaye, S; Masursky, H; McEwen, A; Morrison, D; Owen, T; Owen, W; Pollack, J B; Porco, C C; Rages, K; Rogers, P; Rudy, D; Sagan, C; Schwartz, J; Shoemaker, E M; Showalter, M; Sicardy, B; Simonelli, D; Spencer, J; Sromovsky, L A; Stoker, C; Strom, R G; Suomi, V E; Synott, S P; Terrile, R J; Thomas, P; Thompson, W R; Verbiscer, A; Veverka, J

    1989-12-15

    Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices. Neptune's atmosphere is dominated by a large anticyclonic storm system that has been named the Great Dark Spot (GDS). About the same size as Earth in extent, the GDS bears both many similarities and some differences to the Great Red Spot of Jupiter. Neptune's zonal wind profile is remarkably similar to that of Uranus. Neptune has three major rings at radii of 42,000, 53,000, and 63,000 kilometers. The outer ring contains three higher density arc-like segments that were apparently responsible for most of the ground-based occultation events observed during the current decade. Like the rings of Uranus, the Neptune rings are composed of very dark material; unlike that of Uranus, the Neptune system is very dusty. Six new regular satellites were found, with dark surfaces and radii ranging from 200 to 25 kilometers. All lie inside the orbit of Triton and the inner four are located within the ring system. Triton is seen to be a differentiated body, with a radius of 1350 kilometers and a density of 2.1 grams per cubic centimeter; it exhibits clear evidence of early episodes of surface melting. A now rigid crust of what is probably water ice is overlain with a brilliant coating of nitrogen frost, slightly darkened and reddened with organic polymer material. Streaks of organic polymer suggest seasonal winds strong enough to move particles of micrometer size or larger, once they become airborne. At least two active plumes were seen, carrying dark material 8 kilometers above the surface before being transported downstream by high level winds. The plumes may be driven by solar heating and the subsequent violent vaporization of subsurface nitrogen. PMID:17755997

  15. Voyager 2 at Neptune: Imaging science results

    SciTech Connect

    Smith, B.A.; Croft, S.K.; Haemmerle, V.R.; Kargel, J.; Porco, C.C.; Strom, R.G. ); Soderblom, L.A.; Kirk, R.; Masursky, H.; McEwen, A.; Shoemaker, E.M. ); Banfield, D.; Danielson, G.E.; DeJong, E.; Howell, C.; Ingersoll, A.P.; Schwartz, J. ); Barnet, C.; Beebe, R.F.; Kuehn, D.I. ); Basilevsky, A.T. ); Bollinger, K.; Brown, R.H.; Collins, Crisp, D.; Goguen, J.; Hammel, H.; Hansen, C.J.; Johnson, T.V.; Owen, W.; Rudy, D.; Synnott, S.P.; Terrile, R.J. ); Boyce, J.M.; Briggs, G.A. ); Brahic, A.; Grenier, I.; Sicardy, B. ); Chyba, C.; Helfenstein, C.P.; Sagan, C.; Simonelli, D.; Thomas, P.; Thompson, W.R.; Veverka, J.; Verbiscer, A. (Cornell Univ., Ithaca,

    1989-12-15

    Voyager 2 images of Neptune reveal a windy planet characterized by bright clouds of methane ice suspended in an exceptionally clear atmosphere above a lower deck of hydrogen sulfide or ammonia ices. Neptune's atmosphere is dominated by a large anticyclonic storm system that has been named the Great Dark Spot (GDS). About the same size as Earth in extent,the GDS bears both many similarities and some differences to the Great Red Spot of Jupiter. Neptune's zonal wind profile is remarkably similar to that of Uranus. Neptune has three major rings at radii of 42,000, 53,000, and 63,000 kilometers. The outer ring contains three higher density arc-like segments that were apparently responsible for most of the ground-based occultation events observed during the current decade. Like the rings of Uranus, the Neptune rings are composed of very dark material; unlike that of Uranus, the Neptune system is very dusty. Six new regular satellites were found, with dark surfaces and radii ranging from 200 to 25 kilometers. All lie inside the orbit of Triton and the inner four are located within the ring system. Triton is seen to be a differentiated body, with a radius of 1350 kilometers and a density of 2.1 grams per cubic centimeter; it exhibits clear evidence of early episodes of surface melting. A now rigid crust of what is probably water ice is overlain with a brilliant coating of nitrogen frost, slightly darkened and reddened with organic polymer material. Streaks of organic polymer suggest seasonal winds strong enough to move particles of micrometer size or larger, once they become airborne. At least two active plumes were seen, carrying dark material 8 kilometers above the surface before being transported downstream by high level winds. The plumes may be driven by solar heating and the subsequent violent vaporization of subsurface nitrogen.

  16. Infrared observations of the saturnian system from voyager 2.

    PubMed

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

    1982-01-29

    During the passage of Voyager 2 through the Saturn system, infrared spectral and radiometric data were obtained for Saturn, Titan, Enceladus, Tethys, Iapetus, and the rings. Combined Voyager 1 and Voyager 2 observations of temperatures in the upper troposphere of Saturn indicate a seasonal asymmetry between the northern and southern hemispheres, with superposed small-scale meridional gradients. Comparison of high spatial resolution data from the two hemispheres poleward of 60 degrees latitude suggests an approximate symmetry in the small-scale structure, consistent with the extension of a symmetric system of zonal jets into the polar regions. Longitudinal variations of 1 to 2 K are observed. Disk- averaged infrared spectra of Titan show little change over the 9-month interval between Voyager encounters. By combining Voyager 2 temperature measurements with ground-based geometric albedo determinations, phase integrals of 0.91 +/- 0.13 and 0.89 +/- 0.09 were derived for Tethys and Enceladus, respectively. The subsolar point temperature of dark material on Iapetus must exceed 110 K. Temperatures (and infrared optical depths) for the A and C rings and for the Cassini division are 69 +/- 1 K (0.40 +/- 0.05), 85 +/- 1 K (0.10 +/- 0.03), and 85 +/- 2 K (0.07 +/- 0.04), respectively. PMID:17771275

  17. Voyager 2 observations of plasma in the heliosheath

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.

    2011-12-01

    Voyager 2 is now at 96 AU and provides the only direct observations of plasma in the heliosheath. I will present the most recent plasma observations and try to assimilate them with other Voyager measurements and observations at 1 AU. The heliosheath is highly variable on scales of tens of minutes in both plasma and magnetic field parameters. The distribution of plasma parameters is Gaussian; this enables us to determine flow directions as the flow angles approach the instrument cutoff. The plasma speeds observed at Voyager 2 remain well above those inferred at Voyager 1 at similar distances into the heliosheath. The Voyager 2 flows continue to divert toward the heliotail. The direction of flow is more in the T than N direction (using the RTN coordinate system). The density and temperature have decreased across the heliosheath until the beginning of 2011; since then the density has increased by a factor of 2 and the speed and temperature have also increased. These results will be compared to model predictions.

  18. Voyager 2 solar plasma and magnetic field spectral analysis for intermediate data sparsity

    NASA Astrophysics Data System (ADS)

    Gallana, Luca; Fraternale, Federico; Iovieno, Michele; Fosson, Sophie M.; Magli, Enrico; Opher, Merav; Richardson, John D.; Tordella, Daniela

    2016-05-01

    The Voyager probes are the furthest, still active, spacecraft ever launched from Earth. During their 38 year trip, they have collected data regarding solar wind properties (such as the plasma velocity and magnetic field intensity). Unfortunately, a complete time evolution of the measured physical quantities is not available. The time series contains many gaps which increase in frequency and duration at larger distances. The aim of this work is to perform a spectral and statistical analysis of the solar wind plasma velocity and magnetic field using Voyager 2 data measured in 1979, when the gap density is between the 30% and 50%. For these gap densities, we show the spectra of gapped signals inherit the characteristics of the data gaps. In particular, the algebraic decay of the intermediate frequency range is underestimated and discrete peaks result not from the underlaying data but from the gap sequence. This analysis is achieved using five different data treatment techniques coming from the multidisciplinary context: averages on linearly interpolated subsets, correlation without data interpolation, correlation of linearly interpolated data, maximum likelihood data reconstruction, and compressed sensing spectral estimation. With five frequency decades, the spectra we obtained have the largest frequency range ever computed at five astronomical units from the Sun; spectral exponents have been determined for all the components of the velocity and magnetic field fluctuations. Void analysis is also useful in recovering other spectral properties such as micro and integral scales.

  19. Observed Coupling Between the International Space Station PCU Plasma and a FPMU Langmuir Probe Facilitated by the Geomagnetic Field

    NASA Technical Reports Server (NTRS)

    Hartman, William; Koontz, Steven L.

    2010-01-01

    Electrical charging of the International Space Station (ISS) is a matter of serious concern resulting from the possibility of vehicle arcing and electrical shock hazard to crew during extravehicular activity (EVA). A Plasma Contactor Unit (PCU) was developed and integrated into ISS in order to control the ISS floating potential, thereby, minimize vehicle charging and associated hazards. One of the principle factors affecting ISS electrical charging is the ionosphere plasma state (i.e., electron temperature and density). To support ISS electrical charging studies a Floating Potential Monitoring Unit (FPMU) is also integrated into ISS in order to measure the ionosphere properties using Langmuir probes (LP). The FPMU was located on the Starboard side of ISS. The PCU is located near the center of ISS with its plasma exhaust pointed to port. From its integration on ISS in 2006 through November of 2009, the FPMU data exhibited nominal characteristics during PCU operation. On November 21, 2009 the FPMU was relocated from the Starboard location to a new Port location. After relocation significant enhanced noise was observed in both the LP current-voltage sweeps and the derived electron temperature data. The enhanced noise only occurred when the PCU was in discharge and at unique and repeatable locations of the ISS orbit. The cause of this enhanced noise was investigated. It was found that there is coupling occurring between the PCU plasma and the FPMU LP. In this paper we shall 1) present the on-orbit data and the presence of enhanced noise, 2) demonstrate that the coupling of the PCU plasma and the FPMU measurements is geomagnetically organized, 3) show that coupling of the PCU plasma and the FPMU is primarily due to and driven by particle-wave interaction and 4) show that the ionosphere conditions are adequate for Alfven waves to be generated by the PCU plasma.

  20. Preliminary results of a gamma-ray burst study in the Konus experiment on the Venera-11 and Venera-12 space probes

    NASA Technical Reports Server (NTRS)

    Mazets, Y. P.; Golentskiy, S. V.; Ilinskiy, V. N.; Panov, V. N.; Aptekar, R. L.; Guryan, Y. A.; Sokolov, I. A.; Sokolova, Z. Y.; Kharitonova, T. V.

    1979-01-01

    Twenty-one gamma-ray bursts and 68 solar flares in the hard X-ray range were detected on Venera-11 and Venera-12 space probes during the initial 50-day observation period. Major characteristics of the equipment used and preliminary data on the temporal structure and energy spectra of the gamma-ray bursts are considered. The pattern of gamma-ray burst frequency distribution vs. intensity, N(S), is established.

  1. Additional Features of the Plasma Environment in the Heliosheath and Outer Heliosphere: Further Examination of the Voyager 2 Plasma Observations

    NASA Astrophysics Data System (ADS)

    Intriligator, D. S.; Intriligator, J.; Miller, W.; Webber, W. R.

    2009-12-01

    We continue our examination of the plasma distributions obtained by the MIT plasma probe on Voyager 2 in 2007. Last year we presented an identification of High Energy Ions (HEIs) in the plasma data in the vicinity of the termination shock. These HEIs are reminiscent of the multiple reflected gyrating and pickup protons observed in the vicinity of planetary foreshocks. We continue to examine some of the details of the MIT plasma data and to compare these plasma data with other in-situ spacecraft measurements including with the enhanced signals in the plasma wave subsystem. We also evaluate our findings in terms of theoretical expectations. Our detailed analyses show that in 2007, in the vicinity of Voyager 2, the characteristics of the outer heliosphere and heliosheath were quite complex with variations occurring on many scales and indicating the need for further theoretical and empirical study. This work is sponsored by NASA Grant NNX08AE40G and by Carmel Research Center. We are grateful to John Richardson for providing the Voyager 2 MIT plasma data.

  2. In situ observations of interstellar plasma with Voyager 1.

    PubMed

    Gurnett, D A; Kurth, W S; Burlaga, L F; Ness, N F

    2013-09-27

    Launched over 35 years ago, Voyagers 1 and 2 are on an epic journey outward from the Sun to reach the boundary between the solar plasma and the much cooler interstellar medium. The boundary, called the heliopause, is expected to be marked by a large increase in plasma density, from about 0.002 per cubic centimeter (cm(-3)) in the outer heliosphere, to about 0.1 cm(-3) in the interstellar medium. On 9 April 2013, the Voyager 1 plasma wave instrument began detecting locally generated electron plasma oscillations at a frequency of about 2.6 kilohertz. This oscillation frequency corresponds to an electron density of about 0.08 cm(-3), very close to the value expected in the interstellar medium. These and other observations provide strong evidence that Voyager 1 has crossed the heliopause into the nearby interstellar plasma. PMID:24030496

  3. Characteristics of the Termination Shock: Insights from Voyager

    SciTech Connect

    Cummings, A.C.; Stone, E.C.

    2005-08-01

    We examine the energy spectra obtained from the cosmic ray instrument on the Voyager 1 spacecraft during 2002/215 through 2005/60. We find that the energy spectra of protons below {approx}20 MeV often resemble two power laws with a relatively hard index at low energies and a softer index at higher energies. The point of intersection of the two power laws is {approx}3 MeV. Beginning in 2005, the low-energy index is typically -1.5, corresponding to a shock strength (compression ratio) of 2.5. We attribute these characteristics to a restricted region of the solar wind termination shock that is sporadically connected to the Voyager 1 spacecraft by the interplanetary magnetic field. The absence of significant spectral variability in 2005 suggests that Voyager 1 entered a region with minimal spatial gradients of the lowest energy ions.

  4. Magnetic field studies at Jupiter by Voyager 2 - 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

    The Voyager 2 magnetic field experiment, for which the instrumentation is identical to that on Voyager 1, operated flawlessly throughout the second Jupiter encounter. The paper presents a brief overview of the results obtained to date on the Jovian magnetosphere, the bow shock, the magnetopause, and the extended magnetic tail. The results and the magnetic field geometry confirm the earlier conclusion from Voyager 1 that Jupiter has an enormous magnetic tail, approximately 300-400 Jupiter radii in diameter, trailing behind the planet with respect to the supersonic flow of the solar wind. Additional observations of the distortion of the inner magnetosphere by a concentrated plasma show a spatial merging of the equatorial magnetodisk current with the current sheet in the magnetic tail. Disturbances near Ganymede are discussed.

  5. Solar-Heliospheric-Interstellar Cosmic Ray Tour with the NASA Virtual Energetic Particle Observatory and the Space Physics Data Facility

    NASA Astrophysics Data System (ADS)

    Cooper, John F.; Papitashvili, Natalia E.; Johnson, Rita C.; Lal, Nand; McGuire, Robert E.

    2015-04-01

    NASA now has a large collection of solar, heliospheric, and local interstellar (Voyager 1) cosmic ray particle data sets that can be accessed through the data system services of the NASA Virtual Energetic Particle Observatory (VEPO) in collaboration with the NASA Space Physics Data Facility SPDF), respectively led by the first and last authors. The VEPO services were developed to enhance the long-existing OMNIWeb solar wind and energetic particle services of SPDF for on-line browse, correlative, and statistical analysis of NASA and ESA mission fields, plasma, and energetic particle data. In this presentation we take of tour through VEPO and SPDF of SEP reservoir events, the outer heliosphere earlier surveyed by the Pioneer, Voyager, and Ulysses spacecraft and now being probed by New Horizons, and the heliosheath-heliopause-interstellar regions now being explored by the Voyagers and IBEX. Implications of the latter measurements are also considered for the flux spectra of low to high energy cosmic rays in interstellar space.

  6. Reconstruction of the Voyager 2 Neptune Encounter in the ICRF System

    NASA Technical Reports Server (NTRS)

    Jacobson, Robert A.

    2008-01-01

    The Neptunian system was visited by the Voyager 2 spacecraft in August of 1989. We have re-examined the Voyager mission taking advantage of improvements made in dynamical and observational modelling and data processing.

  7. Voyager observations of the azimuthal brightness variations in Saturn's rings

    NASA Technical Reports Server (NTRS)

    Franklin, F. A.; Cook, A. F., II; Barrey, R. T. F.; Roff, C. A.; Hunt, G. E.; De Rueda, H. B.

    1987-01-01

    The present Voyagers I and II measurements of Saturn A ring azimuthal brightness variations in reflected light are noted to be in general agreement with earth-based measurements. Voyager images of the rings in light transmitted through them also indicate the presence of these brightness variations, but with greater amplitude and an about 65-deg phase discrepancy with those seen in reflection. These differences in photometric behavior are qualitatively accounted for in terms of the widespread presence of particle wakes in the A ring.

  8. Performance model of the Argonne Voyager multimedia server

    SciTech Connect

    Disz, T.; Olson, R.; Stevens, R.

    1997-07-01

    The Argonne Voyager Multimedia Server is being developed in the Futures Lab of the Mathematics and Computer Science Division at Argonne National Laboratory. As a network-based service for recording and playing multimedia streams, it is important that the Voyager system be capable of sustaining certain minimal levels of performance in order for it to be a viable system. In this article, the authors examine the performance characteristics of the server. As they examine the architecture of the system, they try to determine where bottlenecks lie, show actual vs potential performance, and recommend areas for improvement through custom architectures and system tuning.

  9. The Voyager spacecraft /James Watt International Gold Medal Lecture/

    NASA Technical Reports Server (NTRS)

    Heacock, R. L.

    1980-01-01

    The Voyager Project background is reviewed with emphasis on selected features of the Voyager spacecraft. Investigations by the Thermo-electric Outer Planets Spacecraft Project are discussed, including trajectories, design requirements, and the development of a Self Test and Repair computer, and a Computer Accessed Telemetry System. The design and configuration of the spacecraft are described, including long range communications, attitude control, solar independent power, sequencing and control data handling, and spacecraft propulsion. The development program, maintained by JPL, experienced a variety of problems such as design deficiencies, and process control and manufacturing problems. Finally, the spacecraft encounter with Jupiter is discussed, and expectations for the Saturn encounter are expressed.

  10. Magnetic field studies at Jupiter by Voyager 2: 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

    The Voyager 2 magnetic field experiment is described and compared to the Voyager 1 experiment and data. The magnetosphere, the bow shock, the magnetopause, and the extended magnetic tail of Jupiter are discussed. Two crossings of the near equatorial current sheet were observed in the magnetosphere and its tail every 10 hour rotation period of the planet. A definitive mapping of the geometry and character of these enhanced plasma and depressed magnetic field regions is discussed. The interaction of the satellite Ganymede with the Jovian magnetosphere, which leads to disturbances as the Jovian magnetosphere corotates with the planet past the satellite is analyzed.

  11. 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

  12. Conductivity Probe

    NASA Technical Reports Server (NTRS)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air.

    The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air.

    The needles on the probe are 15 millimeters (0.6 inch) long.

    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.

  13. 46 CFR 30.01-6 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 1 2011-10-01 2011-10-01 false Application to vessels on an international voyage. 30.01... PROVISIONS Administration § 30.01-6 Application to vessels on an international voyage. (a) Except as provided... vessel on an international voyage apply to a vessel that: (1) Is mechanically propelled and of at...

  14. 46 CFR 117.10 - Applicability to vessels on an international voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Applicability to vessels on an international voyage. 117.10 Section 117.10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER... international voyage. A vessel on an international voyage subject to the International Convention for Safety...

  15. 46 CFR 180.10 - Applicability to vessels on an international voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Applicability to vessels on an international voyage. 180... Applicability to vessels on an international voyage. A vessel on an international voyage subject to the International Convention for the Safety of Life at Sea, 1974, (SOLAS) must meet the requirements in subchapter...

  16. 46 CFR 30.01-6 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Application to vessels on an international voyage. 30.01... PROVISIONS Administration § 30.01-6 Application to vessels on an international voyage. (a) Except as provided... vessel on an international voyage apply to a vessel that: (1) Is mechanically propelled and of at...

  17. 46 CFR 196.07-1 - Notice and reporting of casualty and voyage records.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... RESEARCH VESSELS OPERATIONS Notice and Reporting of Casualty and Voyage Records § 196.07-1 Notice and reporting of casualty and voyage records. The requirements for providing notice and reporting of marine... 46 Shipping 7 2010-10-01 2010-10-01 false Notice and reporting of casualty and voyage records....

  18. 46 CFR 185.220 - Records of a voyage resulting in a marine casualty.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Records of a voyage resulting in a marine casualty. 185.220 Section 185.220 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Marine Casualties and Voyage Records § 185.220 Records of a voyage resulting in a marine casualty....

  19. 46 CFR 185.220 - Records of a voyage resulting in a marine casualty.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Records of a voyage resulting in a marine casualty. 185.220 Section 185.220 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) SMALL PASSENGER VESSELS (UNDER 100 GROSS TONS) OPERATIONS Marine Casualties and Voyage Records § 185.220 Records of a voyage resulting in a marine casualty....

  20. 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.

  1. IBEX Observations provide strong Evidence that Voyager 1 is still in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Gloeckler, G.; Fisk, L. A.

    2015-09-01

    After plasma wave measurements by Voyager 1 (V1) revealed a surprisingly high value for the plasma electron density, a value close to that expected in the local interstellar medium, all principal investigators of the Voyager mission currently exploring the heliosheath suddenly reversed their position on the location of V1. They concluded unanimously, and NASA announced that V1 has crossed the heliopause and is now in local interstellar space. We have disputed this conclusion, pointing out that to account for all the V1 observations, particularly of the magnetic field direction together with the density, it is necessary to conclude that the higher densities observed by V1 are due to compressed solar wind. In this paper we show that our model for the nose region of the heliosheath can account in detail for the spectral shapes and intensities of Energetic Neutral Hydrogen (ENH) observed by the Interstellar Boundary Explorer (IBEX) looking in the directions of V1 and Voyager 2 (V2). A key feature of our model is the existence of a region, the hot heliosheath, where the outward-moving solar wind is gradually compressed and thus heated, followed by a region, the cold heliosheath, where the solar wind is still compressed but now cold. It is the existence of this cold heliosheath, the region of cold but high-density solar wind, which provides a unique and simple explanation for the low-energy IBEX ENH differential intensities. Finally, since this cold heliosheath is the region where V1 must now reside, the low-energy IBEX observations provide strong evidence that V1 is still in the heliosphere.

  2. Heat stress: a major contributor to poor animal welfare associated with long-haul live export voyages.

    PubMed

    Caulfield, Malcolm P; Cambridge, Heather; Foster, Susan F; McGreevy, Paul D

    2014-02-01

    Recent investigations by the Australian Department of Agriculture, Fisheries and Forestry into high mortalities on live export voyages from Australia to the Middle East during the Northern hemisphere summer suggest that animal welfare may be compromised by heat stress. The live export industry has generated a computer model that aims to assess the risk of heat stress and to contain mortality levels on live export ships below certain arbitrary limits. Although the model must be complied with under Australian law, it is not currently available for independent scientific scrutiny, and there is concern that model and the mandated space allowances are inadequate. This review appraises the relevant literature on heat stress in sheep and cattle, including laboratory studies aimed at mimicking the ambient temperatures and humidity levels likely to be encountered on live export voyages. Animal welfare is likely to be very poor as a result of heat stress in some shipments. PMID:24157340

  3. On-board estimation technology for space station - Current status and future developments.

    NASA Technical Reports Server (NTRS)

    Rodriguez, G.; Lin, Y. H.; Cameron, J. M.; Szirmay, S. Z.

    1983-01-01

    Design considerations and projected solutions to on-board automated estimation techniques for advanced technology controls on a space station are described, with emphasis on the state estimator. The space station is modelled as a collection of rigid and flexible bodies connected at a finite number of hinges. The systems dynamics are characterized by angular velocities of the base body, gimbal angles, and deflections of the flexible appendages. The state estimator evolution is projected to occur in four generations, with the first being control logic in the Viking and Voyager spacecraft, the second in the Shuttle and Galileo probe, the third being large antennas and the prototype space station, the last, around the year 2000, for the actual space station. Considerations for attitude, ephemeris, shape determination, and position estimation through each generation are discussed.

  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

    will include: (1) Continuing operations with regard to the receipt, processing, verification, cataloging, display, and distribution of the data from the LECP instruments on Voyager 1 and 2, (2) Monitoring the health and performance of the LECP instruments, and evaluating and characterizing the response of the LECP instruments to various energetic particle and plasma environments, (3) Participating in, and supporting Voyager Project planning exercises and other coordinated activities relevant to exploration of the outer heliosphere, (4) Developing analysis techniques and operational procedures suitable for searching for and characterizing the boundaries and unique regions of the outher heliosphere, (5) Continuing the preparation of data sets appropriate for submission to the National Space Sciences Data Center (NSSDC) and, where appropriate, the Planetary Data System (PDS), (6) Maintaining direct Web access to online LECP data through the JHU/APL Voyager LECP home page, (7) Performing scientific evaluations of the Voyager 1 and 2 LECP data sets in conjunction with other data sets and other investigators, with particular focus on the outer regions of the heliosphere, and (8) Publishing the results of these evaluations in the scientific literature and presenting the results in scientific conferences.

  5. Plasma observations near Neptune: Initial results for Voyager 2

    SciTech Connect

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

    1989-12-15

    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 by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates.

  6. Plasma observations near neptune: initial results from voyager 2.

    PubMed

    Belcher, J W; Bridge, H S; Bagenal, F; Coppi, B; Divers, O; Eviatar, A; Gordon, G S; Lazarus, A J; McNutt, R L; Ogilvie, K W; Richardson, J D; Siscoe, G L; Sittler, E C; Steinberg, J T; Sullivan, J D; Szabo, A; Villanueva, L; Vasyliunas, V M; Zhang, M

    1989-12-15

    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 by Voyager 2 was not sharp but rather appeared as a gradual decrease in plasma density and temperature. The maximum plasma density observed in the magnetosphere is inferred to be 1.4 per cubic centimeter (the exact value depends on the composition), the smallest observed by Voyager in any magnetosphere. The plasma has at least two components; light ions (mass, 1 to 5) and heavy ions (mass, 10 to 40), but more precise species identification is not yet available. Most of the plasma is concentrated in a plasma sheet or plasma torus and near closest approach to the planet. A likely source of the heavy ions is Triton's atmosphere or ionosphere, whereas the light ions probably escape from Neptune. The large tilt of Neptune's magnetic dipole produces a dynamic magnetosphere that changes configuration every 16 hours as the planet rotates. PMID:17756003

  7. 33 CFR 164.80 - Tests, inspections, and voyage planning.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... breaking up larger tows; (B) For harbor-assist; (C) For assistance towing as defined by 46 CFR 10.103; (D... Captain of the Port (COTP). (2) If you think your towing vessel should be exempt from these voyage... approach, special conditions, and critical maneuvers; and (ix) Whether the towing vessel has...

  8. Voyages Home: "The Wanderer"&"The Odyssey." Thematic Unit.

    ERIC Educational Resources Information Center

    Sekula, Diane

    Sophie and Cody in "The Wanderer" (Sharon Creech) share the duties of recording their journey to an ancestor's birth land. The strong bond of family and accomplishments through the voyage home personified the embodiment of an adventurer. For Sophie and Cody, close family bonds were forged and washed clean by the sea. Odysseus, the protagonist in…

  9. A Curriculum Review: The Voyage of the Mimi.

    ERIC Educational Resources Information Center

    Johns, Kenneth W.

    1988-01-01

    The curriculum package, "The Voyage of the Mimi," uses computer, videocassette, student text, and workbook for integrated study of the great whales and the impact of social actions on society and the environment. This review suggests that the package also offers many ancillary teaching opportunities. (CB)

  10. 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.

  11. Introducing Students to Darwin via the Voyage of HMS "Beagle"

    ERIC Educational Resources Information Center

    Swab, Janice C.

    2010-01-01

    I use the diary that Darwin wrote during the voyage of HMS Beagle and recent images of a few of the places he visited to illustrate some comparisons between Darwin's world and ours. For today's students, increasingly committed to environmental issues, this may be an especially promising way to introduce Darwin.

  12. 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…

  13. Voyager 1 and 2 Atlas of Six Saturnian Satellites

    NASA Technical Reports Server (NTRS)

    Batson, R. M.

    1984-01-01

    Maps, compiled with data gathered primarily by Voyager 1 and 2 spacecraft, are presented which show the diversity among six of the Saturnian moons. Mimas and Enceladus are mapped in detail. Prelimary maps are given for the other four satellites. Diameter, density, albedo, and distance from mother planet, among much more data, is given for each moon.

  14. The Voyager 2 Encounter with the Uranian System.

    ERIC Educational Resources Information Center

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

    1986-01-01

    A series of 12 reports on the Voyager Two experiments in the Uranian system. Reports are included on: (1) imaging science; (2) photometry; (3) infrared; (4) ultraviolet; (5) radio science; (6) magnetic fields; (7) plasma; (8) charged particles; (9) magnetosphere (hot plasma and radiation); (10) radion observations; and (11) plasma waves. An…

  15. Implications of Voyager 1 observations beyond the heliopause for the local interstellar electron spectrum

    SciTech Connect

    Bisschoff, D.; Potgieter, M. S.

    2014-10-20

    Cosmic-ray observations made by the Voyager 1 spacecraft outside the dominant modulating influence of the heliosphere finally allow the comparison of computed galactic spectra with experimental data at lower energies. These computed spectra, based on galactic propagation models, can now be compared with observations at low energies by Voyager 1 and at high energies by the PAMELA space detector at Earth. This improves understanding of basic propagation effects and also provides solar modulation studies with reliable input spectra from 1 MeV to 100 GeV. We set out to reproduce the Voyager 1 electron observations in the energy range of 6-60 MeV, as well as the PAMELA electron spectrum above 10 GeV, using the GALPROP code. By varying the source spectrum and galactic diffusion parameters, specifically the rigidity dependence of spatial diffusion, we find local interstellar spectra that agree with both power-law spectra observed by Voyager 1 beyond the heliopause. The local interstellar spectrum between ∼1 MeV and 100 GeV indicates that it is the combination of two power laws, with E {sup –(1.45} {sup ±} {sup 0.15)} below ∼100 MeV and E {sup –(3.15} {sup ±} {sup 0.05)} above ∼100 MeV. A gradual turn in the spectral shape matching the power laws is found, between 2.0 ± 0.5) GeV and (100 ± 10) MeV. According to our simplified modeling, this transition is caused primarily by galactic propagation effects. We find that the intensity beyond the heliopause at 10 MeV is (350 ± 50) electrons m{sup –2} s{sup –1} sr{sup –1} MeV{sup –1}, decreasing to (50 ± 5) electrons m{sup –2} s{sup –1} sr{sup –1} MeV{sup –1} at 100 MeV.

  16. Energetic Particles at Voyager 1 in the Heliosheath and Voyager 2 in the Termination Foreshock

    NASA Astrophysics Data System (ADS)

    Decker, R. B.; Krimigis, S. M.; Roelof, E. C.

    2007-05-01

    As of 2007.16, Voyager 1 (V1) is in the heliosheath (HSH), having moved radially outward 8 AU since crossing the termination shock (TS) at 94 AU in late 2004 (V1 is at 102 AU, N34° lat., 173° long.). Voyager 2 (V2) is upstream of the TS in its foreshock (TFS) region (V2 is at 82 AU, S27° lat., 216° long.). We discuss variations of intensities and angular distributions of ions >40 keV and electrons >30 keV measured by the LECP instruments on V1 and V2. Measurements made in the TFS region are characterized by large intensity variations, by factors >10, that occur over a range of time scales, from a few hours to tens of days. TFS ion angular distributions often show unidirectional, or beamlike, anisotropies consistent with propagation along the solar wind magnetic field from the source region (i.e., from the TS and the HSH) to the spacecraft under relatively weak-scattering conditions. Notable differences between the V1 and V2 data in the TFS include (1) ion beaming directions that are oppositely directed at the two spacecraft, which may result from the different locations of the two spacecraft relative to an asymmetric TS, and (2) the TFS ion energy spectrum at V2 extends down only to about 0.2 MeV, while that at V1 extends down to at least 0.04 MeV. Data from V1 taken in the HSH are characterized by high intensities of low-energy ions that remain fairly steady, varying by factors <2, and by anisotropies produced mainly by convection at the HSH plasma flow velocity. V1 was crossed by the TS as the shock moved radially inward in late 2004. As a result, conditions in the HSH at V1 were highly disturbed until about mid-2005. Thereafter, the plasma flow velocity V in the HSH, estimated by analysis of low-energy ion angular distributions, has shown mean speed ~ 70 km/s and direction angle ~ -35° to the radial, i.e., on average VR ~ 58 km/s and VT ~ -40 km/s (in RTN coordinates). Also, during the past six months, the energy spectrum at V1 of ions 0.04 to ~1 MeV shows

  17. Laser-pump/X-ray-probe experiments with electrons ejected from a Cu(111) target: space-charge acceleration.

    PubMed

    Schiwietz, G; Kühn, D; Föhlisch, A; Holldack, K; Kachel, T; Pontius, N

    2016-09-01

    A comprehensive investigation of the emission characteristics for electrons induced by X-rays of a few hundred eV at grazing-incidence angles on an atomically clean Cu(111) sample during laser excitation is presented. Electron energy spectra due to intense infrared laser irradiation are investigated at the BESSY II slicing facility. Furthermore, the influence of the corresponding high degree of target excitation (high peak current of photoemission) on the properties of Auger and photoelectrons liberated by a probe X-ray beam is investigated in time-resolved pump and probe measurements. Strong electron energy shifts have been found and assigned to space-charge acceleration. The variation of the shift with laser power and electron energy is investigated and discussed on the basis of experimental as well as new theoretical results. PMID:27577771

  18. 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

  19. COMPARISON OF PIONEER 10, VOYAGER 1, AND VOYAGER 2 ULTRAVIOLET OBSERVATIONS WITH ANTI-SOLAR LYMAN-ALPHA BACKSCATTER SIMULATIONS

    SciTech Connect

    Fayock, B.; Zank, G. P.; Heerikhuisen, J. E-mail: garyp.zank@gmail.com

    2013-09-20

    Observations made by ultraviolet (UV) detectors on board Pioneer 10, Voyager 1, and Voyager 2 can be used to analyze the distribution of neutral hydrogen throughout the heliosphere, including the interaction regions of the solar wind and local interstellar medium. Previous studies of the long-term trend of decreasing intensity with increasing heliocentric distance established the need for more sophisticated heliospheric models. Here we use state-of-the-art three-dimensional (3D) magnetohydrodynamic (MHD) neutral models to simulate Lyman-alpha backscatter as would be seen by the three spacecrafts, exploiting a new 3D Monte Carlo radiative transfer code under solar minimum conditions. Both observations and simulations of the UV backscatter intensity are normalized for each spacecraft flight path at {approx}15 AU, and we focus on the slope of decreasing intensity over an increasing heliocentric distance. Comparisons of simulations with Voyager 1 Lyman-alpha data results in a very close match, while the Pioneer 10 comparison is similar due to normalization, but not considered to be in agreement. The deviations may be influenced by a low resolution of photoionization in the 3D MHD-neutral model, a lack of solar cycle activity in our simulations, and possibly issues with instrumental sensitivity. Comparing the slope of Voyager 2 and the simulated intensities yields an almost identical match. Our results predict a large increase in the Lyman-alpha intensity as the hydrogen wall is approached, which would signal an imminent crossing of the heliopause.

  20. Ganymede - Galileo Mosaic Overlayed on Voyager Data in Uruk Sulcus Region

    NASA Technical Reports Server (NTRS)

    1996-01-01

    A mosaic of four Galileo high-resolution images of the Uruk Sulcus region of Jupiter's moon Ganymede is shown within the context of an image of the region taken by Voyager 2 in 1979. The image shows details of parallel ridges and troughs that are the principal features in the brighter regions of Ganymede. The Galileo frames unveil the fine-scale topography of Ganymede's ice-rich surface, permitting scientists to develop a detailed understanding of the processes that have shaped Ganymede. Resolution of the Galileo images is 74 meters (243 feet) per pixel, while resolution of the Voyager image is 1.3 kilometers (0.8 mile) per pixel. In this view, north is to the top, and the sun illuminates the surface from the lower left nearly overhead. The area shown, at latitude 10 degrees north, longitude 168 degrees west, is about 120 by 110 kilometers (75 by 68 miles) in extent. The image was taken June 27 at a range of 7,448 kilometers (4,628 miles). The Jet Propulsion Laboratory manages the Galileo mission for NASA's Office of Space Science.

  1. Turbulence in the solar wind: spectra from Voyager 2 data at 5 AU

    NASA Astrophysics Data System (ADS)

    Fraternale, F.; Gallana, L.; Iovieno, M.; Opher, M.; Richardson, J. D.; Tordella, D.

    2016-02-01

    Fluctuations in the flow velocity and magnetic fields are ubiquitous in the Solar System. These fluctuations are turbulent, in the sense that they are disordered and span a broad range of scales in both space and time. The study of solar wind turbulence is motivated by a number of factors all keys to the understanding of the Solar Wind origin and thermodynamics. The solar wind spectral properties are far from uniformity and evolve with the increasing distance from the sun. Most of the available spectra of solar wind turbulence were computed at 1 astronomical unit, while accurate spectra on wide frequency ranges at larger distances are still few. In this paper we consider solar wind spectra derived from the data recorded by the Voyager 2 mission during 1979 at about 5 AU from the sun. Voyager 2 data are an incomplete time series with a voids/signal ratio that typically increases as the spacecraft moves away from the sun (45% missing data in 1979), making the analysis challenging. In order to estimate the uncertainty of the spectral slopes, different methods are tested on synthetic turbulence signals with the same gap distribution as V2 data. Spectra of all variables show a power law scaling with exponents between -2.1 and -1.1, depending on frequency subranges. Probability density functions (PDFs) and correlations indicate that the flow has a significant intermittency.

  2. Determination of the position of Jupiter from radio metric tracking of Voyager 1

    NASA Technical Reports Server (NTRS)

    Folkner, W. M.; Haw, R. J.

    1995-01-01

    The Voyager 1 spacecraft flew by Jupiter on March 5, 1979. Spacecraft navigation was performed with radio tracking data from NASA's Deep Space Network. In the years since then, there has been a great deal of progress in the definition of celestial reference frames and in determining the orbit and orientation of the Earth. Using these improvements, the radio metric range and Doppler data acquired from the Voyager 1 spacecraft near its encounter with Jupiter have been reanalyzed to determine the plane-of-sky position of Jupiter with much greater accuracy than was possible at the time of the encounter. The position of Jupiter at the time of encounter has been determined with an accuracy of 40 nrad in right ascension and 140 nrad in declination with respect to the celestial reference frame defined by the International Earth Rotation Service. This position estimate has been done to improve the ephemeris of Jupiter prior to the upcoming encounter of the Galileo spacecraft with Jupiter.

  3. Spectra and correlations in the solar wind from Voyager 2 around 5 AU

    NASA Astrophysics Data System (ADS)

    Gallana, Luca; Fraternale, Federico; Iovieno, Michele; Magli, Enrico; Fosson, Sophie; Opher, Merav; Richardson, John; Tordella, Daniela

    2014-11-01

    Solar wind spectra deduced from the data recorded by the Voyager 2 mission during 1979 at about 5 astronomical units from the sun are considered. The data are time series which contain voids that typically become larger and irregularly sparse as the craft moves away from the sun (45% missing data in 1979). By extracting complete subsets and filling gaps with different techniques (polynomial interpolation, Rybicki (AJ 1992) and compressed sensing (e.g. Candes et al. CPAM 2006) reconstruction methods, global DFT for irregularly spaced data) we obtain velocity and magnetic field fluctuations between 10-5 and 10-2 Hz in the MHD inertial range of solar wind. Spectra of all variables show a power law scaling with exponents in between -1.5 and -1.8. PDFs and correlations indicate that the flow has a significant intermittency. The reliability of the reconstruction methods used is analyzed by introducing the same sequence of gaps observed in the Voyager data into a reference dataset extracted from direct numerical simulations of incompressible Navier-Stokes turbulence as well as from synthetic turbulence, and then by comparing the statistics obtained with those of the complete reference dataset.

  4. 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

  5. From Convicts to Colonists: the Health of Prisoners and the Voyage to Australia, 1823 – 1853

    PubMed Central

    Foxhall, Katherine

    2012-01-01

    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 direct 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

  6. The ISS as a platform for a fully simulated mars voyage

    NASA Astrophysics Data System (ADS)

    Narici, Livio; Reitz, Guenther

    2016-07-01

    The ISS can mimic the impact of microgravity, radiation, living and psychological conditions that astronauts will face during a deep space cruise, for example to Mars. This suggests the ISS as the most valuable "analogue" for deep space exploration. NASA has indeed suggested a 'full-up deep space simulation on last available ISS Mission: 6/7 crew for one year duration; full simulation of time delays & autonomous operations'. This idea should be pushed further. It is indeed conceivable to use the ISS as the final "analogue", performing a real 'dry-run' of a deep space mission (such as a mission to Mars), as close as reasonably possible to what will be the real voyage. This Mars ISS dry run (ISS4Mars) would last 500-800 days, mimicking most of the challenges which will be undertaken such as length, isolation, food provision, decision making, time delays, health monitoring diagnostic and therapeutic actions and more: not a collection of "single experiments", but a complete exploration simulation were all the pieces will come together for the first in space simulated Mars voyage. Most of these challenges are the same that those that will be encountered during a Moon voyage, with the most evident exceptions being the duration and the communication delay. At the time of the Mars ISS dry run all the science and technological challenges will have to be mostly solved by dedicated works. These solutions will be synergistically deployed in the dry run which will simulate all the different aspects of the voyage, the trip to Mars, the permanence on the planet and the return to Earth. During the dry run i) There will be no arrivals/departure of spacecrafts; 2) Proper communications delay with ground will be simulated; 3) Decision processes will migrate from Ground to ISS; 4) Permanence on Mars will be simulated. Mars ISS dry run will use just a portion of the ISS which will be totally isolated from the rest of the ISS, leaving to the other ISS portions the task to provide the

  7. Probing in Space and Time the Nuclear Motion Driven by Nonequilibrium Electronic Dynamics in Ultrafast Pumped N2.

    PubMed

    Ajay, J; Šmydke, J; Remacle, F; Levine, R D

    2016-05-19

    An ultrafast electronic excitation of N2 in the vacuum ultraviolet creates a nonstationary coherent linear superposition of interacting valence and Rydberg states resulting in a net oscillating dipole moment. There is therefore a linear response to an electrical field that can be queried by varying the time delay between the pump and a second optical probe pulse. Both the pump and probe pulses are included in our computation as part of the Hamiltonian, and the time-dependent wave function for both electronic and nuclear dynamics is computed using a grid representation for the internuclear coordinate. Even on an ultrafast time scale there are several processes that can be discerned beyond the expected coherence oscillations. In particular, the coupling between the excited valence and Rydberg states of the same symmetry is very evident and can be directly probed by varying the delay between pulse and probe. For quite a number of vibrations the nuclear motion does not dephase the electronic disequilibrium. However, the nuclear motion does modulate the dipolar response by taking the wave packet in and out of the Franck-Condon region and by its strong influence on the coupling of the Rydberg and valence states. A distinct isotope effect arises from the dependence of the interstate coupling on the nuclear mass. PMID:26937745

  8. 46 CFR 108.209 - Hospital spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Hospital spaces. 108.209 Section 108.209 Shipping COAST... Construction and Arrangement Accommodation Spaces § 108.209 Hospital spaces. (a) Each unit carrying twelve or more persons on a voyage of more than three days must have a hospital space. (b) Each hospital...

  9. 46 CFR 108.209 - Hospital spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Hospital spaces. 108.209 Section 108.209 Shipping COAST... Construction and Arrangement Accommodation Spaces § 108.209 Hospital spaces. (a) Each unit carrying twelve or more persons on a voyage of more than three days must have a hospital space. (b) Each hospital...

  10. 46 CFR 108.209 - Hospital spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Hospital spaces. 108.209 Section 108.209 Shipping COAST... Construction and Arrangement Accommodation Spaces § 108.209 Hospital spaces. (a) Each unit carrying twelve or more persons on a voyage of more than three days must have a hospital space. (b) Each hospital...

  11. 46 CFR 108.209 - Hospital spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Hospital spaces. 108.209 Section 108.209 Shipping COAST... Construction and Arrangement Accommodation Spaces § 108.209 Hospital spaces. (a) Each unit carrying twelve or more persons on a voyage of more than three days must have a hospital space. (b) Each hospital...

  12. 46 CFR 108.209 - Hospital spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Hospital spaces. 108.209 Section 108.209 Shipping COAST... Construction and Arrangement Accommodation Spaces § 108.209 Hospital spaces. (a) Each unit carrying twelve or more persons on a voyage of more than three days must have a hospital space. (b) Each hospital...

  13. Radio science with Voyager 2 at Uranus - Results on masses and densities of the planet and five principal satellites

    NASA Technical Reports Server (NTRS)

    Anderson, J. D.; Campbell, J. K.; Jacobson, R. A.; Sweetnam, D. N.; Taylor, A. H.

    1987-01-01

    Phase-coherent Doppler data generated by the Deep Space Network with the radio communication system during the Voyager 2 encounter with Uranus in January 1986, optical navigation data generated by the Voyager Navigation Team with the Voyager 2 imaging system, and ground-based astrometric data obtained over an 8-yr period are compiled and analyzed to determine the masses and densities of Uranus and its principal satellites. The data-analysis procedures are explained in detail, and the results are presented in tables and graphs. The mean density of Uranus is found to be 1.285 + or - 0.001 g/cu cm, whereas the mean uncompressed mass of all five satellites is 1.48 + or - 0.06 g/cu cm, or 0.10 g/cu cm above the density expected for a homogeneous solar mix of rock, H2O and NH3 ice, and CH4 as clathrate hydrate. This difference is tentatively attributed to the presence of 15 mass percent of pure graphite, which would provide the thermal conductivity required to keep the satellites cold and undifferentiated.

  14. Data analysis to separate particles of different speed regimes and charges. [lunar ejecta and meteorite experiment and pioneer space probe data

    NASA Technical Reports Server (NTRS)

    Wolf, H.

    1977-01-01

    Although the instruments on the lunar ejecta and meteorite experiment (LEAM) and the Pioneer 8 and 9 space probes were essentially similar, a comparison of their results indicates that different sets of particles caused the different responses. On Pioneer, the events were caused by the impact of cosmic dust, the so-called beta particles expelled from the vicinity of the sun by solar radiation pressure, augmented by extremely high energy but definitely identifiable interstellar grains. On the moon, the events were due to the impact of slowly moving, highly charged lunar dust being propelled electrostatically across the terminator. Both theoretical analysis and experimental testing confirming these conclusions are discussed.

  15. 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…

  16. The Phase Space of z~1.2 SpARCS Clusters: Using Herschel to Probe Dust Temperature as a Function of Environment and Accretion History

    NASA Astrophysics Data System (ADS)

    Noble, A. G.; Webb, T. M. A.; Yee, H. K. C.; Muzzin, A.; Wilson, G.; van der Burg, R. F. J.; Balogh, M. L.; Shupe, D. L.

    2016-01-01

    We present a five-band Herschel study (100-500 μm) of three galaxy clusters at z˜ 1.2 from the Spitzer Adaptation of the Red-Sequence Cluster Survey. With a sample of 120 spectroscopically confirmed cluster members, we investigate the role of environment on galaxy properties utilizing the projected cluster phase space (line-of-sight velocity versus clustercentric radius), which probes the time-averaged galaxy density to which a galaxy has been exposed. We divide cluster galaxies into phase-space bins of (r/{r}200)× ({{Δ }}v/{σ }v), tracing a sequence of accretion histories in phase space. Stacking optically star-forming cluster members on the Herschel maps, we measure average infrared star formation rates, and, for the first time in high-redshift galaxy clusters, dust temperatures for dynamically distinct galaxy populations—namely, recent infalls and those that were accreted onto the cluster at an earlier epoch. Proceeding from the infalling to virialized (central) regions of phase space, we find a steady decrease in the specific star formation rate and increase in the stellar age of star-forming cluster galaxies. We perform a probability analysis to investigate all acceptable infrared spectral energy distributions within the full parameter space and measure a ˜ 4σ drop in the average dust temperature of cluster galaxies in an intermediate phase-space bin, compared to an otherwise flat trend with phase space. We suggest one plausible quenching mechanism which may be consistent with these trends, invoking ram-pressure stripping of the warmer dust for galaxies within this intermediate accretion phase. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.

  17. Measuring the Thickness and Potential Profiles of the Space-Charge Layer at Organic/Organic Interfaces under Illumination and in the Dark by Scanning Kelvin Probe Microscopy.

    PubMed

    Rojas, Geoffrey A; Wu, Yanfei; Haugstad, Greg; Frisbie, C Daniel

    2016-03-01

    Scanning Kelvin probe microscopy was used to measure band-bending at the model donor/acceptor heterojunction poly(3-hexylthiophene) (P3HT)/fullerene (C60). Specifically, we measured the variation in the surface potential of C60 films with increasing thicknesses grown on P3HT to produce a surface potential profile normal to the substrate both in the dark and under illumination. The results confirm a space-charge carrier region with a thickness of 10 nm, consistent with previous observations. We discuss the possibility that the domain size in bulk heterojunction organic solar cells, which is comparable to the space-charge layer thickness, is actually partly responsible for less than expected electron/hole recombination rates. PMID:26890658

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

    SciTech Connect

    Richardson, J. D.; Wang, C. E-mail: cw@spaceweather.ac.cn

    2012-11-01

    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 decreased by a factor of two and the temperature decreased by a factor of three. At the beginning of 2011 the plasma density in the heliosheath began to increase and in mid-2012 it was up by more than a factor of two. The temperature rose by about 50% and the speed remained constant, although the flow direction continues to turn tailward. These changes may signal the end of solar minimum conditions at V2 in the heliosheath, although we do not understand why the speed did not decrease. The increased dynamic pressure has lead to an outward movement of the termination shock from its very compressed state at solar minimum.

  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. Voyager 2 observations of plasma in the heliosheath.

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.; Belcher, J. W.; Tordella, D.; Fraternale, F.; Gallana, L.; Iovieno, M.

    2015-12-01

    Voyager 2 has observed the plasma in the heliosheath since 2007 from 84 to 109 AU. No signs of the stagnation region observed by Voyager 1 have been observed. Instead, the plasma speed have remained relatively constant and the flow has turned tailward. Latest results from 2015 show that the flow is about 80 degrees from radial, with most of the flow in the T direction (using RTN coordinates). Temperature and density averages have remained constant since increases observed in 2011. The plasma parameters are highly variable; we show the distributions of the variabillty with time. We also show compare variations in the magnetic field and plasma on short (few hour) time scales through 2012.

  1. Neptune's Wind Speeds Obtained by Tracking Clouds in Voyager Images.

    PubMed

    Hammel, H B; Beebe, R F; De Jong, E M; Hansen, C J; Howell, C D; Ingersoll, A P; Johnson, T V; Limaye, S S; Magalhaes, J A; Pollack, J B; Sromovsky, L A; Suomi, V E; Swift, C E

    1989-09-22

    Images of Neptune obtained by the narrow-angle camera of the Voyager 2 spacecraft reveal large-scale cloud features that persist for several months or longer. The features' periods of rotation about the planetary axis range from 15.8 to 18.4 hours. The atmosphere equatorward of -53 degrees rotates with periods longer than the 16.05-hour period deduced from Voyager's planetary radio astronomy experiment (presumably the planet's internal rotation period). The wind speeds computed with respect to this radio period range from 20 meters per second eastward to 325 meters per second westward. Thus, the cloud-top wind speeds are roughly the same for all the planets ranging from Venus to Neptune, even though the solar energy inputs to the atmospheres vary by a factor of 1000. PMID:17798743

  2. Voyager 1 Planetary Radio Astronomy Observations Near Jupiter

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Pearce, J. B.; Riddle, A. C.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Thieman, J. R.; Carr, T. B.; Gulkis, S.; Boischot, A.

    1979-01-01

    Results are reported from the first low frequency radio receiver to be transported into the Jupiter magnetosphere. Dramatic new information was obtained both because Voyager was near or in Jupiter's radio emission sources and also because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio arcs, from above 30 MHz to about 1 MHz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Studies in progress are outlined briefly.

  3. Voyager 1 planetary radio astronomy observations near Jupiter

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Pearce, J. B.; Riddle, A. C.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Thieman, J. R.; Carr, T. D.; Gulkis, S.; Boischot, A.

    1979-01-01

    Results from the first low-frequency radio receiver to be transported into the Jupiter magnetosphere are reported. Dramatic new information was obtained, both because Voyager was near or in Jupiter's radio emission sources and because it was outside the relatively dense solar wind plasma of the inner solar system. Extensive radio spectral arcs, from above 30 to about 1 MHz, occurred in patterns correlated with planetary longitude. A newly discovered kilometric wavelength radio source may relate to the plasma torus near Io's orbit. In situ wave resonances near closest approach define an electron density profile along the Voyager trajectory and form the basis for a map of the torus. Detailed studies are in progress and are outlined briefly.

  4. The galilean satellites and Jupiter: Voyager 2 imaging science results

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.A.; Beebe, R.; Boyce, J.; Briggs, G.; Carr, M.; Collins, S.A.; Cook, A.F., II; Danielson, G.E.; Davies, M.E.; Hunt, G.E.; Ingersoll, A.; Johnson, T.V.; Masursky, H.; McCauley, J.; Morrison, D.; Owen, editors, Timothy W.; Sagan, C.; Shoemaker, E.M.; Strom, R.; Suomi, V.E.; Veverka, J.

    1979-01-01

    Voyager 2, during its encounter with the Jupiter system, provided images that both complement and supplement in important ways the Voyager 1 images. While many changes have been observed in Jupiter's visual appearance, few, yet significant, changes have been detected in the principal atmospheric currents. Jupiter's ring system is strongly forward scattering at visual wavelengths and consists of a narrow annulus of highest particle density, within which is a broader region in which the density is lower. On Io, changes are observed in eruptive activity, plume structure, and surface albedo patterns. Europa's surface retains little or no record of intense meteorite bombardment, but does reveal a complex and, as yet, little-understood system of overlapping bright and dark linear features. Ganymede is found to have at least one unit of heavily cratered terrain on a surface that otherwise suggests widespread tectonism. Except for two large ringed basins, Callisto's entire surface is heavily cratered. Copyright ?? 1979 AAAS.

  5. Voyager Saturn encounter attitude and articulation control experience

    NASA Technical Reports Server (NTRS)

    Carlisle, G.; Hill, M.

    1981-01-01

    The Voyager attitude and articulation control system is designed for a three-axis stabilized spacecraft; it uses a biasable sun sensor and a Canopus Star Tracker (CST) for celestial control, as well as a dry inertial reference unit, comprised of three dual-axis dry gryos, for inertial control. A series of complex maneuvers was required during the first of two Voyager spacecraft encounters with Saturn (November 13, 1980); these maneuvers involved rotating the spacecraft simultaneously about two or three axes while maintaining accurate pointing of the scan platform. Titan and Saturn earth occulation experiments and a ring scattering experiment are described. Target motion compensation and the effects of celestial sensor interference are also considered. Failure of the CST, which required an extensive reevaluation of the star reference and attitude control mode strategy, is discussed. Results analyzed thus far show that the system performed with high accuracy, gathering data deeper into Saturn's atmosphere than on any previous planetary encounter.

  6. Voyager 2 Observes a Large Density Increase in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Richardson, J. D.; Wang, C.

    2012-11-01

    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 decreased by a factor of two and the temperature decreased by a factor of three. At the beginning of 2011 the plasma density in the heliosheath began to increase and in mid-2012 it was up by more than a factor of two. The temperature rose by about 50% and the speed remained constant, although the flow direction continues to turn tailward. These changes may signal the end of solar minimum conditions at V2 in the heliosheath, although we do not understand why the speed did not decrease. The increased dynamic pressure has lead to an outward movement of the termination shock from its very compressed state at solar minimum.

  7. Comparison of Metal-Backed Free-Space and Open-Ended Coaxial Probe Techniques for the Dielectric Characterization of Aeronautical Composites †

    PubMed Central

    López-Rodríguez, Patricia; Escot-Bocanegra, David; Poyatos-Martínez, David; Weinmann, Frank

    2016-01-01

    The trend in the last few decades is that current unmanned aerial vehicles are completely made of composite materials rather than metallic, such as carbon-fiber or fiberglass composites. From the electromagnetic point of view, this fact forces engineers and scientists to assess how these materials may affect their radar response or their electronics in terms of electromagnetic compatibility. In order to evaluate this, electromagnetic characterization of different composite materials has become a need. Several techniques exist to perform this characterization, all of them based on the utilization of different sensors for measuring different parameters. In this paper, an implementation of the metal-backed free-space technique, based on the employment of antenna probes, is utilized for the characterization of composite materials that belong to an actual drone. Their extracted properties are compared with those given by a commercial solution, an open-ended coaxial probe (OECP). The discrepancies found between both techniques along with a further evaluation of the methodologies, including measurements with a split-cavity resonator, conclude that the implemented free-space technique provides more reliable results for this kind of composites than the OECP technique. PMID:27347966

  8. Comparison of Metal-Backed Free-Space and Open-Ended Coaxial Probe Techniques for the Dielectric Characterization of Aeronautical Composites.

    PubMed

    López-Rodríguez, Patricia; Escot-Bocanegra, David; Poyatos-Martínez, David; Weinmann, Frank

    2016-01-01

    The trend in the last few decades is that current unmanned aerial vehicles are completely made of composite materials rather than metallic, such as carbon-fiber or fiberglass composites. From the electromagnetic point of view, this fact forces engineers and scientists to assess how these materials may affect their radar response or their electronics in terms of electromagnetic compatibility. In order to evaluate this, electromagnetic characterization of different composite materials has become a need. Several techniques exist to perform this characterization, all of them based on the utilization of different sensors for measuring different parameters. In this paper, an implementation of the metal-backed free-space technique, based on the employment of antenna probes, is utilized for the characterization of composite materials that belong to an actual drone. Their extracted properties are compared with those given by a commercial solution, an open-ended coaxial probe (OECP). The discrepancies found between both techniques along with a further evaluation of the methodologies, including measurements with a split-cavity resonator, conclude that the implemented free-space technique provides more reliable results for this kind of composites than the OECP technique. PMID:27347966

  9. Review of the NASA Voyager spacecraft polycarbonate capacitor failure incident

    NASA Technical Reports Server (NTRS)

    Ott, F. M.; Yen, S. P. S.; Somoano, R. B.

    1985-01-01

    The premission failure of a Voyager spacecraft capacitor has prompted an investigation into the use of polycarbonate capacitors in high impedance circuits, during which capacitor failures were induced by thermal cycling together with extended periods at high temperature. Measurement of leakage path temperature coefficients indicates that there are two distinct leakage types whose mechanisms are complicated by movement within the capacitor during temperature changes. A novel system for pulse detection during capacitor burn-in and ramp testing has proven to be beneficial.

  10. Mapping the Galilean satellites of Jupiter with Voyager data.

    USGS Publications Warehouse

    Batson, R.M.

    1980-01-01

    The four Galilean satellites of Jupiter are being mapped using image data from the Voyager 1 and 2 spacecraft. The maps are published at several scales and in several versions. Preliminary maps at 1:25,000,000-required for mission planning and preliminary science reports-were compiled within three weeks of data acquisition and have been published. Later maps incorporate Rand Corporation photogrammetric triangulations. - from Authors

  11. Voyager spacecraft radio observations of Jupiter: Initial cruise results

    NASA Technical Reports Server (NTRS)

    Kaiser, M. L.; Desch, M. D.; Riddle, A. C.; Lecacheux, A.; Pearce, J. B.; Alexander, J. K.; Warwick, J. W.; Thieman, J. R.

    1979-01-01

    Jupiter's low-frequency radio emission were detected by the planetary radio astronomy instruments onboard the two Voyager spacecraft. The emission is surprisingly similar in morphology but opposite in polarization to the high-frequency Jovian radio noise that were observed with ground-based telescopes for more than two decades. Several possible explanations for the behavior of the low-frequency emission are examined, but none of them is completely satisfactory.

  12. Voyager radio science observations of neptune and triton.

    PubMed

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

    1989-12-15

    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 the large store of collected data has begun. The initial search of the data revealed no detectable effects of ring material with optical depth tau [unknown] 0.01. Preliminary representative results include the following: 1.0243 x 10(26) and 2.141 x 10(22) kilograms for the masses of Neptune and Triton; 1640 and 2054 kilograms per cubic meter for their respective densities; 1355 +/- 7 kilometers, provisionally, for the radius of Triton; and J(2) = 3411 +/- 10(x 10(-6)) and J(4) = -26(+12)(-20)(x10(-6)) for Neptune's gravity field (J>(2) and J(4) are harmonic coefficients of the gravity field). The equatorial and polar radii of Neptune are 24,764 +/- 20 and 24,340 +/- 30 kllometers, respectively, at the 10(5)-pascal (1 bar) pressure level. Neptune's atmosphere was probed to a pressure level of about 5 x 10(5) pascals, and effects of a methane cloud region and probable ammonia absorption below the cloud are evident in the data. Results for the mixing ratios of helium and ammonia are still being investigated; the methane abundance below the clouds is at least 1 percent by volume. Derived temperature-pressure profiles to 1.2 x 10(5) pascals and 78 kelvins (K) show a lapse rate corresponding to "frozen" equilibrium of the para- and ortho-hydrogen states. Neptune's ionosphere exhibits an extended topside at a temperature of 950 +/- 160 K if H(+) is the dominant ion, and narrow ionization layers of the type previously seen at the other three giant planets. Triton has a dense ionosphere with a peak electron concentration of 46 x 10(9) per cubic meter at an

  13. 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.

  14. Abundances of Jupiter's Trace Hydrocarbons from Voyager and Cassini

    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 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 (C2H2) and ethane (C2H6). 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 C2H6 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 C2H2 on tile 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.

  15. Planetary radio astronomy observations from Voyager-2 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Evans, D. R.; Romig, J. H.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Aubier, M.; Leblanc, Y.; Lecacheux, A.; Pedersen, B. M.

    1981-01-01

    Voyager-2 planetry radio astronomy measurements obtained near Saturn are discussed. They indicate that Saturnian kilometric radiation is emitted by a strong, dayside source at auroral latitudes in the northern hemisphere and by a weaker (by more than an order of magnitude) source at complementary latitudes in the southern hemisphere. These emissions are variable both due to Saturn's rotation and, on longer time scales, probably due to influences of the solar wind and the satellite Dione. The Saturn electrostatic discharge bursts first discovered by Voyager-1 and attributed to emissions from the B-ring were again observed with the same broadband spectral properties and a 10(h)11(m) + or - 5(m) episodic recurrence period but with an occurrence frequency of only of about 30 percent of that detected with Voyager-1. During the crossing of the ring plane at a distance of 2.88 R sub S, an intense noise event is interpreted to be consequence of the impact/vaporization/ionization of charged micron-size G-ring particles distributed over a total vertical thickness of about 1500 km.

  16. Planetary radio astronomy observations from Voyager 2 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Evans, D. R.; Romig, J. H.; Alexander, J. K.; Desch, M. D.; Kaiser, M. L.; Aubier, M.; Leblanc, Y.; Lecacheux, A.; Pedersen, B. M.

    1982-01-01

    Planetary radio astronomy measurements obtained by Voyager 2 near Saturn have added further evidence that Saturnian kilometric radiation is emitted by a strong dayside source at auroral latitudes in the northern hemisphere and by a weaker source at complementary latitudes in the southern hemisphere. These emissions are variable because of Saturn's rotation and, on longer time scales, probably because of influences of the solar wind and Dione. The electrostatic discharge bursts first discovered by Voyager 1 and attributed to emissions from the B ring were again observed with the same broadband spectral properties and an episodic recurrence period of about 10 hours, but their occurrence frequency was only about 30 percent of that detected by Voyager 1. While crossing the ring plane at a distance of 2.88 Saturn radii, the spacecraft detected an intense noise event extending to above 1 megahertz and lasting about 150 seconds. The event is interpreted to be a consequence of the impact, vaporization, and ionization of charged, micrometer-size G ring particles distributed over a vertical thickness of about 1500 kilometers.

  17. Extreme and far ultraviolet astronomy from Voyagers 1 and 2

    NASA Technical Reports Server (NTRS)

    Holberg, J. B.

    1990-01-01

    The instrumental characteristics, observational capabilities and scientific results of the Voyager 1 and 2 ultraviolet spectrometers are reviewed. These instruments provide current and ongoing access to low resolution spectra for a wide variety of astronomical sources in the 500 to 1700 A band. Observations of the brightest OB stars and hot subluminous stars as faint as V = 15 mag, are possible. In the EUV, at wavelengths shortward of 900 A, several new sources have been detected and a host of potential sources ruled out. In the far UV, particularly at wavelengths between 900 and 1200 A, Voyager is capable of observing a wide range of stellar and non-stellar sources. Such observations can often provide a valuable complement to IUE and other data sets at longer wavelengths. The Voyager spectrometers have proved remarkably stable photon counting instruments, capable of extremely long integration times. The long integration times, relatively large field of view, and location in the outer solar system also provide an ideal platform for observations of sources of faint diffuse emission, such as nebulae and the general sky background.

  18. Voyager observations in the outer heliosphere and interstellar medium

    NASA Astrophysics Data System (ADS)

    Richardson, John D.

    2016-03-01

    The Voyager spacecraft are making the first direct plasma measurements of the heliosheath and interstellar medium. This paper discusses the differences in the heliosheath observations of Voyager 1 (V1) and Voyager 2 (V2), the V1 heliopause crossing, and observations of transient structures in the local interstellar medium (LISM). The heliosheath velocities at V1 are smaller than expected throughout the heliosheath and are zero in the stagnation region, which persists for 8 AU before the heliopause crossing. The V2 flow profile is very different from that at V1; the average speed stays constant at 145 km/s but the flow has turned over 60° from radial. The heliopause crossing region has numerous structures in cosmic rays, termination shock particles, and magnetic field so that the exact heliopause crossing point is still controversial. Solar transients drive shocks which propagate through the LISM, generate anisotropies and intensity changes in the galactic cosmic rays (GCRs) and excite plasma and radio waves.

  19. Heat pipe cooled probe

    NASA Technical Reports Server (NTRS)

    Camarda, C. J. (Inventor); Couch, L. M.

    1984-01-01

    The basic heat pipe principle is employed to provide a self-contained passively cooled probe that may be placed into a high temperature environment. The probe consists of an evaporator region of a heat pipe and a sensing instrument. Heat is absorbed as the working fluid evaporates in the probe. The vapor is transported to the vapor space of the condenser region. Heat is dissipated from the condenser region and fins causing condensation of the working fluid, which returns to the probe by gravity and the capillary action of the wick. Working fluid, wick and condenser configurations and structure materials can be selected to maintain the probe within an acceptable temperature range.

  20. Detail of Ganymede's Uruk Sulcus Region as Viewed by Galileo and Voyager

    NASA Technical Reports Server (NTRS)

    1996-01-01

    View of the region of Ganymede's Uruk Sulcus placed on a lower resolution Voyager view taken 17 years earlier. North is to the top of the picture and the sun illuminates the surface from almost overhead in the Galileo view. The finest details that can be discerned in the Galileo picture are about 80 meters across. The four boxes outlined in white show the extent of Galileo's initial look at this area. The Jet Propulsion Laboratory, Pasadena, CA manages the mission for NASA's Office of Space Science, Washington, DC. This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  1. Changes on Io between Voyager 1 and Galileo's second orbit around an unnamed vent North of

    NASA Technical Reports Server (NTRS)

    1996-01-01

    Detail of changes around a probable vent about 650 kilometers north of Prometheus on Jupiter's moon Io as seen in images obtained by the Voyager 1 spacecraft in April 1979 (left) and the imaging system aboard NASA's Galileo spacecraft on September 7th, 1996 (right). The re-arranging of dark and light radial surface patterns may be a result of plume fallout. North is to the top of both images which are approximately 400 kilometers square.

    The Jet Propulsion Laboratory, Pasadena, CA manages the Galileo mission for NASA's Office of Space Science, Washington, DC. JPL is an operating division of California Institute of Technology (Caltech).

    This image and other images and data received from Galileo are posted on the World Wide Web, on the Galileo mission home page at URL http://galileo.jpl.nasa.gov. Background information and educational context for the images can be found at URL http://www.jpl.nasa.gov/galileo/sepo

  2. Jules Verne Voyager: A Web Interactive Tool for Comparative Planetology

    NASA Astrophysics Data System (ADS)

    Estey, L.; Pappalardo, R.; Meertens, C.

    2004-12-01

    A Web interactive map tool called "Jules Verne Voyager" was originally developed in 1999 by UNAVCO and continues to evolve. The Voyager tool can easily be used for comparative planetology studies by grades 8-14. Thematic mapping datasets, now totaling about 70 Gb, can be accessed by the tool and include global-scale maps of the inner solar system planets and moons, plus Jupiter and the Galilean moons. The map images are viewed on a Web browser created on demand by the server system. On the client-side, only a Java-enabled browser is required, and the Voyager Java applet runs well with common browsers like Netscape, Mozilla, Opera, and Internet Explorer. The applet sends a key-value pair URL to the http://jules.unavco.org server which queues incoming requests and sends them to a bank of computers dedicated to map image creation. The engine for map image creation makes use of the "Generic Mapping Tools" (GMT) software of Paul Wessel and Walter Smith, followed by image conversion of the GMT-created PostScript to GIF for raster image export and display back on the client browser. Because of the GMT-based engine on the server system, the student user can easily create the same type of images from real planetary data that researchers create. The tool also gives a student the ability to switch background datasets and overlay certain other thematic datasets, thus providing a minimal GIS capability. To our knowledge, the map tool has not yet formally been used in a 8-14 classroom environment, though informal use by students and teachers in these grades suggest that it would be well received. The server system is currently capable of handing a moderate level of requests that would result from classroom use; for example, as a system benchmark, over 800 Voyager images were created and served in about an hour during a DLESE 2003 annual meeting workshop. The Voyager map tool is being used by instructors in earth science and comparative planetology as a means to create customized

  3. 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.

  4. Space motion sickness status report

    NASA Technical Reports Server (NTRS)

    Kutyna, Frank

    1986-01-01

    The space motion sickness (SMS) component of the multifactor space adaptation syndrome is anticipated to be a major problem in the spaceflight and habitation conditions that will be encountered in NASA Space Station tours and Mars voyages. The minimization of maladaptive physiological responses while enhancing those mechanisms that can best cope with the gravitoinertial conditions of space flight will require an intimate knowledge of the physiology of adaptive processes. The homeostatic mechanisms involved in SMS are inherent in human physiology.

  5. 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.

  6. 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.

  7. Exploring the brain, looking for thoughts: on Asimov's second Fantastic Voyage.

    PubMed

    Cassou-Noguès, Pierre

    2011-01-01

    The aim of this paper is to investigate various concerns which appear in Isaac Asimov's Fantastic Voyage II: Destination Brain. I will disregard his first voyage inside a human body in Fantastic Voyage I, which the author disavows as not being his own work. In contrast, the second voyage is intricate, suggesting problems drawn from a variety of sources. In a nutshell, Asimov's explorers enter the body of a comatose man in order to read his thoughts. The story can be related both to philosophical thought-experiments, such as those of Gottfried Wilhelm Leibniz and of Herbert Feigl, as well as to personal anxieties peculiar to Asimov. PMID:21936209

  8. 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…

  9. Energetic Particle Anisotropies at Voyager 1 in the Local Interstellar Medium and at Voyager 2 in the Heliosheath

    NASA Astrophysics Data System (ADS)

    Decker, R. B.; Krimigis, S. M.; Hill, M. E.; Roelof, E. C.

    2015-12-01

    We describe angular variations of energetic ion and electron intensities measured by the Low Energy Charged Particle instruments on Voyager 1 in the very local interstellar medium, and for context, at Voyager 2 in the heliosheath. We emphasize measurements made in 2014-2015. At Voyager 1, now at 132 AU and 11 AU beyond the heliopause, intensities of low-energy ions and electrons and of anomalous cosmic rays remain at background levels. Galactic cosmic ray ions continue to show small departures from isotropy, with broad (0.3-0.5 year) episodes of intensity depletions of ions gyrating nearly perpendicular to the magnetic field. Percentage intensity decreases during these depletions, relative to intensities of cosmic rays propagating along the field, peak at -7% in 2013.35, -3% in 2014.50, and at least -4% in 2015.60 (when the most recent data were examined). Two episodes in March-April 2013 and April-May 2014 when cosmic ray ion intensities showed small increases lasting 10-20 days indicate small energy boosts, produced possibly by magnetic disturbances from solar activity entering the interstellar medium [Gurnett et al., Ap. J. 2015]. During these two periods intensities of cosmic rays with pitch angles nearer 90 degrees were increased more than those with pitch angles nearer 0 and 180 degrees. At Voyager 2, now 24 AU beyond the termination shock, intensities of ions >30 keV and electrons >20 keV continue to recover in a step-like fashion from minima reached in early 2013. We reported previously that during the rapid initial recovery from these minima as particle intensities rose at Voyager 2, angular data for ions 30 keV to 30 MeV (i.e., including anomalous cosmic rays) showed strong and long lasting (about 4 months) net streaming away from the heliospheric nose toward the flank. A similar streaming episode lasting about 2 months occurred in early 2015, again during a period when intensities were rapidly increasing.

  10. Electrical resistivity probes

    DOEpatents

    Lee, Ki Ha; Becker, Alex; Faybishenko, Boris A.; Solbau, Ray D.

    2003-10-21

    A miniaturized electrical resistivity (ER) probe based on a known current-voltage (I-V) electrode structure, the Wenner array, is designed for local (point) measurement. A pair of voltage measuring electrodes are positioned between a pair of current carrying electrodes. The electrodes are typically about 1 cm long, separated by 1 cm, so the probe is only about 1 inch long. The electrodes are mounted to a rigid tube with electrical wires in the tube and a sand bag may be placed around the electrodes to protect the electrodes. The probes can be positioned in a borehole or on the surface. The electrodes make contact with the surrounding medium. In a dual mode system, individual probes of a plurality of spaced probes can be used to measure local resistance, i.e. point measurements, but the system can select different probes to make interval measurements between probes and between boreholes.

  11. PREFACE: 13th Annual International Astrophysics Conference: Voyager, IBEX, and the Interstellar Medium

    NASA Astrophysics Data System (ADS)

    Zank, G. P.

    2015-01-01

    The 13th Annual International Astrophysics Conference was held in scenic Myrtle Beach, South Carolina, USA, during the week of 10-14 March 2014. The meeting drew nearly 80 participants from all over the world, representing a wide range of interests and expertise in the interplanetary medium, the solar wind, observations, and theory. The theme of the meeting was Voyager, IBEX, and the Interstellar Medium. This decade may one day be viewed as the golden age in the exploration of the large-scale heliosphere and the local interstellar medium (LISM). Voyager 1 and 2 and IBEX are yielding remarkable new discoveries about the boundaries of the solar wind - LISM region and the interstellar medium. Hitherto, our basic understanding of the interstellar medium has been provided by telescope observations across multiple wavelengths that are typically integrated over many parsecs. For the first time, with these three spacecraft, we are making detailed measurements of the interstellar plasma, energetic particles (charged and neutral), magnetic field, and plasma waves in situ or with very short integration distances. IBEX provides insight into the global characteristics of the very local interstellar medium and Voyager 1 has just crossed the heliopause and is now in the interstellar medium. Remarkable results can be anticipated as discoveries over the next decade are made and the physics of the interstellar medium unfolds. As described in the papers in this volume, the new observations are already challenging theoretical models. The 13th Annual International Conference focused on the physics of the solar wind - LISM boundaries and the emerging physics of the local interstellar medium. To address this, astrophysicists and space physicists assembled to share their combined expertise to address in a highly interdisciplinary fashion the physics of the interaction between the solar wind and the interstellar medium. We thank Adele Corona and ICNS for her continued excellent

  12. Science with the space-based interferometer eLISA. III: probing the expansion of the universe using gravitational wave standard sirens

    NASA Astrophysics Data System (ADS)

    Tamanini, Nicola; Caprini, Chiara; Barausse, Enrico; Sesana, Alberto; Klein, Antoine; Petiteau, Antoine

    2016-04-01

    We investigate the capability of various configurations of the space interferometer eLISA to probe the late-time background expansion of the universe using gravitational wave standard sirens. We simulate catalogues of standard sirens composed by massive black hole binaries whose gravitational radiation is detectable by eLISA, and which are likely to produce an electromagnetic counterpart observable by future surveys. The main issue for the identification of a counterpart resides in the capability of obtaining an accurate enough sky localisation with eLISA. This seriously challenges the capability of four-link (2 arm) configurations to successfully constrain the cosmological parameters. Conversely, six-link (3 arm) configurations have the potential to provide a test of the expansion of the universe up to z ~ 8 which is complementary to other cosmological probes based on electromagnetic observations only. In particular, in the most favourable scenarios, they can provide a significant constraint on H0 at the level of 0.5%. Furthermore, (ΩM, ΩΛ) can be constrained to a level competitive with present SNIa results. On the other hand, the lack of massive black hole binary standard sirens at low redshift allows to constrain dark energy only at the level of few percent.

  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

  14. Small sensor probe for monitoring the space electromagnetic environments by the application of the miniaturized plasma wave receiver

    NASA Astrophysics Data System (ADS)

    Kojima, Hirotsugu; Fukuhara, Hajime; Okada, Satoshi; Yagitani, Satoshi; Ikeda, Hirokazu; Miyake, Yohei; Usui, Hideyuki; Yamakawa, Hiroshi; Ueda, Yoshikatsu

    2010-05-01

    Plasma waves act as the medium in the transport of kinetic energies through wave-particle interactions in space plasmas. Therefore, most of the space missions to investigate space plasmas carry the onboard plasma wave receivers, which is a kind of radio receivers with very high sensitivities. Recently, the downsized satellites in science missions such as formation flights and small satellites require the further reduction of power and mass budget for onboard instruments. We also face the similar requirement from the lack of the spacecraft resources in planetary missions. To meet the requirement, we developed the very small plasma wave receiver using the analogue ASIC (Application Specific Integrated Circuit) technology. Since the plasma wave receiver needs to receive very weak signals in the various frequency ranges, it accommodates filters with different frequency responses, low noise amplifiers with high gains and oscillators. This leads to the large occupation of the board by the analogue circuits. Therefore, the breakthrough to the extreme miniaturization of the plasma wave receiver does not occur without the miniaturization of the analogue electronic circuit. We have already confirmed the feasibility in realizing six channels (three for electric fields and three for magnetic fields) of waveform receivers inside the small chip with the size of 3mm x 3mm. The developed waveform receiver shows the good feature enough for the use in scientific missions. This success in the miniaturization of plasma wave receivers allow us to develop a new system measuring plasma waves in multiple points. Based on the technology of the miniaturization of plasma wave receivers, we propose a new system for monitoring the electromagnetic environment in space. We address it MSEE (Monitor System for space Electromagnetic Environments). The MSEE is a kind of the sensor network system in space. It consists of palm-sized sensor nodes, which are randomly distributed in the target area. The

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

    SciTech Connect

    Lew, Bartosz

    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

  16. THE LOCAL INTERSTELLAR SPECTRUM BEYOND THE HELIOPAUSE: WHAT CAN BE LEARNED FROM VOYAGER IN THE INNER HELIOSHEATH?

    SciTech Connect

    Herbst, K.; Heber, B.; Kopp, A.; Sternal, O.; Steinhilber, F.

    2012-12-10

    The local interstellar spectrum (LIS) is one of the most important but unknown parameters used in all modeling efforts to describe the modulation of Galactic cosmic rays on their way from the galaxy through a possible bow shock, heliosheath, and heliosphere toward the Earth. Because it has not been measured thus far, several LIS models derived from numerical simulations or data on Earth were developed. A new method to determine the LIS was introduced when the Voyager spacecraft crossed the termination shock and entered the heliosheath. Webber and Higbie derived a new LIS, which is lower than all previous LIS models over the entire energy range, on the basis of these measurements. Numerical simulations by Scherer et al. showed that particles already in the outer heliosheath (OHS) are modulated, suggesting that the LIS by Webber and Higbie is a heliopause spectrum (HPS) rather than the ''true'' LIS. By using the same simplified simulation model, we estimate the diffusion coefficient in the OHS to be consistent with several 10{sup 26} to 10{sup 27} cm{sup 2} s{sup -1} for all LIS models under consideration by mapping them to this HPS and conclude that the Voyager measurements will not be able to determine the LIS in the near future. We then discuss the circumstances under which the terrestrial archive can be used to at least exclude LIS models, unless one awaits a dedicated mission like e.g., the Interstellar Probe.

  17. 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.

  18. Voyager Interactive Web Interface to EarthScope

    NASA Astrophysics Data System (ADS)

    Eriksson, S. C.; Meertens, C. M.; Estey, L.; Weingroff, M.; Hamburger, M. W.; Holt, W. E.; Richard, G. A.

    2004-12-01

    Visualization of data is essential in helping scientists and students develop a conceptual understanding of relationships among many complex types of data and keep track of large amounts of information. Developed initially by UNAVCO for study of global-scale geodynamic processes, the Voyager map visualization tools have evolved into interactive, web-based map utilities that can make scientific results accessible to a large number and variety of educators and students as well as the originally targeted scientists. A portal to these map tools can be found at: http://jules.unavco.org. The Voyager tools provide on-line interactive data visualization through pre-determined map regions via a simple HTML/JavaScript interface (for large numbers of students using the tools simultaneously) or through student-selectable areas using a Java interface to a Generic Mapping Tools (GMT) engine. Students can access a variety of maps, satellite images, and geophysical data at a range of spatial scales for the earth and other planets of the solar system. Students can also choose from a variety of base maps (satellite mosaics, global topography, geoid, sea-floor age, strain rate and seismic hazard maps, and others) and can then add a number of geographic and geophysical overlays, for example coastlines, political boundaries, rivers and lakes, earthquake and volcano locations, stress axes, and observed and model plate motion, as well as deformation velocity vectors representing a compilation of over 5000 geodetic measurements from around the world. The related educational website, "Exploring our Dynamic Planet", (http://www.dpc.ucar.edu/VoyagerJr/jvvjrtool.html) incorporates background materials and curricular activities that encourage students to explore Earth processes. One of the present curricular modules is designed for high school students or introductory-level undergraduate non-science majors. The purpose of the module is for students to examine real data to investigate how plate

  19. Uranus' southern circulation revealed by Voyager 2: Unique characteristics

    NASA Astrophysics Data System (ADS)

    Karkoschka, Erich

    2015-04-01

    Revised calibration and processing of 1600 images of Uranus by Voyager 2 revealed dozens of discrete features south of -45° latitude, where only a single feature was known from Voyager images and none has been seen since. Tracking of these features over five weeks defined the southern rotational profile of Uranus with high accuracy and no significant gap. The profile has kinks unlike previous profiles and is strongly asymmetric with respect to the northern profile by Sromovsky et al. (Sromovsky, L.A., Fry, P.M., Hammel, H.B., de Pater, I., Rages, K.A. [2012]. Icarus 220, 694-712). The asymmetry is larger than that of all previous data on jovian planets. A spot that included the South Pole off-center rotated with a period of 12.24 h, 2 h outside the range of all previous observations of Uranus. The region between -68° and -59° latitude rotated almost like a solid body, with a shear that was about 30 times smaller than typical shears on Uranus. At lower latitudes, features were sheared into tightly wound spirals as Voyager watched. The zone at -84° latitude was exceptionally bland; reflectivity variations were only 18 ppm, consistent with a signal-to-noise ratio estimated at 55,000. The low noise was achieved by smoothing over dozens of pixels per image and averaging 1600 images. The presented data set in eight filters contains rich information about temporal evolution and spectral characteristics of features on Uranus that will be the basis for further analysis.

  20. Probe assembly

    SciTech Connect

    Avera, C.J.

    1981-01-06

    A hand-held probe assembly, suitable for monitoring a radioactive fibrinogen tracer, is disclosed comprising a substantially cylindrically shaped probe handle having an open end. The probe handle is adapted to be interconnected with electrical circuitry for monitoring radioactivity that is sensed or detected by the probe assembly. Mounted within the probe handle is a probe body assembly that includes a cylindrically shaped probe body inserted through the open end of the probe handle. The probe body includes a photomultiplier tube that is electrically connected with a male connector positioned at the rearward end of the probe body. Mounted at the opposite end of the probe body is a probe head which supports an optical coupler therewithin. The probe head is interconnected with a probe cap which supports a detecting crystal. The probe body assembly, which consists of the probe body, the probe head, and the probe cap is supported within the probe handle by means of a pair of compressible o-rings which permit the probe assembly to be freely rotatable, preferably through 360*, within the probe handle and removable therefrom without requiring any disassembly.

  1. Microwave communications from outer planets - The Voyager Project

    NASA Technical Reports Server (NTRS)

    Brejcha, A. G.

    1980-01-01

    The paper summarizes the Voyager Project, the mission objectives, and the spacecraft communications system required to meet the mission objectives. The primary emphasis of the mission is on comparative studies of the Jupiter and Saturn systems in the areas of: (1) the environment, atmosphere and body characteristics of the planets, and one or more of the satellites, (2) the nature of the recently discovered Jovian ring and the rings of Saturn, and (3) the interplanetary medium at increasing distances from the sun. The complexities and problems, such as power consumption, weight, and antenna pointing constraints are presented, along with a detailed description of the radio frequency and S/X-band antenna subsystems.

  2. Planetary radio astronomy observations from voyager 1 near saturn.

    PubMed

    Warwick, J W; Pearce, J B; Evans, D R; Carr, T D; Schauble, J J; Alexander, J K; Kaiser, M L; Desch, M D; Pedersen, M; Lecacheux, A; Daigne, G; Boischot, A; Barrow, C H

    1981-04-10

    The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings. PMID:17783837

  3. 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.

  4. The Jupiter system through the eyes of Voyager 1

    NASA Technical Reports Server (NTRS)

    Smith, B. A.; Soderblom, L. A.; Shoemaker, E. M.; Masursky, H.; Johnson, T. V.; Ingersoll, A. P.; Collins, S. A.; Hunt, G. E.; Carr, M. H.; Davies, M. E.; Morrison, D.

    1979-01-01

    The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions - the interaction of cloud systems - display complex vorticity. On its dark side, lightening and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanism on Io, complex tectonism on Ganymede and possibly Europa, and flattened remnants of enormous impact features on Callisto.

  5. 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.

  6. 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.

  7. DETAIL OF PLAQUE COMMEMORATING THE JULY/ AUGUST 1958 VOYAGE OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF PLAQUE COMMEMORATING THE JULY/ AUGUST 1958 VOYAGE OF THE USS NAUTILUS (SSN-571) TO THE NORTH POLE. NOTE: THIS PLAQUE IS NOT LOCATED AT WHARFS S13-S19; IT IS AT THE SUBMARINE MEMORIAL PARK, ABOUT 1,000' SOUTH OF THE WHARFS. THE LOCATION AND ORIENTATION OF THIS PHOTO IS NOT SHOWN ON THE PHOTO KEY MAP - U.S. Naval Base, Pearl Harbor, Additional Piers and Quay Walls, S13 to S19, Northeast end of Magazine Loch, Pearl City, Honolulu County, HI

  8. Planetary radio astronomy observations during the Voyager 1 Titan flyby

    NASA Technical Reports Server (NTRS)

    Daigne, G.; Pedersen, B. M.; Kaiser, M. L.; Desch, M. D.

    1982-01-01

    During the Voyager 1 Titan flyby, unusual radio emissions were observed by the planetary radio astronomy experiment in the 20- to 97-kHz frequency range. It is shown that Titan itself is not the source of the observed radio emission. The emission features are attributed to modification of the normal Saturn kilometric radiation by propagation effects in enhanced density structures within the Titan wake. Furthermore, spiky emissions observed in the magnetic wake of Titan are interpreted in terms of local electrostatic instabilities at the electron plasma frequency. From these measurements a range of electron densities in the wake region is derived, and the consistency of the results is discussed.

  9. Planetary radio astronomy observations from Voyager 1 near Saturn

    NASA Technical Reports Server (NTRS)

    Warwick, J. W.; Pearce, J. B.; Evans, D. R.; Carr, T. D.; Schauble, J. J.; Alexander, J. K.; Kaiser, M. L.; Desch, M. D.; Pedersen, M.; Lecacheux, A.

    1981-01-01

    The Voyager 1 planetary radio astronomy experiment detected two distinct kinds of radio emissions from Saturn. The first, Saturn kilometric radiation, is strongly polarized, bursty, tightly correlated with Saturn's rotation, and exhibits complex dynamic spectral features somewhat reminiscent of those in Jupiter's radio emission. It appears in radio frequencies below about 1.2 megahertz. The second kind of radio emission, Saturn electrostatic discharge, is unpolarized, extremely impulsive, loosely correlated with Saturn's rotation, and very broadband, appearing throughout the observing range of the experiment (20.4 kilohertz to 40.2 megahertz). Its sources appear to lie in the planetary rings.

  10. The jupiter system through the eyes of voyager 1.

    PubMed

    Smith, B A; Soderblom, L A; Johnson, T V; Ingersoll, A P; Collins, S A; Shoemaker, E M; Hunt, G E; Masursky, H; Carr, M H; Davies, M E; Cook, A F; Boyce, J; Danielson, G E; Owen, T; Sagan, C; Beebe, R F; Veverka, J; Strom, R G; McCauley, J F; Morrison, D; Briggs, G A; Suomi, V E

    1979-06-01

    The cameras aboard Voyager 1 have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. PMID:17800430

  11. The Jupiter system through the eyes of Voyager 1

    USGS Publications Warehouse

    Smith, B.A.; Soderblom, L.A.; Johnson, T.V.; Ingersoll, A.P.; Collins, S.A.; Shoemaker, E.M.; Hunt, G.E.; Masursky, H.; Carr, M.H.; Davies, M.E.; Cook, A.F., II; Boyce, J.; Danielson, G.E.; Owen, editors, Timothy W.; Sagan, C.; Beebe, R.F.; Veverka, J.; Strom, R.G.; McCauley, J.F.; Morrison, D.; Briggs, G.A.; Suomi, V.E.

    1979-01-01

    The cameras aboard Voyager I have provided a closeup view of the Jupiter system, revealing heretofore unknown characteristics and phenomena associated with the planet's atmosphere and the surfaces of its five major satellites. On Jupiter itself, atmospheric motions-the interaction of cloud systems-display complex vorticity. On its dark side, lightning and auroras are observed. A ring was discovered surrounding Jupiter. The satellite surfaces display dramatic differences including extensive active volcanismn on Io, complex tectonism on Ganymnede and possibly Europa, and flattened remnants of enormous impact features on Callisto. Copyright ?? 1979 AAAS.

  12. Magnetic field experiment for Voyagers 1 and 2

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

    The magnetic field experiments of the Voyager program involve studies of the planetary fields of Jupiter, Saturn, possibly Uranus, and several satellites; the solar wind and satellite interactions with the planetary fields, as well as large- and micro-scale features of the interplanetary magnetic field will also be investigated. Dual low field and high field magnetometer systems with dynamic ranges of + or - 0.5 G and + or - 20 G respectively provide high reliability for the missions and permit the separation of the spacecraft and ambient fields. Quantization uncertainty, rms noise levels and data compaction schemes of the magnetometer systems are also mentioned.

  13. Radio propagation experiments in the outer solar system with Voyager

    NASA Technical Reports Server (NTRS)

    Tyler, G. Leonard

    1987-01-01

    The outer solar system's planetary atmospheres, ionospheres, rings, and magnetic fields are under study in light of microwave telecommunications from the two Voyager spacecraft. The use of the hydrogen maser frequency standards on the ground, in conjunction with thermally controlled quartz oscillators aboard the spacecraft, ensures long coherence intervals and allows the application of novel signal processing methods. On this basis, studies of atmospheric structure and scintillation parameters, planetary ring structure, and magnetic control of small ionospheric irregularities have been undertaken; information concerning planetary evolution, composition, and dynamics is thereby obtained.

  14. Preliminary science results of Voyager 1 Saturn encounter

    NASA Technical Reports Server (NTRS)

    Bane, D.

    1981-01-01

    Preliminary science results of the Voyager 1 encounter of the planet Saturn are reported. On August 22, 1980, the spacecraft was 109 million km (68 million mi) from Saturn. Closest approach to Saturn took place on November 12, at 3:46 p.m. (PDT), when the spacecraft passed 126,000 km (78,000 mi) from the cloud tops. Measurements of the atmosphere, wind speed, radiation, six surrounding rings, and the planet's old and newly found satellites were recorded. The encounter ended December 15, 1980. The spacecraft took more than 17,500 photographs of Saturn and its satellites.

  15. 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.

  16. Far-ultraviolet extinction determined from Voyager data

    NASA Technical Reports Server (NTRS)

    Snow, Theodore P.; Allen, M. M.; Polidan, R. S.

    1990-01-01

    Data from the Voyager UV spectrometers are used to derive FUV extinction curves for 19 stars, using the pair-comparison method after the removal of the effects of line absorption due to H I and H2. It is shown that the FUV extinction rise continues to the limit of the data at about 925 A, supporting the theoretical prediction by Longo et al. (1989) that the FUV extinction continues to rise toward short wavelengths all the way to the Lyman limit at 912 A.

  17. 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.

  18. CASSIOPE Enhanced Polar Outflow Probe (e-POP) Small Satellite Mission: Space Plasma Observations and International Collaborations

    NASA Astrophysics Data System (ADS)

    Yau, A. W.; James, H. G.

    2009-06-01

    In-situ observation of the micro-scale characteristics of plasma acceleration and related outflow processes is a primary scientific target of the Canadian Enhanced Polar Outflow Probe (e-POP) small satellite mission. The e-POP instrument payload will include imaging plasma and neutral particle sensors, magnetometers, dual-frequency GPS receivers, CCD cameras, a radio wave receiver and a beacon transmitter. The imaging plasma sensors will measure particle distributions and the magnetometers will measure field-aligned currents on the time scale of 10 ms and spatial scale of ~100 m. The CCD cameras will perform auroral imaging on the time scale of 100 ms and at spatial (pixel) resolution up to 0.4 km. The GPS and radio-wave receivers will perform near real-time imaging studies of the ionosphere in conjunction with ground-based radars, and the beacon transmitter in conjunction with ground receiving stations. The e-POP payload will be flown on the Canadian CASSIOPE small satellite, which is scheduled for launch in late 2008 into a polar orbit (325×1500 km, 80° inclination). International collaboration is an important and integral part of the e-POP mission strategy. Two of the 8 e-POP science instruments will be contributed by JAXA/ISAS, Japan, and Naval Research Laboratory, USA, respectively. Many of the planned e-POP investigations will entail coordinated observations using Canadian as well as foreign ground facilities, including magnetic and optical observatories, radars and heaters, such as the HAARP facility in Alaska, the EISCAT radar, and the NSF Antarctic facility. International collaboration in these investigations is expected to significantly enhance the science returns of the e-POP mission.

  19. 46 CFR 188.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... mandate, whose international relations are the responsibility of a contracting SOLAS 74 government, or... 46 Shipping 7 2011-10-01 2011-10-01 false Application to vessels on an international voyage. 188... international voyage. (a) Except as provided in paragraphs (b), (c), and (d) of this section, the regulations...

  20. 46 CFR 70.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., whose international relations are the responsibility of a contracting SOLAS 74 government, or which is... 46 Shipping 3 2011-10-01 2011-10-01 false Application to vessels on an international voyage. 70.05... VESSELS GENERAL PROVISIONS Application § 70.05-10 Application to vessels on an international voyage....

  1. 46 CFR 14.201 - Voyages upon which shipping articles are required.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 1 2012-10-01 2012-10-01 false Voyages upon which shipping articles are required. 14.201 Section 14.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN SHIPMENT AND DISCHARGE OF MERCHANT MARINERS Shipment of Merchant Mariners § 14.201 Voyages upon which shipping articles are required....

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

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Voyages upon which shipping articles are required. 14.201 Section 14.201 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY MERCHANT MARINE OFFICERS AND SEAMEN SHIPMENT AND DISCHARGE OF MERCHANT MARINERS Shipment of Merchant Mariners § 14.201 Voyages upon which shipping articles are required....

  3. 46 CFR 188.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Application to vessels on an international voyage. 188... international voyage. (a) Except as provided in paragraphs (b), (c), and (d) of this section, the regulations in this subchapter that apply to a vessel on an “international voyage” apply to a vessel that— (1)...

  4. 46 CFR 70.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 3 2012-10-01 2012-10-01 false Application to vessels on an international voyage. 70.05... VESSELS GENERAL PROVISIONS Application § 70.05-10 Application to vessels on an international voyage. (a... that apply to a vessel on an “international voyage” apply to a vessel that— (1) Is...

  5. 33 CFR 104.297 - Additional requirements-vessels on international voyages.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Security Certificate (ISSC) as provided in 46 CFR § 2.01-25 is obtained for the vessel. This certificate... on international voyages. 104.297 Section 104.297 Navigation and Navigable Waters COAST GUARD... § 104.297 Additional requirements—vessels on international voyages. (a) An owner or operator of a...

  6. 78 FR 32008 - Requested Administrative Waiver of the Coastwise Trade Laws: Vessel BOND VOYAGE; Invitation for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-28

    ... Maritime Administration Requested Administrative Waiver of the Coastwise Trade Laws: Vessel BOND VOYAGE... of the vessel BOND VOYAGE is: Intended Commercial Use of Vessel: ``6-pack non-inspected harbor tours... and the vessel name in order for MARAD to properly consider the comments. Comments should also...

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

    SciTech Connect

    Tsurutani, B.T. )

    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. Documentation for the machine-readable version of the Lick Jupiter-Voyager Reference Star Catalogue

    NASA Technical Reports Server (NTRS)

    Warren, W. H., Jr.

    1982-01-01

    A machine-readable version is described of the Lick Jupiter-Voyager Reference Star Catalogue (Klemola, Morabito Taraji 1978) prepared for purposes of determining up-to-date, reasonably accurate, equatorial coordinates for reference stars in a band of sky against which cameras of the Voyager spacecraft were aligned for observations of Jovian satellites during the flyby.

  9. 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…

  10. 46 CFR 30.01-6 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... relations are the responsibility of a contracting SOLAS 74 government, or which is administered by the... 46 Shipping 1 2010-10-01 2010-10-01 false Application to vessels on an international voyage. 30.01... PROVISIONS Administration § 30.01-6 Application to vessels on an international voyage. (a) Except as...

  11. 46 CFR 188.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... mandate, whose international relations are the responsibility of a contracting SOLAS 74 government, or... 46 Shipping 7 2010-10-01 2010-10-01 false Application to vessels on an international voyage. 188... international voyage. (a) Except as provided in paragraphs (b), (c), and (d) of this section, the regulations...

  12. 46 CFR 70.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., whose international relations are the responsibility of a contracting SOLAS 74 government, or which is... 46 Shipping 3 2010-10-01 2010-10-01 false Application to vessels on an international voyage. 70.05... VESSELS GENERAL PROVISIONS Application § 70.05-10 Application to vessels on an international voyage....

  13. 46 CFR 90.05-10 - Application to vessels on an international voyage.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Application to vessels on an international voyage. 90.05-10 Section 90.05-10 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) CARGO AND MISCELLANEOUS VESSELS GENERAL PROVISIONS Application § 90.05-10 Application to vessels on an international voyage. (a) Except for yachts and...

  14. ALEX neutral beam probe

    SciTech Connect

    Pourrezaei, K.

    1982-01-01

    A neutral beam probe capable of measuring plasma space potential in a fully 3-dimensional magnetic field geometry has been developed. This neutral beam was successfully used to measure an arc target plasma contained within the ALEX baseball magnetic coil. A computer simulation of the experiment was performed to refine the experimental design and to develop a numerical model for scaling the ALEX neutral beam probe to other cases of fully 3-dimensional magnetic field. Based on this scaling a 30 to 50 keV neutral cesium beam probe capable of measuring space potential in the thermal barrier region of TMX Upgrade was designed.

  15. Simulating Scenes In Outer Space

    NASA Technical Reports Server (NTRS)

    Callahan, John D.

    1989-01-01

    Multimission Interactive Picture Planner, MIP, computer program for scientifically accurate and fast, three-dimensional animation of scenes in deep space. Versatile, reasonably comprehensive, and portable, and runs on microcomputers. New techniques developed to perform rapidly calculations and transformations necessary to animate scenes in scientifically accurate three-dimensional space. Written in FORTRAN 77 code. Primarily designed to handle Voyager, Galileo, and Space Telescope. Adapted to handle other missions.

  16. Multifractal Structures Detected by Voyager 1 at the Heliospheric Boundaries

    NASA Astrophysics Data System (ADS)

    Macek, W. M.; Wawrzaszek, A.; Burlaga, L. F.

    2014-10-01

    To better understand the dynamics of turbulent systems, we have proposed a phenomenological model based on a generalized Cantor set with two rescaling and one weight parameters. In this Letter, using recent Voyager 1 magnetic field data, we extend our two-scale multifractal analysis further in the heliosheath beyond the heliospheric termination shock, and even now near the heliopause, when entering the interstellar medium for the first time in human history. We have identified the scaling inertial region for magnetized heliospheric plasma between the termination shock and the heliopause. We also show that the degree of multifractality decreases with the heliocentric distance and is still modulated by the phases of the solar cycle in the entire heliosphere including the heliosheath. Moreover, we observe the change of scaling toward a nonintermittent (nonmultifractal) behavior in the nearby interstellar medium, just beyond the heliopause. We argue that this loss of multifractal behavior could be a signature of the expected crossing of the heliopause by Voyager 2 in the near future. The results obtained demonstrate that our phenomenological multifractal model exhibits some properties of intermittent turbulence in the solar system plasmas, and we hope that it could shed light on universal characteristics of turbulence.

  17. Plasma properties at the Voyager 1 crossing of the heliopause

    NASA Astrophysics Data System (ADS)

    Fuselier, S. A.; Cairns, I. H.

    2015-09-01

    In August 2012, Voyager 1 crossed the heliopause at a distance of 121.5 AU from the Sun. It is argued that the spacecraft entered a region in the outer heliosheath that had the characteristics of a plasma depletion layer. Observed plasma parameters at the heliopause, properties of plasma depletion layers, and some assumptions are used to derive a set of plasma parameters on both sides of the heliopause. Using the density, temperature, and magnetic field magnitude on each side, the corresponding plasma beta and Alfven Mach number (in the outer heliosheath) are derived. These plasma parameters are used to demonstrate that the plasma depletion process is occurring in the outer heliosheath adjacent to the heliopause and these parameters are used to determine if lower hybrid waves are generated locally and if magnetic reconnection is occurring locally at the location of the Voyager 1 crossing. Reconnection may not be an effective source of superthermal electrons at the heliopause, based on the small Alfven speeds there (VA ≤ 100 km/s) and an empirical connection between electron heating and Alfven speed found in inner solar system studies.

  18. MULTIFRACTAL STRUCTURES DETECTED BY VOYAGER 1 AT THE HELIOSPHERIC BOUNDARIES

    SciTech Connect

    Macek, W. M.; Burlaga, L. F. E-mail: anna.wawrzaszek@cbk.waw.pl

    2014-10-01

    To better understand the dynamics of turbulent systems, we have proposed a phenomenological model based on a generalized Cantor set with two rescaling and one weight parameters. In this Letter, using recent Voyager 1 magnetic field data, we extend our two-scale multifractal analysis further in the heliosheath beyond the heliospheric termination shock, and even now near the heliopause, when entering the interstellar medium for the first time in human history. We have identified the scaling inertial region for magnetized heliospheric plasma between the termination shock and the heliopause. We also show that the degree of multifractality decreases with the heliocentric distance and is still modulated by the phases of the solar cycle in the entire heliosphere including the heliosheath. Moreover, we observe the change of scaling toward a nonintermittent (nonmultifractal) behavior in the nearby interstellar medium, just beyond the heliopause. We argue that this loss of multifractal behavior could be a signature of the expected crossing of the heliopause by Voyager 2 in the near future. The results obtained demonstrate that our phenomenological multifractal model exhibits some properties of intermittent turbulence in the solar system plasmas, and we hope that it could shed light on universal characteristics of turbulence.

  19. Encounter with saturn: voyager 1 imaging science results.

    PubMed

    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; Cuzzi, J; Pollack, J B; Danielson, G E; 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

    1981-04-10

    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. PMID:17783827

  20. 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.