Science.gov

Sample records for space probes implications

  1. 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.

  2. Surface morphology implications on Langmuir probe measurements

    NASA Astrophysics Data System (ADS)

    Suresh, Padmashri

    2011-12-01

    Langmuir probes are extensively employed to study the plasmas in space and laboratory environments. Successful measurements require a comprehensive modeling of both the plasma environment and the probe conditions in the form of current collection models. In this thesis, the surface morphology implications on the probe current collection are investigated. This problem is applied and solved in the context of a CubeSat regime. The first problem that is investigated is the consequence of surface structural variability on the current measurements. A new model for dealing with non-uniformity of the probe surface structure is developed in this paper. This model is applied to analyze the Langmuir probe data from a sounding rocket mission that was subjected to surface structural non-homogeneities. This model would be particularly useful for CubeSat platforms where elaborate probe design procedures are not feasible. The second problem that is investigated is the surface area implications on Langmuir probe measurements. It has been established that surface area ratio of the spacecraft to that of the probe needs to be sufficiently large to make successful plasma measurements. CubeSats would therefore pose a challenge for employing Langmuir-type instruments to study the space plasma. We inspect the feasibility of making plasma measurements using Langmuir probes subjected to CubeSat area constraints. This analysis is done for a forthcoming Utah State University (USU)/Space Dynamics Lab (SDL) CubeSat mission.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  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. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Implications of conformal invariance in momentum space

    NASA Astrophysics Data System (ADS)

    Bzowski, Adam; McFadden, Paul; Skenderis, Kostas

    2014-03-01

    We present a comprehensive analysis of the implications of conformal invariance for 3-point functions of the stress-energy tensor, conserved currents and scalar operators in general dimension and in momentum space. Our starting point is a novel and very effective decomposition of tensor correlators which reduces their computation to that of a number of scalar form factors. For example, the most general 3-point function of a conserved and traceless stress-energy tensor is determined by only five form factors. Dilatations and special conformal Ward identities then impose additional conditions on these form factors. The special conformal Ward identities become a set of first and second order differential equations, whose general solution is given in terms of integrals involving a product of three Bessel functions (`triple- K integrals'). All in all, the correlators are completely determined up to a number of constants, in agreement with well-known position space results. In odd dimensions 3-point functions are finite without renormalisation while in even dimensions non-trivial renormalisation in required. In this paper we restrict ourselves to odd dimensions. A comprehensive analysis of renormalisation will be discussed elsewhere. This paper contains two parts that can be read independently of each other. In the first part, we explain the method that leads to the solution for the correlators in terms of triple- K integrals while the second part contains a self-contained presentation of all results. Readers interested only in results may directly consult the second part of the paper.

  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. Space industrialization. Volume 3: World and domestic implications

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The status of worldwide space industralization activities is assessed as well as the benefits to be anticipated from enhanced activities. Methods for stimulating space industralization growth are discussed with emphasis on foreign and international activities, national and world impact assessments, industry/government interfaces, legal implications, institutional implications, economics and capitalization, and implementation issues and recommendations.

  8. 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.

  9. 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.

  10. U.S. commercial space policies - Implications for developing countries

    NASA Technical Reports Server (NTRS)

    Gillam, Isaac T., IV; Stone, Barbara A.

    1987-01-01

    Recent U.S. policy developments on the commercial use of space are summarized and their international implications are considered. Attention is given to successful applications of technology developed in space, including an implantable cancer medication system, an implantable defibrillator, an ultrasonic residual stress monitor, and aquaculture treatment techniques. NASA projects involving bioengineering and rehabilitation applications are summarized, and plans to investigate high-temperature superconductors in space are addressed. Recent agreements entred into by NASA for space commercial studies are reviewed.

  11. 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.

  12. 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.

  13. 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.

  14. Military space station implications. Study project

    SciTech Connect

    Bourne, G.D.; Skirvin, G.D.; Wilson, G.R.

    1987-03-23

    Justifying the relevancy of a Manned Military Space Station (MMSS) and subsequently proposing its deployment to capitalize upon the United States' national security interests is the essence and purpose of this group study project. The MMSS is intended to perform a two-fold purpose: (1) facilitate military peacetime operations while simultaneously supporting and promoting civilian space initiatives; and, (2) act as a force multiplier for space and terrestrial force operations in the event of conventional, theater nuclear, and/or strategic nuclear war. Data to support the future value of the MMSS was obtained from individual and group research using unclassified sources such as professional journals, books, US Air Force Staff College reference material, and information from the US Air Force space coordinating staff in Washington, DC. The importance of space to our future and especially of a MMSS by America's national leaders and its people has yet to be fully appreciated and/or realized. The significance of space and its nexus to the United States' national security has been growing dramatically in importance since the launching of the Sputnik in 1957 by Russian. Space, as the forth dimension, cannot and should not be understated in importance as it relates to commercialism, deterrence to war, and to the stability of world order.

  15. 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.

  16. Space Biosensor Systems: Implications for Technology Transfer

    NASA Technical Reports Server (NTRS)

    Hines, J. W.; Somps, C. J.; Madou, M.; Imprescia, Clifford C. (Technical Monitor)

    1997-01-01

    To meet the need for continuous, automated monitoring of animal subjects, including; humans, during space flight, NASA is developing advanced physiologic sensor and biotelemetry system technologies. The ability to continuously track basic physiological parameters, such as heart rate, blood pH, and body temperature, in untethered subjects in space is a challenging task. At NASA's Ames Research Center, where a key focus is gravitational biology research, engineers have teamed with life scientists to develop wireless sensor systems for automated physiologic monitoring of animal models as small as the rat. This technology is also being adapted, in collaboration with medical professionals, to meet human clinical monitoring needs both in space and on the ground. Thus, these advanced monitoring technologies have important dual-use functions; they meet space flight data collection requirements and constraints, while concurrently addressing a number of monitoring and data acquisition challenges on the ground in areas of clinical monitoring and biomedical research. Additional applications for these and related technologies are being sought and additional partnerships established that enhance development efforts, reduce costs and facilitate technology infusion between the public and private sectors. This paper describes technology transfer and co-development projects that have evolved out of NASA's miniaturized, implantable chemical sensor development efforts.

  17. 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.

  18. Toxicological implications of extended space flights

    NASA Technical Reports Server (NTRS)

    Weiss, Bernard; Utell, Mark; Morrow, Paul

    1992-01-01

    This paper draws attention to the needs and mechanisms for shielding crewmembers on long-duration space flights from hazards related to chemical toxicants. Specific attention is given to existing data on sources of impaired performance, namely, neurotoxicants, respiratory infections, pulmonary function. The behavioral effects associated with long-term exposure to volatile organic solvents can impair crucial functional parameters of space flight and mission objectives. Respiratory infections contribute to performance decrements of up to 20 percent, and pulmonary function can be impaired by contaminants such as ozone leading to reduced performance. It is concluded that these and other sources of toxicologically induced performance reductions be studied since they impinge on vehicle design and mission objectives.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. 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.

  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. Legal Implications of Military Uses of Outer Space

    NASA Astrophysics Data System (ADS)

    Catena, Johanna

    2002-01-01

    Acquisition of Space Weapons, the Legal, Political and Military Impact for International Peace and At the dawn of a new century an immediate danger is upon us: The weaponization of outer space, including potential cost implications upon the prospect of ushering an era of peace and prosperity. But, can such statements be explained as pure sentimentality for hopes of a new era? Or is the danger misplaced that the threat to peace and security is an ever more ominous? By militarising outer space one could monitor crisis areas that could become a potential threat and this would in turn build confidence and security amongst nations. However the Outer Space Treaty prohibits placing in orbit nuclear and other weapons of mass destruction. This does not include other military systems. Many countries feel the prohibition should be extended in the Treaty. Other military systems may involve anti-satellite weapons, (ASATS), emitting or simply placing technologies in space using laser and /or particle beams from space to intercept presently specific military targets such as ballistic missiles and hostile satellites, but in the future this may extend to destroying a target on earth. Military presence in space however, is not founded on weapons alone, but also through military surveillance systems and seen by some countries as an effective measure in verification on arms control. It is also seen as intensifying an arms race. At the forefront of the debate for space weapons is the possibility of countries deploying a National Missile Defence system. How does one reconcile such a system with present treaties? There has always been a direct relationship between weapons and space exploration, particularly if traced through the history of the late nineteenth century to the era of the space race. Konstantin Tsiolkovsky, (1857 - 1935), was one of the founders to astronautics. Robert Goddard, (1882-1945) an Englishman, developed Tsiolkovskys' work further. He built the first liquid

  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. CIM in space: Corporate Information Management (CIM) implications for space-based information systems

    NASA Astrophysics Data System (ADS)

    Mock, Richard V.

    1993-04-01

    This paper describes the DOD corporate information management (CIM) initiative, space forces, and space-based information systems used by the DOD. It then describes implications of CIM in the space industry. CIM is defined as a philosophy which has management and technical components. The CIM management philosophy includes concepts for standardization, system engineering, and the use of commercial systems and technology. The technical component uses the information engineering discipline to improve business processes. The paper provides examples of the CIM management philosophy in operation as well as opportunities for CIM application. Information engineering is described as it applies to space-based information systems. The appendix includes an illustrative example of the integrated definition (IDEF) methodology applied to the tactical warning/attack assessment mission.

  8. Cosmological Implications of the First Year Wilkinson Microwave Anisotropy Probe Results

    NASA Astrophysics Data System (ADS)

    Verde, L.

    The Wilkinson Microwave Anisotropy Probe (WMAP) team has recently analyzed and released the first-year data. We will review the implications for cosmology of these results. The highlight is that cosmology now has a standard cosmological model. With only 6 parameters the model fits not only WMAP data remarkably well, but also a host of other astronomical observations. We also present the results on neutrino mass limits and on dark energy properties from a joint likelihood analysis of WMAP data with small-scale CMB experiments and large-scale structure surveys. The data and supplementary information are publicly available and can be found on the experiment web site at .

  9. 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.

  10. Implications of Responsive Space on the Flight Software Architecture

    NASA Technical Reports Server (NTRS)

    Wilmot, Jonathan

    2006-01-01

    The Responsive Space initiative has several implications for flight software that need to be addressed not only within the run-time element, but the development infrastructure and software life-cycle process elements as well. The runtime element must at a minimum support Plug & Play, while the development and process elements need to incorporate methods to quickly generate the needed documentation, code, tests, and all of the artifacts required of flight quality software. Very rapid response times go even further, and imply little or no new software development, requiring instead, using only predeveloped and certified software modules that can be integrated and tested through automated methods. These elements have typically been addressed individually with significant benefits, but it is when they are combined that they can have the greatest impact to Responsive Space. The Flight Software Branch at NASA's Goddard Space Flight Center has been developing the runtime, infrastructure and process elements needed for rapid integration with the Core Flight software System (CFS) architecture. The CFS architecture consists of three main components; the core Flight Executive (cFE), the component catalog, and the Integrated Development Environment (DE). This paper will discuss the design of the components, how they facilitate rapid integration, and lessons learned as the architecture is utilized for an upcoming spacecraft.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. Mir Contamination Observations and Implications to the International Space Station

    NASA Technical Reports Server (NTRS)

    Soares, Carlos; Mikatarian, Ron

    2000-01-01

    A series of external contamination measurements were made on the Russian Mir Space Station. The Mir external contamination observations summarized in this paper were essential in assessing the system level impact of Russian Segment induced contamination on the International Space Station (ISS). Mir contamination observations include results from a series of flight experiments: CNES Comes-Aragatz, retrieved NASA camera bracket, Euro-Mir '95 ICA, retrieved NASA Trek blanket, Russian Astra-II, Mir Solar Array Return Experiment (SARE), etc. Results from these experiments were studied in detail to characterize Mir induced contamination. In conjunction with Mir contamination observations, Russian materials samples were tested for condensable outgassing rates in the U.S. These test results were essential in the characterization of Mir contamination sources. Once Mir contamination sources were identified and characterized, activities to assess the implications to ISS were implemented. As a result, modifications in Russian materials selection and/or usage were implemented to control contamination and mitigate risk to ISS.

  16. 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.

  17. Cosmological Implications of the First Year Wilkinson Microwave Anisotropy Probe Results

    NASA Astrophysics Data System (ADS)

    Verde, L.

    2004-02-01

    The Wilkinson Microwave Anisotropy Probe (WMAP) team has recently analyzed and released the first-year data. We will review the implications for cosmology of these results. The highlight is that cosmology now has a standard cosmological model. With only 6 parameters the model fits not only WMAP data remarkably well, but also a host of other astronomical observations. We also present the results on neutrino mass limits and on dark energy properties from a joint likelihood analysis of WMAP data with small-scale CMB experiments and large-scale structure surveys. The data and supplementary information are publicly available and can be found on the experiment web site at .

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

    NASA Astrophysics Data System (ADS)

    Yumoto, Kiyohumi

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

  19. 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

  20. 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

  1. The implications of force reflection for teleoperation in space

    SciTech Connect

    Draper, J.V.; Herndon, J.N.; Moore, W.E.

    1987-01-01

    This paper reviews previous research on teleoperator force feedback and reports results of a testing program which assessed the impact of force reflection on teleoperator task performance. Force reflection is a type of force feedback in which the forces acting on the remote portion of the teleoperator are displayed to the operator by back-driving the master controller. The testing program compared three force reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to tasks components, and variability in forces applied to components during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force reflection than they did without it. These data support the hypothesis that force reflection provides useful information for teleoperator users. The earlier literature and the results of the experiment are discussed in terms of their implications for space-based teleoperator systems. The discussion describes the impact of force reflection on task completion performance and task strategies, as suggested by the literature. It is important to understand the trade-offs involved in using telerobotic systems with and without force reflection. Force-reflecting systems are typically more expensive (in mass, volume, and price per unit), but they reduce mean time to repair and may be safer to use, compared to systems without force reflection.

  2. Exploring Local Electrostatic Effects with Scanning Probe Microscopy: Implications for Piezoresponse Force Microscopy and Triboelectricity

    DOE PAGESBeta

    Balke, Nina; Maksymovych, Petro; Jesse, Stephen; Kravchenko, Ivan I.; Li, Qian; Kalinin, Sergei V.

    2014-09-25

    The implementation of contact mode Kelvin probe force microscopy (KPFM) utilizes the electrostatic interactions between tip and sample when the tip and sample are in contact with each other. Surprisingly, the electrostatic forces in contact are large enough to be measured even with tips as stiff as 4.5 N/m. As for traditional non-contact KPFM, the signal depends strongly on electrical properties of the sample, such as the dielectric constant, and the tip-properties, such as the stiffness. Since the tip is in contact with the sample, bias-induced changes in the junction potential between tip and sample can be measured with highermore » lateral and temporal resolution compared to traditional non-contact KPFM. Significant and reproducible variations of tip-surface capacitance are observed and attributed to surface electrochemical phenomena. Lastly, observations of significant surface charge states at zero bias and strong hysteretic electromechanical responses at non-ferroelectric surface have significant implications for fields such as triboelectricity and piezoresponse force microscopy.« less

  3. Exploring Local Electrostatic Effects with Scanning Probe Microscopy: Implications for Piezoresponse Force Microscopy and Triboelectricity

    SciTech Connect

    Balke, Nina; Maksymovych, Petro; Jesse, Stephen; Kravchenko, Ivan I.; Li, Qian; Kalinin, Sergei V.

    2014-09-25

    The implementation of contact mode Kelvin probe force microscopy (KPFM) utilizes the electrostatic interactions between tip and sample when the tip and sample are in contact with each other. Surprisingly, the electrostatic forces in contact are large enough to be measured even with tips as stiff as 4.5 N/m. As for traditional non-contact KPFM, the signal depends strongly on electrical properties of the sample, such as the dielectric constant, and the tip-properties, such as the stiffness. Since the tip is in contact with the sample, bias-induced changes in the junction potential between tip and sample can be measured with higher lateral and temporal resolution compared to traditional non-contact KPFM. Significant and reproducible variations of tip-surface capacitance are observed and attributed to surface electrochemical phenomena. Lastly, observations of significant surface charge states at zero bias and strong hysteretic electromechanical responses at non-ferroelectric surface have significant implications for fields such as triboelectricity and piezoresponse force microscopy.

  4. 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

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. Evidence of Second-Order Factor Structure in a Diagnostic Problem Space: Implications for Medical Education.

    ERIC Educational Resources Information Center

    Papa, Frank J.; And Others

    1997-01-01

    Chest pain was identified as a specific medical problem space, and disease classes were modeled to define it. Results from a test taken by 628 medical residents indicate a second-order factor structure that suggests that chest pain is a multidimensional problem space. Implications for medical education are discussed. (SLD)

  16. Implications of Privacy Needs and Interpersonal Distancing Mechanisms for Space Station Design

    NASA Technical Reports Server (NTRS)

    Harrison, A. A.; Sommer, R.; Struthers, N.; Hoyt, K.

    1986-01-01

    The literature on privacy needs, personal space, interpersonal distancing, and crowding is reveiwed with special reference to spaceflight and spaceflight analogous conditions. A quantitative model is proposed for understanding privacy, interpersonal distancing, and performance. The implications for space station design is described.

  17. IMPLICATIONS OF NEW MEDIA FOR SPACE AND BUILDING DESIGN.

    ERIC Educational Resources Information Center

    CHRISTIANSEN, KENNETH A.

    THE EXPANDING ROLE OF EDUCATIONAL TELEVISION AND OTHER INSTRUCTIONAL AIDS AND MEDIA IN THE LEARNING MEDIA IS DISCUSSED IN TERMS OF APPROPRIATE SPACE DESIGN AND SPACE UTILIZATION. THREE AREAS ARE IDENTIFIED IN THE NEW MEDIA--(1) PROJECTION DEVICES, (2) NONPROJECTION DEVICES, AND (3) TELEVISION. ARCHITECTURE AND DESIGN CONCERNS ARE DEFINED AS--(1)…

  18. 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.

  19. Atrial Arrhythmias and Their Implications for Space Flight - Introduction

    NASA Technical Reports Server (NTRS)

    Polk, J. D.; Barr, Y. R.; Bauer, P.; Hamilton, D. R.; Kerstman, E.; Tarver, B.

    2010-01-01

    This panel will discuss the implications of atrial arrhythmias in astronauts from a variety of perspectives; including historical data, current practices, and future challenges for exploration class missions. The panelists will present case histories, outline the evolution of current NASA medical standards for atrial arrhythmias, discuss the use of predictive tools, and consider potential challenges for current and future missions.

  20. Space Weathering of Itokawa Particles: Implications for Regolith Evolution

    NASA Technical Reports Server (NTRS)

    Berger, Eve L.; Keller, Lindsay P.

    2015-01-01

    Space weathering processes such as solar wind irradiation and micrometeorite impacts are known to alter the the properties of regolith materials exposed on airless bodies. The rates of space weathering processes however, are poorly constrained for asteroid regoliths, with recent estimates ranging over many orders of magnitude. The return of surface samples by JAXA's Hayabusa mission to asteroid 25143 Itokawa, and their laboratory analysis provides "ground truth" to anchor the timescales for space weathering processes on airless bodies. Here, we use the effects of solar wind irradiation and the accumulation of solar flare tracks recorded in Itokawa grains to constrain the rates of space weathering and yield information about regolith dynamics on these timescales.

  1. Space-Derived Transparency: Players, Policies, Implications, and Synergies

    NASA Astrophysics Data System (ADS)

    Kinnan, C. J.

    2001-06-01

    Space-derived transparency will become a common means of monitoring, preventing, and mitigating crises, verifying compliance with treaties and law, and enabling confidence and security building measures. Democratization and globalization, the proliferation of information technologies, the availability of commercial space high-resolution imagery, and the growing influence of NGOs invite this question: What is (space-derived) transparency and what effect does it have on US security policy? Three camps have emerged in the debate -Horaeists who seek to build a transnational society through complete transparency; Preservationists, mostly military, who fear the threat to national security, want to deny most space-derived information to non-traditional/non-state actors; and Synergists who seek to capitalize on the best of both camps. There is evidence suggesting that space-derived transparency is an inevitable trend and will resist even the best means of preservationist control. Space-derived transparency may change the dynamic of the security environment by introducing new players into the policy fomentation and implementation process. These players, if not properly schooled in imagery analysis or the potential effects of their use of misinterpreted space-derived imagery, could force policy makers to make fast, ill-considered decisions in order to respond to incidents. In some cases this fast response will defuse potential crises and in other situations these rushed decisions might result in policies without considering the potential consequences, which could turn incidents into crises. Space-derived transparency is a step forward into the future for each camp . . . the challenge for the United States lies in forging synergies in an increasingly transparent world while maintaining the balance between openness and security.

  2. Some Implications of Space Tourism for Extraterrestrial Resources

    NASA Astrophysics Data System (ADS)

    Rogers, T. F.

    1999-01-01

    The Purpose and Scope of the Roundtable "to bring together people with ideas about what will be useful products in the space environment with those who know how to produce materials on Earth." When considering extraterrestrial resources in the context of their use in support of general public space tourism it is important to broaden this definition of Scope in certain ways. The first stages of extraterrestrial space tourism will probably take place in the Earth's lower atmosphere - far from the Moon or the planets, and even well below Earth orbit. Sophisticated aircraft could take tourists up to altitudes approaching 20 miles for short periods. And the earliest of fully reusable space transportation vehicles should be able to reach some 50 miles in altitude for short trips. Later, Earth multi-orbit trips could be offered, to be followed by stays in residence in LEO hotels for days. In time, trips could take place to/from the Moon, eventually with stays there. It should be appreciated that there are two most important extraterrestrial resources immediately available for space tourism use. They are not "materials" or "products," but are two vital space "resource intangibles."

  3. Legal Implications of Nuclear Propulsion for Space Objects

    NASA Astrophysics Data System (ADS)

    Pop, V.

    2002-01-01

    This paper is intended to examine nuclear propulsion concepts such as "Project Orion", "Project Daedalus", NERVA, VASIMIR, from the legal point of view. The UN Principles Relevant to the Use of Nuclear Power Sources in Outer Space apply to nuclear power sources in outer space devoted to the generation of electric power on board space objects for non-propulsive purposes, and do not regulate the use of nuclear energy as a means of propulsion. However, nuclear propulsion by means of detonating atomic bombs (ORION) is, in principle, banned under the 1963 Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space, and Under Water. The legality of use of nuclear propulsion will be analysed from different approaches - historical (i.e. the lawfulness of these projects at the time of their proposal, at the present time, and in the future - in the light of the mutability and evolution of international law), spatial (i.e. the legal regime governing peaceful nuclear explosions in different spatial zones - Earth atmosphere, Earth orbit, Solar System, and interstellar space), and technical (i.e, the legal regime applicable to different nuclear propulsion techniques, and to the various negative effects - e.g. damage to other space systems as an effect of the electromagnetic pulse, etc). The paper will analyse the positive law, and will also come with suggestions "de lege ferenda".

  4. 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.

  5. 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

  6. Implications of Public Opinion for Space Program Planning, 1980 - 2000

    NASA Technical Reports Server (NTRS)

    Overholt, W.; Wiener, A. J.; Yokelson, D.

    1975-01-01

    The effect of public opinion on future space programs is discussed in terms of direct support, apathy, or opposition, and concern about the tax burden, budgetary pressures, and national priorities. Factors considered include: the salience and visibility of NASA as compared with other issues, the sources of general pressure on the federal budget which could affect NASA, the public's opinions regarding the size and priority of NASA'S budget, the degree to which the executive can exercise leverage over NASA's budget through influencing or disregarding public opinion, the effects of linkages to other issues on space programs, and the public's general attitudes toward the progress of science.

  7. 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.

  8. Implications of Gun Launch to Space for Nanosatellite Architectures

    NASA Technical Reports Server (NTRS)

    Palmer, Miles R.

    1995-01-01

    Engineering and economic scaling factors for gun launch to space (GLTS) systems are compared to conventional rocket launch systems. It is argued that GLTS might reduce the cost of small satellite development and launch in the mid to far term, thereby inducing a shift away from large centralized geosynchronous communications satellites to small proliferated low earth orbit systems.

  9. International Space Station Execution Replanning Process: Trends and Implications

    NASA Technical Reports Server (NTRS)

    McCormick, Robet J.

    2007-01-01

    International Space Station is a joint venture. Because of this, ISS execution planning- planning within the week for the ISS requires coordination across multiple partner, and the associated processes and tools to allow this coordination to occur. These processes and tools are currently defined and are extensively used. This paper summarizes these processes, and documents the current data trends associated with these processes and tools, with a focus on the metrics provided from the ISS Planning Product Change Request (PPCR) tool. As NASA's Vision for Space Exploration and general Human spaceflight trends are implemented, the probability of joint venture long duration programs such as ISS, with varying levels of intergovernmental and/or corporate partnership, will increase. Therefore, the results of this PPCR analysis serve as current Lessons learned for the ISS and for further similar ventures.

  10. 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.

  11. Insurance and indemnification implications of future space projects

    NASA Technical Reports Server (NTRS)

    O'Brien, John E.

    1987-01-01

    NASA options regarding insurance and indemnification policies as they relate to NASA customers and contractors are described. The foundation for the discussion is the way in which NASA is planning to return the Space Shuttle fleet to safe flight as well as current U.S. policy concerning future uses of the Shuttle fleet. Issues discussed include: the nature of the Shuttle manifest; the policy regarding property damage or destruction; insurance against liability to third parties; the reduction of the scope of the risk to be insured; NASA as the insurer; a sharing arrangement between the user and NASA; and contractors and subcontractors involved in Shuttle operations.

  12. Fluorescent probe partitioning in GUVs of binary phospholipid mixtures: implications for interpreting phase behavior.

    PubMed

    Juhasz, Janos; Davis, James H; Sharom, Frances J

    2012-01-01

    The phase behavior of membrane lipids is known to influence the organization and function of many integral proteins. Giant unilamellar vesicles (GUVs) provide a very useful model system in which to examine the details of lipid phase separation using fluorescence imaging. The visualization of domains in GUVs of binary and ternary lipid mixtures requires fluorescent probes with partitioning preference for one of the phases present. To avoid possible pitfalls when interpreting the phase behavior of these lipid mixtures, sufficiently thorough characterization of the fluorescent probes used in these studies is needed. It is now evident that fluorescent probes display different partitioning preferences between lipid phases, depending on the specific lipid host system. Here, we demonstrate the benefit of using a panel of fluorescent probes and confocal fluorescence microscopy to examine phase separation in GUVs of binary mixtures of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC)/1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). Patch and fibril gel phase domains were found to co-exist with liquid disordered (l(d)) domains on the surface of GUVs composed of 40:60 mol% DOPC/DPPC, over a wide range of temperatures (14-25°C). The fluorescent lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(7-nitro-2-1,3-benzoxadiazol-4-yl (NBD-DPPE), proved to be the most effective probe for visualization of fibril domains. In the presence of Lissamine(TM) rhodamine B 1,2-dihexadecanoyl-sn-glycero-3-phosphoethanolamine (Rh-DPPE) we were unable to detect fibril domains. This fluorophore also affected the partitioning behavior of other fluorescent probes. Overall, we show that the selection of different fluorescent probes as lipid phase reporters can result in very different interpretation of the phase behavior of DOPC/DPPC mixtures. PMID:21945563

  13. Human factors in space station architecture 1: Space station program implications for human factors research

    NASA Technical Reports Server (NTRS)

    Cohen, M. M.

    1985-01-01

    The space station program is based on a set of premises on mission requirements and the operational capabilities of the space shuttle. These premises will influence the human behavioral factors and conditions on board the space station. These include: launch in the STS Orbiter payload bay, orbital characteristics, power supply, microgravity environment, autonomy from the ground, crew make-up and organization, distributed command control, safety, and logistics resupply. The most immediate design impacts of these premises will be upon the architectural organization and internal environment of the space station.

  14. 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.

  15. 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.

  16. 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.

  17. Gravitational biology and space life sciences: current status and implications for the Indian space programme.

    PubMed

    Dayanandan, P

    2011-12-01

    This paper is an introduction to gravitational and space life sciences and a summary of key achievements in the field. Current global research is focused on understanding the effects of gravity/microgravity onmicrobes, cells, plants, animals and humans. It is now established that many plants and animals can progress through several generations in microgravity. Astrobiology is emerging as an exciting field promoting research in biospherics and fabrication of controlled environmental life support systems. India is one of the 14-nation International Space Exploration Coordination Group (2007) that hopes that someday humans may live and work on other planets within the Solar System. The vision statement of the Indian Space Research Organization (ISRO) includes planetary exploration and human spaceflight. While a leader in several fields of space science, India is yet to initiate serious research in gravitational and life sciences. Suggestions are made here for establishing a full-fledged Indian space life sciences programme. PMID:22116289

  18. Loss of Water to Space from Mars: Processes and Implications

    NASA Astrophysics Data System (ADS)

    Kass, D. M.

    2001-12-01

    One of the major sinks for water on Mars is the loss to space. This occurs via a complex series of processes that transport the individual atoms to the upper atmosphere, where several escape mechanisms remove them. Hydrogen and deuterium are lost primarily by Jeans escape. Non-thermal processes also remove H and D, but are only important in determining D loss at solar minimum under modern conditions. The present H loss rate is equivalent to the loss of 10-3~pr-\\micron~yr-1 of water. The loss of oxygen is more complicated. The three main processes are indirect (or ionospheric) sputtering, solar wind pickup of O+, and O2+ dissociative recombination. Their relative importance has varied over the history of Mars. The combined effect of the O loss processes is to remove a ~ 50~m global layer of water over the last 3.5 Gyr. Based on photochemical modeling, the loss of oxygen and hydrogen are balanced (over geological timescales) by a feedback process. During the early history of Mars, impact erosion and hydrodynamic blow-off may have removed significant water. But, it is difficult to estimate their quantitative effects. The transport of individual H, D and O atoms to the exosphere where they can escape is not completely understood. It occurs primarily via intermediate species, H2, HD, O2 and CO2. The H2 and HD are formed by photolysis of water and the odd hydrogen photochemistry. One open issue is the mechanism regulating the partitioning of D between HDO and HD (which controls the supply of D available for escape from the exosphere). The various loss processes isotopically enrich Martian water since the exospheric escape source region is depleted. Jeans escape and the transport from the lower atmosphere further fractionate hydrogen, the most useful isotopic system. Based on recent observations, the D/H fractionation factor, F ~ 0.02. Measurements of atmospheric water vapor indicate it is enriched in deuterium, with a D/H ratio ~ 5 times the terrestrial value. Since

  19. Space shuttle ram glow: Implication of NO2 recombination continuum

    NASA Technical Reports Server (NTRS)

    Swenson, G. R.; Mende, S. B.; Clifton, S.

    1985-01-01

    The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from the surface). Emission continuum is rare in molecular systems but the measured spectrum does resemble the laboratory spectrum of NO2 (B) recombination continuum. The thickness of the observed emission is consistent with the NO2 hypothesis given an exit velocity of approx. 2.5 km/sec (1.3 eV) which leaves approx. 3.7 eV of ramming OI energy available for unbonding the recombined NO2 from the surface. The NO2 is formed in a 3-body recombination of OI + NO + m = NO2 + m where OI originates from the atmosphere and NO is chemically formed on the surface from atmospheric NI and OI. The spacecraft surface then acts as the n for the reaction: Evidence exists from orbital mass spectrometer data that the NO and NO2 chemistry described in this process does occur on surfaces of spectrometer orifices in orbit. Surface temperature effects are likely a factor in the NO sticking efficiency and, therefore, glow intensities.

  20. Space shuttle Ram glow: Implication of NO2 recombination continuum

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.; Mende, S. B.; Clifton, S.

    1985-09-01

    The ram glow data gathered to data from imaging experiments on space shuttle suggest the glow is a continuum (within 34 angstrom resolution); the continuum shape is such that the peak is near 7000 angstroms decreasing to the blue and red, and the average molecular travel leading to emission after leaving the surface is 20 cm (assuming isotropic scattering from the surface). Emission continuum is rare in molecular systems but the measured spectrum does resemble the laboratory spectrum of NO2 (B) recombination continuum. The thickness of the observed emission is consistent with the NO2 hypothesis given an exit velocity of approx. 2.5 km/sec (1.3 eV) which leaves approx. 3.7 eV of ramming OI energy available for unbonding the recombined NO2 from the surface. The NO2 is formed in a 3-body recombination of OI + NO + m = NO2 + m where OI originates from the atmosphere and NO is chemically formed on the surface from atmospheric NI and OI. The spacecraft surface then acts as the n for the reaction: Evidence exists from orbital mass spectrometer data that the NO and NO2 chemistry described in this process does occur on surfaces of spectrometer orifices in orbit. Surface temperature effects are likely a factor in the NO sticking efficiency and, therefore, glow intensities.

  1. Bioavailability of xenobiotics in unsaturated soils – implications for nucleic acid based stable isotope probing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of stable isotopes to label phylogenetically informative biomolecules (phospholipid fatty acids, DNA, or RNA), typically referred to as stable isotope probing (SIP) has the potential of providing definitive evidence that a detected population is active in a specific process, if that process ...

  2. Practical implications of probe- and sample-related variables in puncture testing of clingstone peaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit processors want to correlate processing-relevant field measurements (such as the Magness-Taylor penetrometer test) with similar measurements (such as the puncture test) obtained on laboratory instruments. The objective of this work was to compare a Magness-Taylor probe to standard, flat-tippe...

  3. 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

  4. 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.

  5. Human physiological adaptation to extended Space Flight and its implications for Space Station

    NASA Technical Reports Server (NTRS)

    Kutyna, F. A.; Shumate, W. H.

    1985-01-01

    Current work evaluating short-term space flight physiological data on the homeostatic changes due to weightlessness is presented as a means of anticipating Space Station long-term effects. An integrated systems analysis of current data shows a vestibulo-sensory adaptation within days; a loss of body mass, fluids, and electrolytes, stabilizing in a month; and a loss in red cell mass over a month. But bone demineralization which did not level off is seen as the biggest concern. Computer algorithms have been developed to simulate the human adaptation to weightlessness. So far these paradigms have been backed up by flight data and it is hoped that they will provide valuable information for future Space Station design. A series of explanatory schematics is attached.

  6. Galactic exploration by directed self-replicating probes, and its implications for the Fermi paradox

    NASA Astrophysics Data System (ADS)

    Barlow, Martin T.

    2013-01-01

    This paper proposes a long-term scheme for robotic exploration of the galaxy, and then considers the implications in terms of the `Fermi paradox' and our search for extraterrestrial intelligence (ETI). We discuss the `Galactic ecology' of civilizations in terms of the parameters T (time between ET civilizations arising) and L, the lifetime of these civilizations. Six different regions are described.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. The space density of magnetic and non-magnetic cataclysmic variables, and implications for CV evolution

    NASA Astrophysics Data System (ADS)

    Pretorius, M.

    2014-07-01

    I will present estimates of the space densities of both non-magnetic and magnetic cataclysmic variables (CVs), based on X-ray flux-limited samples. The measurements can be used to address several questions relevant to the evolution of CVs and to the makeup of Galactic X-ray source populations. I will discuss the implications of these results for the high predicted space density of non-magnetic CVs, the evolutionary relationship between intermediate polars and polars, the fraction of CVs with strongly magnetic white dwarfs, and for the contribution of magnetic CVs to Galactic populations of hard X-ray sources.

  12. Implications for Earth and space in new K-12 science standards

    NASA Astrophysics Data System (ADS)

    Wysession, Michael E.

    2012-11-01

    New science standards for national K-12 science education are in the process of being written by a states-led team of writers organized by Achieve, Inc., with important implications for teaching Earth and space sciences. The final version of these "Next Generation Science Standards" (NGSS) is scheduled to be released in early 2013, but a second draft of the standards will be made public in December 2012. Members of the Earth and space science (ESS) research communities can review this draft of NGSS and provide constructive feedback. Such feedback will help ensure that American students receive instruction that is accurate, relevant, and engaging.

  13. 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…

  14. 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.

  15. 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.

  16. 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.

  17. Modeling the disequilibrium species for Jupiter and Saturn: Implications for Juno and Saturn entry probe

    NASA Astrophysics Data System (ADS)

    Wang, Dong; Lunine, Jonathan I.; Mousis, Olivier

    2016-09-01

    Disequilibrium species have been used previously to probe the deep water abundances and the eddy diffusion coefficient for giant planets. In this paper, we present a diffusion-kinetics code that predicts the abundances of disequilibrium species in the tropospheres of Jupiter and Saturn with updated thermodynamic and kinetic data. The dependence on the deep water abundance and the eddy diffusion coefficient is investigated. We quantified the disagreements in CO kinetics that comes from using different reaction networks and identified C2H6 as a useful tracer for the eddy diffusion coefficient. We first apply an H/P/O reaction network to Jupiter and Saturn's atmospheres and suggest a new PH3 destruction pathway. New chemical pathways for SiH4 and GeH4 destruction are also suggested, and another AsH3 destruction pathway is investigated thanks to new thermodynamic and kinetic data. These new models should enhance the interpretation of the measurement of disequilibrium species by JIRAM on board Juno and allow disentangling between methods for constraining the Saturn's deep water abundance with the Saturn entry probes envisaged by NASA or ESA.

  18. Probing BoNT/A protease exosites: implications for inhibitor design and light chain longevity.

    PubMed

    Xue, Song; Javor, Sacha; Hixon, Mark S; Janda, Kim D

    2014-11-01

    Botulinum neurotoxin serotype A (BoNT/A) is one of the most lethal toxins known. Its extreme toxicity is due to its light chain (LC), a zinc protease that cleaves SNAP-25, a synaptosome-associated protein, leading to the inhibition of neuronal activity. Studies on BoNT/A LC have revealed that two regions, termed exosites, can play an important role in BoNT catalytic activity. A clear understanding of how these exosites influence neurotoxin catalytic activity would provide a critical framework for deciphering the mechanism of SNAP-25 cleavage and the design of inhibitors. Herein, based on the crystallographic structure of BoNT/A LC complexed with its substrate, we designed an α-exosite binding probe. Experiments with this unique probe demonstrated that α-exosite binding enhanced both catalytic activity and stability of the LC. These data help delineate why α-exosite binding is needed for SNAP-25 cleavage and also provide new insights into the extended lifetime observed for BoNT/A LC in vivo. PMID:25295706

  19. Payload test philosophy. [implications of STS development at Goddard Space Flight Center

    NASA Technical Reports Server (NTRS)

    Arman, A.

    1979-01-01

    The implications of STS development for payload testing at the Goddard Space Flight Center are reviewed. The biggest impact of STS may be that instead of testing the entire payload, most of the testing may have to be limited to the subsystem or subassembly level. Particular consideration is given to the Goddard protoflight concept in which the test is geared to the design qualification levels, the test durations being those that are expected during the actual launch sequence.

  20. Muscle changes with eccentric exercise: implications on Earth and in space.

    PubMed

    Hargens, A R; Parazynski, S; Aratow, M; Friden, J

    1989-01-01

    The effects of eccentric exercise on skeletal muscle fluid pressure, morphology, and enzyme activities are reviewed. Topics related to muscle injury are the exercise protocol, intramuscular pressures, muscle soreness, resting intramuscular pressures, peak pressure during eccentric and concentric exercise, and peak pressure during isometric contractions. Enzyme activity examined levels of serum glutamic oxaloacetic transaminase, lactic dehydrogenase, and serum creatine kinase. Muscle morphology was examined with light microscopy and electron microscopy. Implications for exercise in space are examined. PMID:11540912

  1. Space adaptation syndrome: Incidence and operational implications for the space transportation system program

    NASA Technical Reports Server (NTRS)

    Homick, J. L.; Reschke, M. F.; Vanderploeg, J. M.

    1984-01-01

    Better methods for the prediction, prevention, and treatment of the space adaptation syndome (SAS) were developed. A systematic, long range program of operationally oriented data collection on all individuals flying space shuttle missions was initiated. Preflight activities include the use of a motion experience questionnaire, laboratory tests of susceptibility to motion sickness induced by Coriolis stimuli and determinations of antimotion sickness drug efficacy and side effects. During flight, each crewmember is required to provide a daily report of symptom status, use of medications, and other vestibular related sensations. Additional data are obtained postflight. During the first nine shuttle missions, the reported incidence of SAS has been48%. Self-induced head motions and unusual visual orientation attitudes appear to be the principal triggering stimuli. Antimotion sickness medication, was of limited therapeutic value. Complete recovery from symptoms occurred by mission day three or four. Also of relevance is the lack of a statistically significant correlation between the ground based Coriolis test and SAS. The episodes of SAS have resulted in no impact to shuttle mission objectives and, no significant impact to mission timelines.

  2. Waves in Venus's middle and upper atmosphere - Implications of Pioneer Venus probe data above the clouds

    NASA Technical Reports Server (NTRS)

    Seiff, Alvin

    1991-01-01

    This paper reevaluates Pioneer Venus probe data which show the presence of waves in Venus's middle and upper atmosphere. The data are extended to 138 km. Uncertainties in the temperature are typically about 0.1 times amplitude, supporting the reliability of large-amplitude oscillations approaching 40 K at 120 km. Growth rates above 100 km follow approximately the inverse square root of density and 'saturation' occurs. The waves then break at the 120 km level, providing a source for the 'friction' required in models to match the observed day-night temperature contrast in the lower thermosphere. The data correlated to an unexpected degree with temperatures from the Pioneer Venus orbiter atmospheric drag experiment. The observations lead to the suggestion that the thermospheric waves are solar-fixed, induced either by the major subsidence across the termination or as continuation upward of waves in the middle atmosphere.

  3. Leonid Shower Probe of Aerothermochemistry in Meteoric Plasmas and Implication for the Origin of Life

    NASA Technical Reports Server (NTRS)

    Jenniskens, Peter S. I.; Packan, D.; Laux, C.; Wilson, Mike; Boyd, I. D.; Kruger, C. H.; Popova, O.; Fonda, M.; DeVincenzi, Donald L. (Technical Monitor)

    2000-01-01

    The rarefied and high Mach number (up to 270) of the flow field of a typical meteoroid as it enters the Earth's atmosphere implies conditions of ablation and atmospheric chemistry that have proven to be as difficult to grasp as the proverbial shooting star. An airborne campaign was organized to study these processes during an intense Leonid shower. A probe of molecular band emission now demonstrates that the flash of light from a common meteor originates in the wake of the object rather than in the meteor head. A new theoretical approach using the direct simulation Monte Carlo technique demonstrates that the ablation process is critical in heating the air in that wake. Air molecules impinge on a dense cloud of ablated material in front of the meteoroid head into an extended wake that has the observed excitation temperatures. These processes determine what extraterrestrial materials may have been delivered to Earth at the time of the origin of life.

  4. The Phase Space of z=1.2 Clusters: Probing Dust Temperature and Star Formation Rate as a Function of Environment and Accretion History

    NASA Astrophysics Data System (ADS)

    Noble, Allison; SpARCS Collaboration

    2016-01-01

    Understanding the influence of environment is a fundamental goal in studies of galaxy formation and evolution, and galaxy clusters offer ideal laboratories with which to examine environmental effects on their constituent members. Clusters continually evolve and build up mass through the accumulation of galaxies and groups, resulting in distinct galaxy populations based on their accretion history. In Noble et al. 2013, we presented a novel definition for environment using the phase space of line-of-sight velocity and clustercentric radius, which probes the time-averaged density to which a galaxy has been exposed and traces out accretion histories. Using this dynamical definition of environment reveals a decline in specific star formation towards the cluster core in the earliest accreted galaxies, and was further shown to isolate post-starburst galaxies within clusters (Muzzin et al. 2014). We have now extended this work to higher-redshift clusters at z=1.2 using deep Herschel-PACS and -SPIRE data. With a sample of 120 spectroscopically-confirmed cluster members, we investigate various galaxy properties as a function of phase-space environment. Specifically, we use 5-band Herschel photometry to estimate the dust temperature and star formation rate for dynamically distinct galaxy populations, namely recent infalls and those that were accreted into the cluster at an earlier epoch (Noble et al. submitted). These properties are then compared to a field sample of star-forming galaxies at 1.1 < z < 1.2 to shed light on cluster-specific processes in galaxy evolution. In this talk I will discuss the various implications of a phase-space definition for environment, and present our most recent results, focusing on how this accretion-based definition aids our understanding of quenching mechanisms within z=1.2 galaxies.

  5. 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.

  6. 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).

  7. 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.

  8. Implications of privacy needs and interpersonal distancing mechanisms for space station design

    NASA Technical Reports Server (NTRS)

    Harrison, A. A.; Sommer, R.; Struthers, N.; Hoyt, K.

    1985-01-01

    Privacy needs, or the need of people to regulate their degree of contact with one another, and interpersonal distancing mechanisms, which serve to satisfy these needs, are common in all cultures. Isolation, confinement, and other conditions accociated with space flight may at once accentuate privacy needs and limit the availability of certain common interpersonal contact. Loneliness occurs when people have less contact with one another than they desire. Crowding occurs when people have more contact with one another than they desire. Crowding, which is considered the greater threat to members of isolated and confined groups, can contribute to stress, a low quality of life, and poor performance. Drawing on the general literature on privacy, personal space, and interpersonal distancing, and on specialized literature on life aboard spacecraft and in spacecraft-analogous environments, a quantitative model for understanding privacy, interpersonal distancing, loneliness, and crowding was developed and the practical implications of this model for space station design were traced.

  9. Flight Experience from Space Photovoltaic Concentrator Arrays and its Implication on Terrestrial Concentrator Systems

    NASA Technical Reports Server (NTRS)

    Piszczor, Michael F., Jr.

    2003-01-01

    Nearly all photovoltaic solar arrays flown in space have used a planar (non- concentrating) design. However, there have been a few notable exceptions where photovoltaic concentrators have been tested and used as the mission s primary power source. Among these are the success experienced by the SCARLET (Solar Concentrator Array with Refractive Linear Element Technology) concept used to power NASA's Deep Space 1 mission and the problems encountered by the original Boeing 702 reflective trough concentrator design. This presentation will give a brief overview of past photovoltaic concentrator systems that have flown in space, specifically addressing the valuable lessons learned from flight experience, and other viable concentrator concepts that are being proposed for the future. The general trends of this flight experience will be noted and discussed with regard to its implications on terrestrial photovoltaic concentrator designs.

  10. 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.

  11. 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

  12. Ceruloplasmin (ferroxidase) oxidizes hydroxylamine probes: deceptive implications for free radical detection

    PubMed Central

    Ganini, Douglas; Canistro, Donatella; Jang, JinJie; Stadler, Krisztian; Mason, Ronald P.; Kadiiska, Maria B.

    2012-01-01

    Ceruloplasmin (ferroxidase) is a copper-binding protein known to promote Fe2+ oxidation in plasma of mammals. Besides its classical ferroxidase activity, ceruloplasmin is known to catalyze the oxidation of various substrates, such as amines and catechols. Assays based on cyclic hydroxylamine oxidation are used to quantify and detect free radicals in biological samples ex vivo and in vitro. We show here that human ceruloplasmin promotes the oxidation of the cyclic hydroxylamine 1-hydroxy-3-carboxy-2,2,5,5-tetramethylpyrrolidine hydrochloride (CPH) and related probes in Chelex-treated phosphate buffer and rat serum. The reaction is suppressed by the metal chelators DTPA, EDTA and Desferal, while heparin and bathocuproine have no effect. Catalase or SOD additions do not interfere with the CPH-oxidation yield, demonstrating that free radicals are not involved in the CPH oxidation mediated by ceruloplasmin. Plasma samples immunodepleted of ceruloplasmin have lower levels of CPH oxidation, which confirms the role of ceruloplasmin (ferroxidase) as a biological oxidizing agent of cyclic hydroxylamines. In conclusion, we show that the ferroxidase activity of ceruloplasmin is a possible biological source of artifacts in the cyclic hydroxylamine-oxidation assay used for ROS detection and quantification. PMID:22824865

  13. Probing the Chemical Stability of Mixed Ferrites: Implications for MR Contrast Agent Design

    PubMed Central

    Schultz-Sikma, Elise A.; Joshi, Hrushikesh M.; Ma, Qing; MacRenaris, Keith W.; Eckermann, Amanda L.; Dravid, Vinayak P.; Meade, Thomas J.

    2011-01-01

    Nanomaterials with mixed composition, in particular magnetic spinel ferrites, are emerging as efficient contrast agents for magnetic resonance imaging (MRI). Many factors, including size, composition, atomic structure, and surface properties are crucial in the design of such nanoparticle-based probes due to their influence on the magnetic properties. Silica-coated iron oxide (IO-SiO2) and cobalt ferrite (CoIO-SiO2) nanoparticles were synthesized using standard high temperature thermal decomposition and base-catalyzed water-in-oil microemulsion techniques. Under neutral aqueous conditions, it was found that 50–75% of the cobalt content in the CoIO-SiO2 nanoparticles leached out of the core structure. Leaching caused a 7.2-fold increase in longitudinal relaxivity and an increase in the saturation magnetization from ~48 emu/g core to ~65 emu/g core. X-ray absorption fine structure studies confirmed that the atomic structure of the ferrite core was altered following leaching, while TEM and DLS confirmed that the morphology and size of the nanoparticle remained unchanged. The CoIO-SiO2 nanoparticles converted from a partially inverted spinel cation arrangement (unleached state) to an inverse spinel arrangement (leached state). The control IO-SiO2 nanoparticles remained stable with no change in structure and negligible changes in magnetic behavior. This detailed analysis highlights how important understanding the properties of nanomaterials is in the development of reliable agents for diagnostic and therapeutic applications. PMID:21603070

  14. 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.

  15. 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.

  16. Probing the Chemical Stability of Mixed Ferrites: Implications for Magnetic Resonance Contrast Agent Design

    SciTech Connect

    Schultz-Sikma, Elise A.; Joshi, Hrushikesh M.; Ma, Qing; MacRenaris, Keith W.; Eckermann, Amanda L.; Dravid, Vinayak P.; Meade, Thomas J.

    2011-09-16

    Nanomaterials with mixed composition, in particular magnetic spinel ferrites, are emerging as efficient contrast agents for magnetic resonance imaging. Many factors, including size, composition, atomic structure, and surface properties, are crucial in the design of such nanoparticle-based probes because of their influence on the magnetic properties. Silica-coated iron oxide (IO-SiO{sub 2}) and cobalt ferrite (CoIO-SiO{sub 2}) nanoparticles were synthesized using standard high-temperature thermal decomposition and base-catalyzed water-in-oil microemulsion techniques. Under neutral aqueous conditions, it was found that 50-75% of the cobalt content in the CoIO-SiO{sub 2} nanoparticles leached out of the core structure. Leaching caused a 7.2-fold increase in the longitudinal relaxivity and an increase in the saturation magnetization from {approx}48 to {approx}65 emu/g of the core. X-ray absorption fine structure studies confirmed that the atomic structure of the ferrite core was altered following leaching, while transmission electron microscopy and dynamic light scattering confirmed that the morphology and size of the nanoparticle remained unchanged. The CoIO-SiO{sub 2} nanoparticles converted from a partially inverted spinel cation arrangement (unleached state) to an inverse spinel arrangement (leached state). The control IO-SiO{sub 2} nanoparticles remained stable with no change in the structure and negligible changes in the magnetic behavior. This detailed analysis highlights how important understanding the properties of nanomaterials is in the development of reliable agents for diagnostic and therapeutic applications.

  17. DNA-based stable isotope probing coupled with cultivation methods implicates Methylophaga in hydrocarbon degradation

    PubMed Central

    Mishamandani, Sara; Gutierrez, Tony; Aitken, Michael D.

    2014-01-01

    Marine hydrocarbon-degrading bacteria perform a fundamental role in the oxidation and ultimate removal of crude oil and its petrochemical derivatives in coastal and open ocean environments. Those with an almost exclusive ability to utilize hydrocarbons as a sole carbon and energy source have been found confined to just a few genera. Here we used stable isotope probing (SIP), a valuable tool to link the phylogeny and function of targeted microbial groups, to investigate hydrocarbon-degrading bacteria in coastal North Carolina sea water (Beaufort Inlet, USA) with uniformly labeled [13C]n-hexadecane. The dominant sequences in clone libraries constructed from 13C-enriched bacterial DNA (from n-hexadecane enrichments) were identified to belong to the genus Alcanivorax, with ≤98% sequence identity to the closest type strain—thus representing a putative novel phylogenetic taxon within this genus. Unexpectedly, we also identified 13C-enriched sequences in heavy DNA fractions that were affiliated to the genus Methylophaga. This is a contentious group since, though some of its members have been proposed to degrade hydrocarbons, substantive evidence has not previously confirmed this. We used quantitative PCR primers targeting the 16S rRNA gene of the SIP-identified Alcanivorax and Methylophaga to determine their abundance in incubations amended with unlabeled n-hexadecane. Both showed substantial increases in gene copy number during the experiments. Subsequently, we isolated a strain representing the SIP-identified Methylophaga sequences (99.9% 16S rRNA gene sequence identity) and used it to show, for the first time, direct evidence of hydrocarbon degradation by a cultured Methylophaga sp. This study demonstrates the value of coupling SIP with cultivation methods to identify and expand on the known diversity of hydrocarbon-degrading bacteria in the marine environment. PMID:24578702

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. 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.

  4. A simple real space density functional theory of freezing, with implications for the glass transition

    SciTech Connect

    Stoessel, J.P.; Wolynes, P.G.

    1989-01-01

    With analogy to the ''highly accurate'' summation of cluster diagrams for hard sphere fluids a la Carnahan-Starling, we present a simple, real space free energy density functional for arbitrary potential systems, based on the generalization of the second virial coefficient to inhomogeneous systems which, when applied to hard sphere, soft-sphere, and Lennard-Jones freezing, yield melting characteristics in remarkable agreement with experiment. Implications for the liquid-glass transition in all three potential systems are also presented. 45 refs., 7 figs., 1 tab.

  5. 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.

  6. Gravity Probe B Inspection

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The space vehicle Gravity Probe B (GP-B) is the relativity experiment 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. In this photograph, engineer Gary Reynolds is inspecting the inside of the probe neck during probe thermal repairs. GP-B is scheduled for launch in April 2004 and managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Leese, Gravity Probe B, Stanford University)

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Technological implications of SNAP reactor power system development on future space nuclear power systems

    SciTech Connect

    Anderson, R.V.

    1982-11-16

    Nuclear reactor systems are one method of satisfying space mission power needs. The development of such systems must proceed on a path consistent with mission needs and schedules. This path, or technology roadmap, starts from the power system technology data base available today. Much of this data base was established during the 1960s and early 1970s, when government and industry developed space nuclear reactor systems for steady-state power and propulsion. One of the largest development programs was the Systems for Nuclear Auxiliary Power (SNAP) Program. By the early 1970s, a technology base had evolved from this program at the system, subsystem, and component levels. There are many implications of this technology base on future reactor power systems. A review of this base highlights the need for performing a power system technology and mission overview study. Such a study is currently being performed by Rockwell's Energy Systems Group for the Department of Energy and will assess power system capabilities versus mission needs, considering development, schedule, and cost implications. The end product of the study will be a technology roadmap to guide reactor power system development.

  16. Implications of previous space commercialization experiences for the reusable launch vehicle

    NASA Astrophysics Data System (ADS)

    Obermann, Richard M.; Williamson, Ray A.

    2003-07-01

    The United States' 1994 National Space Transportation Policy directed the National Aeronautics and Space Administration (NASA) to work with industry on the development of technologies required for a reusable launch vehicle (RLV). In the partnership that has evolved from that directive, NASA envisions its role as providing support for technological risk reduction and for developing space transportation to serve government needs. NASA officials assume that the development of an operational, commercial RLV will be carried out by the private sector without use of government funds. Under that scenario, the Federal government will simply become a customer for commercial RLV services. In evaluating the prospects for the development of a commercially viable RLV, it may be useful to examine "lessons learned" from previous space commercialization efforts—both those that succeeded and those that did not. It can be argued that several distinct streams of market and technological development may have to converge for successful commercialization of space systems to occur. Potential factors influencing the prospects for commercialization include the size and growth rate of the potential customer base, the extent to which a governmental customer exists to underpin the market, the development of associated "value-added" markets, the stability of governmental policies, the levels of technological and business risk, and the degree to which competitive markets exist. This paper examines two previous space commercialization experiences, evaluates the relative importance of the various factors that influence the prospects for success of commercialization efforts, and assesses the implications of those factors for the commercial viability of the proposed RLV.

  17. Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology

    NASA Astrophysics Data System (ADS)

    Spergel, D. N.; Bean, R.; Doré, O.; Nolta, M. R.; Bennett, C. L.; Dunkley, J.; Hinshaw, G.; Jarosik, N.; Komatsu, E.; Page, L.; Peiris, H. V.; Verde, L.; Halpern, M.; Hill, R. S.; Kogut, A.; Limon, M.; Meyer, S. S.; Odegard, N.; Tucker, G. S.; Weiland, J. L.; Wollack, E.; Wright, E. L.

    2007-06-01

    A simple cosmological model with only six parameters (matter density, Ωmh2, baryon density, Ωbh2, Hubble constant, H0, amplitude of fluctuations, σ8, optical depth, τ, and a slope for the scalar perturbation spectrum, ns) fits not only the 3 year WMAP temperature and polarization data, but also small-scale CMB data, light element abundances, large-scale structure observations, and the supernova luminosity/distance relationship. Using WMAP data only, the best-fit values for cosmological parameters for the power-law flat Λ cold dark matter (ΛCDM) model are (Ωmh2,Ωbh2,h,ns,τ,σ8)=(0.1277+0.0080-0.0079,0.02229+/-0.00073,0.732+0.031-0.032,0.958+/-0.016,0.089+/-0.030,0.761+0.049-0.048). The 3 year data dramatically shrink the allowed volume in this six-dimensional parameter space. Assuming that the primordial fluctuations are adiabatic with a power-law spectrum, the WMAP data alone require dark matter and favor a spectral index that is significantly less than the Harrison-Zel'dovich-Peebles scale-invariant spectrum (ns=1, r=0). Adding additional data sets improves the constraints on these components and the spectral slope. For power-law models, WMAP data alone puts an improved upper limit on the tensor-to-scalar ratio, r0.002<0.65 (95% CL) and the combination of WMAP and the lensing-normalized SDSS galaxy survey implies r0.002<0.30 (95% CL). Models that suppress large-scale power through a running spectral index or a large-scale cutoff in the power spectrum are a better fit to the WMAP and small-scale CMB data than the power-law ΛCDM model; however, the improvement in the fit to the WMAP data is only Δχ2=3 for 1 extra degree of freedom. Models with a running-spectral index are consistent with a higher amplitude of gravity waves. In a flat universe, the combination of WMAP and the Supernova Legacy Survey (SNLS) data yields a significant constraint on the equation of state of the dark energy, w=-0.967+0.073-0.072. If we assume w=-1, then the deviations from the

  18. 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

  19. 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

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. Implications of privacy needs and interpersonal distancing mechanisms for space station design

    NASA Technical Reports Server (NTRS)

    Harrison, Albert A.; Sommer, Robert; Struthers, Nancy; Hoyt, Kathleen

    1988-01-01

    Isolation, confinement, and the characteristics of microgravity will accentuate the need for privacy in the proposed NASA space station, yet limit the mechanism available for achieving it. This study proposes a quantitative model for understanding privacy, interpersonal distancing, and performance, and discusses the practical implications for Space Station design. A review of the relevant literature provided the basis for a database, definitions of physical and psychological distancing, loneliness, and crowding, and a quantitative model of situational privacy. The model defines situational privacy (the match between environment and task), and focuses on interpersonal contact along visual, auditory, olfactory, and tactile dimensions. It involves summing across pairs of crew members, contact dimensions, and time, yet also permits separate analyses of subsets of crew members and contact dimensions. The study concludes that performance will benefit when the type and level of contact afforded by the environment align with that required by the task. The key to achieving this is to design a flexible, definable, and redefinable interior environment that provides occupants with a wide array of options to meet their needs for solitude, limited social interaction, and open group activity. The report presents 49 recommendations in five categories to promote a wide range of privacy options despite the space station's volumetric limitations.

  5. 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.

  6. The implications of the LDEF results on Space Station Freedom power system materials

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Rutledge, Sharon K.; Degroh, Kim K.; Mirtich, Michael J.; Gebauer, Linda; Olle, Raymond; Hill, Carol M.

    1993-01-01

    Results and implications of Long Duration Exposure Facility (LDEF) exposure of materials relevant to the Space Station Freedom (SSF) power system materials are presented. Atomic oxygen interactions with potential synergistic UV effects on silicone materials on LDEF were shown to result in the deposition of a dark contaminant film on adjoining surfaces. Silicones associated with solar array construction have the potential for causing reduced solar illumination of the solar cells if such silicone molecular fragments are found to be surface mobile. Results of LDEF atomic oxygen protective coatings on polyimide Kapton indicated acceptable durability to the synergistic effects of atomic oxygen, UV, thermal cycling, and micrometeoroid or debris impact. Results of combined atomic oxygen, UV radiation, thermal cycling, and micrometeoroid and debris impacts on LDEF high emittance radiator coatings indicate long term emittance and absorptance durability of Z 93 (zinc oxide pigment in a potassium silicate binder) coatings which have been selected for SSF radiator surfaces.

  7. 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

  8. Cosmological probes of gravity

    NASA Astrophysics Data System (ADS)

    Rassat, Anais Marie Melanie

    This Thesis is concerned with two cosmological probes of linear gravity. The first relates to Large Scale Structure (LSS) in the Universe, probed by galaxy surveys. The second to temperature anisotropics of the Cosmic Microwave Background (CMB), probed by the Wilkinson Microwave Anisotropy Map (WMAP). Both probe the matter and dark energy distributions in the Universe and can be used to test general relativity. The first part of this Thesis (Chapters 2 to 4) is concerned with the analysis of galaxy clustering in redshift space. The second part (Chapters 5 to 7) is concerned with the Integrated Sachs-Wolfe (ISW) effect using LSS-CMB cross-correlations. Chapter 1 introduces the cosmological theory and overviews the subsequent chapters. Chapter 2 gives a review of recent results from the 2 Micron All-Sky Survey (2MASS) and its Redshift Survey (2MRS). It includes work published in Erdogdu (a) et al. (2006) and Erdogdu (b) et al. (2006). Chapter 3 quantifies the clustering of 2MRS galaxies in redshift space. Chapter 4 uses results from Chapter 3 to constrain cosmological parameters. A selection of work from Chapters 3 and 4 will shortly become available in Rassat et al. (2008), entitled 'Redshift Space Analysis of 2MRS'. Chapter 5 overviews the late-time Integrated Sachs-Wolfe effect (ISW) and cross- correlations between the LSS and the CMB. Chapter 6 is also published in Rassat et al. (2007), entitled "Cross-correlation of 2MASS and WMAP3: Implications for the Integrated Sachs-Wolfe effect". It investigates a detection of the ISW effect and correlations which may affect statistical isotropy in the CMB ('Axis of Evil'). Chapter 7 uses the ISW effect to forecast constraints on dark energy parameters and general modifications of general relativity for the next generation of galaxy surveys, particularly the Dark UNiverse Explorer (DUNE) and the Dark Energy Survey (DES). Chapter 8 presents the overall conclusions of this Thesis. Chapter 9 discusses possible extensions to

  9. Implications of Prolonged Solar Minimum Conditions for the Space Debris Population

    NASA Astrophysics Data System (ADS)

    Lewis, Hugh G.; Horbury, Timothy

    2013-08-01

    Observations of the current solar cycle show the likely continuation of a long-term decline in solar activity that began during the 1980s. This decline could lead to conditions similar to the Maunder minimum within 40 years [1], which would have consequences for the space debris environment. Solar activity is a key driver of atmospheric mass density and, subsequently, drag on orbiting spacecraft and debris. Whilst several studies have investigated potential effects on the global climate, no assessment has been made of the impact of a Maunder-like minimum on the space debris population in Low Earth Orbit (LEO). Consequently, we present a new study of the future debris environment under Maunder minimum conditions and provide an assessment of the possible consequences to the LEO space debris population and space operations. The University of Southampton's Debris Analysis and Monitoring Architecture to the Geosynchronous Environment (DAMAGE) has been used to analyse the consequences of a Maunder minimum of approximately 50 years duration and to quantify the impact on the effectiveness of debris mitigation measures. Results from these studies suggest an increase in collision activity and a corresponding, rapid growth of the debris population during a Maunder minimum period, in spite of on-going mitigation efforts. In the best case, the DAMAGE results suggest that the population of debris > 10 cm could double in number by the end of Maunder minimum conditions. However, the rapid growth in the population is followed by a strong recovery period on exit from a Maunder minimum. The recovery is characterised by a decrease in the debris population, which can be to a level similar to that seen before the onset of the Maunder minimum, if mitigation efforts are sustained. As such, prolonged solar minimum conditions may have relatively benign implications for the long-term evolution of the debris environment. However, the risks to spacecraft from collisions with debris during a

  10. 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.

  11. Consolidated fuel reprossing program: The implications of force reflection for teleoperation in space

    NASA Technical Reports Server (NTRS)

    Draper, John V.; Herndon, Joseph N.; Moore, Wendy E.

    1987-01-01

    Previous research on teleoperator force feedback is reviewed and results of a testing program which assessed the impact of force reflection on teleoperator task performance are reported. Force relection is a type of force feedback in which the forces acting on the remote portion of the teleoperator are displayed to the operator by back-driving the master controller. The testing program compared three force reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to tasks components, and variability in forces applied to components during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force relection than they did without it. These data support the hypothesis that force reflection provides useful information for teleoperator users. The earlier literature and the results of the experiment are discussed in terms of their implications for space based teleoperator systems. The discussion described the impact of force reflection on task completion performance and task strategies, as suggested by the literature. It is important to understand the trade-offs involved in using telerobotic systems with and without force reflection.

  12. Scientific Implications of the Modified Observing Strategy of the Fermi Gamma-ray Space Telescope

    NASA Astrophysics Data System (ADS)

    McEnery, Julie E.; Fermi-LAT Collaboration; Fermi-GBM Team

    2014-01-01

    Near the end of 2013 the Fermi Gamma-ray Space Telescope (Fermi) mission plans to change to a modified observing strategy designed to favor the Galactic center while maintaining full sky-survey capabilities. This change would have important implications for the science of the Fermi Large Area Telescope (Fermi-LAT). In particular, this change will 1) substantially increase the Fermi-LAT sensitivity to young pulsars in the inner Galaxy, 2) provide simultaneous observations of the Galactic center with a suite of other instruments that have extended observing campaigns of the expected disruption of the G2 gas cloud complex (see https://wiki.mpe.mpg.de/gascloud/ProposalList) , 3) double the rate of improvement of statistical power for of searches for spectral lines from the Galactic center. In this contribution we discuss these topics. We also investigate ways in which the modified observing strategy can induce systematic biases, and discuss how those biases can be studied and mitigated with studies of control samples of LAT data.

  13. Lower limb kinematics during treadmill walking after space flight: implications for gaze stabilization

    NASA Technical Reports Server (NTRS)

    McDonald, P. V.; Basdogan, C.; Bloomberg, J. J.; Layne, C. S.

    1996-01-01

    We examined the lower limb joint kinematics observed during pre- and postflight treadmill walking performed by seven subjects from three Space Shuttle flights flown between March 1992 and February 1994. Basic temporal characteristics of the gait patterns, such as stride time and duty cycle, showed no significant changes after flight. Evaluation of phaseplane variability across the gait cycle suggests that postflight treadmill walking is more variable than preflight, but the response throughout the course of a cycle is joint dependent and, furthermore, the changes are subject dependent. However, analysis of the phaseplane variability at the specific locomotor events of heel strike and toe off indicated statistically significant postflight increases in knee variability at the moment of heel strike and significantly higher postflight hip joint variability at the moment of toe off. Nevertheless, the observation of component-specific variability was not sufficient to cause a change in the overall lower limb joint system stability, since there was no significant change in an index used to evaluate this at both toe off and heel strike. The implications of the observed lower limb kinematics for head and gaze control during locomotion are discussed in light of a hypothesized change in the energy attenuation capacity of the musculoskeletal system in adapting to weightlessness.

  14. 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.

  15. Gravity Probe B Encapsulated

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is being encapsulated atop the Delta II launch vehicle. The GP-B is the relativity experiment 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  16. HNO/NO Conversion Mechanisms of Cu-Based HNO Probes with Implications for Cu,Zn-SOD

    PubMed Central

    2015-01-01

    HNO has broad biological effects and pharmacological activities. Direct HNO probes for in vivo applications were recently reported, which are CuII-based complexes having fluorescence reporters with reaction to HNO resulting in CuI systems and the release of NO. Their coordination environments are similar to that in Cu,Zn-superoxide dismutase (SOD), which plays a significant role in cellular HNO/NO conversion. However, none of these conversion mechanisms are known. A quantum chemical investigation was performed here to provide structural, energetic, and electronic profiles of HNO/NO conversion pathways via the first CuII-based direct HNO probe. Results not only are consistent with experimental observations but also provide numerous structural and mechanistic details unknown before. Results also suggest the first HNO/NO conversion mechanism for Cu,Zn-SOD, as well as useful guidelines for future design of metal-based HNO probes. These results shall facilitate development of direct HNO probes and studies of HNO/NO conversions via metal complexes and metalloproteins. PMID:24803995

  17. 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.

  18. A model of heat transfer in sapwood and implications for sap flux density measurements using thermal dissipation probes

    SciTech Connect

    Wullschleger, Stan D; Childs, Kenneth W; King, Anthony Wayne; Hanson, Paul J

    2011-01-01

    A variety of thermal approaches are used to estimate sap flux density in stems of woody plants. Models have proven valuable tools for interpreting the behavior of heat pulse, heat balance, and heat field deformation techniques, but have seldom been used to describe heat transfer dynamics for the heat dissipation method. Therefore, to better understand the behavior of heat dissipation probes, a model was developed that takes into account the thermal properties of wood, the physical dimensions and thermal characteristics of the probes, and the conductive and convective heat transfer that occurs due to water flow in the sapwood. Probes were simulated as aluminum tubes 20 mm in length and 2 mm in diameter, whereas sapwood, heartwood, and bark each had a density and water fraction that determined their thermal properties. Base simulations assumed a constant sap flux density with sapwood depth and no wounding or physical disruption of xylem beyond the 2 mm diameter hole drilled for probe installation. Simulations across a range of sap flux densities showed that the dimensionless quantity k defined as ( Tm T)/ T where Tm is the temperature differential ( T) between the heated and unheated probe under zero flow conditions was dependent on the thermal conductivity of the sapwood. The relationship between sap flux density and k was also sensitive to radial gradients in sap flux density and to xylem disruption near the probe. Monte Carlo analysis in which 1000 simulations were conducted while simultaneously varying thermal conductivity and wound diameter revealed that sap flux density and k showed considerable departure from the original calibration equation used with this technique. The departure was greatest for abrupt patterns of radial variation typical of ring-porous species. Depending on the specific combination of thermal conductivity and wound diameter, use of the original calibration equation resulted in an 81% under- to 48% over-estimation of sap flux density at

  19. 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

  20. Interaction of solar wind with Mercury and its magnetic field. [as observed by Mariner 10 space probe

    NASA Technical Reports Server (NTRS)

    Ness, N. F.; Behannon, K. W.; Lepping, R. P.; Whang, Y. C.

    1976-01-01

    A brief review is presented of magnetic field and solar wind electron observations by Mariner 10 spacecraft. The intrinsic magnetic field of the planet Mercury and the implications of such a field for the planetary interior are also discussed.

  1. Radiation Effects on Emerging Technologies: Implications of Space Weather Risk Management

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.; Barth, Janet L.

    2000-01-01

    As NASA and its space partners endeavor to develop a network of satellites capable of supporting humankind's needs for advanced space weather prediction and understanding, one of the key challenges is to design a space system to operate in the natural space radiation environment In this paper, we present a description of the natural space radiation environment, the effects of interest to electronic or photonic systems, and a sample of emerging technologies and their specific issues. We conclude with a discussion of operations in the space radiation hazard and considerations for risk management.

  2. 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

  3. Nitroxidative chemistry interferes with fluorescent probe chemistry: implications for nitric oxide detection using 2,3-diaminonaphthalene.

    PubMed

    Hu, Teh-Min; Chiu, Shih-Jiuan; Hsu, Yu-Ming

    2014-08-22

    Simultaneous production of nitric oxide (NO) and superoxide generates peroxynitrite and causes nitroxidative stress. The fluorometric method for NO detection is based on the formation of a fluorescent product from the reaction of a nonfluorescent probe molecule with NO-derived nitrosating species. Here, we present an example of how nitroxidative chemistry could interact with fluorescent probe chemistry. 2,3-Naphthotriazole (NAT) is the NO-derived fluorescent product of 2,3-diaminonaphthalene (DAN), a commonly used NO-detecting molecule. We show that NO/superoxide cogeneration, and particularly peroxynitrite, mediates the chemical decomposition of NAT. Moreover, the extent of NAT decomposition depends on the relative fluxes of NO and superoxide; the maximum effect being reached at almost equivalent generation rates for both radicals. The rate constant for the reaction of NAT with peroxynitrite was determined to be 2.2×10(3)M(-1)s(-1). Further, various peroxynitrite scavengers were shown to effectively inhibit NO/superoxide- and peroxynitrite-mediated decomposition of NAT. Taken together, the present study suggests that the interference of a fluorometric NO assay can be originated from the interaction between the final fluorescent product and the formed reactive nitrogen and oxygen species. PMID:25078618

  4. 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.

  5. 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.

  6. Effects of target fragmentation on evaluation of LET spectra from space radiations: implications for space radiation protection studies

    NASA Technical Reports Server (NTRS)

    Cucinotta, F. A.; Wilson, J. W.; Shinn, J. L.; Badavi, F. F.; Badhwar, G. D.

    1996-01-01

    We present calculations of linear energy transfer (LET) spectra in low earth orbit from galactic cosmic rays and trapped protons using the HZETRN/BRYNTRN computer code. The emphasis of our calculations is on the analysis of the effects of secondary nuclei produced through target fragmentation in the spacecraft shield or detectors. Recent improvements in the HZETRN/BRYNTRN radiation transport computer code are described. Calculations show that at large values of LET (> 100 keV/micrometer) the LET spectra seen in free space and low earth orbit (LEO) are dominated by target fragments and not the primary nuclei. Although the evaluation of microdosimetric spectra is not considered here, calculations of LET spectra support that the large lineal energy (y) events are dominated by the target fragments. Finally, we discuss the situation for interplanetary exposures to galactic cosmic rays and show that current radiation transport codes predict that in the region of high LET values the LET spectra at significant shield depths (> 10 g/cm2 of Al) is greatly modified by target fragments. These results suggest that studies of track structure and biological response of space radiation should place emphasis on short tracks of medium charge fragments produced in the human body by high energy protons and neutrons.

  7. 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

  8. Fifty years of human space travel: implications for bone and calcium research.

    PubMed

    Smith, S M; Abrams, S A; Davis-Street, J E; Heer, M; O'Brien, K O; Wastney, M E; Zwart, S R

    2014-01-01

    Calcium and bone metabolism remain key concerns for space travelers, and ground-based models of space flight have provided a vast literature to complement the smaller set of reports from flight studies. Increased bone resorption and largely unchanged bone formation result in the loss of calcium and bone mineral during space flight, which alters the endocrine regulation of calcium metabolism. Physical, pharmacologic, and nutritional means have been used to counteract these changes. In 2012, heavy resistance exercise plus good nutritional and vitamin D status were demonstrated to reduce loss of bone mineral density on long-duration International Space Station missions. Uncertainty continues to exist, however, as to whether the bone is as strong after flight as it was before flight and whether nutritional and exercise prescriptions can be optimized during space flight. Findings from these studies not only will help future space explorers but also will broaden our understanding of the regulation of bone and calcium homeostasis on Earth. PMID:24995691

  9. Space Flight Calcium: Implications for Astronaut Health, Spacecraft Operations, and Earth

    PubMed Central

    Smith, Scott M.; McCoy, Torin; Gazda, Daniel; Morgan, Jennifer L. L.; Heer, Martina; Zwart, Sara R.

    2012-01-01

    The space flight environment is known to induce bone loss and, subsequently, calcium loss. The longer the mission, generally the more bone and calcium are lost. This review provides a history of bone and calcium studies related to space flight and highlights issues related to calcium excretion that the space program must consider so that urine can be recycled. It also discusses a novel technique using natural stable isotopes of calcium that will be helpful in the future to determine calcium and bone balance during space flight. PMID:23250146

  10. Space flight calcium: implications for astronaut health, spacecraft operations, and Earth.

    PubMed

    Smith, Scott M; McCoy, Torin; Gazda, Daniel; Morgan, Jennifer L L; Heer, Martina; Zwart, Sara R

    2012-12-01

    The space flight environment is known to induce bone loss and, subsequently, calcium loss. The longer the mission, generally the more bone and calcium are lost. This review provides a history of bone and calcium studies related to space flight and highlights issues related to calcium excretion that the space program must consider so that urine can be recycled. It also discusses a novel technique using natural stable isotopes of calcium that will be helpful in the future to determine calcium and bone balance during space flight. PMID:23250146

  11. Cancer Risk from Exposure to Galactic Cosmic Rays - Implications for Human Space Exploration

    NASA Technical Reports Server (NTRS)

    Cucinotta, Francis A.; Durant, marco

    2006-01-01

    Current space programs are shifting toward planetary exploration, and in particular towards human missions to the moon and Mars. However, space radiation is a major barrier to human exploration of the solar system because the biological effects of high-energy and charge (HZE) ions, which are the main contributors to radiation risks in deep space, are poorly understood. Predictions of the nature and magnitude of the risks posed by space radiation are subject to very large uncertainties. Great efforts have been dedicated worldwide in recent years toward a better understanding of the oncogenic potential of galactic cosmic rays. A review of the new results in this field will be presented here.

  12. 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

  13. 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

  14. Legal and Political Implications of Offensive Actions from and Against the Space Segment

    NASA Astrophysics Data System (ADS)

    de Angelis, Iole M.

    2002-01-01

    Hundreds of satellites now present in space benefit the people of the world economically, scientifically and by their contribution to international security. So far, activities in space have proceeded without much conflict. Means have been found for regulation and agreement to minimize interference in the radio spectrum, while making more efficient use of limited spectrum resources. The Outer Space Treaty bars the stationing of nuclear weapons in space, or other weapons of mass destruction. Nations are responsible for damages that their space activities may cause to others, perhaps including destruction of the space assets of another nation. Today, maintaining the peaceful use of space is becoming more complicated by the privatisation of the notion of security by commercial actors and by the emerging of high technology non-state threats, that are not bind by international treaties. SPACE WEAPONS The Outer Space Treaty had been adopted to avoid the possible denial of peaceful uses of outer space, and because, technically speaking, jeopardizing a satellite was a difficult task to perform. For example, an orbiting laser might take hours or days for the Earth to rotate and the laser to be at an appropriate point in its orbit to threaten a target on the ground or in the air. Conversely, a substantial number of such weapons in space might be able to destroy targets within minutes of the command to do so, if the targets were visible and not below clouds. It is currently very difficult to oppose space weapons. For this reason, they could be significantly effective against an adversary. However, there are several obvious ways to counter nation controlled space-based weapons: anti-satellite systems, economic and technological blockade and an international legal system that forbids/restricts such weapons. The problem remains for non-state international actors which are not bound by international treaties. For this reason, the principle established by the United States to tie

  15. 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.

  16. Exercise Countermeasures for Bone Loss During Space Flight: A Method for the Study of Ground Reaction Forces and Their Implications for Bone Strain

    NASA Technical Reports Server (NTRS)

    Peterman, M.; McCrory, J. L.; Sharkey, N. A.; Piazza, S.; Cavanagh, P. R.

    1999-01-01

    The human zero-gravity locomotion simulator and the cadaver simulator offer a powerful combination for the study of the implications of exercise for maintaining bone quality during space flight. Such studies, when compared with controlled in-flight exercise programs, could help in the identification of a strain threshold for the prevention of bone loss during space flight.

  17. Space Psychology: A New Frontier. Implications for the Profession of Psychology.

    ERIC Educational Resources Information Center

    Ponterotto, Joseph G.; Hayden, Davis C.

    As many of the physical problems of space travel are solved, scientists are beginning to address the psychological needs of the astronauts. While the last decade has produced technological advances making space travel and work a definite possibility, psychologists and the public are largely unaware of the psychological and socio-psychological…

  18. Information Disclosure on MySpace--the What, the Why and the Implications

    ERIC Educational Resources Information Center

    De Souza, Zaineb; Dick, Geoffrey N.

    2008-01-01

    This paper reports the results of the first academic study of the use of a major social networking website, MySpace, by children. The study examined the degree of, and reasons for, information disclosure by children in high schools in Sydney, Australia. Social networking sites such as MySpace are a huge Internet phenomenon, some with hundreds of…

  19. The Space Radiation Environment and Its Implication for Designing Reliable Electronic Systems: A NASA Perspective

    NASA Technical Reports Server (NTRS)

    LaBel, Kenneth A.

    2004-01-01

    The contents include the following: The space radiation environment. The effects on electronics. The environment in action NASA approaches to commercial electronics: flight projects; and proactive research. Living with a star space environment testbed status. Final thoughts: atomic interactions; direct ionization; interaction with nucleus.

  20. Quantitative Aspects of Space Weathering: Implications for Regolith Breccia Meteorites and Asteroids

    NASA Technical Reports Server (NTRS)

    Noble, S. K.; Pieters, C. M.; Keller, L. P.

    2004-01-01

    Space weathering is defined as the physical and optical changes incurred by material exposed to the space environment. Through studies of lunar soils, these changes are becoming well understood. However, the effects of space weathering are dependent on the physical environment to which the host materials are exposed, and thus, the effects will likely vary from body to body. The optical effects of space weathering result from nanophase iron (npFe(sup 0)) created during micrometeorite bombardment and solar wind sputtering. In the asteroid belt, bodies are farther from the sun than our Moon, and are widely known to incur less solar wind implantation and sputtering. The velocity of impacts is smaller resulting in less melting and vaporization, and therefore fewer space weathering products. The impact rate in the asteroid belt is greater, which will result in more comminution, further diluting any weathering products. Ergo, asteroidal regoliths should contain fewer space weathering products than lunar soils. However, even very small degrees of space weathering can have dramatic consequences for the optical properties of soils. A discussion on the optical effects of space weathering is presented.

  1. Creating a "Third Space" in Student Teaching: Implications for the University Supervisor's Status as Outsider

    ERIC Educational Resources Information Center

    Cuenca, Alexander; Schmeichel, Mardi; Butler, Brandon M.; Dinkelman, Todd; Nichols, Joseph R., Jr.

    2011-01-01

    The work of teacher education during student teaching typically takes place in two distinct "spaces": placement sites and college/university settings. The program featured in this article is structured in ways that clearly mark out those two spaces. Yet this configuration led our university supervisors, whose work primarily took place in the…

  2. Fifty years of human space travel: implications for bone and calcium research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Calcium and bone metabolism remain key concerns for space travelers, and ground-based models of space flight have provided a vast literature to complement the smaller set of reports from flight studies. Increased bone resorption and largely unchanged bone formation result in the loss of calcium and ...

  3. A review of adaptive change in musculoskeletal impedance during space flight and associated implications for postflight head movement control

    NASA Technical Reports Server (NTRS)

    McDonald, P. V.; Bloomberg, J. J.; Layne, C. S.

    1997-01-01

    We present a review of converging sources of evidence which suggest that the differences between loading histories experienced in 1-g and weightlessness are sufficient to stimulate adaptation in mechanical impedance of the musculoskeletal system. As a consequence of this adaptive change we argue that we should observe changes in the ability to attenuate force transmission through the musculoskeletal system both during and after space flight. By focusing attention on the relation between human sensorimotor activity and support surfaces, the importance of controlling mechanical energy flow through the musculoskeletal system is demonstrated. The implications of such control are discussed in light of visual-vestibular function in the specific context of head and gaze control during postflight locomotion. Evidence from locomotory biomechanics, visual-vestibular function, ergonomic evaluations of human vibration, and specific investigations of locomotion and head and gaze control after space flight, is considered.

  4. Building a quality culture in the Office of Space Flight: Approach, lessons learned and implications for the future

    NASA Technical Reports Server (NTRS)

    Roberts, C. Shannon

    1992-01-01

    The purpose of this paper is to describe the approach and lessons learned by the Office of Space Flight (OSF), National Aeronautics and Space Administration (NASA), in its introduction of quality. In particular, the experience of OSF Headquarters is discussed as an example of an organization within NASA that is considering both the business and human elements of the change and the opportunities the quality focus presents to improve continuously. It is hoped that the insights shared will be of use to those embarking upon similar cultural changes. The paper is presented in the following parts: the leadership challenge; background; context of the approach to quality; initial steps; current initiatives; lessons learned; and implications for the future.

  5. Building a quality culture in the Office of Space Flight: Approach, lessons learned and implications for the future

    NASA Astrophysics Data System (ADS)

    Roberts, C. Shannon

    The purpose of this paper is to describe the approach and lessons learned by the Office of Space Flight (OSF), National Aeronautics and Space Administration (NASA), in its introduction of quality. In particular, the experience of OSF Headquarters is discussed as an example of an organization within NASA that is considering both the business and human elements of the change and the opportunities the quality focus presents to improve continuously. It is hoped that the insights shared will be of use to those embarking upon similar cultural changes. The paper is presented in the following parts: the leadership challenge; background; context of the approach to quality; initial steps; current initiatives; lessons learned; and implications for the future.

  6. Slab melting in the Aleutians: implications of an ion probe study of clinopyroxene in primitive adakite and basalt

    NASA Astrophysics Data System (ADS)

    Yogodzinski, G. M.; Kelemen, P. B.

    1998-05-01

    An ion probe study of trace elements in Mg-rich clinopyroxene phenocrysts in primitive Aleutian lavas provides constraints on the genesis of Aleutian adakites, and possible insights into the source of common Aleutian magmas. Clinopyroxene (cpx) phenocrysts in the primitive adakites have high Sr and Nd/Yb compared to cpx in Aleutian basalts. In the adakites, Sr and Nd/Yb are highest for high Mg# cpx, and these concentrations decrease toward lower Mg# compositions. These trends are the opposite of those seen in basalt cpx which generally show increasing incompatible trace element contents with decreasing Mg#, and are unlike antithetic compatible-incompatible trace element trends produced by chemical or kinetic effects of crystal growth. Petrographic observations and major and trace element zonation in cpx phenocrysts indicate that primitive Aleutian adakites are in part the product of mixing between primitive and relatively evolved magmas. The adakite trace element signature (high Sr, Nd/Yb) is clearly associated with the primitive mixing end-member. This observation supports the idea that adakites are derived by equilibration of slab melts with mantle olivine, and appears to rule out an origin by melting in the lower crust. Adakites are relatively rare in the Aleutians, but arc-wide correlations between Sr and La/Yb indicates that an adakite-type slab melt component may be present in the magmatic source throughout the arc.

  7. Gravity Probe B Assembled

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is being assembled at the Sunnyvale, California location of the Lockheed Martin Corporation. The GP-B is the relativity experiment 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  8. Detection of GRB 060927 at zeta = 5.47: Implications for the Use of Gamma-Ray Bursts as Probes of the End of the Dark Ages

    NASA Technical Reports Server (NTRS)

    Ruiz-Velasco, A. E.; Swan, H.; Troja, E.; Malesani, D.; Fynbo, J. P. U.; Sterling, R. L. C.; Xu, D.; Aharonian, F.; Akerlof, C.; Andersen, M. I.; Ashley, M. C. B.; Barthelmy, S. D.; Bersier, D.; CastroCeron, J. M.; Castro-Tirado, A. J.; Gehrels, N.; Gogus, E.; Gorosabel, J.; Guidorzi, C.; Guver, T.; Hjorth, J.; Horns, D.; Huang, K. Y.; Jakobsson, P.; Jensen, B. L.

    2007-01-01

    We report on follow-up observations of the gamma-ray burst GRB 060927 using the robotic ROTSE-IIIa telescope and a suite of larger aperture groundbased telescopes. An optical afterglow was detected 20 s after the burst, the earliest rest-frame detection of optical emission from any GRB. Spectroscopy performed with the VLT about 13 hours after the trigger shows a continuum break at lambda approx. equals 8070 A, produced by neutral hydrogen absorption at zeta = 5.6. We also detect an absorption line at 8158 A which we interpret as Si II lambda 1260 at zeta = 5.467. Hence, GRB 060927 is the second most distant GRB with a spectroscopically measured redshift. The shape of the red wing of the spectral break can be fitted by a damped Ly(alpha) profile with a column density with log(N(sub HI)/sq cm) = 22.50 +/- 0.15. We discuss the implications of this work for the use of GRBs as probes of the end of the dark ages and draw three main conclusions: i) GRB afterglows originating from zeta greater than or approx. equal to 6 should be relatively easy to detect from the ground, but rapid near-infrared monitoring is necessary to ensure that they are found; ii) The presence of large H I column densities in some GRBs host galaxies at zeta > 5 makes the use of GRBs to probe the reionization epoch via spectroscopy of the red damping wing challenging; iii) GRBs appear crucial to locate typical star-forming galaxies at zeta > 5 and therefore the type of galaxies responsible for the reionization of the universe.

  9. Global Survey on Future Trends in Human Spaceflight: the Implications for Space Tourism

    NASA Astrophysics Data System (ADS)

    Gurtuna, O.; Garneau, S.

    2002-01-01

    With the much-publicized first ever space tourist flight, of Dennis Tito, and the announcement of the second space tourist flight to take place in April 2002, it is clear that an alternative motivation for human spaceflight has emerged. Human spaceflight is no longer only about meeting the priorities of national governments and space agencies, but is also about the tangible possibility of ordinary people seeing the Earth from a previously exclusive vantage point. It is imperative that major space players look beyond the existing human spaceflight rationale to identify some of the major driving forces behind space tourism, including the evolving market potential and developments in enabling technologies. In order to determine the influence of these forces on the future of commercial human spaceflight, the responses of a Futuraspace survey on future trends in human spaceflight are analyzed and presented. The motivation of this study is to identify sought-after space destinations, explore the expected trends in enabling technologies, and understand the future role of emerging space players. The survey will reflect the opinions of respondents from around the world including North America, Europe (including Russia) and Asia. The profiles of targeted respondents from space industry, government and academia are high-level executives/managers, senior researchers, as well as former and current astronauts. The survey instrument is a questionnaire which is validated by a pilot study. The sampling method is non-probabilistic, targeting as many space experts as possible who fit our intended respondent profile. Descriptive and comparative statistical analysis methods are implemented to investigate both global and regional perceptions of future commercial trends in human spaceflight. This study is not intended to be a formal market study of the potential viability of the space tourism market. Instead, the focus is on the future trends of human spaceflight, by drawing on the

  10. Autonomic neural control and implications for remote medical monitoring in space.

    PubMed

    Cooke, William H

    2007-07-01

    Long-duration space travel or extended stays on the moon or Mars will pose new challenges for maintaining and monitoring the health status of astronauts. Remote medical monitoring systems will need to be developed for a number of applications, including providing decision support for care-givers in the event of traumatic injury in space. The focus of this brief review is to introduce potential methods of monitoring astronaut status remotely from simple ECG recordings. PMID:18372692

  11. Implications of number-space synesthesia on the automaticity of numerical processing

    PubMed Central

    Gertner, Limor; Henik, Avishai; Reznik, Daniel; Cohen Kadosh, Roi

    2013-01-01

    Number-space synesthetes visualize numbers in specific spatial configurations. Their spatial-numerical perceptions are assumed to be automatic in nature and have been found to affect performance in various numerical tasks. The current study tested whether synesthetic number-space associations can modulate the well-established Size Congruency Effect (SiCE), which is considered to be an indication for the automaticity of numerical processing. Two groups, number-space synesthetes and matched controls, were tested on a numerical Stroop task (Henik and Tzelgov, 1982). In separate blocks, participants were presented with two digits and asked to make comparative judgments regarding either numerical values (numerical comparison) or physical size (physical comparison). Both dimensions were manipulated orthogonally, creating three congruency levels: congruent (e.g., 2 7), incongruent (e.g., 2 7) and neutral (e.g., 2 2 and 2 7 for physical and numerical blocks, respectively). For the numerical block, both synesthetes and controls showed the classic SiCE, indicating similar automatic processing of physical magnitude. However, in the physical block, synesthetes showed a lack of automatic numerical magnitude processing when the numbers to be compared were presented incompatibly with their relative position on the synesthetic number-form. This finding strongly suggests that synesthetes’ number-space perceptions affect their ability to automatically process the semantic meaning of numerals. The involvement of space in automatic magnitude processing for number-space synesthetes and non-synesthetes is discussed. PMID:22578710

  12. 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…

  13. Fluid volume control during short-term space flight and implications for human performance.

    PubMed

    Watenpaugh, D E

    2001-09-01

    Space flight exerts substantial effects on fluid volume control in humans. Cardiac distension occurs during the first 1-2 days of space flight relative to supine and especially upright 1g conditions. Plasma volume contraction occurs quickly in microgravity, probably as a result of transcapillary fluid filtration into upper-body interstitial spaces. No natriuresis or diuresis has been observed in microgravity, such that diuresis cannot explain microgravity-induced hypovolemia. Reduction of fluid intake occurs irrespective of space motion sickness and leads to hypovolemia. The fourfold elevation of urinary antidiuretic hormone (ADH) levels on flight day 1 probably results from acceleration exposures and other stresses of launch. Nevertheless, it is fascinating that elevated ADH levels and reduced fluid intake occur simultaneously early in flight. Extracellular fluid volume decreases by 10-15% in microgravity, and intracellular fluid volume appears to increase. Total red blood cell mass decreases by approximately 10% within 1 week in space. Inflight Na(+) and volume excretory responses to saline infusion are approximately half those seen in pre-flight supine conditions. Fluid volume acclimation to microgravity sets the central circulation to homeostatic conditions similar to those found in an upright sitting posture on Earth. Fluid loss in space contributes to reduced exercise performance upon return to 1g, although not necessarily in flight. In-flight exercise training may help prevent microgravity-induced losses of fluid and, therefore, preserve the capacity for upright exercise post-flight. Protection of orthostatic tolerance during space flight probably requires stimulation of orthostatic blood pressure control systems in addition to fluid maintenance or replacement. PMID:11581336

  14. Observations of Radiative Cooling By Nitric Oxide and Carbon Dioxide in the E and F Regions: Implications for Space Weather and Space Climate

    NASA Astrophysics Data System (ADS)

    Mlynczak, M. G.; Hunt, L. A.; Russell, J. M., III

    2014-12-01

    Infrared emission by nitric oxide (NO, 5.3 um), carbon dioxide (CO2, 15 um), and atomic oxygen (O, 63 um) is the mechanism for radiative cooling of the thermosphere. Heat conduction transports energy from the warmer, higher layers of the thermosphere to lower layers where CO2 and NO ultimately radiate the energy. These radiative processes play a large role in governing the neutral temperature of the ionosphere E and F regions. The SABER instrument on the NASA TIMED satellite has been observing radiative cooling by NO and CO2 for 13 years. Substantial variability in the radiative cooling is observed on timescales ranging from one day to the 11-year solar cycle. Harmonics of the annual cycle are evident in the CO2 cooling rates, implying strong coupling to the lower atmosphere. Harmonics of the solar rotation period are evident in the NO cooling, but only during solar minimum conditions. To date the NO cooling data have been helpful in understanding space weather forecasts and the interaction of co-rotating interaction regions with the ionosphere. The cooling rate data will be reviewed in light of their observed variability over the past 13 years, including the implications for variations in the thermal structure of the E and F regions. The potential for development of proxies and empirical models of the NO and CO2 emissions will also be presented. Such models could become part of an overall space weather forecasting tool.

  15. Functional implications of variation in tooth spacing and crown size in pinnipedimorpha (mammalia: carnivora).

    PubMed

    Churchill, Morgan; Clementz, Mark T

    2015-05-01

    Pinnipeds (seals, sea lions, and walruses) show variation in tooth morphology that relates to ecology. However, crown size and spacing are two aspects of morphology that have not been quantified in prior studies. We measured these characters for nearly all extant pinnipeds and three fossil taxa and then determined the principal sources of variation in tooth size and spacing using principal components (PCAs) and hierarchical cluster analysis (HCA). PCA and HCA showed that species sorted into three groups: taxa with small crowns and large diastemata, taxa with large crowns and small diastemata, and taxa that fell between these two extremes. We then performed discriminant function analysis (DFA) to determine if tooth morphology correlated with foraging strategy or diet. DFA results indicated weak correlation with diet, and stronger correlation with prey capture strategies. Tooth size and spacing were most strongly correlated with the importance of teeth in prey acquisition, with tooth size decreasing and tooth spacing increasing as teeth become less necessary in capturing food items. Taxa which relied on teeth for filtering prey from the water column or processing larger or tougher food items generally had larger crowns and smaller tooth spacing then taxa which swallowed prey whole. We found the fossil taxa Desmatophoca and Enaliarctos were most similar in tooth morphology to extant otariids, suggesting that both taxa were generalist feeders. This study established the relationship between tooth size and feeding behavior, and provides a new tool to explore the paleoecology of fossil pinnipeds and other aquatic tetrapods. PMID:25367223

  16. Effects of isolation and confinement on humans-implications for manned space explorations.

    PubMed

    Pagel, J I; Choukèr, A

    2016-06-15

    Human psychology and physiology are significantly altered by isolation and confinement. In light of planned exploration class interplanetary missions, the related adverse effects on the human body need to be explored and defined as they have a large impact on a mission's success. Terrestrial space analogs offer an excellent controlled environment to study some of these stressors during a space mission in isolation without the complex environment of the International Space Station. Participants subjected to these space analog conditions can encounter typical symptoms ranging from neurocognitive changes, fatigue, misaligned circadian rhythm, sleep disorders, altered stress hormone levels, and immune modulatory changes. This review focuses on both the psychological and the physiological responses observed in participants of long-duration spaceflight analog studies, such as Mars500 or Antarctic winter-over. They provide important insight into similarities and differences encountered in each simulated setting. The identification of adverse effects from confinement allows not only the crew to better prepare for but also to design feasible countermeasures that will help support space travelers during exploration class missions in the future. PMID:26846554

  17. 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.

  18. Lessons learned in creating spacecraft computer systems: Implications for using Ada (R) for the space station

    NASA Technical Reports Server (NTRS)

    Tomayko, James E.

    1986-01-01

    Twenty-five years of spacecraft onboard computer development have resulted in a better understanding of the requirements for effective, efficient, and fault tolerant flight computer systems. Lessons from eight flight programs (Gemini, Apollo, Skylab, Shuttle, Mariner, Voyager, and Galileo) and three reserach programs (digital fly-by-wire, STAR, and the Unified Data System) are useful in projecting the computer hardware configuration of the Space Station and the ways in which the Ada programming language will enhance the development of the necessary software. The evolution of hardware technology, fault protection methods, and software architectures used in space flight in order to provide insight into the pending development of such items for the Space Station are reviewed.

  19. Behavioral health in Antarctica: implications for long-duration space missions

    NASA Technical Reports Server (NTRS)

    Lugg, Desmond J.

    2005-01-01

    Ideally, evidence from long-duration spaceflight should be used to predict likely occurrences of behavioral health events and for planning management strategies for such events. With small numbers of space travelers, and limited long-duration missions of a year or more, Earth analogues and simulations must be used as the evidence base, despite such analogues lacking microgravity, radiation, rapidly altering photoperiodicity, and fidelity to space. Antarctic health data are reviewed and an assessment made of the likely frequency of behavioral health events. Based on the Antarctic evidence, the likelihood of behavioral health problems in space is low. However, such cases may be serious and of high consequence, placing considerable demands on the mission crew and ground support to achieve a successful outcome, given the availability of pharmaceuticals and resources.

  20. Effects of Varying Surface Inclines and Suit Pressure: Implications on Space Suit Design

    NASA Technical Reports Server (NTRS)

    Clowers, Kurt; Clark, Timothy; Harvill, Lauren; Morency, Richard; Rajulu, Sudhakar

    2008-01-01

    Suited human performance studies in reduced gravity environments to date include limited observations from Apollo Lunar surface Extravehicular Activities (EVA) and from previous studies conducted in partial gravity simulation environments. The Constellation Program EVA Systems Project office has initiated tests to develop design requirements for the next generation Lunar EVA suit. Theses studies were conducted in the Space Vehicle Mock-Up Facility (SVMF) at Johnson Space Center from which the results provided recommendations for suit weight, mass, center of gravity, pressure, and suit kinematic constraints that optimize human performance in partial gravity environments.

  1. 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.

  2. 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

  3. Response of Silicon-Based Linear Energy Transfer Spectrometers: Implication for Radiation Risk Assessment in Space Flights

    NASA Technical Reports Server (NTRS)

    Badhwar, G. D.; O'Neill, P. M.

    2001-01-01

    There is considerable interest in developing silicon-based telescopes because of their compactness and low power requirements. Three such telescopes have been flown on board the Space Shuttle to measure the linear energy transfer spectra of trapped, galactic cosmic ray, and solar energetic particles. Dosimeters based on single silicon detectors have also been flown on the Mir orbital station. A comparison of the absorbed dose and radiation quality factors calculated from these telescopes with that estimated from measurements made with a tissue equivalent proportional counter show differences which need to be fully understood if these telescopes are to be used for astronaut radiation risk assessments. Instrument performance is complicated by a variety of factors. A Monte Carlo-based technique was developed to model the behavior of both single element detectors in a proton beam, and the performance of a two-element, wide-angle telescope, in the trapped belt proton field inside the Space Shuttle. The technique is based on: (1) radiation transport intranuclear-evaporation model that takes into account the charge and angular distribution of target fragments, (2) Landau-Vavilov distribution of energy deposition allowing for electron escape, (3) true detector geometry of the telescope, (4) coincidence and discriminator settings, (5) spacecraft shielding geometry, and (6) the external space radiation environment, including albedo protons. The value of such detailed modeling and its implications in astronaut risk assessment is addressed. c2001 Elsevier Science B.V. All rights reserved.

  4. Response of silicon-based linear energy transfer spectrometers: implication for radiation risk assessment in space flights.

    PubMed

    Badhwar, G D; O'Neill, P M

    2001-07-11

    There is considerable interest in developing silicon-based telescopes because of their compactness and low power requirements. Three such telescopes have been flown on board the Space Shuttle to measure the linear energy transfer spectra of trapped, galactic cosmic ray, and solar energetic particles. Dosimeters based on single silicon detectors have also been flown on the Mir orbital station. A comparison of the absorbed dose and radiation quality factors calculated from these telescopes with that estimated from measurements made with a tissue equivalent proportional counter show differences which need to be fully understood if these telescopes are to be used for astronaut radiation risk assessments. Instrument performance is complicated by a variety of factors. A Monte Carlo-based technique was developed to model the behavior of both single element detectors in a proton beam, and the performance of a two-element, wide-angle telescope, in the trapped belt proton field inside the Space Shuttle. The technique is based on: (1) radiation transport intranuclear-evaporation model that takes into account the charge and angular distribution of target fragments, (2) Landau-Vavilov distribution of energy deposition allowing for electron escape, (3) true detector geometry of the telescope, (4) coincidence and discriminator settings, (5) spacecraft shielding geometry, and (6) the external space radiation environment, including albedo protons. The value of such detailed modeling and its implications in astronaut risk assessment is addressed. PMID:11858255

  5. Response of silicon-based linear energy transfer spectrometers: implication for radiation risk assessment in space flights

    NASA Astrophysics Data System (ADS)

    Badhwar, G. D.; O'Neill, P. M.

    2001-07-01

    There is considerable interest in developing silicon-based telescopes because of their compactness and low power requirements. Three such telescopes have been flown on board the Space Shuttle to measure the linear energy transfer spectra of trapped, galactic cosmic ray, and solar energetic particles. Dosimeters based on single silicon detectors have also been flown on the Mir orbital station. A comparison of the absorbed dose and radiation quality factors calculated from these telescopes with that estimated from measurements made with a tissue equivalent proportional counter show differences which need to be fully understood if these telescopes are to be used for astronaut radiation risk assessments. Instrument performance is complicated by a variety of factors. A Monte Carlo-based technique was developed to model the behavior of both single element detectors in a proton beam, and the performance of a two-element, wide-angle telescope, in the trapped belt proton field inside the Space Shuttle. The technique is based on: (1) radiation transport intranuclear-evaporation model that takes into account the charge and angular distribution of target fragments, (2) Landau-Vavilov distribution of energy deposition allowing for electron escape, (3) true detector geometry of the telescope, (4) coincidence and discriminator settings, (5) spacecraft shielding geometry, and (6) the external space radiation environment, including albedo protons. The value of such detailed modeling and its implications in astronaut risk assessment is addressed.

  6. 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

  7. A new method of spatial analysis of irregularly spaced HLB data and biological implications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field data on intensity of plant diseases is very often irregularly spaced (i.e., there are varying amounts of distance between rows, ponds, voids, roads, houses, or other land areas). A new method of analysis, sometimes called second-generation wavelet analysis, can be used on this type of irregula...

  8. Implications of Outside-the-Box Technologies on Future Space Exploration and Colonization

    NASA Astrophysics Data System (ADS)

    Loder, Theodore C.

    2003-01-01

    In general, planning for future manned space exploration either to the moon, Mars, or an asteroid has depended on a somewhat linear extrapolation of our present technologies. Two major prohibitive cost issues regarding such planning are payload lift and in-flight energy generation. The costs of these in both engineering and actual flight costs, coupled with the planning necessary to carry out such exploration have prevented us from actively moving forward. Although, it will be worthwhile to continue to plan for such exploration using ``present'' technologies, I recommend that planning be concerned mainly with mission strategies and goals utilizing both present technology and totally new energy breakthroughs. There are presently in research and development an entire suite of relevant outside-the-box technologies which will include both zero point energy generation and antigravity technologies that will replace our present solar/nuclear/fuel cell energy technologies and liquid/solid fuel rockets. This paper describes some of these technologies, the physics behind them and their potential use for manned space exploration. The companies and countries that first incorporate these technologies into their space programs will lead the way in exploring and colonizing space.

  9. Space science to the twenty-first century and the technological implications for implementation

    NASA Technical Reports Server (NTRS)

    Herman, D. H.

    1979-01-01

    The paper presents the specific plan for NASA space science missions to the 21st century and highlights the major technological advances that must be effected to accomplish the planned missions. Separate consideration is given to plans for astrophysics, planetary exploration, the solar terrestrial area, and life sciences. The technological consequences of the plans in these separate areas are discussed.

  10. Physical and Social Organization of Space in a Combined Credential Programme: Implications for Inclusion

    ERIC Educational Resources Information Center

    Young, Kathryn S.

    2008-01-01

    Social geography brings a new perspective to understanding longstanding separation between general and special education in higher education. This paper uses methods from social geography to consider how the structures and processes of space function to maintain longstanding divisions between general and special education in a US teacher education…

  11. Implications of acceleration environments on scaling materials processing in space to production

    NASA Technical Reports Server (NTRS)

    Demel, Ken

    1990-01-01

    Some considerations regarding materials processing in space are covered from a commercial perspective. Key areas include power, proprietary data, operational requirements (including logistics), and also the center of gravity location, and control of that location with respect to materials processing payloads.

  12. 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.

  13. Implications for space radiation environment models from CREAM & CREDO measurements over half a solar cycle.

    PubMed

    Dyer, C S; Truscott, P R; Peerless, C L; Watson, C J; Evans, H E; Knight, P; Cosby, M; Underwood, C; Cousins, T; Noulty, R; Maag, C

    1999-10-01

    Flight data obtained between 1990 and 1997 from the Cosmic Radiation Environment Monitors CREAM & CREDO carried on UoSAT-3, Space Shuttle, STRV-1a (Space Technology Research Vehicle) and APEX (Advanced Photovoltaic and Electronics Experiment Spacecraft) provide coverage over half a solar cycle. The modulation of cosmic rays and evolution of the South Atlantic Anomaly are observed, the former comprising a factor of three increase at high latitudes and the latter a general increase accompanied by a north-westward drift. Comparison of particle fluxes and linear energy transfer (LET) spectra is made with improved environment & radiation transport calculations which account for shield distributions and secondary particles. While there is an encouraging convergence between predictions and observations, significant improvements are still required, particularly in the treatment of locally produced secondary particles. Solar-particle events during this time period have LET spectra significantly below the October 1989 event which has been proposed as a worst case model. PMID:11542668

  14. Portable microwave frequency dissemination in free space and implications on ground-to-satellite synchronization.

    PubMed

    Miao, J; Wang, B; Bai, Y; Yuan, Y B; Gao, C; Wang, L J

    2015-05-01

    Frequency dissemination and synchronization in free space play an important role in global navigation satellite system, radio astronomy, and synthetic aperture radar. In this paper, we demonstrated a portable radio frequency dissemination scheme via free space using microwave antennas. The setup has a good environment adaptability and high dissemination stability. The frequency signal was disseminated at different distances ranging from 10 to 640 m with a fixed 10 Hz locking bandwidth, and the scaling law of dissemination stability on distance and averaging time was discussed. The preliminary extrapolation shows that the dissemination stability may reach 1 × 10(-12)/s in ground-to-satellite synchronization, which far exceeds all present methods, and is worthy for further study. PMID:26026543

  15. Transcriptome analyses of Arabidopsis thaliana seedlings grown in space: implications for gravity-responsive genes.

    PubMed

    Correll, Melanie J; Pyle, Tyler P; Millar, Katherine D L; Sun, Yijun; Yao, Jin; Edelmann, Richard E; Kiss, John Z

    2013-09-01

    The transcriptome of seedlings was analyzed from experiments performed on the International Space Station to study the interacting effects of light and gravity on plant tropisms (project named TROPI-2; Kiss et al. 2012). Seeds of Arabidopsis were germinated in space, and seedlings were then grown in the European Modular Cultivation System for 4 days at ~1g followed by exposure to a range of gravitational accelerations (from microgravity to 1g) and two light treatments (blue light with or without a 1 h pretreatment with red). At the end of the experiments, the cassettes containing the seedlings were frozen in the minus eighty laboratory freezer and returned to Earth on space shuttle mission STS-131. The RNA was extracted from whole seedlings and used for the transcriptome analyses. A comparison of 1g spaceflight samples with 1g ground controls identified 230 genes that were differentially regulated at least twofold, emphasizing the need for "in situ" tissue fixation on a 1g centrifuge as an important control for spaceflight experiments. A further comparison of all spaceflight samples with ground controls identified approximately 280 genes that were differentially regulated at least twofold. Of these genes, several were involved in regulating cell polarity (i.e., auxin, calcium, lipid metabolism), cell-wall development, oxygen status, and cell defense or stress. However, when the transcriptome of the all g-treated spaceflight samples was compared with microgravity samples, only ~130 genes were identified as being differently regulated (P ≤ 0.01). Of this subset, only 27 genes were at least twofold differently regulated between microgravity and 1g space samples and included putative/pseudo/undefined genes (14), transposable elements (5), an expansin (ATEXP24; At1g21240), a cell-wall kinase (WAK3; At1g21240), a laccase-like flavonoid oxidase (TT10; At5g48100), among others. PMID:23771594

  16. Implication of microdosimetry in estimation of radiation quality in space environment

    NASA Technical Reports Server (NTRS)

    Shinn, J. L.; Wilson, J. W.; Singleterry, R. C.; Xapsos, M. A.

    1999-01-01

    Errors introduced using a tissue equivalent proportional counter to estimate radiation quality of an arbitrary ion field as related to space radiations are examined. This is accomplished by using a generalized analytic model to calculate the effect of energy loss straggling, track structure, and pathlength distribution on the microdosimetric distribution. The error can be as large as a factor of two, but no systematic trend could be found.

  17. Measurements of Unexpected Ozone Loss in a Nighttime Space Shuttle Exhaust Plume: Implications for Geo-Engineering Projects

    NASA Astrophysics Data System (ADS)

    Avallone, L. M.; Kalnajs, L. E.; Toohey, D. W.; Ross, M. N.

    2008-12-01

    Measurements of ozone, carbon dioxide and particulate water were made in the nighttime exhaust plume of the Space Shuttle (STS-116) on 9 December 2006 as part of the PUMA/WAVE campaign (Plume Ultrafast Measurements Acquisition/WB-57F Ascent Video Experiment). The launch took place from Kennedy Space Center at 8:47 pm (local time) on a moonless night and the WB-57F aircraft penetrated the shuttle plume approximately 25 minutes after launch in the lowermost stratosphere. Ozone loss is not predicted to occur in a nighttime Space Shuttle plume since it has long been assumed that the main ozone loss mechanism associated with rocket emissions requires solar photolysis to drive several chlorine-based catalytic cycles. However, the nighttime in situ observations show an unexpected loss of ozone of approximately 250 ppb in the evolving exhaust plume, inconsistent with model predictions. We will present the observations of the shuttle exhaust plume composition and the results of photochemical models of the Space Shuttle plume. We will show that models constrained by known rocket emission kinetics, including afterburning, and reasonable plume dispersion rates, based on the CO2 observations, cannot explain the observed ozone loss. We will propose potential explanations for the lack of agreement between models and the observations, and will discuss the implications of these explanations for our understanding of the composition of rocket emissions. We will describe the potential consequences of the observed ozone loss for long-term damage to the stratospheric ozone layer should geo-engineering projects based on rocket launches be employed.

  18. High Voltage Solar Concentrator Experiment with Implications for Future Space Missions

    NASA Technical Reports Server (NTRS)

    Mehdi, Ishaque S.; George, Patrick J.; O'Neill, Mark; Matson, Robert; Brockschmidt, Arthur

    2004-01-01

    This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005 meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the 'direct drive' of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

  19. Voluntary immunomodulation: potentiality and implications for long-duration manned space-flights

    NASA Astrophysics Data System (ADS)

    Geuna, Stefano

    The influence of psychological and neural factors on immunologic activity has been dedicated a growing interest over the past fifteen years, since the publication ofPsychoneuroimmunology by Robert Ader in 1981. Studies on this topic gave evidence for bi-directional communication between psychosocial, behavioural, neuroanatomical and neuroendocrine processes with the immune system and the detrimental effects of various stressors, physical and psychological, on immune reactions were widely investigated with reports of stress-induced changes in immune paramenters and immunocompetence. Much of the evidence support the notion that stress is associated with an increase in those diseases against which the immune system defends. Recently, several studies showed that immune functions can be influenced voluntarily and the term voluntary immunomodulation was coined to describe the use of various hypnosis-like and relaxation/imagery techniques for the self-regulation of immune activity. Alterations in the immune regulatory system are one of the most critical issues to be addressed in relation to crew health management during space missions, especially long-term ones. Providing crewmembers with a tool to enhance immunocompetence might be of great value to defend against some severe diseases, such as cancer and infectious illness, which may be elicited in outer space. In this view, a critical assessment of the potential usefulness of voluntary immunomodulation for crew health maintenance during manned space-flight is presented and discussed.

  20. Adaptive changes of rhythmic EEG oscillations in space implications for brain-machine interface applications.

    PubMed

    Cheron, G; Cebolla, A M; Petieau, M; Bengoetxea, A; Palmero-Soler, E; Leroy, A; Dan, B

    2009-01-01

    The dramatic development of brain machine interfaces has enhanced the use of human brain signals conveying mental action for controlling external actuators. This chapter will outline current evidences that the rhythmic electroencephalographic activity of the brain is sensitive to microgravity environment. Experiments performed in the International Space Station have shown significant changes in the power of the astronauts' alpha and mu oscillations in resting condition, and other adaptive modifications in the beta and gamma frequency range during the immersion in virtual navigation. In this context, the dynamic aspects of the resting or default condition of the awaken brain, the influence of the "top-down" dynamics, and the possibility to use a more constrained configuration by a new somatosensory-evoked potential (gating approach) are discussed in the sense of future uses of brain computing interface in space mission. Although, the state of the art of the noninvasive BCI approach clearly demonstrates their ability and the great expectance in the field of rehabilitation for the restoration of defective communication between the brain and external world, their future application in space mission urgently needs a better understanding of brain neurophysiology, in particular in aspects related to neural network rhythmicity in microgravity. PMID:19607999

  1. 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.

  2. 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.

  3. A modified method for locating parapharyngeal space neoplasms on magnetic resonance images: implications for differential diagnosis

    PubMed Central

    Liu, Xue-Wen; Wang, Ling; Li, Hui; Zhang, Rong; Geng, Zhi-Jun; Wang, De-Ling; Xie, Chuan-Miao

    2014-01-01

    The parapharyngeal space (PPS) is an inverted pyramid-shaped deep space in the head and neck region, and a variety of tumors, such as salivary gland tumors, neurogenic tumors, nasopharyngeal carcinomas with parapharyngeal invasion, and lymphomas, can be found in this space. The differential diagnosis of PPS tumors remains challenging for radiologists. This study aimed to develop and test a modified method for locating PPS tumors on magnetic resonance (MR) images to improve preoperative differential diagnosis. The new protocol divided the PPS into three compartments: a prestyloid compartment, the carotid sheath, and the areas outside the carotid sheath. PPS tumors were located in these compartments according to the displacements of the tensor veli palatini muscle and the styloid process, with or without blood vessel separations and medial pterygoid invasion. This protocol, as well as a more conventional protocol that is based on displacements of the internal carotid artery (ICA), was used to assess MR images captured from a series of 58 PPS tumors. The consequent distributions of PPS tumor locations determined by both methods were compared. Of all 58 tumors, our new method determined that 57 could be assigned to precise PPS compartments. Nearly all (13/14; 93%) tumors that were located in the pre-styloid compartment were salivary gland tumors. All 15 tumors within the carotid sheath were neurogenic tumors. The vast majority (18/20; 90%) of trans-spatial lesions were malignancies. However, according to the ICA-based method, 28 tumors were located in the pre-styloid compartment, and 24 were located in the post-styloid compartment, leaving 6 tumors that were difficult to locate. Lesions located in both the pre-styloid and the post-styloid compartments comprised various types of tumors. Compared with the conventional ICA-based method, our new method can help radiologists to narrow the differential diagnosis of PPS tumors to specific compartments. PMID:25104280

  4. Food predictability determines space use of endangered vultures: implications for management of supplementary feeding.

    PubMed

    López-López, Pascual; García-Ripollés, Clara; Urios, Vicente

    2014-07-01

    Understanding space use of free-living endangered animals is key to informing management decisions for conservation planning. Like most scavengers, vultures have evolved under a context of unpredictability of food resources (i.e., exploiting scattered carcasses that are intermittently available). However, the role of predictable sources of food in shaping spatial ecology of vultures has seldom been studied in detail. Here, we quantify the home range of the Egyptian Vulture (Neophron percnopterus), a long-lived raptor that has experienced severe population decline throughout its range and is qualified as endangered worldwide. To this end, six adults were tracked by satellite telemetry in Spain during the breeding season, from 2007 to 2012, recording 10360 GPS locations. Using Resource Utilization Functions, we assessed the topology of the Utilization Distribution, a three-dimensional measure that shows the probability of finding an animal within the home range. Our results showed how food availability, and principally, how food predictability, determines ranging behavior of this species. Egyptian Vultures showed consistent site fidelity across years, measured as the two- and three-dimensional overlap in their home ranges. Space use varied considerably within the home range and remarkably, places located far from nesting sites were used more frequently than some areas located closer. Therefore, traditional conservation measures based on establishing restrictive rules within a fixed radius around nesting sites could be biologically meaningless if other areas within the home range are not protected too. Finally, our results emphasize the importance of anthropogenic predictable sources of food (mainly vulture restaurants) in shaping the space use of scavengers, which is in agreement with recent findings. Hence, measures aimed at ensuring food availability are essential to preserve this endangered vulture, especially in the present context of limiting carrion dumping in

  5. The Implications of Reduced Ground Reaction Forces During Space Flight for Bone Strains

    NASA Technical Reports Server (NTRS)

    Peterman, Marc M.; Hamel, Andrew J.; Sharkey, Neil A.; Piazza, Stephen J.; Cavanagh, Peter R.

    1998-01-01

    The specific mechanisms regulating bone mass are not known, but most investigators agree that bone maintenance is largely dependent upon mechanical demand and the resultant local bone strains. During space flight, bone loss such as that reported by LeBlanc et al. may result from failure to effectively load the skeleton and generate sufficient localized bone strains. In microgravity, a gravity replacement system can be used to tether an exercising subject to a treadmill. It follows that the ability to prevent bone loss is critically dependent upon the external ground reaction forces (GRFs) and skeletal loads imparted by the tethering system. To our knowledge, the loads during orbital flight have been measured only once (on STS 81). Based on these data and data from ground based experiments, it appears likely that interventions designed to prevent bone loss in micro-gravity generate GRFs substantially less than body weight. It is unknown to what degree reductions in external GRFs will affect internal bone strain and thus the bone maintenance response. To better predict the efficacy of treadmill exercise in micro-gravity we used a unique cadaver model to measure localized bone strains under conditions representative of those that might be produced by a gravity replacement system in space.

  6. Latitudinal variation in spectral properties of the lunar maria and implications for space weathering

    NASA Astrophysics Data System (ADS)

    Hemingway, Douglas J.; Garrick-Bethell, Ian; Kreslavsky, Mikhail A.

    2015-11-01

    Space weathering alters the optical properties of exposed surfaces over time, complicating the interpretation of spectroscopic observations of airless bodies like asteroids, Mercury, and the Moon. Solar wind and micrometeoroids are likely the dominant agents of space weathering, but their relative contributions are not yet well understood. Based primarily on Clementine mosaics, we report a previously unrecognized systematic latitudinal variation in the near-infrared spectral properties of the lunar maria and show that the characteristics of this latitudinal trend match those observed at 'lunar swirls', where magnetic fields alter local solar wind flux without affecting the flux of micrometeoroids. We show that the observed latitudinal color variations are not artifacts of phase angle effects and cannot be accounted for by compositional variation alone. We propose that reduced solar wind flux, which should occur both at swirls and toward higher latitudes, is the common mechanism behind these color variations. This model helps us quantify the distinct effects of solar wind and micrometeoroid weathering and could aid in interpreting the spectra of airless bodies throughout the Solar System.

  7. Implications of the Next Generation Science Standards for Earth and Space Sciences

    NASA Astrophysics Data System (ADS)

    Wysession, M. E.; Colson, M.; Duschl, R. A.; Huff, K.; Lopez, R. E.; Messina, P.; Speranza, P.; Matthews, T.; Childress, J.

    2012-12-01

    The Next Generation Science Standards (NGSS), due to be released in 2013, set a new direction for K-12 science education in America. These standards will put forth significant changes for Earth and space sciences. The NGSS are based upon the recommendations of the National Research Council's 2011 report "A Framework for K-12 Science Education: Practices, Cross-Cutting Concepts, and Core Ideas." The standards are being written by a large group of authors who represent many different constituencies, including 26 participating states, in a process led by Achieve, Inc. The standards encourage innovative ways to teach science at the K-12 level, including enhanced integration between the content, practices, and crosscutting ideas of science and greater assimilation among the sciences and engineering, and among the sciences, mathematics, and English language arts. The NGSS presents a greater emphasis on Earth and space sciences than in previous standards, recommending a year at both the middle and high school levels. The new standards also present a greater emphasis on areas of direct impact between humans and the Earth system, including climate change, natural hazards, resource management, and sustainability.

  8. Fatigue-induced glenohumeral and scapulothoracic kinematic variability: Implications for subacromial space reduction.

    PubMed

    Chopp-Hurley, Jaclyn N; O'Neill, John M; McDonald, Alison C; Maciukiewicz, Jacquelyn M; Dickerson, Clark R

    2016-08-01

    Superior humeral head translation and scapula reorientation can reduce the subacromial space. While these kinematic abnormalities exist in injured populations, the effect of muscle fatigue is unclear. Additionally, these mechanisms were typically studied independently, thereby neglecting potential covariance. This research evaluated the influence of upper extremity muscle fatigue on glenohumeral and scapulothoracic kinematics and defined their relationship. Radiography and motion tracking systems captured these kinematic relationships, during scapula plane elevation, both before and after fatigue. Fatigue-induced changes in humeral head position, scapular orientation and the minimum subacromial space width were measured. High inter-subject variability existed for each measure which precluded identification of mean differences at the population level. However, significant scapular upward rotation occurred following fatigue (p=0.0002). Despite similar population mean results, between 39% and 57% of participants exhibited fatigue-related changes in disadvantageous orientations. Additionally, correlations between measures were generally fair (0.21-0.40) and highly dependent on elevation, likely attributed to the variable fatigue responses. Overall, the data confirms that fatigue-induced changes in kinematics poses highly variable risk of subacromial impingement syndrome across individuals. Thus, solely considering the "average" or mean population response likely underestimates potentially injurious fatigue consequences. PMID:26320811

  9. Estimating the temporal cutoff-rigidity variations and their implication on manned space missions

    NASA Astrophysics Data System (ADS)

    Herbst, K.; Labrenz, J.; Kopp, A.; Heber, B.; Burmeister, S.; Berger, T.

    2014-12-01

    Using the PLANETOCOSMICS code the vertical cutoff rigidity or equivalently the minimum energy a particle must have in order to reach a given location on Earth is calculated. The program allows investigations that depend on the Earth's magnetic field strength and geometry as a function of time. Today it is well known that the magnetic field is the subject of temporal variations on long as well as short time-scales which reflects itself, e.g., in the global vertical cutoff-rigidity distribution at 20 km altitude (see Herbst et al., 2013). Focusing on the changes during the era of manned space missions (1961-2014) we extend our analysis of the vertical cutoff rigidity variations to about 450 km i.e. to the International Space Station (ISS) orbit. The outcome of this analysis will be compared to measurements of the DOSimetry TELescope (DOSTEL), an instrument that has been operational for several time periods onboard the ISS, allowing to determine the response function of the instrument. Using the Force-Field parameter derived from neutron monitors (see Usoskin et al., 2011) we will present maps of DOSTEL measurements for more than 50 years that are caused by galactic cosmic ray variations along hypothetical ISS orbits.

  10. Space Flight and Manual Control: Implications for Sensorimotor Function on Future Missions

    NASA Technical Reports Server (NTRS)

    Reschke, Millard F.; Kornilova, Ludmila; Tomilovskaya, Elena; Parker, Donald E.; Leigh, R. John; Kozlovskaya, Inessa

    2009-01-01

    Control of vehicles, and other complex mechanical motion systems, is a high-level integrative function of the central nervous system (CNS) that requires good visual acuity, eye-hand coordination, spatial (and, in some cases, geographic) orientation perception, and cognitive function. Existing evidence from space flight research (Paloski et.al., 2008, Clement and Reschke 2008, Reschke et al., 2007) demonstrates that the function of each of these systems is altered by removing (and subsequently by reintroducing) a gravitational field that can be sensed by vestibular, proprioceptive, and haptic receptors and used by the CNS for spatial orientation, navigation, and coordination of movements. Furthermore, much of the operational performance data collected as a function of space flight has not been available for independent analysis, and those data that have been reviewed are equivocal owing to uncontrolled environmental and/or engineering factors. Thus, our current understanding, when it comes to manual control, is limited primarily to a review of those situations where manual control has been a factor. One of the simplest approaches to the manual control problem is to review shuttle landing data. See the Figure below for those landing for which we have Shuttle velocities over the runway threshold.

  11. Exo-C: a probe-scale space observatory for direct imaging and spectroscopy of extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

    "Exo-C" is NASAs first community study of a modest aperture space telescope mission that is optimized for high contrast observations of exoplanetary systems. The mission will be capable of taking optical spectra of nearby exoplanets in reflected light, discovering previously undetected planets, and imaging structure in a large sample of circumstellar disks. It will obtain unique science results on planets down to super-Earth sizes and serve as a technology pathfinder toward an eventual flagship-class mission to find and characterize habitable Earth-like exoplanets. We present the mission/payload design and highlight steps to reduce mission cost/risk relative to previous mission concepts. Key elements are an unobscured telescope aperture, an internal coronagraph with deformable mirrors for precise wavefront control, and an orbit and observatory design chosen for high thermal stability. Exo-C has a similar telescope aperture, orbit, lifetime, and spacecraft bus requirements to the highly successful Kepler mission (which is our cost reference). Much of the needed technology development is being pursued under the WFIRST coronagraph study and would support a mission start in 2017, should NASA decide to proceed. This paper summarizes the study final report completed in March 2015.

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

    NASA Technical Reports Server (NTRS)

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

    1980-01-01

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

  13. Probing the Effect of Molecular Nonuniformity in Directed Self-Assembly of Diblock Copolymers in Nanoconfined Space.

    PubMed

    Pitet, Louis M; Alexander-Moonen, Els; Peeters, Emiel; Druzhinina, Tamara S; Wuister, Sander F; Lynd, Nathaniel A; Meijer, E W

    2015-10-27

    Various complex self-assembled morphologies of lamellar- and cylinder-forming block copolymers comprising poly(dimethylsiloxane)-b-polylactide (PDMS-b-PLA) confined in cylindrical channels were generated. Combining top-down lithography with bottom-up block copolymer self-assembly grants access to morphologies that are otherwise inaccessible with the bulk materials. Channel diameter (D) was systematically varied with four diblock copolymers having different compositions and bulk domain spacing (L0), corresponding to a range of frustration ratios (D/L0 from 2 to 4). Excessive packing frustration imposed by the channels leads to contorted domains. The resulting morphologies depend strongly on both D/L0 and copolymer composition. Under several circumstances, mixtures of complex morphologies were observed, which hypothetically arise from the severe sensitivity to D/L0 combined with the inherent compositional/molar mass dispersities associated with the nonuniform synthetic materials and silicon templates. Stochastic calculations offer compelling support for the hypothesis, and tractable pathways toward solving this apparent conundrum are proposed. The materials hold great promise for next-generation nanofabrication to address several emerging technologies, offering significantly enhanced versatility to basic diblock copolymers as templates for fabricating complex nanoscale objects. PMID:26503195

  14. Implication of dc-space-charge-induced velocity spread on gyrotron gun performance

    SciTech Connect

    Liu, C.; Antonsen, T.M. Jr.

    1998-06-01

    The confinement of mirror-trapped electrons under the influence of dc space charge and their effect on the velocity distribution in a magnetron injection gun is investigated theoretically and computationally. Most trapped electrons are found to escape from the gun due to pitch angle scattering by the spatially periodic electrostatic potential created by the forward propagating beam. However, a small portion scatters into orbits which are more deeply trapped and can escape only by striking the modulation anode. As electrons diffuse in velocity, the velocity distribution in the gun region extends toward increasing perpendicular velocity. On the other hand, the accumulation of trapped particles near the cathode induces an additional velocity spread in the main beam. Consequently, the main beam exhibits an increased velocity spread and a reduced transverse momentum when it enters the cavity.

  15. The oxidation state of nanophase Fe particles in lunar soil: Implications for space weathering

    NASA Astrophysics Data System (ADS)

    Thompson, Michelle S.; Zega, Thomas J.; Becerra, Patricio; Keane, James T.; Byrne, Shane

    2016-05-01

    We report measurements of the oxidation state of Fe nanoparticles within lunar soils that experienced varied degrees of space weathering. We measured >100 particles from immature, submature, and mature lunar samples using electron energy-loss spectroscopy (EELS) coupled to an aberration-corrected transmission electron microscope. The EELS measurements show that the nanoparticles are composed of a mixture of Fe0, Fe2+, and Fe3+ oxidation states, and exhibit a trend of increasing oxidation state with higher maturity. We hypothesize that the oxidation is driven by the diffusion of O atoms to the surface of the Fe nanoparticles from the oxygen-rich matrix that surrounds them. The oxidation state of Fe in the nanoparticles has an effect on modeled reflectance properties of lunar soil. These results are relevant to remote sensing data for the Moon and to the remote determination of relative soil maturities for various regions of the lunar surface.

  16. The oxidation state of nanophase Fe particles in lunar soil: Implications for space weathering

    NASA Astrophysics Data System (ADS)

    Thompson, Michelle S.; Zega, Thomas J.; Becerra, Patricio; Keane, James T.; Byrne, Shane

    2016-06-01

    We report measurements of the oxidation state of Fe nanoparticles within lunar soils that experienced varied degrees of space weathering. We measured >100 particles from immature, submature, and mature lunar samples using electron energy-loss spectroscopy (EELS) coupled to an aberration-corrected transmission electron microscope. The EELS measurements show that the nanoparticles are composed of a mixture of Fe0, Fe2+, and Fe3+ oxidation states, and exhibit a trend of increasing oxidation state with higher maturity. We hypothesize that the oxidation is driven by the diffusion of O atoms to the surface of the Fe nanoparticles from the oxygen-rich matrix that surrounds them. The oxidation state of Fe in the nanoparticles has an effect on modeled reflectance properties of lunar soil. These results are relevant to remote sensing data for the Moon and to the remote determination of relative soil maturities for various regions of the lunar surface.

  17. Biological basis for space-variant sensor design II: implications for VLSI sensor design

    NASA Astrophysics Data System (ADS)

    Rojer, Alan S.; Schwartz, Eric L.

    1991-03-01

    We analyze the characteristics of a synthetic sensor comparable with respect to field width and resolution to the primate visual system. We estimate that 150 pixels are sufficient using a logarithmic sensor geometry and demonstrate that this calculation is consistent with known characteristics of biological vision e. g. the number of fibers in the optic nerve. To obtain the field width and resolution of the primate eye with a uniform sensor requires between iOiO'' times the number of pixels estimated for the comparable log sensor. Another interesting observation is that the field width and resolution of a conventional 512x512 sensor can be obtained with around 5000 pixels using the log geometry. We conclude with consideration of the prospects for achieving human-like performance with contemporary VLSI technology and briefly discuss progress on space-variant VLSI sensor design.

  18. Growth of pea epicotyl in low magnetic field implication for space research

    NASA Astrophysics Data System (ADS)

    Negishi, Y.; Hashimoto, A.; Tsushima, M.; Dobrota, C.; Yamashita, M.; Nakamura, T.

    1999-01-01

    A magnetic field is an inescapable environmental factor for plants on the earth. However, its impact on plant growth is not well understood. In order to survey how magnetic fields affect plant, Alaska pea seedlings were incubated under low magnetic field (LMF) and also in the normal geo-magnetic environment. Two-day-old etiolated seedlings were incubated in a magnetic shield box and in a control box. Sedimentation of amyloplasts was examined in the epicotyls of seedlings grown under these two conditions. The elongation of epicotyls was promoted by LMF. Elongation was most prominent in the middle part of the epicotyls. Cell elongation and increased osmotic pressure of cell sap were found in the epidermal cells exposed to LMF. When the gravitational environment was 1G, the epicotyls incubated under both LMF and normal geomagnetic field grew straight upward and amyloplasts sedimented similarly. However, under simulated microgravity (clinostat), epicotyl and cell elongation was promoted. Furthermore, the epicotyls bent and amyloplasts were dispersed in the cells in simulated microgravity. The dispersion of amyloplasts may relate to the posture control in epicotyl growth under simulated microgravity generated by 3D clinorotation, since it was not observed under LMF in 1G. Since enhanced elongation of cells was commonly seen both at LMF and in simulated microgravity, all elongation on the 3D-clinostat could result from pseudo-low magnetic field, as a by-product of clinorotation. (i.e., clinostat results could be based on randomization of magnetic field together with randomization of gravity vector.) Our results point to the possible use of space for studies in magnetic biology. With space experiments, the effects of dominant environmental factors, such as gravity on plants, could be neutralized or controlled for to reveal magnetic effects more clearly.

  19. Tectonic implications of space-time patterns of Cenozoic magmatism in the western United States

    USGS Publications Warehouse

    Snyder, W.S.; Dickinson, W.R.; Silberman, M.L.

    1976-01-01

    Locations of 2,100 radiometrically dated igneous rocks were plotted on a series of 20 maps, each representing an interval within the period 80 m.y. B.P. to present. Derivative maps showing the distributions in space and time of dated granitic intrusive rocks, silicic lavas and domes, ash-flow tuffs, andesitic-dacitic rocks, and basalts depict well the two main petrogenetic assemblages noted previously by others: (1) mainly intermediate andesitic-dacitic suites, including associated granitic intrusive rocks, silicic extrusive rocks, and minor basaltic lavas, are interpreted as reflecting plate interactions related to subduction along the continental margin; and (2) bimodal suites, dominantly basaltic but with minor silicic extrusive rocks, are interpreted as reflecting extensional tectonics. Space-time distribution of the two assemblages suggests that magmatic arcs extended continously parallel to the continental margin from Canada to Mexico in latest Mesozoic and in Oligocene times. An early Cenozoic null in magmatism in the Great Basin may delineate the region where subduction was arrested temporarily by development of the proto-San Andreas fault as a transform in coastal California or, alternatively, may reflect complex subsurface configurations of subducted plates. The late Cenozoic transition from subduction-related magmatism to extention-related basaltic volcanism in the southern Cordillera occurred at different times in different areas in harmony with current concepts about the migration of the Mendocino triple junction as the modern San Andreas transform fault was formed. The plots also reveal the existence of several discrete magmatic loci where igneous activity of various kinds was characteristically more intense and long-lived than elsewhere. ?? 1976.

  20. Variability of HCHO over the Southeastern United States observed from space: Implications for VOC emissions

    NASA Astrophysics Data System (ADS)

    Zhu, L.; Mickley, L. J.; Jacob, D. J.; Cohan, D. S.; Li, Y.; Chen, Y.; Chance, K.

    2012-12-01

    Satellite observations of formaldehyde (HCHO) have been used as proxies for biogenic isoprene emissions, but the observed multiscale variability of HCHO is still not well understood. We use OMI and GOME2 HCHO column densities at 0.5x0.5 degree resolution to investigate both fine-scale and interannual patterns of HCHO variability in the Southeastern United States. By several statistical methods (step-wise variable selection, principle component analysis, least absolute shrinkage and selection operator), we find that temperature is the most important meteorological variable controlling HCHO, with implications for better understanding the variability of isoprene emissions. Both OMI and GOME2 observe a turnover of HCHO at high temperatures (307~310 K), as expected from process models of isoprene emission. Daily GOME2 and OMI HCHO column densities match well (R=0.91, bias = 9%) in 2007-2008, implying that GOME2 data can provide continuity following the degradation of OMI data after 2008. We used the fine-pixel information from OMI to search for HCHO enhancements in urban areas such as Houston that could serve as proxy for anthropogenic VOC emissions. We could find no such enhancements, including in winter. This illustrates the complete dominance of biogenic over anthropogenic VOC emissions in the Southeastern United States. Using the long-term archive of HCHO satellite measurements compiled by de Smedt et al. [GRL, 37, L18808, 2010], we find a significant decline in HCHO column density over the Southeastern United States from 1996 to 2011. Such a trend might be related to changes in ecosystem type or function.

  1. Gravity Probe B Gyroscope Rotor

    NASA Technical Reports Server (NTRS)

    2003-01-01

    The Gravity Probe B (GP-B) is the relativity experiment 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. This photograph is a close up of a niobium-coated gyroscope motor and its housing halves. 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Don Harley.)

  2. Space.

    ERIC Educational Resources Information Center

    Web Feet K-8, 2001

    2001-01-01

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

  3. Stability constraints for oceanic numerical models: implications for the formulation of time and space discretizations

    NASA Astrophysics Data System (ADS)

    Lemarié, F.; Debreu, L.; Madec, G.; Demange, J.; Molines, J. M.; Honnorat, M.

    2015-08-01

    Except for vertical diffusion (and possibly the external mode and bottom drag), oceanic models usually rely on explicit time-stepping algorithms subject to Courant-Friedrichs-Lewy (CFL) stability criteria. Implicit methods could be unconditionally stable, but an algebraic system must be solved at each time step and other considerations such as accuracy and efficiency are less straightforward to achieve. Depending on the target application, the process limiting the maximum allowed time-step is generally different. In this paper, we introduce offline diagnostics to predict stability limits associated with internal gravity waves, advection, diffusion, and rotation. This suite of diagnostics is applied to a set of global, regional and coastal numerical simulations with several horizontal/vertical resolutions and different numerical models. We show that, for resolutions finer that 1/2°, models with an Eulerian vertical coordinate are generally constrained by vertical advection in a few hot spots and that numerics must be extremely robust to changes in Courant number. Based on those results, we review the stability and accuracy of existing numerical kernels in vogue in primitive equations oceanic models with a focus on advective processes and the dynamics of internal waves. We emphasize the additional value of studying the numerical kernel of oceanic models in the light of coupled space-time approaches instead of studying the time schemes independently from spatial discretizations. From this study, we suggest some guidelines for the development of temporal schemes in future generation multi-purpose oceanic models.

  4. Roof of the parapharyngeal space: defining its boundaries and clinical implications.

    PubMed

    Maheshwar, Arcot A; Kim, Eun-Young; Pensak, Myles L; Keller, Jeffrey T

    2004-04-01

    The roof of the parapharyngeal space (PPS) is poorly defined. Although it is generally described as having prestyloid and poststyloid compartments, we believe that these terms are imprecise. Therefore, we define its boundaries, partition, and compartments. We completed macroanatomical and microanatomical dissections in 10 specimens from 5 human cadaver heads; bone measurements in 50 dry skulls; and axial and coronal cross-sectional studies in 2 cadaveric specimens. The PPS roof is bordered laterally by the medial pterygoid fascia and medially by the pharyngobasilar fascia. The tensor veli palatini fascia (TVPF) partitions this roof into an anterolateral compartment containing fat and part of the deep lobe of the parotid gland, and a posteromedial compartment containing the cartilaginous part of the eustachian tube, internal carotid artery, internal jugular vein, and cranial nerves IX through XII. The anteroposterior length measures 32 mm (range, 26.1 to 36.9 mm), and the mediolateral width measures 16.3 mm (range, 12.1 to 21.3 mm). The PPS roof has 3 important bony landmarks (ie, scaphoid fossa, styloid process, sphenoid spine); 3 important fasciae (ie, medial pterygoid fascia, TVPF, pharyngobasilar fascia); and 2 compartments, which are anterolateral and posteromedial to the TVPF. We believe that this is the first report to specifically focus on the roof of the PPS. PMID:15112970

  5. Bone Loss During Space Flights: Implication of the Vestibular System, Sex-Dependence and Countermeasure

    NASA Astrophysics Data System (ADS)

    Vignaux, G.; Besnard, S.; Philoxene, B.; Sabatier, J. P.; Allouche, S.; Denise, P.

    2008-06-01

    The decrease of mechanical load due to microgravity induces bone loss (BL) during long-term space flights. We previously postulated that vestibular system could also be involved in bone modeling. Herein, we evaluated by tomography, long-term (2 months) effects of bilateral vestibular lesion (Bilab) on BL compared to a model of diffuse osteoporosis induced by gonadectomy in male and female rats. BL (about 12%) was observed on femoral metaphysis and femoral metaphysis/diaphysis respectively in male and female Bilab groups compared to shams. Whole body and spine mineralization remained unchanged in Bilab groups while it appeared decreased in gonadectomy groups as expected. BL in Bilab groups was reported at 1 month and recovered at 2 months while it remained decreased at 2 months in our model of diffuse osteoporosis. Risedronate over counterbalanced BL in both models of BL (Bilab and gonadectomy) at 1 and 2 months. Bilateral vestibular lesions on Earth induced regional bone loss focused on bearing bones in male and female at 1 month with unknown compensatory mechanisms 2 months later.

  6. Muscle changes with eccentric exercise: Implications on earth and in space

    NASA Technical Reports Server (NTRS)

    Hargens, Alan R.; Parazynski, Scott; Aratow, Michael; Friden, Jan

    1989-01-01

    Recent investigations of fluid pressure, morpholo gy, and enzyme activities of skeletal muscle exercised eccentrically or concentrically in normal human subjects are reviewed. Intramuscular pressures were measured before, during, and after submaximal exercise and correlated with subjective muscle soreness, fiber size, water content, and blood indices of muscle enzymes. High intensity eccentric exercise is characterized by post exercise pain, elevated intramuscular pressures, and swelling of both type 1 and 2 fibers as compared to concentric exercise. Thus, long periods of unaccustomed, high level eccentric contraction may cause muscle injury, fiber swelling, fluid accumulation, elevated intramuscular pressure, and delayed muscle soreness. Training regimens of progressively increasing eccentric exercise, however, cause less soreness and are extremely efficacious in increasing muscle mass and strength. It is proposed that on Earth, postural muscles are uniquely adapted to low levels of prolonged eccentric contraction that are absent during weightlessness. The almost complete absence of eccentric exercise in space may be an important contributor to muscle atrophy and therefore equipment should be designed to integrate eccentric contractions into exercise protocols for long-term spaceflight.

  7. Instability of ocular torsion in zero gravity - Possible implications for space motion sickness

    NASA Technical Reports Server (NTRS)

    Diamond, Shirley G.; Markham, Charles H.; Money, Ken E.

    1990-01-01

    It is proposed that study of the eye torsion reflex and its behavior under novel gravitational states may possibly provide the basis for a long-sought test to predict space motion sickness (SMS). Measures of eye torsion such as ocular counterrolling and spontaneous eye torsion, were examined during hypo- and hypergravity in parabolic flight on the NASA KC-135 aircraft. Ten subjects, including two astronauts, one who had experienced SMS and one who had not, were ranked according to scores of torsional inability at 0 G and divided into two equal groups of high and low susceptibility to SMS. At 1.8 G the groups were significantly different in both the instability measure and the measure of torsional ability. No differences were detected in eye torsion in either 0 G or 1.8 G and none of the tests were significantly different in 1 G. Results suggest that tests of eye torsion on the KC-135 might differentiate those who would experience SMS from those who would not, although it is noted that this is not yet proven.

  8. Operational implications of a cloud model simulation of space shuttle exhaust clouds in different atmospheric conditions

    NASA Technical Reports Server (NTRS)

    Zak, J. A.

    1989-01-01

    A three-dimensional cloud model was used to characterize the dominant influence of the environment on the Space Shuttle exhaust cloud. The model was modified to accept the actual heat and moisture from rocket exhausts and deluge water as initial conditions. An upper-air sounding determined the ambient atmosphere in which the cloud would grow. The model was validated by comparing simulated clouds with observed clouds from four actual Shuttle launches. Results are discussed with operational weather forecasters in mind. The model successfully produced clouds with dimensions, rise, decay, liquid water contents, and vertical motion fields very similar to observed clouds whose dimensions were calculated from 16 mm film frames. Once validated, the model was used in a number of different atmospheric conditions ranging from very unstable to very stable. Wind shear strongly affected the appearance of both the ground cloud and vertical column cloud. The ambient low-level atmospheric moisture governed the amount of cloud water in model clouds. Some dry atmospheres produced little or no cloud water. An empirical forecast technique for Shuttle cloud rise is presented and differences between natural atmospheric convection and exhaust clouds are discussed.

  9. Xanthophyll Cycle In Chromophyte Algae: Variations Over Different Temporal and Space Scales and Their Ecological Implications.

    NASA Astrophysics Data System (ADS)

    Brunet, C.

    As a response to excess light, algae present photoprotective reactions, resulting in a re- duction of the light harvesting efficiency. One of these reactions involves the so-called xanthophyll-cycle between diadinoxanthin (Dd) and diatoxanthin (Dt) pigments in chlc-containing brown algae, the latter acting as photoprotective avoiding photooxy- dation of LHC. Presence and concentrations of these two xanthophylls are valuable indicators of the light history of algae in the natural environment and can be used to obtain ecological information at different time and space scales. Data are presented from the Mediterranean Sea and the English Channel. At mesoscale, significant rela- tionships between Dt and Dd and physical (light, salinity) or biological (Fv/Fm ratio) data can be drawn, suggesting that they strictly reflect water mass characteristics and behavior. In the Gulf of Naples (Med. Sea), from vertical profiles of photoadaptative index (ratio between Dt and Dd), we can estimate a mixing rate of 0.07 cm.sec-1 in the upper layer. From this velocity, we are able to infer kinetic coefficients for different photophysiological parameters reacting over different time scales within the mixed layer. At the diel scale, this photoadaptative index follows significant oscillations in the upper water column, and equations are found expressing them as function of light and time. Also in this case, mixing rates are estimated, lying around 0.05 cm.sec-1.

  10. Crossmodal visual-tactile extinction: Modulation by posture implicates biased competition in proprioceptively reconstructed space

    PubMed Central

    Kennett, Steffan; Rorden, Chris; Husain, Masud; Driver, Jon

    2010-01-01

    Extinction is a common consequence of unilateral brain injury: contralesional events can be perceived in isolation, yet are missed when presented concurrently with competing events on the ipsilesional side. This can arise crossmodally, where a contralateral touch is extinguished by an ipsilateral visual event. Recent studies showed that repositioning the hands in visible space, or making visual events more distant, can modulate such crossmodal extinction. Here, in a detailed single-case study, we implemented a novel spatial manipulation when assessing crossmodal extinction. This was designed not only to hold somatosensory inputs and hand/arm-posture constant, but also to hold (retinotopic) visual inputs constant, yet while still changing the spatial relationship of tactile and visual events in the external world. Our right hemisphere patient extinguished left-hand touches due to visual stimulation of the right visual field (RVF) when tested in the usual default posture with eyes/head directed straight ahead. But when her eyes/head were turned to the far left (and any visual events shifted along with this), such that the identical RVF retinal stimulation now fell at the same external location as the left-hand touch, crossmodal extinction was eliminated. Since only proprioceptive postural cues could signal this changed spatial relationship for the critical condition, our results show for the first time that such postural cues alone are sufficient to modulate crossmodal extinction. Identical somatosensory and retinal inputs can lead to severe crossmodal extinction, or none, depending on current posture. PMID:19822034

  11. Investigation of outer planet atmospheres using the pioneer entry probe radio system

    NASA Technical Reports Server (NTRS)

    Croft, T. A.

    1974-01-01

    The requirements for a telecommunication link which will relay information from a space probe to a carrier spacecraft during space exploration missions are examined. Specific experiments are described and the relative value of the proposed techniques are evaluated. Radio science methods as related to telecommunications systems are discussed. Operational implications of the various approaches to scientific measurement by telemetry of tracking radios are analyzed. Emphasis is placed on a conceptual description of the physics rather than the mathematical development.

  12. Probing Pre-Protostellar Cores with Formaldehyde

    NASA Astrophysics Data System (ADS)

    Young, K. E.; Lee, J.-E.; Evans, N. J., II; Goldsmith, P. F.; Doty, S. D.

    2004-05-01

    We present maps of the 6 cm and 1.3 mm transitions of H2CO toward three cold, dense pre-protostellar cores: L1498, L1512, and L1544. The 6 cm transition is uniquely suited to probe high density gas at low temperature. Our models indicate that H2CO is depleted in the interiors of PPCs. Depletion significantly affects how H2CO probes the earliest stages of star formation. Multi-stage, self-consistent models, including gas--dust energetics, of both H2CO transitions are presented, and the implications of the results discussed. This work was supported by the National Aeronautics and Space Administration, the National Science Foundation, and the Research Corporation.

  13. Titan Probe navigation analysis

    NASA Technical Reports Server (NTRS)

    Vijayaraghavan, A.; Wood, L. J.

    1986-01-01

    In the proposed Cassini mission, a combined Saturn Orbiter/Titan Probe spacecraft will be launched from the Space Shuttle to arrive at Saturn around 2002, by means of a delta-VEGA trajectory. After Saturn-orbit insertion and a pericrone raise maneuver, the probe will be released to enter the Titan atmosphere and impact onto its surface. During its descent phase and impact onto Titan, the probe will maintain radio contact with the orbiter. Since the Titan-probe experimental phase lasts for only about four hours, probe-orbiter geometry and probe-delivery accuracy are critical to successful completion of this part of the mission. From a preliminary navigation analysis for probe delivery accuracy, it seems feasible to deliver the probe within 50 km (1-sigma value) of the desired aim-point in the Titan B-plane. The covariance study, however, clearly indicates the need for optical data, in addition to radio metric data. A Monte Carlo study indicates that a Delta-V capability of 98 m/sec for trajectory correction maneuvers will be sufficient to cover 99 percent of all contingencies during the segment from Saturn-orbit insertion to Titan-probe release.

  14. Cratering and penetration experiments in aluminum and teflon: Implications for space-exposed surfaces

    NASA Astrophysics Data System (ADS)

    Hörz, Friedrich

    2012-04-01

    Whether a target is penetrated or not during hypervelocity impact depends strongly on typical impactor dimensions (Dp) relative to the absolute target thickness (T). We have therefore conducted impact experiments in aluminum1100 and TeflonFEP targets that systematically varied Dp/T (=D*), ranging from genuine cratering events in thick targets (Dp << T) to the nondisruptive passage of the impactor through very thin films (Dp >> T). The objectives were to (1) delineate the transition from cratering to penetration events, (2) characterize the diameter of the penetration hole (Dh) as a function of D*, and (3) determine the threshold target thickness that yields Dh = Dp. We employed spherical soda-lime glass (SLG) projectiles of Dp = 50-3175 μm at impact velocities (V) from 1 to 7 km s-1, and varied target thicknesses from microns to centimeters. The transition from cratering to penetration processes in thick targets forms a continuum in all morphologic aspects. The entrance side of the target resembles that of a standard crater even when the back of the target suffers substantial, physical perforations via spallation and plastic deformation. We thus suggest that the cratering-to-penetration transition does not occur when the target becomes physically perforated (i.e., at the "ballistic limit"), but when the shock pulse duration in the projectile (tp) is identical to that in the target (tt), i.e., tp = tt. This condition is readily calculated from equation-of-state data. As a consequence, in reconstructing impactor dimensions from observations of space-exposed substrates, we recommend that crater size (Dc) be used for the case of tp < tt, and that penetration hole diameter (Dh) be used when tp > tt. The morphologic evolution of the penetration hole and its size also forms a continuum that strongly depends on both the scaled parameter D* and on V, but it is independent of the absolute scale. The condition of Dh = Dp is approached at D* > 50. The dependence of Dh on T

  15. Atmospheric methane observed from space over the Asian monsoon: implications for emission from Asian rice paddies

    NASA Astrophysics Data System (ADS)

    Hayashida, S.; Yoshizaki, S.; Frankenberg, C.; Yan, X.

    2010-12-01

    More than 40% of anthropogenic emissions of methane, the second most important greenhouse gas, is estimated to be from agricultural sources, including rice cultivation. Unfortunately, the strength of individual sources of methane remains uncertain, despite the importance of its effect in global warming. Here we focus on the Asian monsoon region to improve our understanding of methane emission from rice paddy fields. This region contains about 90% of the world’s rice fields. We analyze the temporal and spatial distribution of atmospheric methane concentrations observed from space and compare it with ground-based measurements and bottom-up emission inventory data coupled with rice field maps. Recently, Frankenberg et al. [2008] derived an updated version of methane concentration from the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY: SCIA hereafter) instrument onboard ENVISAT. This showed a clear signature of methane enhancement over the Asian monsoon. As SCIA retrievals include all involve column densities, we carefully examined potential biases and variability due to the gradient of methane concentration over source regions by comparing these data with ground-based measurements at 53 stations of the WDCGG network. After evaluating the bias and variability of methane concentration over the source regions, we examined selected areas where rice paddies were highly concentrated, and the methane emission inventories were estimated to be large. The sampled areas were North and South India, Bangladesh, Myanmar, Thailand, South China, and the Sichuan Basin. All of these are known to be major rice cultivation areas. The time series of monthly mean SCIA retrievals were compared with the emission inventory data for rice cultivation archived in the GISS dataset and Yan et al. [2009], as well as with precipitation data (Huffman et al., 1997). The phase of seasonal variation of SCIA retrievals corresponded closely to those of emission

  16. The Ethical Implications of Cultural Intervention by Space-faring Civilizations -- What Science Fiction Has to Say

    NASA Astrophysics Data System (ADS)

    Ciupa, M.

    Science fiction (Scifi) plays out the concerns of our possible scientistic futures; it is a source for exploring the deep rooted psychological concerns of mankind with science and the humanities. In this paper it is proposed Scifi is a valid source of hypotheses to examine, not as "evidence", but as candidate ­ often cautionary ­ notions, i.e., scenarios to be studied. Scifi represents a kind of Jungian mythological based story-telling, putting forward tales that express our conscious/unconscious concerns. Thus, when looking into ethical questions like, "where will techno-progressive futures take us?", we import into them these archetypes, hopes and fears, as a result they frequently reappear as familiar tropes. In this respect it is appropriate not to ignore them, but to openly challenge/appreciate them: to see what scenarios are indeed likely and how they may impact us reciprocally. This paper examines some of these aspects, and provides examples of how they are represented in the Scifi genre, in particular with consideration of the ethical implications of cultural intervention by space-faring civilizations. Given the specific analysis/examples provided, it concludes with an ethical scenario analysis (a dialectic argument), within the limiting conditions of the Drake Equation, Fermi Paradox and Cultural History. It comments on the potential existential risk of the Active SETI programmes recently initiated, indeed the need for an ethical exosociological review of all proposed Interstellar projects that express an "Intervention-Propensity".

  17. Considering the Ethical Implications of Space Exploration and Potential Impacts on Planetary Environments and Possible Indigenous Life

    NASA Astrophysics Data System (ADS)

    Race, Margaret

    Since the early days of the Outer Space Treaty, a primary concern of planetary protection policy has been to avoid contamination of planetary environments by terrestrial microbes that could compromise current or subsequent scientific investigations, particularly those searching for indigenous life. Over the past decade robotic missions and astrobiological research have greatly increased our understanding of diverse planetary landscapes and altered our views about the survivability of terrestrial organisms in extreme environments. They have also expanded notions about the prospect for finding evidence of extraterrestrial life. Recently a number of different groups, including the COSPAR Planetary Protection Workshop in Montreal (January 2008), have questioned whether it is advisable to re-examine current biological planetary protection policy in light of the ethical implications and responsibilities to preserve planetary environments and possible indigenous life. This paper discusses the issues and concerns that have led to recent recommendations for convening an international workshop specifically to discuss planetary protection policy and practices within a broader ethical and practical framework, and to consider whether revisions to policy and practices should be made. In addition to including various international scientific and legal organizations and experts in such a workshop, it will be important to find ways to involve the public in these discussions about ethical aspects of planetary exploration.

  18. EMISSION-LINE GALAXIES FROM THE HUBBLE SPACE TELESCOPE PROBING EVOLUTION AND REIONIZATION SPECTROSCOPICALLY (PEARS) GRISM SURVEY. I. THE SOUTH FIELDS

    SciTech Connect

    Straughn, Amber N.; Gardner, Jonathan P.; Pirzkal, Norbert; Grogin, Norman; Panagia, Nino; Meurer, Gerhardt R.; Cohen, Seth H.; Windhorst, Rogier A.; Malhotra, Sangeeta; Rhoads, James; Jansen, Rolf A.; Hathi, Nimish P.; Di Serego Alighieri, Sperello; Gronwall, Caryl; Walsh, Jeremy; Pasquali, Anna; Xu, Chun

    2009-10-15

    We present results of a search for emission-line galaxies (ELGs) in the southern fields of the Hubble Space Telescope Probing Evolution And Reionization Spectroscopically (PEARS) grism survey. The PEARS South Fields consist of five Advanced Camera for Surveys pointings (including the Hubble Ultra Deep Field) with the G800L grism for a total of 120 orbits, revealing thousands of faint object spectra in the GOODS-South region of the sky. ELGs are one subset of objects that are prevalent among the grism spectra. Using a two-dimensional detection and extraction procedure, we find 320 emission lines originating from 226 galaxy 'knots' within 192 individual galaxies. Line identification results in 118 new grism-spectroscopic redshifts for galaxies in the GOODS-South Field. We measure emission-line fluxes using standard Gaussian fitting techniques. At the resolution of the grism data, the H{beta} and [O III] doublet are blended. However, by fitting two Gaussian components to the H{beta} and [O III] features, we find that many of the PEARS ELGs have high [O III]/H{beta} ratios compared to other galaxy samples of comparable luminosities. The star formation rates of the ELGs are presented, as well as a sample of distinct giant star-forming regions at z {approx} 0.1-0.5 across individual galaxies. We find that the radial distances of these H II regions in general reside near the galaxies' optical continuum half-light radii, similar to those of giant H II regions in local galaxies.

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

    SciTech Connect

    Pirzkal, Nor; Rothberg, Barry; Ly, Chun; Grogin, Norman A.; Dahlen, Tomas; Noeske, Kai G.; Bellini, Andrea; Malhotra, Sangeeta; Rhoads, James E.; Cohen, Seth H.; Mechtley, Matthew; Windhorst, Rogier A.; Meurer, Gerhardt R.; Walsh, Jeremy R.; Hathi, Nimish P.; Holwerda, Benne W.; Straughn, Amber N.

    2013-07-20

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

  20. A review of the findings of the plasma diagnostic package and associated laboratory experiments: Implications of large body/plasma interactions for future space technology

    NASA Technical Reports Server (NTRS)

    Murphy, Gerald B.; Lonngren, Karl E.

    1986-01-01

    The discoveries and experiments of the Plasma Diagnostic Package (PDP) on the OSS 1 and Spacelab 2 missions are reviewed, these results are compared with those of other space and laboratory experiments, and the implications for the understanding of large body interactions in a low Earth orbit (LEO) plasma environment are discussed. First a brief review of the PDP investigation, its instrumentation and experiments is presented. Next a summary of PDP results along with a comparison of those results with similar space or laboratory experiments is given. Last of all the implications of these results in terms of understanding fundamental physical processes that take place with large bodies in LEO is discussed and experiments to deal with these vital questions are suggested.

  1. Counts and Sizes of Galaxies in the Hubble Deep Field South: Implications for the Next Generation Space Telescope

    NASA Astrophysics Data System (ADS)

    Gardner, Jonathan P.; Satyapal, Shobita

    2000-06-01

    Science objectives for the Next Generation Space Telescope (NGST) include a large component of galaxy surveys, both imaging and spectroscopy. The Hubble Deep Field data sets include the deepest observations ever made in the ultraviolet, optical, and near-infrared, reaching depths comparable to that expected for NGST spectroscopy. We present the source counts, galaxy sizes, and isophotal filling factors of the Hubble Deep Field South (HDF-S) images. The observed integrated galaxy counts reach over 500 galaxies per square arcminute at magnitudes AB < 30. We extend these counts to fainter levels and further into the infrared using galaxy-count models. It was determined from the HDF (North) and other deep Wide Field Planetary Camera 2 imaging that fainter galaxies are smaller. This trend continues to AB=29 in the high-resolution HDF-S Space Telescope Imaging Spectrograph (STIS) image, where galaxies have a typical half-light radius of 0.1". We have run extensive Monte Carlo simulations of the galaxy detection in the HDF-S, and we show that the small measured sizes are not due to selection effects until AB > 29. We compare observed sizes in the optical and near-infrared using the HDF-S Near Infrared Camera and Multi-Object Spectrometer image, showing that after taking into account the different point-spread functions and pixel sizes of the images, galaxies are smaller in the near-infrared than they are in the optical. We analyze the isophotal filling factor of the HDF-S STIS image and show that this image is mostly empty sky even at the limits of galaxy detection, a conclusion we expect to hold true for NGST spectroscopy. At the surface brightness limits expected for NGST imaging, however, about a quarter of the sky is occupied by the outer isophotes of AB < 30 galaxies, requiring deblending to detect the faintest objects. We discuss the implications of these data on several design concepts for the NGST near-infrared spectrography. We compare the effects of resolution

  2. Noninvariance of Space- and Time-Scale Ranges under a Lorentz Transformation and the Implications for the Study of Relativistic Interactions

    SciTech Connect

    Vay, J.-L.

    2007-03-30

    We present an analysis which shows that the ranges of space and time scales spanned by a system are not invariant under Lorentz transformation. This implies the existence of a frame of reference which minimizes an aggregate measure of the range of space and time scales. Such a frame is derived, for example, for the following cases: free electron laser, laser-plasma accelerator, and particle beams interacting with electron clouds. The implications for experimental, theoretical, and numerical studies are discussed. The most immediate relevance is the reduction by orders of magnitude in computer simulation run times for such system000.

  3. On the non-invariance of space and time scale ranges under Lorentztransformation, and its implications for the study of relativisticinteractions

    SciTech Connect

    Vay, J.-L.

    2007-01-16

    We present an analysis which shows that the ranges of space and time scales spanned by a system are not invariant under the Lorentz transformation. This implies the existence of a frame of reference which minimizes an aggregate measure of the range of space and time scales. Such a frame is derived for example cases: free electron laser, laser-plasma accelerator, and particle beam interacting with electron clouds. Implications for experimental, theoretical and numerical studies are discussed. The most immediate relevance is the reduction by orders of magnitude in computer simulation run times for such systems.

  4. Noninvariance of Space and Time Scale Ranges under a Lorentz Transformation and the Implications for the Numerical Study of Relativistic Systems

    SciTech Connect

    Vay, J.-L.; Vay, J.-L.

    2007-11-12

    We present an analysis which shows that the ranges of space and time scales spanned by a system are not invariant under the Lorentz transformation. This implies the existence of a frame of reference which minimizes an aggregate measure of the range of space and time scales. Such a frame is derived for example cases: free electron laser, laser-plasma accelerator, and particle beam interacting with electron clouds. Implications for experimental, theoretical and numerical studies are discussed. The most immediate relevance is the reduction by orders of magnitude in computer simulation run times for such systems.

  5. Contrasting strike-slip motions on thrust and normal faults: Implications for space-geodetic monitoring of surface deformation

    NASA Astrophysics Data System (ADS)

    Hampel, Andrea; Li, Tao; Maniatis, Georgios

    2013-04-01

    emphasizes that understanding fault-parallel slip components and associated surface displacements is essential for inferring regional deformation patterns from space-geodetic and fault-slip data. References: Cheloni, D., N. D'Agostino, E. D'Anastasio, A. Avallone, S. Mantenuto, R. Giuliani, M. Mattone, S. Calcaterra, P. Gambino, D. Dominici, F. Radicioni, G. Fastellini (2010) Coseismic and initial post-seismic slip of the 2009 Mw 6.3 L'Aquila earthquake, Italy, from GPS measurements: Geophysical Journal International, 181, 1539-1546. Hampel, A., T. Li, G. Maniatis (in press) Contrasting strike-slip motions on thrust and normal faults: Implications for space-geodetic monitoring of surface deformation: Geology. Hsu, Y.-J., S.-B Yu, H.-Y. Chen (2009) Coseismic and postseismic deformation associated with the 2003 Chengkung, Taiwan, earthquake: Geophysical Journal International, 176, 420-430. Jackson, J.A., J. Gagnepain, G. Houseman, G.C.P. King, P. Papadimitriou, C. Soufleris, J. Virieux (1982) Seismicity, normal faulting, and the geomorphological development of the Gulf of Corinth (Greece): The Corinth earthquakes of February and March 1981: Earth and Planetary Science Letters, 57, 377-397. Roberts, G.P., I. Koukouvelas (1996) Structural and seismological segmentation of the Gulf of Corinth fault system: Implications for models of fault growth: Annali di Geofisica, 39, 619-646. Serpelloni, E., L. Anderlini, M.E. Belardinelli (2012) Fault geometry, coseismic-slip distribution and Coulomb stress change associated with the 2009 April 6, Mw 6.3, L'Aquila earthquake from inversion of GPS displacements: Geophysical Journal International, 188, 473-489.

  6. Monitoring Earthquake Fault Slip from Space: Model Implications for a High Precision, High Resolution Dedicated Gravity Mission (Invited)

    NASA Astrophysics Data System (ADS)

    Rundle, J. B.; Sachs, M. K.; Tiampo, K. F.; Fernandez, J.; Turcotte, D. L.; Donnellan, A.; Heien, E. M.; Kellogg, L. H.

    2013-12-01

    Monitoring deformation produced by slip on earthquake faults can be carried out via GPS or InSAR measurements. Both of these types of observations have their advantages and disadvantages, in terms of cost, availability, and technical difficulty. It has been suggested that another method to accomplish many of the same objectives would be via a dedicated gravity mission. The GRACE mission has shown that it is possible to make detailed gravity measurements from space for climate dynamics and other purposes. An important question is what level of accuracy will be needed for precise estimation of fault slip in earthquakes of interest to researchers. To answer this question, we turn to numerical simulations of earthquake fault systems and use these to estimate gravity changes. Rundle (1978) considered the question of gravity changes from dilation sources and thrust faults, and found that gravity changes in these cases were free air anomaly (dilation) and Bouguer anomaly (thrust fault). Walsh and Rice (1978) computed these by a different method and found the same result. Okada (1991) listed gravity and potential Green functions for all possible sources for the general case. Hayes et al (2006) then took the Okada Greens functions and applied them computed from an earlier version of Virtual California earthquake fault system simulations. Those simulations only involved vertical strike slip faults. The current far more advanced generation of Virtual California simulations involves faults of any orientation, dip, and rake. In this talk, we discuss these computations and the implications they have for accuracies needed for a dedicated gravity monitoring mission. Preliminary results are in agreement with previous results from Hayes et al (2006). Computed gravity changes are in the range of tens to hundreds of microgals over distances of few to many tens of kilometers. These values are presumably well within the range of measurement for a modern gravity mission flown either at

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

    NASA Technical Reports Server (NTRS)

    1974-01-01

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

  8. RECONSTRUCTING CORONAL MASS EJECTIONS WITH COORDINATED IMAGING AND IN SITU OBSERVATIONS: GLOBAL STRUCTURE, KINEMATICS, AND IMPLICATIONS FOR SPACE WEATHER FORECASTING

    SciTech Connect

    Liu Ying; Luhmann, Janet G.; Lin, Robert P.; Bale, Stuart D.; Thernisien, Arnaud; Vourlidas, Angelos; Davies, Jackie A.

    2010-10-20

    We reconstruct the global structure and kinematics of coronal mass ejections (CMEs) using coordinated imaging and in situ observations from multiple vantage points. A forward modeling technique, which assumes a rope-like morphology for CMEs, is used to determine the global structure (including orientation and propagation direction) from coronagraph observations. We reconstruct the corresponding structure from in situ measurements at 1 AU with the Grad-Shafranov method, which gives the flux-rope orientation, cross section, and a rough knowledge of the propagation direction. CME kinematics (propagation direction and radial distance) during the transit from the Sun to 1 AU are studied with a geometric triangulation technique, which provides an unambiguous association between solar observations and in situ signatures; a track fitting approach is invoked when data are available from only one spacecraft. We show how the results obtained from imaging and in situ data can be compared by applying these methods to the 2007 November 14-16 and 2008 December 12 CMEs. This merged imaging and in situ study shows important consequences and implications for CME research as well as space weather forecasting: (1) CME propagation directions can be determined to a relatively good precision as shown by the consistency between different methods; (2) the geometric triangulation technique shows a promising capability to link solar observations with corresponding in situ signatures at 1 AU and to predict CME arrival at the Earth; (3) the flux rope within CMEs, which has the most hazardous southward magnetic field, cannot be imaged at large distances due to expansion; (4) the flux-rope orientation derived from in situ measurements at 1 AU may have a large deviation from that determined by coronagraph image modeling; and (5) we find, for the first time, that CMEs undergo a westward migration with respect to the Sun-Earth line at their acceleration phase, which we suggest is a universal

  9. Floating Potential Probe Langmuir Probe Data Reduction Results

    NASA Technical Reports Server (NTRS)

    Morton, Thomas L.; Minow, Joseph I.

    2002-01-01

    During its first five months of operations, the Langmuir Probe on the Floating Potential Probe (FPP) obtained data on ionospheric electron densities and temperatures in the ISS orbit. In this paper, the algorithms for data reduction are presented, and comparisons are made of FPP data with ground-based ionosonde and Incoherent Scattering Radar (ISR) results. Implications for ISS operations are detailed, and the need for a permanent FPP on ISS is examined.

  10. Molecular cytogenetic analysis of Inv Dup(15) chromosomes, using probes specific for the Pradar-Willi/Angelman syndrome region: Clinical implications

    SciTech Connect

    Leana-Cox, J. ); Jenkins, L. ); Palmer, C.G.; Plattner, R. ); Sheppard, L. ); Flejter, W.L. ); Zackowski, J. ); Tsien, F. ); Schwartz, S. )

    1994-05-01

    Twenty-seven cases of inverted duplications of chromosome 15 (inv dup[15]) were investigated by FISH with two DNA probes specific for the Prader-Willi syndrome/Angelman syndrome (PWS/AS) region on proximal 15q. Sixteen of the marker chromosomes displayed two copies of each probe, while in the remaining 11 markers no hybridization was observed. A significant association was found between the presence of this region and an abnormal phenotype (P<.01). This is the largest study to date of inv dup(15) chromosomes, that uses molecular cytogenetic methods and is the first to report a significant association between the presence of a specific chromosomal region in such markers and an abnormal phenotype. 30 refs., 1 fig., 4 tabs.

  11. Gravity Probe B Completed With Solar Arrays

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In this photo, the Gravity Probe B (GP-B) space vehicle is completed during the solar array installation. The GP-B is the relativity experiment 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. GP-B is scheduled for launch in April 2004 and managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation).

  12. Mapping social values for urban green spaces using Public Participation GIS: the influence of spatial scale and implications for landscape planning.

    NASA Astrophysics Data System (ADS)

    Ives, Christopher

    2015-04-01

    Measuring social values for landscapes is an emerging field of research and is critical to the successful management of urban ecosystems. Green open space planning has traditionally relied on rigid standards and metrics without considering the physical requirements of green spaces that are valued for different reasons and by different people. Relating social landscape values to key environmental variables provides a much stronger evidence base for planning landscapes that are both socially desirable and environmentally sustainable. This study spatially quantified residents' values for green space in the Lower Hunter Valley of New South Wales, Australia by enabling participants to mark their values for specific open spaces on interactive paper maps. The survey instrument was designed to evaluate the effect of spatial scale by providing maps of residents' local area at both suburb and municipality scales. The importance of open space values differed depending on whether they were indicated via marker dots or reported on in a general aspatial sense. This suggests that certain open space functions were inadequately provided for in the local area (specifically, cultural significance and health/therapeutic value). Additionally, all value types recorded a greater abundance of marker dots at the finer (suburb) scale compared to the coarser (municipality) scale, but this pattern was more pronounced for some values than others (e.g. physical exercise value). Finally, significant relationships were observed between the abundance of value marker dots in parks and their environmental characteristics (e.g. percentage of vegetation). These results have interesting implications when considering the compatibility between different functions of green spaces and how planners can incorporate information about social values with more traditional approaches to green space planning.

  13. Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 2

    NASA Technical Reports Server (NTRS)

    Collette, J. G. R.

    1991-01-01

    A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering and Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Additional information is given in tabular form.

  14. Results of the space shuttle vehicle ascent air data system probe calibration test using a 0.07-scale external tank forebody model (68T) in the AEDC 16-foot transonic wind tunnel (IA-310), volume 1

    NASA Technical Reports Server (NTRS)

    Collette, J. G. R.

    1991-01-01

    A recalibration of the Space Shuttle Vehicle Ascent Air Data System probe was conducted in the Arnold Engineering Development Center (AEDC) transonic wind tunnel. The purpose was to improve on the accuracy of the previous calibration in order to reduce the existing uncertainties in the system. A probe tip attached to a 0.07-scale External Tank Forebody model was tested at angles of attack of -8 to +4 degrees and sideslip angles of -4 to +4 degrees. High precision instrumentation was used to acquire pressure data at discrete Mach numbers ranging from 0.6 to 1.55. Pressure coefficient uncertainties were estimated at less than 0.0020. Data is given in graphical and tabular form.

  15. Mingling, observing, and lingering: everyday public spaces and their implications for well-being and social relations.

    PubMed

    Cattell, Vicky; Dines, Nick; Gesler, Wil; Curtis, Sarah

    2008-09-01

    The rejuvenation of public spaces is a key policy concern in the UK. Drawing on a wide literature and on qualitative research located in a multi-ethnic area of East London, this paper explores their relationship to well-being and social relations. It demonstrates that ordinary spaces are a significant resource for both individuals and communities. The beneficial properties of public spaces are not reducible to natural or aesthetic criteria, however. Social interaction in spaces can provide relief from daily routines, sustenance for people's sense of community, opportunities for sustaining bonding ties or making bridges, and can influence tolerance and raise people's spirits. They also possess subjective meanings that accumulate over time and can contribute to meeting diverse needs. Different users of public spaces attain a sense of well- being for different reasons: the paper calls for policy approaches in which the social and therapeutic properties of a range of everyday spaces are more widely recognised and nurtured. PMID:18083621

  16. Reflections on Electric Probes

    NASA Astrophysics Data System (ADS)

    Braithwaite, Nicholas

    2007-10-01

    One of the more immediate temptations for an experimental plasma physicist is to insert some kind of refractory, conducting material into a plasma, as a simple means of probing its charge composition. Irvine Langmuir tried it in the 1920s and was one of the first to develop an electrical probe method in his early work on electrical discharge plasmas. There are now numerous variations on the theme including planar, cylindrical and spherical geometry with single, double and triple probes. There are also probes that resonate, propagate and reciprocate. Some probes are electrostatic and others are electromagnetic; some are effectively wireless; most absorb but some emit. All types can be used in steady and transient plasmas, while special schemes have been devised for RF plasmas, using passive and active compensation. Magnetised plasmas pose further challenges. Each configuration is accompanied by assumptions that constrain both their applicability and the analytical methods that translate the measured currents and voltages variously into charge densities, space potentials, particle fluxes, energy distributions and measures of collisionality. This talk will take a broad look at the options and opportunities for electric probes, principally in the environment of non-equilibrium plasma.

  17. Public opinion and interest group positions on open-space issues in Albuquerque, New Mexico, USA: Implications for resource management

    NASA Astrophysics Data System (ADS)

    Tannery, Thomas Allan

    1987-07-01

    The purpose of this research was to elicit and compare the open-space preferences of citizens and openspace experts in Albuquerque, New Mexico, USA. A randomly selected sample of 492 citizens and 35 open-space experts participated in a telephone survey during May 5 18, 1986. The following hypothesis was tested and used as a guideline for the study: HO1: There is no significant difference between respondents' status and preference for open space in Albuquerque, New Mexico. The hypothesis was rejected. Findings confirmed respondents' status affected preference for open space. Of the eight issues on which the citizen and expert groups were compared, five recorded significant differences in response profiles. The open-space expert group was significantly more supportive of using open space to accommodate offroad vehicle facilities, wildlife preserves, a citywide recreational trail, and a trail system along the arroyos and city ditches. The citizen sample was significantly more supportive of using open space to accommodate overnight camping facilities. Both groups equally supported using open space to accommodate an outdoor amphitheater, outdoor education facilities, and rafting, kayaking, and canoeing facilities. The finding indicated that expert preferences did not represent an aggregate of citizen preferences for managing open-space resources. Understanding both expert and citizen positions will facilitate decision-making processes and help resolve environmental disputes.

  18. Solar and Space Physics PhD Production and Job Availability: Implications for the Future of the Space Weather Research Workforce

    NASA Astrophysics Data System (ADS)

    Moldwin, M.; Morrow, C. A.; Moldwin, L. A.; Torrence, J.

    2012-12-01

    To assess the state-of-health of the field of Solar and Space Physics an analysis of the number of Ph.D.s produced and number of Job Postings each year was done for the decade 2001-2010. To determine the number of Ph.D's produced in the field, the University of Michigan Ph.D. Dissertation Archive (Proquest) was queried for Solar and Space Physics dissertations produced in North America. The field generated about 30 Ph.D. per year from 2001 to 2006, but then saw the number increase to 50 to 70 per year for the rest of the decade. Only 14 institutions account for the majority of Solar and Space Physics PhDs. To estimate the number of jobs available each year in the field, a compilation of the job advertisements listed in the American Astronomical Society's Solar Physics Division (SPD) and the American Geophysical Union's Space Physics and Aeronomy (SPA) electronic newsletters was done. The positions were sorted into four types (Faculty, Post-doctoral Researcher, and Scientist/Researcher or Staff), institution type (academic, government lab, or industry) and if the position was located inside or outside the United States. Overall worldwide, 943 Solar and Space Physics positions were advertised over the decade. Of this total, 52% were for positions outside the US. Within Solar Physics, 44% of the positions were in the US, while in Space Physics 57% of the positions were for US institutions. The annual average for positions in the US were 26.9 for Solar Physics and 31.5 for Space Physics though there is much variability year-to-year particularly in Solar Physics positions outside the US. A disconcerting trend is a decline in job advertisements in the last two years for Solar Physics positions and between 2009 and 2010 for Space Physics positions. For both communities within the US in 2010, the total job ads reached their lowest levels in the decade (14), approximately half the decadal average number of job advertisements.

  19. English Vocabulary Learning with Word Lists, Word Cards and Computers: Implications from Cognitive Psychology Research for Optimal Spaced Learning

    ERIC Educational Resources Information Center

    Nakata, Tatsuya

    2008-01-01

    The spacing effect is known to be one of the most robust phenomena in experimental psychology, and many attempts have been made to realize effective spaced learning for L2 vocabulary learning. This study compares vocabulary learning with word lists, word cards, and computers in order to identify which material leads to the most superior spaced…

  20. Auroral Spatial Structures Probe Sub-Orbital Mission Preliminary Results

    NASA Astrophysics Data System (ADS)

    Pratt, J.; Swenson, C.; Martineau, R. J.; Fish, C. S.; Conde, M.; Hampton, D.; Crowley, G.

    2015-12-01

    The NASA Auroral Spatial Structures Probe, 49.002, was launched January 28, 2015 from the Poker Flat Research Range into active aurora over the northern coast of Alaska. The primary objective of this mission was to determine the contribution of small spatial and temporal scale fluctuations of the electric fields to the larger-scale energy deposition processes associated with the aurora. The Auroral Spatial Structures Probe Sub-Orbital Mission consisted of a formation of 7 spacecraft (a main payload with 6 deployable sub-payloads) designed for multiple temporally spaced co-located measurements of electric and magnetic fields in the earth's ionosphere. The mission was able to make observations at a short time scale and small spatial scale convergence that is unobservable by either satellite or ground-based observations. The payloads included magnetometers, electric field double probes, and Langmuir probes as well as a sweeping impedance probe on the main payload. We present here preliminary results from the measurements taken that hint at the underlying spatial structure of the currents and energy deposition in the aurora. The Poynting flux derived from the observations is shown and implications are discussed in terms of the contribution of small spatial scale, rapid temporal scale fluctuations in the currents that deposit energy in the auroral region. Funding provided by NASA Grants NNX11AE23G and NNX13AN20A.

  1. The High School "Space Race": Implications of a School-Choice Market Environment for a Michigan Metropolitan Region

    ERIC Educational Resources Information Center

    Militello, Matthew; Metzger, Scott Alan; Bowers, Alex J.

    2008-01-01

    This article examines the implications of competition between school districts in a mid-Michigan metropolitan area. Over the 10-year period after Michigan's major school-funding reform in 1994, many urban and suburban districts found themselves competing for per-pupil state funding. Suburban districts need extra students to make up budgetary…

  2. Optical probe

    DOEpatents

    Hencken, Kenneth; Flower, William L.

    1999-01-01

    A compact optical probe is disclosed particularly useful for analysis of emissions in industrial environments. The instant invention provides a geometry for optically-based measurements that allows all optical components (source, detector, rely optics, etc.) to be located in proximity to one another. The geometry of the probe disclosed herein provides a means for making optical measurements in environments where it is difficult and/or expensive to gain access to the vicinity of a flow stream to be measured. Significantly, the lens geometry of the optical probe allows the analysis location within a flow stream being monitored to be moved while maintaining optical alignment of all components even when the optical probe is focused on a plurality of different analysis points within the flow stream.

  3. Space Weathering of Ordinary Chondrite Parent Bodies, Its Impact on the Method of Distinguishing H, L, and LL Types and Implications for Itokawa Samples Returned by the Hayabusa Mission

    NASA Technical Reports Server (NTRS)

    Hiroi, T.; Sasaki, S.; Noble, S. K.; Pieters, C. M.

    2011-01-01

    As the most abundance meteorites in our collections, ordinary chondrites potentially have very important implications on the origin and formation of our Solar System. In order to map the distribution of ordinary chondrite-like asteroids through remote sensing, the space weathering effects of ordinary chondrite parent bodies must be addressed through experiments and modeling. Of particular importance is the impact on distinguishing different types (H/L/LL) of ordinary chondrites. In addition, samples of asteroid Itokawa returned by the Hayabusa spacecraft may re veal the mechanism of space weathering on an LLchondrite parent body. Results of space weathering simulations on ordinary chondrites and implications for Itokawa samples are presented here.

  4. Changes in the central nervous system during long-duration space flight: implications for neuro-imaging

    NASA Astrophysics Data System (ADS)

    Newberg, A. B.; Alavi, A.

    The purpose of this paper is to review the potential functional and morphological effects of long duration space flight on the human central nervous system (CNS) and how current neuroimaging techniques may be utilized to study these effects. It must be determined if there will be any detrimental changes to the CNS from long term exposure to the space environment if human beings are to plan interplanetary missions or establish permanent space habitats. Research to date has focused primarily on the short term changes in the CNS as the result of space flight. The space environment has many factors such as weightlessness, electromagnetic fields, and radiation, that may impact upon the function and structure of the CNS. CNS changes known to occur during and after long term space flight include neurovestibular disturbances, cephalic fluid shifts, alterations in sensory perception, changes in proprioception, psychological disturbances, and cognitive changes. Animal studies have shown altered plasticity of the neural cytoarchitecture, decreased neuronal metabolism in the hypothalamus, and changes in neurotransmitter concentrations. Recent progress in the ability to study brain morphology, cerebral metabolism, and neurochemistry in vivo in the human brain would provide ample opportunity to investigate many of the changes that occur in the CNS as a result of space flight. These methods include positron emission tomography (PET), single photon emission computed tomography (SPECT), and magnetic resonance imaging (MRI).

  5. Multispectral imaging probe

    SciTech Connect

    Sandison, David R.; Platzbecker, Mark R.; Descour, Michael R.; Armour, David L.; Craig, Marcus J.; Richards-Kortum, Rebecca

    1999-01-01

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

  6. Multispectral imaging probe

    DOEpatents

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

    1999-07-27

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

  7. Charged Kaon interferometric probes of space-time evolution in Au+Au collisions at sqrt[S(NN)]=200 GeV.

    PubMed

    Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Al-Jamel, A; Aoki, K; Aphecetche, L; Armendariz, R; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bauer, F; Bazilevsky, A; Belikov, S; Bennett, R; Berdnikov, Y; Bjorndal, M T; Boissevain, J G; Borel, H; Boyle, K; Brooks, M L; Brown, D S; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chernichenko, S; Chiba, J; Chi, C Y; Chiu, M; Choi, I J; Chujo, T; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Constantin, P; Csanád, M; Csörgo, T; Dahms, T; Das, K; David, G; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Fields, D E; Fleuret, F; Fokin, S L; Forestier, B; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fukao, Y; Fung, S-Y; Gadrat, S; Gastineau, F; Germain, M; Glenn, A; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-A; Hachiya, T; Hadj Henni, A; Haggerty, J S; Hagiwara, M N; Hamagaki, H; Harada, H; Hartouni, E P; Haruna, K; Harvey, M; Haslum, E; Hasuko, K; Hayano, R; Heffner, M; Hemmick, T K; Heuser, J M; He, X; Hiejima, H; Hill, J C; Hobbs, R; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hur, M G; Ichihara, T; Imai, K; Inaba, M; Isenhower, D; Isenhower, L; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Jacak, B V; Jia, J; Jin, J; Jinnouchi, O; Johnson, B M; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kaneta, M; Kang, J H; Kawagishi, T; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lebedev, A; Le Bornec, Y; Leckey, S; Lee, D M; Lee, M K; Leitch, M J; Leite, M A L; Lim, H; Litvinenko, A; Liu, M X; Li, X H; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Masui, H; Matathias, F; McCain, M C; McGaughey, P L; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mitchell, J T; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; Murata, J; Nagamiya, S; Nagata, Y; Nagle, J L; Naglis, M; Nakamura, T; Newby, J; Nguyen, M; Norman, B E; Nouicer, R; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, H; Okada, K; Omiwade, O O; Oskarsson, A; Otterlund, I; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Rykov, V L; Ryu, S S; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, S; Samsonov, V; Sato, H D; Sato, S; Sawada, S; Semenov, V; Seto, R; Sharma, D; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shohjoh, T; Shoji, K; Sickles, A; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Skutnik, S; Smith, W C; Soldatov, A; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Staley, F; Stankus, P W; Stenlund, E; Stepanov, M; Ster, A; Stoll, S P; Sugitate, T; Suire, C; Sullivan, J P; Sziklai, J; Tabaru, T; Takagi, S; Takagui, E M; Taketani, A; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Taranenko, A; Tarján, P; Thomas, T L; Togawa, M; Tojo, J; Torii, H; Towell, R S; Tram, V-N; Tserruya, I; Tsuchimoto, Y; Tuli, S K; Tydesjö, H; Tyurin, N; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vértesi, R; Vinogradov, A A; Vznuzdaev, E; Wagner, M; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; Woody, C L; Wysocki, M; Xie, W; Yanovich, A; Yokkaichi, S; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zaudtke, O; Zhang, C; Zimányi, J; Zolin, L

    2009-10-01

    Bose-Einstein correlations of charged kaons are used to probe Au+Au collisions at sqrt[S(NN)]=200 GeV and are compared to charged pion probes, which have a larger hadronic scattering cross section. Three-dimensional Gaussian source radii are extracted, along with a one-dimensional kaon emission source function. The centrality dependences of the three Gaussian radii are well described by a single linear function of N(part)1/3 with a zero intercept. Imaging analysis shows a deviation from a Gaussian tail at r greater than or approximately equal to 10 fm, although the bulk emission at lower radius is well described by a Gaussian. The presence of a non-Gaussian tail in the kaon source reaffirms that the particle emission region in a heavy-ion collision is extended, and that similar measurements with pions are not solely due to the decay of long-lived resonances. PMID:19905563

  8. Near-Field Photothermal Heating with a Plasmonic Nanofocusing Probe

    NASA Astrophysics Data System (ADS)

    Chen, Xiang; Dong, Biqing; Balogun, Oluwaseyi

    2016-03-01

    Noble metal nanostructures support plasmon resonances—collective oscillation of charge carriers at optical frequencies—and serve as effective tools to create bright light sources at the nanoscale. These sources are useful in broad application areas including, super-resolution imaging and spectroscopy, nanolithography, and near-field optomechanical transducers. The feasibility of these applications relies on efficient conversion of free-space propagating light to plasmons. Recently, we demonstrated a hybrid nanofocusing scheme for efficient coupling of light to plasmons at the apex of a scanning probe. In the approach, free-space light is coupled to propagating surface plasmon polaritons (SPPs) on the tapered shaft of the scanning probe. The SPPs propagate adiabatically towards the probe tip where they are coupled to localized plasmons (LSPs). The nanofocusing scheme was explored in a near-field scanning optical microscope for super-resolution imaging, near-field transduction of nanomechanical vibrations, and local detection of ultrasound. Owing to the strong concentration of light at the probe, significant heating of the tip and a sample positioned in the optical near-field is expected. This paper investigates the local heating produced by the plasmonic nanofocusing probe under steady-state conditions using the tip-enhanced Raman scattering approach. In addition, a finite element model is explored to study the coupling of free propagating light to LSPs, and to estimate the temperature rise expected in a halfspace heated by absorption of the LSPs. This study has implications for exploring the plasmonic nanofocusing probe in heat-assisted nanofabrication and fundamental studies of nanoscale heat transport in materials.

  9. Gravity Probe B Number 4 Gyro Inspected

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Gravity Probe B (GP-B) is the relativity experiment 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. In this photograph, Stanford engineer, Chris Gray, is inspecting the number 4 gyro under monochromatic light. 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Leese, Stanford University.)

  10. Artist's Concept of Gravity Probe-B

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Gravity Probe-B (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 -- technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by Marshall Space Flight Center, development of GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  11. Artist's Concept of Gravity Probe-B

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Gravity Probe-B (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 -- technologies that are already enlivening other branches of science and engineering. Scheduled for launch in 2003 and managed for NASA by Marshall Space Flight Center, development of the GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  12. Artist's Concept of Gravity Probe-B

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Gravity Probe-B (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 -- 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 GP-B is the responsibility of Stanford University, with major subcontractor Lockheed Martin Corporation.

  13. Study of photoemission and work function of large surface areas, phase 3, phase 4. [wavelength dependences of photoelectric space probe materials

    NASA Technical Reports Server (NTRS)

    1973-01-01

    The photoemission of materials which might be used in probe measurements of the exo-atmospheric electric field is considered by evaluating the wavelength dependence of their photoelectric yield for eleven elements over the range 800 to 3200 A. Yield data for zinc, copper beryllium, platinum, cadmium, graphite, carbon, gold, silver, tantalum, and tungsten show that copper-beryllium is a preferred material. Silver has one of the highest photoemissions when exposed to solar radiation.

  14. Preliminary estimation of color inhomogeneities on the surface of Venus according to the television images obtained by the VENERA-13 and VENERA-14 automated space probes

    NASA Technical Reports Server (NTRS)

    Shkuratov, Yu. G.; Kreslavskiy, M. A.; Bazilevskiy, A. T.

    1987-01-01

    Digital processing of images obtained by the Venera 13 and Venera 14 probes led to the discovery of faint color differences of some areas of the observed surface. Maximum color differences were observed in the right part of 14-1 panorama. Color anomaly is associated with the bedrock outcrop having slightly higher albedo than the surrounding. Possible causes of the discovered color differences are discussed.

  15. Central and peripheral regulation of feeding and nutrition by the mammalian circadian clock: implications for nutrition during manned space flight

    NASA Technical Reports Server (NTRS)

    Cassone, Vincent M.; Stephan, Friedrich K.

    2002-01-01

    Circadian clocks have evolved to predict and coordinate physiologic processes with the rhythmic environment on Earth. Space studies in non-human primates and humans have suggested that this clock persists in its rhythmicity in space but that its function is altered significantly in long-term space flight. Under normal circumstances, the clock is synchronized by the light-dark cycle via the retinohypothalamic tract and the suprachiasmatic nucleus. It is also entrained by restricted feeding regimes via a suprachiasmatic nucleus-independent circadian oscillator. The site of this suboscillator (or oscillators) is not known, but new evidence has suggested that peripheral tissues in the liver and viscera may express circadian clock function when forced to do so by restricted feeding schedules or other homeostatic disruptions. New research on the role of the circadian clock in the control of feeding on Earth and in space is warranted.

  16. Space engineering

    NASA Technical Reports Server (NTRS)

    Alexander, Harold L.

    1991-01-01

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

  17. The Gravity Probe B Flight Dewar

    NASA Technical Reports Server (NTRS)

    2001-01-01

    Gravity Probe B (GP-B) is the relativity experiment developed at Stanford University to test two extraordinary predictions of Albert Einstein's general theory of relativity. This photograph is of the Gravity Probe B flight dewar, a metal container made like a vacuum bottle that is used especially for storing liquefied gases, that will maintain the experiment at a temperature just above absolute zero, staying cold for two years. 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 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 -- technologies that are already enlivening other branches of science and engineering. Launched in 2004 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. (Photo Credit: Lockheed Martin Corporation/R. Underwood)

  18. Preliminary results of space experiment: Implications for the effects of space radiation and microgravity on survival and mutation induction in human cells

    NASA Astrophysics Data System (ADS)

    Yatagai, F.; Honma, M.; Ukai, A.; Omori, K.; Suzuki, H.; Shimazu, T.; Takahashi, A.; Ohnishi, T.; Dohmae, N.; Ishioka, N.

    2012-02-01

    In view of the concern for the health of astronauts that may one day journey to Mars or the Moon, we investigated the effect that space radiation and microgravity might have on DNA damage and repair. We sent frozen human lymphoblastoid TK6 cells to the International Space Station where they were maintained under frozen conditions during a 134-day mission (14 November 2008 to 28 March 2009) except for an incubation period of 8 days under 1G or μG conditions in a CO2 incubator. The incubation period started after 100 days during which the cells had been exposed to 54 mSv of space radiation. The incubated cells were then refrozen, returned to Earth, and compared to ground control samples for the determination of the influence of microgravity on cell survival and mutation induction. The results for both varied from experiment to experiment, yielding a large SD, but the μG sample results differed significantly from the 1G sample results for each of 2 experiments, with the mean ratio of μG to 1G being 0.55 for the concentration of viable cells and 0.59 for the fraction of thymidine kinase deficient (TK-) mutants. Among the mutants, non-loss of zygosity events (point mutations) were less frequent (31%) after μG incubation than after 1G incubation, which might be explained by the influence of μG on cellular metabolic or physiological function. Additional experiments are needed to clarify the effect of μG interferes on DNA repair.

  19. Photodetachment of Zwitterions: Probing Intramolecular Coulomb Repulsion and Attraction in the Gas Phase Using Mono- Decarboxylated Pyridinium Dicarboxylates. Implications on the Mechanism of Orotidine 5' -Monophosphate Decarboxylase

    SciTech Connect

    Wang, Xue B.; Dacres, J E.; Yang, Xin; Lis, Lev; Bedell, Victoria M.; Wang, Lai S.; Kass, Steven R.

    2003-11-11

    Negative ion photoelectron spectra resulting from the decarboxylation of nine zwitterionic pyridinium dicarboxylates (D(x,y)) are reported. Structural assignments are made on the basis of analogy to the spectra of related species, labeling experiments with C-13- or H-2-containing substrates, independent syntheses, and comparison to density functional theory and ab initio (B3LYP and CCSD(T), respectively) results. In some cases, an acid-catalyzed isomerization of the D(xy)-CO2 ions was found to take place. Adiabatic detachment energies of the resulting zwitterionic ions were measured and are well reproduced by theory. The relative stabilities of the D(x,Y)- CO2 decarboxylation products are largely determined by their intramolecular electrostatic interactions, which are directly probed by the photoelectron spectra and were analyzed in terms of the resulting Coulombic forces. Expulsion of carbon dioxide from the D(x,y) ions was also used as an electrostatic model to probe the mechanism of the enzyme-catalyzed conversion of orotidine 5'-monophosphate (OMP) to uridine 5'-monophosphate (UMP). It was found that the loss of CO2 from these zwitterions; and from oxygen-protonated OMP is retarded by the presence of an additional anionic group. This suggests that the formation of a zwitterion intermediate in the enzyme-catalyzed transformation of OMP to UMP may have less of an energetic impact than commonly thought and could be a''red herring''. If so, the electrostatic stress mechanism proposed by Larsen et al. and Pai, Guo, and co-workers maybe followed.

  20. Photodetachment of zwitterions: probing intramolecular Coulomb repulsion and attraction in the gas phase using mono-decarboxylated pyridinium dicarboxylates. Implications on the mechanism of orotidine 5'-monophosphate decarboxylase.

    PubMed

    Wang, Xue-Bin; Dacres, Jelena E; Yang, Xin; Lis, Lev; Bedell, Victoria M; Wang, Lai-Sheng; Kass, Steven R

    2003-06-01

    Negative ion photoelectron spectra resulting from the decarboxylation of nine zwitterionic pyridinium dicarboxylates (D(x,y)) are reported. Structural assignments are made on the basis of analogy to the spectra of related species, labeling experiments with (13)C- or (2)H-containing substrates, independent syntheses, and comparison to density functional theory and ab initio (B3LYP and CCSD(T), respectively) results. In some cases, an acid-catalyzed isomerization of the D(x,y)-CO(2) ions was found to take place. Adiabatic detachment energies of the resulting zwitterionic ions were measured and are well reproduced by theory. The relative stabilities of the D(x,y)-CO(2) decarboxylation products are largely determined by their intramolecular electrostatic interactions, which are directly probed by the photoelectron spectra and were analyzed in terms of the resulting Coulombic forces. Expulsion of carbon dioxide from the D(x,y) ions was also used as an electrostatic model to probe the mechanism of the enzyme-catalyzed conversion of orotidine 5'-monophosphate (OMP) to uridine 5'-monophosphate (UMP). It was found that the loss of CO(2) from these zwitterions and from oxygen-protonated OMP is retarded by the presence of an additional anionic group. This suggests that the formation of a zwitterion intermediate in the enzyme-catalyzed transformation of OMP to UMP may have less of an energetic impact than commonly thought and could be a "red herring". If so, the electrostatic stress mechanism proposed by Larsen et al. and Pai, Guo, and co-workers maybe followed. PMID:12769593

  1. Titan aerosol and gas experiment for the Huygens Probe

    NASA Technical Reports Server (NTRS)

    Carle, G. C.; Kojiro, D. R.; Oberbeck, V.; Ohara, B. J.; Pollack, J. B.; Valentin, J. R.; Bar-Nun, A.; Cohen, M. J.; Ferris, J. P.; Greenberg, J. M.

    1991-01-01

    The Cassini Mission is a joint undertaking of NASA and the European Space Agency (ESA) to explore the Saturnian System with a Saturn Orbiter and a Titan Probe. The launch vehicle and the Saturn Orbiter are the responsibility of NASA while the Huygens Probe (detachable Titan Probe) is the responsibility of ESA. The spacecraft will be launched in 1996 and the Huygens Probe will arrive at Titan in 2003. The Cassini Mission-Huygens Probe provides a unique opportunity to obtain detailed information about the atmosphere and, possibly, the surface of Titan. Titan possesses a substantial nitrogen atmosphere containing methane and many other organic compounds. Aerosols play an important role in the atmospheric processes on Titan. The Huygens Probe offers an opportunity to determine how organic particles are formed and grow which will clarify their role on Earth. A powerful analytical instrument, capable of addressing the above technology and other science questions, was recently proposed for the Huygens Probe. It is comprised of an aerosol and gas sampler and processor, and a gas chromatograph-ion mobility spectrometer. The instrument will be able to measure complex organics that make up the collected aerosols to the approximate 1 ppm level. Gases will be measured to approximately 10 ppb. Because the Titan atmosphere is expected to be quite complex, a gas chromatograph-ion mobility spectrometer is used to provide unequivocal identification of the components of the analytes. Further details of the science question to be investigated and the proposed instrument are described. The expected results and their implications are also addressed.

  2. Droplet monitoring probe

    NASA Technical Reports Server (NTRS)

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

    1973-01-01

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

  3. Phoenix Conductivity Probe

    NASA Technical Reports Server (NTRS)

    2008-01-01

    This image taken by the Surface Stereo Imager on Sol 49, or the 49th Martian day of the mission (July 14, 2008), shows thermal and electrical conductivity probe on NASA's Phoenix Mars Lander's Robotic Arm.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  4. Post-IOC space station: Models of operation and their implications for organizational behavior, performance and effectiveness

    NASA Technical Reports Server (NTRS)

    Danford, S.; Meindl, J.; Hunt, R.

    1985-01-01

    Issues of crew productivity during design work on space station are discussed. The crew productivity is defined almost exclusively in terms of human factors engineering and habitability design concerns. While such spatial environmental conditions are necessary to support crew performance and productivity, they are not sufficient to ensure high levels of crew performance and productivity on the post-Initial Operational Configurations (IOC) space station. The role of the organizational environment as a complement to the spatial environment for influencing crew performance in such isolated and confined work settings is examined. Three possible models of operation for post-IOC space station's organizational environment are identified and it is explained how they and space station's spatial environment will combine and interact to occasion patterns of crew behavior is suggested. A three phase program of research design: (1) identify patterns of crew behavior likely to be occasioned on post-IOC space station for each of the three models of operation; and (2) to determine proactive/preventative management strategies which could be adopted to maximize the emergence of preferred outcomes in crew behavior under each of the several spatial and organizational environment combinations.

  5. Subthalamic Stimulation Reduces Vowel Space at the Initiation of Sustained Production: Implications for Articulatory Motor Control in Parkinson’s Disease

    PubMed Central

    Sidtis, John J.; Alken, Amy G.; Tagliati, Michele; Alterman, Ron; Van Lancker Sidtis, Diana

    2016-01-01

    Background: Stimulation of the subthalamic nuclei (STN) is an effective treatment for Parkinson’s disease, but complaints of speech difficulties after surgery have been difficult to quantify. Speech measures do not convincingly account for such reports. Objective: This study examined STN stimulation effects on vowel production, in order to probe whether DBS affects articulatory posturing. The objective was to compare positioning during the initiation phase with the steady prolongation phase by measuring vowel spaces for three “corner” vowels at these two time frames. Methods: Vowel space was measured over the initial 0.25 sec of sustained productions of high front (/i/), high back (/u/) and low vowels (/a/), and again during a 2 sec segment at the midpoint. Eight right-handed male subjects with bilateral STN stimulation and seven age-matched male controls were studied based on their participation in a larger study that included functional imaging. Mean values: age = 57±4.6 yrs; PD duration = 12.3±2.7 yrs; duration of DBS = 25.6±21.2 mos, and UPDRS III speech score = 1.6±0.7. STN subjects were studied off medication at their therapeutic DBS settings and again with their stimulators off, counter-balanced order. Results: Vowel space was larger in the initiation phase compared to the midpoint for both the control and the STN subjects off stimulation. With stimulation on, however, the initial vowel space was significantly reduced to the area measured at the mid-point. For the three vowels, the acoustics were differentially affected, in accordance with expected effects of front versus back position in the vocal tract. Conclusions: STN stimulation appears to constrain initial articulatory gestures for vowel production, raising the possibility that articulatory positions normally used in speech are similarly constrained. PMID:27003219

  6. Comments on containerless bulk crystal growth and epitaxy in space and on their implications regarding non-contact temperature measurements

    NASA Technical Reports Server (NTRS)

    Bachmann, Klaus J.

    1989-01-01

    Containerless methods are sought for bulk crystal growth and epitaxy which thus far are a less visible component of materials science in space efforts. In the opinion of the author, this is an anomaly which ought to be corrected, because container interactions are a major problem in earth bound materials processing, including crystal growth, and can be avoided or at least significantly reduced in space. The space environment is unique in solving some of these problems, e.g., memory effects in the integration of different classes of materials in high resolution multilayer heterostructures by molecular beam epitaxy or organometallic molecular beam epitaxy. Spectroscopic method of noncontact temperature measurements exist that could be developed in this context. The error in the absolute temperature measurement achieved by these techniques decreases with decreasing substrate temperature and supplements pyrometric measurements that are better suited for high temperature measurements.

  7. Space-time kriging extension of precipitation variability at 12 km spacing from tree-ring chronologies and its implications for drought analysis

    NASA Astrophysics Data System (ADS)

    Biondi, F.

    2013-04-01

    Understanding and preparing for future hydroclimatic variability greatly benefits from long (i.e., multi-century) records at seasonal to annual time steps that have been gridded at km-scale spatial intervals over a geographic region. Kriging is a geostatistical technique commonly used for optimal interpolation of environmental data, and space-time geostatistical models can improve kriging estimates when long temporal sequences of observations exist at relatively few points on the landscape. Here I present how a network of 22 tree-ring chronologies from single-leaf pinyon (Pinus monophylla) in the central Great Basin of North America was used to extend hydroclimatic records both temporally and spatially. First, the Line of Organic Correlation (LOC) method was used to reconstruct October-May total precipitation anomalies at each tree-ring site, as these ecotonal environments at the lower forest border are typically moisture limited. Individual site reconstructions were then combined using a hierarchical model of spatio-temporal kriging that produced annual anomaly maps on a 12 × 12 km grid during the period in common among all chronologies (1650-1976). Hydro-climatic episodes were numerically identified and modeled using their duration, magnitude, and peak. Spatial patterns were more variable during wet years than during dry years, and the evolution of drought episodes over space and time could be visualized and quantified. The most remarkable episode in the entire reconstruction was the early 1900s pluvial, followed by the late 1800s drought. The 1930s "Dust Bowl" drought was among the top ten hydroclimatic episodes in the past few centuries. These results directly address the needs of water and natural resource managers with respect to planning for "worst case" scenarios of drought duration and magnitude at the watershed level. For instance, it is possible to analyze which geographical areas are more likely to be impacted by severe and sustained droughts at annual

  8. Mission Assurance and Flight Safety of Manned Space Flight: Implications for Future Exploration of the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Kezirian, M. T.

    2007-01-01

    As NASA implements the nation's Vision for Space Exploration to return to the moon and travel to Mars, new considerations will be be given to the processes governing design and operations of manned spaceflight. New objectives bring new technical challenges; Safety will drive many of these decisions.

  9. Head movements in non-terrestrial force environments elicit motion sickness - Implications for the etiology of space motion sickness

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Graybiel, A.

    1986-01-01

    Space motion sickness has become an operational concern in manned space flight. Considerable evidence exists that head movements in free fall, especially pitch movements, are provocative until adaptation occurs. The question arises whether space motion sickness is an unique nosological entity or is due to body movements in a nonterrestrial force environment, a force environment for which the body's dynamic sensory-motor adaptions to 1 G are no longer appropriate. To evaluate this issue, subjects were asked to make controlled head movements during exposure to high gravitoinertial force levels, 1.8-2.0 G, in parabolic flight maneuvers. Head movements in pitch with eyes open were most evocative of motion sickness, yaw movements with eyes covered were least provocative. This pattern is identical to that which occurs when the same types of head movements are made in the free fall phase of parabolic maneuvers. It appears that space motion sickness is the consequence of prolonged exposure to a nonterrestrial force background rather than of exposure to free fall per se.

  10. LDEF spacecraft, ground laboratory, and computational modeling implications on Space Station Freedom's solar array materials and surfaces durability

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; Rutledge, Sharon K.; De Groh, Kim K.; Auer, Bruce M.; Mirtich, Michael J.; Gebauer, Linda; Hill, Carol M.; Lebed, Richard F.

    1991-01-01

    The low earth orbital (LEO) durability of Space Station Freedom (SSF) solar array materials and surfaces is evaluated using results from the Long Duration Exposure Facility (LDEF), ground laboratory simulation tests, and Monte Carlo modeling. These results indicate that thin-film SiOx protective coatings are adequately durable to atomic oxygen, ultraviolet (UV) radiation, thermal cycling, and micrometeroid or debris impact.

  11. Future uses of machine intelligence and robotics for the Space Station and implications for the U.S. economy

    NASA Technical Reports Server (NTRS)

    Cohen, A.; Erickson, J. D.

    1985-01-01

    The exciting possibilities for advancing the technologies of artificial intelligence, robotics, and automation on the Space Station is summarized. How these possibilities will be realized and how their realization can benefit the U.S. economy are described. Plans, research programs and preliminary designs that will lead to the realization of many of these possibilities are being formulated.

  12. A three dimensional probe positioner

    SciTech Connect

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

    2008-10-15

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

  13. Are consumers aware of top-bottom but not of left-right inferences? Implications for shelf space positions.

    PubMed

    Valenzuela, Ana; Raghubir, Priya

    2015-09-01

    We propose that the horizontal and vertical position of an item on a display is a source of information that individuals use to make judgments. Six experiments using 1 × 5 or 5 × 5 displays show that consumers judge that products placed at the bottom (vs. top) and on the left-hand (vs. middle and right-hand) side of a display are less expensive and of lower quality (Study 1a using a bar display, Study 1b using wine, and Study 1c using Swatch watches). Results support the claim that verticality effects (top-bottom) are attenuated when participants are less involved with the decision task (Study 2 using Swatch watches and chocolates) and when they are exposed to information that questions the diagnosticity of using vertical position as a cue (Study 3 using wine). However, the horizontality (left-right) effect is robust to both of these manipulations. Horizontality effects are exacerbated for participants primed with a number line (Study 4 also using wine), suggesting that exposure to the number line (where higher numbers are on the right) is a possible antecedent of the horizontality effect. The verticality effects may, on the other hand, reflect people's retail experience of seeing higher priced products on higher shelves, which leads to their forming a similar expectation. The paper concludes with a discussion of theoretical implications for visual information processing as well as practical implications for retail management. PMID:26372081

  14. Pollution Probe.

    ERIC Educational Resources Information Center

    Chant, Donald A.

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

  15. Variations in gravitoinertial force level affect the gain of the vestibulo-ocular reflex - Implications of the etiology of space motion sickness

    NASA Technical Reports Server (NTRS)

    Lackner, J. R.; Graybiel, A.

    1981-01-01

    Recordings of horizontal nystagmus were obtained on 16 male subjects exposed to repeated patterns of horizontal angular acceleration, constant velocity rotation, and sudden-stop deceleration in the laboratory and in the free-fall and high-force periods of parabolic flight. Nystagmus intensity was a clear function of gravitoinertial force level: slow phase velocity and beat frequency increased during exposure to high force levels and decreased in free-fall compared to values obtained at 1 G. These findings indicate that the gain of the vestibulo-ocular reflex decreases in free-fall. This fact likely accounts for the disorientation and dizziness sometimes experienced by astronauts when moving their heads in the early phases of orbital flight and again after splashdown. The implications of the present findings, both for the etiology and for the treatment of space motion sickness, are discussed.

  16. Space science

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A fact sheet on the NASA space science program is presented. Some of the subjects considered include the following: (1) the Orbiting Astronomical Observatory, (2) the Orbiting Solar Observatory, (3) the Small Astronomy Satellite, (4) lunar programs, (5) planetary programs using the Mariner, Pioneer 10, and Viking space probes, and (6) the Scout, Thor-Delta, and Atlas-Centaur launch vehicles. For each program there is a description of the effort, the schedule, management, program officials, and funding aspects in outline form.

  17. Daily travel distances of zoo-housed chimpanzees and gorillas: implications for welfare assessments and space requirements.

    PubMed

    Ross, Stephen R; Shender, Marisa A

    2016-07-01

    The degree to which the relatively smaller area of artificial environments (compared with natural habitats) has measureable effects on the behavior and welfare of captive animals has been debated for many years. While there is little question that these spaces provide far less opportunity for natural ranging behavior and travel, less is known about the degree to which captive animals travel within their environments and what factors influence these travel patterns. We intensively studied the movement of zoo-housed chimpanzees and gorillas using a computer map interface and determined their mean daily travel and found they travelled similar distances each day when restricted to their indoor areas, but when provided additional outdoor space, chimpanzees tended to increase their travel to a greater extent than did gorillas. Both species travelled shorter distances than has been recorded for their wild counterparts, however, when given access to their full indoor-outdoor exhibit; those differences were not as substantive. These findings suggest that while large, complex naturalistic environments might not stimulate comparable species-typical travel patterns in captive apes, larger spaces that include outdoor areas may be better at replicating this behavioral pattern than smaller, indoor areas. PMID:26968410

  18. Indentation of a Punch with Chemical or Heat Distribution at Its Base into Transversely Isotropic Half-Space: Application to Local Thermal and Electrochemical Probes

    SciTech Connect

    Karapetian, E.; Kalinin, Sergei V

    2013-01-01

    The exact solution to the coupled problem of indentation of the punch, subjected to either heat or chemical substance distribution at its base, into three-dimensional semi-infinite transversely isotropic material is presented. The entire set of field components are derived in terms of integrals of elementary functions using methods of the potential theory and recently obtained, by the authors, results for the general solution of the field equations in terms of four harmonic potential functions. The exact solution for the stiffness relations that relate applied force, total chemical diffusion/heat flux in the domain of the contact, with indenter displacement, temperature, or chemical substance distribution of diffusing species at the base, and materials' chemo/thermo-elastic properties are obtained in closed form and in terms of elementary functions. These results can be used to understand the image formation mechanisms in techniques such as thermal scanning probe microscopy and electrochemical strain microscopy

  19. Indentation of a punch with chemical or heat distribution at its base into transversely isotropic half-space: Application to local thermal and electrochemical probes

    NASA Astrophysics Data System (ADS)

    Karapetian, Edgar; Kalinin, Sergei V.

    2013-05-01

    The exact solution to the coupled problem of indentation of the punch, subjected to either heat or chemical substance distribution at its base, into three-dimensional semi-infinite transversely isotropic material is presented. The entire set of field components are derived in terms of integrals of elementary functions using methods of the potential theory and recently obtained, by the authors, results for the general solution of the field equations in terms of four harmonic potential functions. The exact solution for the stiffness relations that relate applied force, total chemical diffusion/heat flux in the domain of the contact, with indenter displacement, temperature, or chemical substance distribution of diffusing species at the base, and materials' chemo/thermo-elastic properties are obtained in closed form and in terms of elementary functions. These results can be used to understand the image formation mechanisms in techniques such as thermal scanning probe microscopy and electrochemical strain microscopy.

  20. Space: The New Frontier.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

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

  1. A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management

    PubMed Central

    Li, Tianxin; Meng, Linglong; Herman, Uwizeyimana; Lu, Zhongming; Crittenden, John

    2015-01-01

    Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease) along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = −0.8267, p = 0.0017) and CAT (r = −0.89, p = 0.0002) activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants. PMID:26457711

  2. A Survey of Soil Enzyme Activities along Major Roads in Beijing: The Implications for Traffic Corridor Green Space Management.

    PubMed

    Li, Tianxin; Meng, Linglong; Herman, Uwizeyimana; Lu, Zhongming; Crittenden, John

    2015-10-01

    Soil quality is critical to the management of urban green space, in particular, along traffic corridors where traffic-related air pollution is significant. Soil quality can be evaluated by soil enzyme activities, which show quick responses to both natural and anthropogenic disturbances. In this study, we investigated three soil enzyme activities (i.e., dehydrogenase, catalase and urease) along the major roads in urban areas of Beijing. Results show the activities of dehydrogenase, catalase and urease in urban samples were 58.8%, 68.2% and 48.5% less than the rural sample, respectively. The content of fluorescent amino acids as indicators of microbial activities was also consistently lower in urban samples than the rural. We observed two times greater exposure of particulate material along the roadsides in urban areas than rural areas. Although traffic air pollutants provide some nutrient sources to stimulate the URE activity, the exposure to traffic-related air pollution leads to the substantial decrease in enzyme activities. There were significant negative correlations for exposure to PM10 with DHA (r = -0.8267, p = 0.0017) and CAT (r = -0.89, p = 0.0002) activities. For the urban soils URE activity increased with the increasing of PM. We conclude that the degraded soil quality can negatively affect the target of developing plants and green spaces along the traffic corridors to mitigate the traffic impact. This study suggests the investigation of integrated strategies to restore the soil quality, reinforce the ecological service functions of green spaces along the traffic corridors and reduce the traffic pollutants. PMID:26457711

  3. Spectral characterization of V-type asteroids - I. Space weathering effects and implications for V-type NEAs

    NASA Astrophysics Data System (ADS)

    Fulvio, Daniele; Perna, Davide; Ieva, Simone; Brunetto, Rosario; Kanuchova, Zuzana; Blanco, Carlo; Strazzulla, Giovanni; Dotto, Elisabetta

    2016-01-01

    Among main belt asteroids, V-types belonging to Vesta's dynamical family are known as `Vestoids' while those lying outside Vesta's family as `non-Vestoids'. V-types have also been found within the population of Near Earth Asteroids (NEAs). Several questions on Vesta, the V-types, and the Howardite-Eucrite-Diogenite meteorites are still unsolved, such as the genesis of each class/subclass, their evolution and mutual relationship, and the existence of other basaltic parent bodies. We present new NIR (0.8-2.4 μm) spectroscopic observations of seven non-Vestoids, carried out at the Telescopio Nazionale Galileo (TNG - INAF). We derived a number of spectral parameters (BI and BII centres, band separations, and BI slopes) and compared them with available spectra of V-types belonging to different subclasses (102 V-types in total), to highlight possible spectral differences useful to shed light on the questions mentioned above. We also considered the data from ion irradiation experiments performed on different samples of eucrites, simulating space weathering effects. Net discrepancies are seen for the BI slope distributions: NEAs show a distribution strongly different from all other V-type subclasses. Ion irradiation experiments induce strong effects on BI slope values and, as irradiation proceeds, the BI slope of eucrites quickly increases, changing the overall aspect of their VIS-NIR spectra (0.4-2.5 μm). Space weathering may explain the whole range of spectral slopes observed for all V-type subclasses. An exception is represented by NEAs, where moderate space weathering effects are evidenced. We propose that this is due to tidal perturbations exposing `fresh' unweathered surface grains during close encounters with the Earth, as previously found for Q-type NEAs.

  4. Head movements in low and high gravitoinertial force environments elicit motion sickness - Implications for space motion sickness

    NASA Technical Reports Server (NTRS)

    Lackner, James R.; Graybiel, Ashton

    1987-01-01

    Astronauts report that head movements in flight tend to bring on symptoms of space motion sickness (SMS). The effects of head movements in pitch, yaw, and roll (made both with normal vision and with eyes occluded) on susceptibility to motion sickness in the zero G phase of parabolic flight maneuvers were evaluated. The findings are clear-cut: pitch head movements are most provocative, yaw least provocative, and roll intermediate. These experiments suggest that SMS is not a unique nosological entity, but is the consequence of exposure to nonterrestrial force levels. Head movements during departures in either direction from 1 G elicit symptoms.

  5. The UV/blue effects of space weathering manifested in S-complex asteroids II: Probing for less-weathered objects in the Solar System

    NASA Astrophysics Data System (ADS)

    Vilas, Faith; Hendrix, Amanda R.; Jensen, Elizabeth A.

    2015-12-01

    High resolution spectrophotometry shows that among S-complex and related asteroids that have undergone varying levels of weathering from space exposure, the break in reflectance spectrophotometry between weathered and fresh surfaces persists across the 360-440 nm spectral range. Using this knowledge, candidate Q- and O-class asteroids that could show the onset of space weathering in the ultraviolet/blue spectral region, not yet seen in the visible/near-infrared spectral region, were culled from the taxonomic classification of the Sloan Digital Sky Survey asteroid data base. Fifty-four main-belt asteroids are identified for further examination, although we believe that greater spectral resolution is necessary to confirm this designation.

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

    NASA Technical Reports Server (NTRS)

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

    2014-01-01

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

  7. Interactions between a lizard and its thermal environment: implications for sprint performance and space utilization in the lizard Uta stansburiana

    SciTech Connect

    Waldschmidt, S.; Tracy, C.R.

    1983-06-01

    At the end of their breeding season, male side-blotched lizards, Uta stansburiana from western Colorado decreased their home range to a size not different from that of females. Both males and females showed a high degree of overlap in home ranges, not found in populations previously studied in Texas. Uta's sprint speed was dependent on body temperature, with maximum sprint speed occurring at body temperatures between 35/sup 0/C and 38/sup 0/C, with lower speeds at higher and lower temperatures. An energy budget model was used to predict the range of body temperatures (and thus sprint speeds) available to lizards in four microhabitats within each animal's home range. Predicted body temperatures were converted to a space-time index. The distribution of the space-time index in each microhabitat was used to predict the spatial and temporal distributions of lizards. Predicted distributions accurately reflected the measured distributions of lizards in the morning and late afternoon, but did not reflect the measured distributions during midday. These inconsistencies are thought to be the result of lizard responses to other temperature-dependent processes, such as evaporite water loss.

  8. Turbulence Climatology at Dallas/Ft.Worth (DFW) Airport: Implications for a Departure Wake Vortex Spacing System

    NASA Technical Reports Server (NTRS)

    Perras, G. H.; Dasey, T. J.

    2000-01-01

    Potential adaptive wake vortex spacing systems may need to rely on wake vortex decay rather than wake vortex transport in reducing wake separations. A wake vortex takeoff-spacing system in particular will need to rely on wake decay. Ambient turbulence is the primary influence on wake decay away from the ground. This study evaluated 18 months of ambient turbulence measurements at Dallas/Ft. Worth (DFW) Airport. The measurements show minor variation in the turbulence levels at various times of the year or times of the day for time periods when a departure system could be used. Arrival system operation was also examined, and a slightly lower overall turbulence level was found as compared to departure system benefit periods. The Sarpkaya model, a validated model of wake vortex behavior, was applied to various turbulence levels and compared to the DFW turbulence statistics. The results show that wake vortices from heavy aircraft on takeoff should dissipate within one minute for the majority of the time and will rarely last two minutes. These results will need to be verified by wake vortex measurements on departure.

  9. Probing many body effects using Fourier Transform Scanning Tunneling Spectroscopy: Can spin-orbit splitting in dispersion be observed in q-space?

    NASA Astrophysics Data System (ADS)

    Farahi, Gelareh; UBC Labortory for Atomic Imaging Research (LAIR)) Team

    Well studied surface systems such as Ag and Cu provide a safe platform to test novel spectroscopy methods that can have extended applications in near future. Our current focus is given to Fourier Transform Scanning Tunneling Spectroscopy (FT-STS) that allows us to study scattering effects (quasiparticle interactions - namely QPI) of CO and Co on Cu(111) surface. Magnetic Co adatoms are expected to generate a spin-orbit split in dispersion in QPI(q) space, the existence of which is confirmed by the k-space angle-resolved photo-emission spectroscopy (ARPES) of Cu(111) surface in the recent years. Hence the previously observed electron-phonon kink and spin-orbit splitting of the dispersion, as well as the scattering properties of CO molecules and Co adatoms, should also be observable in QPI space via FT-STS of Cu(111), and compatible with previous studies on similar systems. We are using a low temperature (4.2 K) commercial Scanning Tunneling Microscope (CREATEC STM) that operates using Nanonis electronic controllers and software which allows us to perform FT-STS as well as topological imaging.

  10. DFT study of the NMR properties of xenon in covalent compounds and van der waals complexes-implications for the use of 129Xe as a molecular probe.

    PubMed

    Bagno, Alessandro; Saielli, Giacomo

    2003-04-01

    The NMR properties (chemical shift and spin-spin coupling constants) of (129)Xe in covalent compounds and weakly bound complexes have been investigated by DFT methods including relativistic effects. For covalent species, a good agreement between experimental and calculated results is achieved without scalar relativistic effects, but their inclusion (with a triple-zeta, double-polarization basis set) leads to some improvement in the quality of the correlation. The spin-orbit coupling term has a significant effect on the shielding constant, but makes a small contribution to the chemical shift. Coupling constants contain substantial contributions from the Fermi contact and paramagnetic spin-orbit terms; unlike light nuclei the spin-dipole term is also large, whereas the diamagnetic spin-orbit term is negligible. For van der Waals dimers, the dependence of the xenon chemical shift and anisotropy is calculated as a function of the distance. Small (<1 Hz) but non-negligible through-space coupling constants between (129)Xe and (13)C or (1)H are predicted. Much larger couplings, of the order of few Hz, are calculated between xenon and (17)O in a model silicate residue. PMID:12658645

  11. Evaluating greater sage-grouse seasonal space use relative to leks: Implications for surface use designations in sagebrush ecosystems

    USGS Publications Warehouse

    Casazza, Michael L.; Coates, Peter S.

    2013-01-01

    The development of anthropogenic structures, especially those related to energy resources, in sagebrush ecosystems is an important concern among developers, conservationists, and land managers in relation to greater sage-grouse (Centrocercus urophasianus; hereafter, sage-grouse) populations. Sage-grouse are dependent on sagebrush ecosystems to meet their seasonal life-phase requirements, and research indicates that anthropogenic structures can adversely affect sage-grouse populations. Land management agencies have attempted to reduce the negative effects of anthropogenic development by assigning surface use (SU) designations, such as no surface occupancy, to areas around leks (breeding grounds). However, rationale for the size of these areas is often challenged. To help inform this issue, we used a spatial analysis of sage-grouse utilization distributions (UDs) to quantify seasonal (spring, summer and fall, winter) sage-grouse space use in relation to leks. We sampled UDs from 193 sage-grouse (11,878 telemetry locations) across 4 subpopulations within the Bi-State Distinct Population Segment (DPS, bordering California and Nevada) during 2003–2009. We quantified the volume of each UD (vUD) within a range of areas that varied in size and were centered on leks, up to a distance of 30 km from leks. We also quantified the percentage of nests within those areas. We then estimated the diminishing gains of vUD as area increased and produced continuous response curves that allow for flexibility in land management decisions. We found nearly 90% of the total vUD (all seasons combined) was contained within 5 km of leks, and we identified variation in vUD for a given distance related to season and migratory status. Five kilometers also represented the 95th percentile of the distribution of nesting distances. Because diminishing gains of vUD was not substantial until distances exceeded 8 km, managers should consider the theoretical optimal distances for SU designation

  12. A Union of Inner Magnetosphere Data from the Van Allen Probes and Related Missions at NASA's Space Physics Data Facility (SPDF)

    NASA Astrophysics Data System (ADS)

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

    2013-12-01

    A wide range of current, public, science-quality particle and field data from the Van Allen Probes and related missions is being ingested, archived and served to the international science community by SPDF. As an active heliophysics archive, SPDF now serves some eighty Level-2 (and increasingly Level-3) data products that fully span the range of measurements from particles-plasma (RBSPICE, ECT) through magnetic-electric fields and waves (EMFISIS, EFW). This coherent collection of mission data, in a standard format (CDF) with standard metadata, is available through SPDF's CDAWeb user interface, CDAWeb's web services and associated APIs for IDL and Matlab users, as well as through direct FTP/HTTP download access supplemented with orbit displays through our SSCWeb and 4D Orbit Viewer services and HDP/VSPO direct links to investigator sites/resources. With the dedicated work of the project and instrument teams, these data products are of increasingly high quality and typically current within 2 months or less. Having this range of data in CDAWeb makes comparison of data among instruments and spacecraft much easier, as well as comparisons and analysis of these data with current data from other missions including THEMIS, TWINS, Cluster, ACE, Wind and now >120 ground magnetometer stations. In addition, SPDF supports data from the BARREL Antarctic balloon program and recent data from instruments on the NOAA GOES spacecraft. SPDF will also support public data from the MMS mission when launched in later 2014.

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

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  14. Human migration to space: Alternative technological approaches for long-term adaptation to extraterrestrial environments and the implications for human evolution

    NASA Astrophysics Data System (ADS)

    Lockard, Elizabeth Song

    As humans embark upon the next phase of Space exploration---establishing human outposts in low-Earth orbit, on the Moon, and on Mars---the scope of human factors must expand beyond the meager requirements for short-term missions to Space to include issues of comfort and well-being necessary for long-term durations. However, to habitate---to dwell in a place---implies more than creature comforts in order to adapt. Human factors research must also include a phenomenological perspective---an understanding of how we experience the places we live in---in order for a community to be robust and to thrive. The first phase of migration will be an especially tenuous one requiring intensive technological intervention. The modes by which those technologies are implemented will have significant bearing on the process of human adaptation: the nature of the mediation can be either one of domination, subordination, avoidance, or integration. Ultimately, adaptation is best ensured if symbiotic processes of negotiation and cooperation between subject and environment are espoused over acts of conquest or acquiescence. The adaptive mechanisms we choose to develop and employ will have wider implications for long-range human evolution. The transformations we will undergo will be influenced by both the initial decision to migrate to Space (technological), as well as the actual conditions of Space (environmental). Migration to extraterrestrial environments will be unequivocally the most profound catalyst for evolution in the history of humankind---not only for the human species itself but also for the new environments we will eventually inhabit. At the same time, we also find ourselves---via a new generation of bio-, nano-, and digital technologies---in the position to consciously and willfully direct our own evolution. Technology has always been transformative, but in the not-so-distant future, we will soon possess the capacity to radically re-invent ourselves in almost any way

  15. Links between dwarf and classical novae, and implications for the space densities and evolution of cataclysmic binaries

    SciTech Connect

    Shara, M.M.; Livio, M.; Moffat, A.F.J.; Orio, M.

    1986-12-01

    The effects of mass and angular momentum losses during a nova eruption are investigated by simulation in the context of a new nova evolution model. It is argued that surveys for cataclysmic variables (CVs) are very incomplete and that the local space density of CVs could well be 0.0001/cu pc. It is shown that the competing effets of mass and angular momentum loss usually increase the separation of a red and white dwarf during a nova eruption. The reasons why old novae remain bright for about a century after eruption and why they reduce the mass transfer rate (MTR) and eventually go into a state of hibernation for a thousand to a million years, eventually reviving as dwarf novae or novalike variables, are discussed. The results of these simulations are used to demonstrate the consistency of variable MTR in resolving the MTR discrepancy. 43 references.

  16. Improved calibration of reflectance data from the LRO Lunar Orbiter Laser Altimeter (LOLA) and implications for space weathering

    NASA Astrophysics Data System (ADS)

    Lemelin, M.; Lucey, P. G.; Neumann, G. A.; Mazarico, E. M.; Barker, M. K.; Kakazu, A.; Trang, D.; Smith, D. E.; Zuber, M. T.

    2016-07-01

    The Lunar Orbiter Laser Altimeter (LOLA) experiment on Lunar Reconnaissance Orbiter (LRO) is a laser altimeter that also measures the strength of the return pulse from the lunar surface. These data have been used to estimate the reflectance of the lunar surface, including regions lacking direct solar illumination. A new calibration of these data is presented that features lower uncertainties overall and more consistent results in the polar regions. We use these data, along with newly available maps of the distribution of lunar maria, also derived from LRO instrument data, to investigate a newly discovered dependence of the albedo of the lunar maria on latitude (Hemingway et al., [2015]). We confirm that there is an increase in albedo with latitude in the lunar maria, and confirm that this variation is not an artifact arising from the distribution of compositions within the lunar maria, using data from the Lunar Prospector Neutron Spectrometer. Radiative transfer modeling of the albedo dependence within the lunar maria is consistent with the very weak to absent dependence of albedo on latitude in the lunar highlands; the lower abundance of the iron source for space weathering products in the lunar highlands weakens the latitude dependence to the extent that it is only weakly detectable in current data. In addition, photometric models and normalization may take into account the fact that the lunar albedo is latitude dependent, but this dependence can cause errors in normalized reflectance of at most 2% for the majority of near-nadir geometries. We also investigate whether the latitude dependent albedo may have obscured detection of small mare deposits at high latitudes. We find that small regions at high latitudes with low roughness similar to the lunar maria are not mare deposits that may have been misclassified owing to high albedos imposed by the latitude dependence. Finally, we suggest that the only modest correlations among space weathering indicators defined

  17. THE SPACE DENSITY OF EXTENDED ULTRAVIOLET (XUV) DISKS IN THE LOCAL UNIVERSE AND IMPLICATIONS FOR GAS ACCRETION ONTO GALAXIES

    SciTech Connect

    Lemonias, Jenna J.; Schiminovich, David; Thilker, David; Bianchi, Luciana; Wyder, Ted K.; Martin, D. Christopher; Seibert, Mark; Madore, Barry F.; Treyer, Marie A.; Heckman, Timothy M.; Rich, R. Michael

    2011-06-01

    We present results of the first unbiased search for extended ultraviolet (XUV)-disk galaxies undertaken to determine the space density of such galaxies. Our sample contains 561 local (0.001 < z < 0.05) galaxies that lie in the intersection of available Galaxy Evolution Explorer (GALEX) deep imaging (exposure time >1.5 x 10{sup 4} s) and Sloan Digital Sky Survey DR7 footprints. We explore modifications to the standard classification scheme for our sample that includes both disk- and bulge-dominated galaxies. Visual classification of each galaxy in the sample reveals an XUV-disk frequency of up to 20% for the most nearby portion of our sample. On average over the entire sample (out to z = 0.05) the frequency ranges from a hard limit of 4%-14%. The GALEX imaging allows us to detect XUV disks beyond 100 Mpc. The XUV regions around XUV-disk galaxies are consistently bluer than the main bodies. We find a surprisingly high frequency of XUV emission around luminous red (NUV-r > 5) and green valley (3 < NUV-r < 5) galaxies. The XUV-disk space density in the local universe is >(1.5-4.2) x 10{sup -3} Mpc{sup -3}. Using the XUV emission as an indicator of recent gas accretion, we estimate that the cold gas accretion rate onto these galaxies is >(1.7-4.6) x 10{sup -3} M{sub sun} Mpc{sup -3} yr{sup -1}. The number of XUV disks in the green valley and the estimated accretion rate onto such galaxies points to the intriguing possibility that 7%-18% of galaxies in this population are transitioning away from the red sequence.

  18. Recent Developments in Reconnection Theory: the Plasmoid Instability, Self-Generated Turbulence, and Implications for Laboratory and Space Plasmas

    NASA Astrophysics Data System (ADS)

    Bhattacharjee, Amitava

    2015-11-01

    In recent years, new developments in reconnection theory have challenged classical nonlinear reconnection models. One of these developments is the so-called plasmoid instability of thin current sheets that grows at super-Alfvenic growth rates. Within the resistive MHD model, this instability alters qualitatively the predictions of the Sweet-Parker model, leading to a new nonlinear regime of fast reconnection in which the reconnection rate itself becomes independent of S. This regime has also been seen in Hall MHD as well as fully kinetic simulations, and thus appears to be a universal feature of thin current sheet dynamics, including applications to reconnection forced by the solar wind in the heliosphere and spontaneously unstable sawtooth oscillations in tokamaks. Plasmoids, which can grow by coalescence to large sizes, provide a powerful mechanism for coupling between global and kinetic scales as well as an efficient accelerator of particles to high energies. In two dimensions, the plasmoids are characterized by power-law distribution functions followed by exponential tails. In three dimensions, the instability produces self-generated and strongly anisotropic turbulence in which the reconnection rate for the mean-fields remain approximately at the two-dimensional value, but the energy spectra deviate significantly from anisotropic strong MHD turbulence phenomenology. A new phase diagram of fast reconnection has been proposed, guiding the design of future experiments in magnetically confined and high-energy-density plasmas, and have important implications for explorations of the reconnection layer in the recently launched Magnetospheric Multiscale (MMS) mission. This research is supported by DOE, NASA, and NSF.

  19. The theory of Langmuir probes in strong electrostatic potential structures

    NASA Technical Reports Server (NTRS)

    Borovsky, J. E.

    1986-01-01

    The operation of collecting and emitting Langmuir probes and double probes within time-stationary strong electrostatic potential structures is analyzed. The cross sections of spherical and cylindrical probes to charged particles within the structures are presented and used to obtain the current-voltage characteristics of idealized probes. The acquisition of plasma parameters from these characteristics is outlined, and the operation of idealized floating double-probe systems is analyzed. Probe surface effects are added to the idealized theory, and some surface effects pertinent to spacecraft probes are quantified. Magnetic field effects on idealized probes are examined, and the time required for floating probes to change their potentials by collecting charge and by emitting photoelectrons is discussed. Calculations on the space-charge effects of probe-perturbed beams and on the space-charge limiting of electron emission are given in an appendix.

  20. A semi-classical relativistic motion integrator (SCRMI), to model the orbits of space probes around the Earth and other planets

    NASA Astrophysics Data System (ADS)

    Pireaux, S.; Barriot, J. P.; Rosenblatt, P.

    Today, the motion of spacecrafts is still described according to the classical Newtonian equations plus the so-called "relativistic corrections", computed with the required precision using the Post-(Post-...) Newtonian formalism. The current approach, with the increase of tracking precision (Ka-Band Doppler, interplanetary lasers) and clock stabilities (atomic fountains) is reaching its limits in terms of complexity, and is furthermore error prone. Those problems are especially relevant when modeling tiny geophysical effects through orbitography, like for example the waxing-waning mechanism of the Martian polar caps, with temporal frequencies in the same band as relativistic effects. In the more appropriate frame of General Relativity, we study a method to numerically integrate the native relativistic equations of motion for a weak gravitational field, taking into account not only gravitational forces, but also non gravitational forces (atmospheric drag, solar radiation pressure, albedo pressure, thermal emission...). The latter are treated as perturbations, in the sense that we assume that both the local structure of space-time is not modified by these forces, and that the unperturbed satellite motion follows the geodesics of the local space-time. We also use a symplectic integrator to compute the unperturbed geodesic motion, in order to insure the constancy of the norm of the proper velocity quadrivector. S. Pireaux acknowledges financial support provided through the European Community's Improving Human Potential Program under contract RTN2-2002-00217, MAGE. P. Rosenblatt is funded under a Belgian ESA/PRODEX contract.

  1. The effects of space flight on the contractile apparatus of antigravity muscles: implications for aging and deconditioning.

    PubMed

    Baldwin, K M; Caiozzo, V J; Haddad, F; Baker, M J; Herrick, R E

    1994-05-01

    Previous studies have shown that the unloading of skeletal muscle, as occurring during exposure to space flight, exerts a profound effect on both the mass (cross sectional area) of skeletal muscle fibers and the relative expression of protein isoforms comprising the contractile system. Available information suggests that slow (type I) fibers, comprising chiefly the antigravity muscles of experimental animals, in addition to atrophying, undergo alterations in the type of myosin heavy chain (MHC) expressed such that faster isoforms become concomitantly expressed in a sub-population of slow fibers when insufficient force-bearing activity is maintained on the muscle. Consequently, these transformations in both mass and myosin heavy chain phenotype could exert a significant impact on the functional properties of skeletal muscle as manifest in the strength, contractile speed, and endurance scope of the muscle. To further explore these issues, a study was performed in which young adult male rats were exposed to zero gravity for six days, following which, the antigravity soleus muscle was examined for a) contractile properties, determined in situ and b) isomyosin expression, as studied using biochemical, molecular biology, and histochemical/immunohistochemical techniques. PMID:11538774

  2. The effects of space flight on the contractile apparatus of antigravity muscles: implications for aging and deconditioning

    NASA Technical Reports Server (NTRS)

    Baldwin, K. M.; Caiozzo, V. J.; Haddad, F.; Baker, M. J.; Herrick, R. E.

    1994-01-01

    Previous studies have shown that the unloading of skeletal muscle, as occurring during exposure to space flight, exerts a profound effect on both the mass (cross sectional area) of skeletal muscle fibers and the relative expression of protein isoforms comprising the contractile system. Available information suggests that slow (type I) fibers, comprising chiefly the antigravity muscles of experimental animals, in addition to atrophying, undergo alterations in the type of myosin heavy chain (MHC) expressed such that faster isoforms become concomitantly expressed in a sub-population of slow fibers when insufficient force-bearing activity is maintained on the muscle. Consequently, these transformations in both mass and myosin heavy chain phenotype could exert a significant impact on the functional properties of skeletal muscle as manifest in the strength, contractile speed, and endurance scope of the muscle. To further explore these issues, a study was performed in which young adult male rats were exposed to zero gravity for six days, following which, the antigravity soleus muscle was examined for a) contractile properties, determined in situ and b) isomyosin expression, as studied using biochemical, molecular biology, and histochemical/immunohistochemical techniques.

  3. HUBBLE SPACE TELESCOPE SPECTRAL OBSERVATIONS NEAR THE He II Ly{alpha} BREAK: IMPLICATIONS FOR He II REIONIZATION

    SciTech Connect

    Syphers, David; Anderson, Scott F.; Haggard, Daryl; Zheng Wei; Meiksin, Avery; Schneider, Donald P.; York, Donald G. E-mail: anderson@astro.washington.edu

    2011-01-10

    Quasars that allow the study of intergalactic medium (IGM) He II are very rare, since they must be at high redshift along sightlines free of substantial hydrogen absorption, but recent work has dramatically expanded the number of such quasars known. We analyze two dozen higher-redshift (z = 3.1-3.9) low-resolution He II quasar spectra from the Hubble Space Telescope and find that their He II Gunn-Peterson troughs suggest exclusion of very early and very late reionization models, favoring a reionization redshift of z {approx} 3. Although the data quality is not sufficient to reveal details such as the expected redshift evolution of helium opacity, we obtain the first ensemble measure of helium opacity at high redshift averaged over many sightlines: {tau} = 4.90 at z {approx} 3.3. We also find that it would be very difficult to observe the IGM red wing of absorption from the beginning of He II reionization, but depending on the redshift of reionization and the size of ionization zones, it might be possible to do so in some objects with the current generation of UV spectrographs.

  4. Survivability of bare, individual Bacillus subtilis spores to high-velocity surface impact: Implications for microbial transfer through space

    NASA Astrophysics Data System (ADS)

    Barney, Brandon L.; Pratt, Sara N.; Austin, Daniel E.

    2016-06-01

    Laboratory experiments show that endospores of Bacillus subtilis survive impact against a solid surface at velocities as high as 299 ±28 m/s. During impact, spores experience and survive accelerations of at least 1010 m/s2. The spores were introduced into a vacuum chamber using an electrospray source and accelerated to a narrow velocity distribution by entrainment in a differentially pumped gas flow. Different velocity ranges were studied by modifying the gas flow parameters. The spores were electrically charged, allowing direct measurement of the velocity of each spore as it passed through an image charge detector prior to surface impact. Spores impacted a glass surface and were collected for subsequent analysis by culturing. Most spores survived impact at all measured velocities. These experiments differ fundamentally from other studies that show either shock or impact survivability of bacteria embedded within or on the surface of a projectile. Bacteria in the present experiments undergo a single interaction with a solid surface at the full impact velocity, in the absence of any other effects such as cushioning due to microbe agglomerations, deceleration due to air or vapor, or transfer of impact shock through solid or liquid media. During these full-velocity impact events, the spores experience extremely high decelerations. This study is the first reported instance of accelerations of this magnitude experienced during a bacteria impact event. These results are discussed in the context of potential transfer of viable microbes in space and other scenarios involving surface impacts at high velocities.

  5. The relation of radar to cloud area-time integrals and implications for rain measurements from space

    NASA Technical Reports Server (NTRS)

    Atlas, David; Bell, Thomas L.

    1992-01-01

    The relationships between satellite-based and radar-measured area-time integrals (ATI) for convective storms are determined, and both are shown to depend on the climatological conditional mean rain rate and the ratio of the measured cloud area to the actual rain area of the storms. The GOES precipitation index of Arkin (1986) for convective storms, an area-time integral for satellite cloud areas, is shown to be related to the ATI for radar-observed rain areas. The quality of GPI-based rainfall estimates depends on how well the cloud area is related to the rain area and the size of the sampling domain. It is also noted that the use of a GOES cloud ATI in conjunction with the radar area-time integral will improve the accuracy of rainfall estimates and allow such estimates to be made in much smaller space-time domains than the 1-month and 5-deg boxes anticipated for the Tropical Rainfall Measuring Mission.

  6. Exo-C: a probe-scale space mission to directly image and spectroscopically characterize exoplanetary systems using an internal coronagraph

    NASA Astrophysics Data System (ADS)

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

    2014-08-01

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

  7. In situ biological resources: Soluble nutrients and electrolytes in carbonaceous asteroids/meteorites. Implications for astroecology and human space populations

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.

    2014-12-01

    Ecosystems in space will need in-situ bioavailable nutrients. The measured nutrients in meteorites allow experiment-based estimates of nutrients in asteroids, and of the biomass and populations that can be derived from these in situ bioresources. In this respect, we found that carbonaceous chondrite meteorites can support microorganisms and plant cultures, suggesting that similar asteroid materials are also biologically fertile. The sustainable biomass and populations are determined by the available resource materials, their yields of nutrients and biomass, the biomass needed to support human populations, the duration of the ecosystem, and wastage. The bioavailable C, N, and electrolytes in carbonaceous chondrite meteorites vary as CM2>CR2>CV3>CO3>CK4>CK5 in correlation with petrologic type, including aqueous alteration. Their average bioavailable C, N, K and P can yield 2.4, 3.5, 2.5, and 0.08 g biomass/kg resource material, respectively, showing phosphorus as the limiting nutrient. On this basis, soluble nutrients in a 100 km radius, 1019 kg resource asteroid can sustain an ecosystem of 108 kg biomass and a human population of 10,000 for >109 years, and its total nutrient contents can sustain a population of one million, by replacing a wastage of 1% of the biomass per year. Overall, the total nutrient contents of the 1022 kg carbonaceous asteroids can yield a biomass of 1020 kg that supports a steady-state human population of one billion during the habitable future of the Solar System, contributing a time-integrated biomass of 1022 kg-years. These astroecology estimates use experimental data on nutrients in asteroids/meteorites to quantify the sustainable biomass and human populations in this and similar solar systems.

  8. Testing the estimated hypothetical response of a major CME impact on Earth and its implications to space weather

    NASA Astrophysics Data System (ADS)

    Bala, Ramkumar; Reiff, Patricia; Russell, C. T.

    2015-05-01

    The high-speed coronal mass ejection (CME), ejected on 23 July 2012, observed by STEREO-A on the same day as the leading edge of the CME arrived at 1AU was unique both in respect to the observed plasma and magnetic structure and the large solar energetic particle flux that dynamically regulated the shock front. Because of its great intensity, it has been hailed as "Carrington 2" by some, warning that, had that CME been heading toward the Earth, it might have caused a major space weather event. We used the Rice Artificial Neural Network algorithms with the solar wind and interplanetary magnetic field parameters measured in situ by STEREO-A as inputs to infer what the "geoeffectiveness" of that storm might have been. We have also used an MHD model in Open Geospace General Circulation Model to understand the global magnetospheric process in time sequence. We presently show our neural network models of Kp and Dst on our real-time prediction site: http://mms.rice.edu/realtime/forecast.html. Running this event through our models showed that, in fact, this would have been an exceptional event. Our results show a prediction resulting in a Kp value of 8+, a Dst of nearly -250 nT, but when assumptions about maximum dipole angle tilt and density are made, predictions resulting in Kp of 11- and Dst dipping close to -700 nT are found. Finally, when solar energetic proton flux is included, the Kp and Dst predictions drop to 8- and ≈-625 nT, respectively.

  9. Asteroids as Propulsion Systems of Space Ships

    NASA Technical Reports Server (NTRS)

    Bolonkin, Alexander

    2003-01-01

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

  10. Observational probes of cosmic acceleration

    NASA Astrophysics Data System (ADS)

    Weinberg, David H.; Mortonson, Michael J.; Eisenstein, Daniel J.; Hirata, Christopher; Riess, Adam G.; Rozo, Eduardo

    2013-09-01

    The accelerating expansion of the universe is the most surprising cosmological discovery in many decades, implying that the universe is dominated by some form of “dark energy” with exotic physical properties, or that Einstein’s theory of gravity breaks down on cosmological scales. The profound implications of cosmic acceleration have inspired ambitious efforts to understand its origin, with experiments that aim to measure the history of expansion and growth of structure with percent-level precision or higher. We review in detail the four most well established methods for making such measurements: Type Ia supernovae, baryon acoustic oscillations (BAO), weak gravitational lensing, and the abundance of galaxy clusters. We pay particular attention to the systematic uncertainties in these techniques and to strategies for controlling them at the level needed to exploit “Stage IV” dark energy facilities such as BigBOSS, LSST, Euclid, and WFIRST. We briefly review a number of other approaches including redshift-space distortions, the Alcock-Paczynski effect, and direct measurements of the Hubble constant H0. We present extensive forecasts for constraints on the dark energy equation of state and parameterized deviations from General Relativity, achievable with Stage III and Stage IV experimental programs that incorporate supernovae, BAO, weak lensing, and cosmic microwave background data. We also show the level of precision required for clusters or other methods to provide constraints competitive with those of these fiducial programs. We emphasize the value of a balanced program that employs several of the most powerful methods in combination, both to cross-check systematic uncertainties and to take advantage of complementary information. Surveys to probe cosmic acceleration produce data sets that support a wide range of scientific investigations, and they continue the longstanding astronomical tradition of mapping the universe in ever greater detail over ever

  11. THIRD-EPOCH MAGELLANIC CLOUD PROPER MOTIONS. I. HUBBLE SPACE TELESCOPE/WFC3 DATA AND ORBIT IMPLICATIONS

    SciTech Connect

    Kallivayalil, Nitya; Van der Marel, Roeland P.; Anderson, Jay; Besla, Gurtina; Alcock, Charles

    2013-02-20

    We present proper motions for the Large and Small Magellanic Clouds (LMC and SMC) based on three epochs of Hubble Space Telescope data, spanning a {approx}7 yr baseline, and centered on fields with background QSOs. The first two epochs, the subject of past analyses, were obtained with ACS/HRC, and have been reanalyzed here. The new third epoch with WFC3/UVIS increases the time baseline and provides better control of systematics. The three-epoch data yield proper-motion random errors of only 1%-2% per field. For the LMC this is sufficient to constrain the internal proper-motion dynamics, as will be discussed in a separate paper. Here we focus on the implied center-of-mass proper motions: {mu} {sub W,LMC} = -1.910 {+-} 0.020 mas yr{sup -1}, {mu} {sub N,LMC} = 0.229 {+-} 0.047 mas yr{sup -1}, and {mu} {sub W,SMC} = -0.772 {+-} 0.063 mas yr{sup -1}, {mu} {sub N,SMC} = -1.117 {+-} 0.061 mas yr{sup -1}. We combine the results with a revised understanding of the solar motion in the Milky Way to derive Galactocentric velocities: v {sub tot,LMC} = 321 {+-} 24 km s{sup -1} and v {sub tot,SMC} = 217 {+-} 26 km s{sup -1}. Our proper-motion uncertainties are now dominated by limitations in our understanding of the internal kinematics and geometry of the Clouds, and our velocity uncertainties are dominated by distance errors. Orbit calculations for the Clouds around the Milky Way allow a range of orbital periods, depending on the uncertain masses of the Milky Way and LMC. Periods {approx}< 4 Gyr are ruled out, which poses a challenge for traditional Magellanic Stream models. First-infall orbits are preferred (as supported by other arguments as well) if one imposes the requirement that the LMC and SMC must have been a bound pair for at least several Gyr.

  12. Failure and frictional sliding envelopes in three-dimensional stress space: Insights from Distinct Element Method (DEM) models and implications for the brittle-ductile transition of rock

    NASA Astrophysics Data System (ADS)

    Schöpfer, Martin; Childs, Conrad; Manzocchi, Tom

    2013-04-01

    Rocks deformed at low confining pressure are brittle, meaning that after peak stress the strength decreases to a residual value determined by frictional sliding. The difference between the peak and residual value is the stress drop. At high confining pressure, however, no stress drop occurs. The transition pressure at which no loss in strength occurs is a possible definition of the brittle-ductile transition. The Distinct Element Method (DEM) is used to illustrate how this type of brittle-ductile transition emerges from a simple model in which rock is idealised as an assemblage of cemented spherical unbreakable grains. These bonded particle models are subjected to loading under constant mean stress and stress ratio conditions using distortional periodic space, which eliminates possible boundary effects arising from the usage of rigid loading platens. Systematic variation of both mean stress and stress ratio allowed determination of the complete three dimensional yield, peak stress and residual strength envelopes. The models suggest that the brittle-ductile transition is a mean stress and stress ratio dependent space curve, which cannot be adequately described by commonly used failure criteria (e.g., Mohr-Coulomb, Drucker-Prager). The model peak strength data exhibit an intermediate principal stress dependency which is, at least qualitatively, similar to that observed for natural rocks deformed under polyaxial laboratory conditions. Comparison of failure envelopes determined for bonded particle models with and without bond shear failure suggests that the non-linear pressure dependence of strength (concave failure envelopes) is, at high mean stress, the result of microscopic shear failure, a result consistent with earlier two-dimensional numerical multiple-crack simulations [D. A. Lockner & T. R. Madden, JGR, Vol. 96, No. B12, 1991]. Our results may have implications for a wide range of geophysical research areas, including the strength of the crust, the seismogenic

  13. The policy implications of urban open space commercial vegetable farmers' willingness and ability to pay for reclaimed water for irrigation in Kumasi, Ghana.

    PubMed

    Amponsah, Owusu; Vigre, Håkan; Braimah, Imoro; Schou, Torben Wilde; Abaidoo, Robert Clement

    2016-03-01

    The acute waste management problems, coupled with the proliferation of small scale industries in many developing countries, make low quality water treatment before use inevitable in the long run. These industries have the potential to discharge effluent containing chemicals and heavy metals into the environment. The indiscriminative use of pharmaceutical products by households in many of these countries is another source of health concern. Low quality water treatment in these countries has however been hampered by the high cost of infrastructure provision and maintenance. Cost-sharing among stakeholders appears to be a promising strategy to finance and maintain the wastewater treatment infrastructure. In this study therefore, the willingness and ability of urban open space commercial vegetable farmers to pay for reclaimed water for irrigation purposes has been assessed. One hundred open space commercial vegetable farmers and four vegetable farmers' associations were selected and interviewed in Kumasi in Ghana using semi-structured interview schedules and interview guides respectively. The results of the study show that approximately three out of every five vegetable farmers were willing to pay for reclaimed water for irrigation. The results further show that the probability of being willing to pay by farmers who agreed that the current water they used for irrigation was harmful is approximately 5.3 times greater than that of those who did not. The analysis of the farmers' ability to pay revealed that all the farmers would be capable of paying for reclaimed water at a price of US$0.11/m(3). This has implications for land tenure security and vegetable consumers' willingness to pay higher prices for the produce. PMID:27441260

  14. Gravity Probe B Detector Mount Assembly

    NASA Technical Reports Server (NTRS)

    2004-01-01

    In this photo, the Gravity Probe B (GP-B) detector mount assembly is shown in comparison to the size of a dime. The assembly is used to detect exactly how much starlight is coming through different beams from the beam splitter in the telescope. The measurements from the tiny chips inside are what keeps GP-B aimed at the guide star. The GP-B is the relativity experiment 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Paul Ehrensberger, Stanford University.)

  15. Hubble space telescope/cosmic origins spectrograph observations of the quasar Q0302–003: Probing the He II reionization epoch and QSO proximity effects

    SciTech Connect

    Syphers, David; Shull, J. Michael

    2014-03-20

    Q0302–003 (z = 3.2860 ± 0.0005) was the first quasar discovered that showed a He II Gunn-Peterson trough, a sign of incomplete helium reionization at z ≳ 2.9. We present its Hubble Space Telescope/Cosmic Origins Spectrograph far-UV medium-resolution spectrum, which resolves many spectral features for the first time, allowing study of the quasar itself, the intergalactic medium, and quasar proximity effects. Q0302–003 has a harder intrinsic extreme-UV spectral index than previously claimed, as determined from both a direct fit to the spectrum (yielding α{sub ν} ≈ –0.8) and the helium-to-hydrogen ion ratio in the quasar's line-of-sight proximity zone. Intergalactic absorption along this sightline shows that the helium Gunn-Peterson trough is largely black in the range 2.87 < z < 3.20, apart from ionization due to local sources, indicating that helium reionization has not completed at these redshifts. However, we tentatively report a detection of nonzero flux in the high-redshift trough when looking at low-density regions, but zero flux in higher-density regions. This constrains the He II fraction to be about 1% in the low-density intergalactic medium (IGM) and possibly a factor of a few higher in the IGM as a whole, suggesting helium reionization has progressed substantially by z ∼ 3.1. The Gunn-Peterson trough recovers to a He II Lyα forest at z < 2.87. We confirm a transmission feature due to the ionization zone around a z = 3.05 quasar just off the sightline, and resolve the feature for the first time. We discover a similar such feature possibly caused by a luminous z = 3.23 quasar further from the sightline, which suggests that this quasar has been luminous for >34 Myr.

  16. PROBING THE GC-LMXB CONNECTION IN NGC 1399: A WIDE-FIELD STUDY WITH THE HUBBLE SPACE TELESCOPE AND CHANDRA

    SciTech Connect

    Paolillo, Maurizio; Puzia, Thomas H.; Goudfrooij, Paul; Zepf, Stephen E.; Maccarone, Thomas J.; Kundu, Arunav; Fabbiano, Giuseppina; Angelini, Lorella

    2011-08-01

    We present a wide-field study of the globular cluster (GC)/low-mass X-ray binary (LMXB) connection in the giant elliptical NGC 1399. The large field of view of the Advanced Camera for Surveys/WFC, combined with Hubble Space Telescope and Chandra high resolution, allow us to constrain the LMXB formation scenarios in elliptical galaxies. We confirm that NGC 1399 has the highest LMXB fraction in GCs of all nearby elliptical galaxies studied so far, even though the exact value depends on galactocentric distance due to the interplay of a differential GC versus galaxy light distribution and the GC color dependence. In fact, LMXBs are preferentially hosted by bright, red GCs out to >5 R{sub eff} of the galaxy light. The finding that GCs hosting LMXBs follow the radial distribution of their parent GC population argues against the hypothesis that the external dynamical influence of the galaxy affects the LMXB formation in GCs. On the other hand, field-LMXBs closely match the host galaxy light, thus indicating that they are originally formed in situ and not inside GCs. We measure GC structural parameters, finding that the LMXB formation likelihood is influenced independently by mass, metallicity, and GC structural parameters. In particular, the GC central density plays a major role in predicting which GCs host accreting binaries. Finally, our analysis shows that LMXBs in GCs are marginally brighter than those in the field, and in particular the only color-confirmed GC with L{sub X} > 10{sup 39} erg s{sup -1} shows no variability, which may indicate a superposition of multiple LMXBs in these systems.

  17. Space methods in oceanology

    NASA Technical Reports Server (NTRS)

    Bolshakov, A. A.

    1985-01-01

    The study of Earth from space with specialized satellites, and from manned orbiting stations, has become important in the space programs. The broad complex of methods used for probing Earth from space are different methods of the study of ocean, dynamics. The different methods of ocean observation are described.

  18. Completed Gravity Probe B Undergoes Thermal Vacuum Testing

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Gravity Probe B (GP-B) is the relativity experiment 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. In this photograph, the completed space vehicle is undergoing thermal vacuum environment testing. 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. Launched April 20, 2004 , the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University along with major subcontractor Lockheed Martin Corporation. (Image credit to Russ Underwood, Lockheed Martin Corporation.)

  19. Effects of Accretion Disks on Spins and Eccentricities of Binaries, and Implications for Gravitational Waves

    NASA Technical Reports Server (NTRS)

    Baker, John

    2012-01-01

    Effects of accretion disks on spins and eccentricities of binaries, and implications for gravitational waves. John Baker Space-based gravitational wave observations will allow exquisitely precise measurements of massive black hole binary properties. Through several recently suggested processes, these properties may depend on interactions with accretion disks through the merger process. I will discuss ways that accretion may influence those binary properties which may be probed by gravitational-wave observations.

  20. Probing the configurational space of a metalloprotein core: an ab initio molecular dynamics study of Duo Ferro 1 binuclear Zn cofactor.

    PubMed

    Papoian, Garegin A; DeGrado, William F; Klein, Michael L

    2003-01-15

    We present three theoretical models of various degree of completeness to explore the chemical phase space available to the Glu4His2Zn2 cofactor found in the four-helix bundle of de novo designed metalloprotein Duo Ferro 1. We have found that the planewave DFT geometry optimization of 94-atom Model I, which contains both the protein scaffold constraints as well as the second shell hydrogen bonding network, reproduces the crystal structure bonding with remarkable accuracy (0.34 A). Surprisingly, the geometry optimization of 66-atom Model II (lacking the second shell hydrogen bonding) and 48-atom Model III (being also free of the protein scaffold constraints) still result in the fidelity with the crystallographic structure (RMSDs 0.29 and 0.34 A, respectively). To examine whether these structures are close to the global minimum as well as to investigate various conformational transitions to which the di-Zn cofactor may be susceptible to, we have carried out a 10 ps Car-Parrinello Molecular Dynamics (CPMD) simulation of Model III. We suggest that weak hydrogen bonds between imidazole hydrogens and carboxylate oxygens modulate the dynamical behavior of the system. One part of the molecule was found to be rigid due to the particular H(imidazole)-O(carboxylate) interaction restricting both the motion of the imidazole ring as well as the terminal carboxylate conformational mobility. The second half of the system was very flexible demonstrating a coupling of a transient formation of H(imidazole)-O(carboxylate) bonds with the spinning of the imidazole ring and syn-anti isomerization of the terminal carboxylate group. In addition, two low-energy snapshots from the 10 ps CPMD run were quenched, and their geometries were optimized, leading to two new isomers 48 kJ/mol lower in energy than the one associated with the crystal structure. We suggest that periodic quenching of the CPMD simulation snapshots of a minimalist model may be used as an efficient method to generate a large

  1. Direct Communication to Earth from Probes

    NASA Technical Reports Server (NTRS)

    Bolton, Scott J.; Folkner, William M.; Abraham, Douglas S.

    2005-01-01

    A viewgraph presentation on outer planetary probe communications to Earth is shown. The topics include: 1) Science Rational for Atmospheric Probes to the Outer Planets; 2) Controlling the Scientific Appetite; 3) Learning more about Jupiter before we send more probes; 4) Sample Microwave Scan From Juno; 5) Jupiter s Deep Interior; 6) The Square Kilometer Array (SKA): A Breakthrough for Radio Astronomy; 7) Deep Space Array-based Network (DSAN); 8) Probe Direct-to-Earth Data Rate Calculations; 9) Summary; and 10) Enabling Ideas.

  2. Temperature Correction in Probe Measurements

    NASA Astrophysics Data System (ADS)

    Gutsev, S. A.

    2015-09-01

    This work is devoted to experimental investigations of a decaying plasma using Langmuir probes. The gas pressure, the discharge current, and the moment of afterglow were selected to obtain probe characteristics in collisionless, intermediate, and drifting regimes of motion of charged particles. The manner in which the shape of the volt- ampere characteristics changes on passage from the collisionless motion to diffusion motion has been shown. A detailed analysis has been made of the source of errors arising when orbital-motion formulas or the logarithmic-operation method are applied to processing of the probe curves. It has been shown that neglect of collisions of charged particles in the probe layer leads to an ion-density value overstated more than three times, an electron-temperature value overstated two times, and an ion temperature overstated three to nine times. A model of interaction of charged particles in the probe layer has been proposed for correction of the procedure of determining temperature. Such an approach makes it possible to determine the space-charge layer in the probe, and also the value of the self-consistent field. The use of the developed procedures gives good agreement between experimental and theoretical results.

  3. Wind measurements by electromagnetic probes

    NASA Technical Reports Server (NTRS)

    Susko, Michael

    1988-01-01

    The emerging technology of electromagnetic probing of the atmosphere to measure winds used in a space vehicle ascent winds load calculations is presented. The frequency range, altitude, and resolution for the following probes are presented: lidars, microwave radars, and clear-air Doppler radars (popularly known as wind profilers). The electromagnetic probing of the atmosphere by clear-air radars and lasers is the new technology to supplement balloon-borne wind sensors used to determine ascent wind loads of space vehicles. The electromagnetic probes measure the wind velocity using the Doppler effect. This is the radar technology used in MSFC's Radar Wind Profiler, and is similar to the technology used in conventional Doppler systems except that the frequency is generally lower, antenna is bigger, and dwell time much longer. Designed for unattended and automated instrumentation in providing measurements of the wind in the troposphere, the profiler employs Doppler radar technology and is currently being put in operation at NASA Kennedy Space Center, Florida.

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

    PubMed Central

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

    2011-01-01

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

  5. Rapid enhancement of low energy (<100 eV) ion flux in response to interplanetary shocks based on two Van Allen Probes case studies: Implications for source regions and heating mechanisms

    DOE PAGESBeta

    Yue, Chao; Li, Wen; Reeves, Geoffrey D.; Nishimura, Yukitoshi; Zong, Qiugang; Ma, Qianli; Bortnik, Jacob; Thorne, Richard M.; Spence, Harlan E.; Kletzing, Craig A.; et al

    2016-07-15

    Interactions between interplanetary (IP) shocks and the Earth's magnetosphere manifest many important space physics phenomena including low-energy ion flux enhancements and particle acceleration. In order to investigate the mechanisms driving shock-induced enhancement of low-energy ion flux, we have examined two IP shock events that occurred when the Van Allen Probes were located near the equator while ionospheric and ground observations were available around the spacecraft footprints. We have found that, associated with the shock arrival, electromagnetic fields intensified, and low-energy ion fluxes, including H+, He+, and O+, were enhanced dramatically in both the parallel and perpendicular directions. During the 2more » October 2013 shock event, both parallel and perpendicular flux enhancements lasted more than 20 min with larger fluxes observed in the perpendicular direction. In contrast, for the 15 March 2013 shock event, the low-energy perpendicular ion fluxes increased only in the first 5 min during an impulse of electric field, while the parallel flux enhancement lasted more than 30 min. In addition, ionospheric outflows were observed after shock arrivals. From a simple particle motion calculation, we found that the rapid response of low-energy ions is due to drifts of plasmaspheric population by the enhanced electric field. Furthermore, the fast acceleration in the perpendicular direction cannot solely be explained by E × B drift but betatron acceleration also plays a role. Adiabatic acceleration may also explain the fast response of the enhanced parallel ion fluxes, while ion outflows may contribute to the enhanced parallel fluxes that last longer than the perpendicular fluxes.« less

  6. Thrust Vector Control using movable probes

    NASA Technical Reports Server (NTRS)

    Cavalleri, Robert; Tiarn, Weihnurng; Readey, Harvey

    1990-01-01

    A study was undertaken to determine if movable probes or struts positioned in the nozzle can be used to provide Thrust Vector Control of the Space Shuttle Solid Rocket Booster. The study employed CFD to determine estimates of the shock standoff distance from the probe. An empirical correlation was used to construct the shock shape and the pressure distribution generated by the probe. The TVC performance for a single and multiple number of probes was then used to determine requirements for a maximum thrust angle offset of 7.5 degrees. Consideration was given to what materials would be suitable for the probe and if active cooling is required. Based on the performance analysis and thermal requirements, a Probe Thrust Vector Control (PTVC) system was sized. Indications are that a PTVC system weight is in the 1500 1bm weight range, compared to the existing weight of 7500 1bm for the SRB nozzle gimble system.

  7. Results of an investigation to determine local flow characteristics at the air data probe locations using an 0.030-scale model (45-0) of the space shuttle vehicle orbiter configuration 140A/B (modified) in the NASA Ames Research Center unitary plan wind tunnel (OA161, A, B, C), volume 1

    NASA Technical Reports Server (NTRS)

    Nichols, M. E.

    1976-01-01

    Results are presented of wind tunnel test 0A161 of a 0.030-scale model 45-0 of the configuration 140A/B (modified) space shuttle vehicle orbiter in the NASA Ames Research Center Unitary Plan Wind Tunnel facilities. The purpose of this test was to determine local total and static pressure environments for the air data probe locations and relative effectiveness of alternate flight-test probe configurations. Testing was done in the Mach number range from 0.30 to 3.5. Angle of attack was varied from -8 to 25 degrees while sideslip varied between -8 and 8 degrees.

  8. PROcess Based Diagnostics PROBE

    NASA Technical Reports Server (NTRS)

    Clune, T.; Schmidt, G.; Kuo, K.; Bauer, M.; Oloso, H.

    2013-01-01

    Many of the aspects of the climate system that are of the greatest interest (e.g., the sensitivity of the system to external forcings) are emergent properties that arise via the complex interplay between disparate processes. This is also true for climate models most diagnostics are not a function of an isolated portion of source code, but rather are affected by multiple components and procedures. Thus any model-observation mismatch is hard to attribute to any specific piece of code or imperfection in a specific model assumption. An alternative approach is to identify diagnostics that are more closely tied to specific processes -- implying that if a mismatch is found, it should be much easier to identify and address specific algorithmic choices that will improve the simulation. However, this approach requires looking at model output and observational data in a more sophisticated way than the more traditional production of monthly or annual mean quantities. The data must instead be filtered in time and space for examples of the specific process being targeted.We are developing a data analysis environment called PROcess-Based Explorer (PROBE) that seeks to enable efficient and systematic computation of process-based diagnostics on very large sets of data. In this environment, investigators can define arbitrarily complex filters and then seamlessly perform computations in parallel on the filtered output from their model. The same analysis can be performed on additional related data sets (e.g., reanalyses) thereby enabling routine comparisons between model and observational data. PROBE also incorporates workflow technology to automatically update computed diagnostics for subsequent executions of a model. In this presentation, we will discuss the design and current status of PROBE as well as share results from some preliminary use cases.

  9. Man's future in space

    NASA Technical Reports Server (NTRS)

    Freitag, R. F.

    1975-01-01

    Studies evaluating potential operational and commercial uses of space are being conducted, taking into account astronomy, astrophysics, manned bases and laboratories in earth orbit, space colonization, terrestrial communications, space processing and manufacturing, interstellar probes, planetary exploration, and the use of space for terrestrial energy supply. The present status in the exploration of the solar system is examined, giving attention to Jupiter, Venus, Mars, and Mercury. A brief outline of the development of human colonies on Mars is presented.

  10. Magnetic-probe diagnostics for railgun plasma armatures

    SciTech Connect

    Parker, J.V.

    1989-06-01

    Magnetic probes were employed on the first plasma armature railgun experiments, and they have been used continuously since then for position determination and qualitative determination of the armature current. In the last few years, improvements in experimental technique and analysis have permitted more accurate measurements of the plasma-armature current distribution. This paper reviews the various probe configurations in use today and presents analytic approximations for the dependence of the probe signal on probe location and railgun geometry. Rail current and armature current probes are compared and contrasted with respect to resolution and accuracy. Further improvements in measurement accuracy are predicted for close-spaced magnetic-probe arrays.

  11. Communication: Probing anomalous diffusion in frequency space

    SciTech Connect

    Stachura, Sławomir; Kneller, Gerald R.

    2015-11-21

    Anomalous diffusion processes are usually detected by analyzing the time-dependent mean square displacement of the diffusing particles. The latter evolves asymptotically as W(t) ∼ 2D{sub α}t{sup α}, where D{sub α} is the fractional diffusion constant and 0 < α < 2. In this article we show that both D{sub α} and α can also be extracted from the low-frequency Fourier spectrum of the corresponding velocity autocorrelation function. This offers a simple method for the interpretation of quasielastic neutron scattering spectra from complex (bio)molecular systems, in which subdiffusive transport is frequently encountered. The approach is illustrated and validated by analyzing molecular dynamics simulations of molecular diffusion in a lipid POPC bilayer.

  12. Gravitational redshift space-probe experiment

    NASA Technical Reports Server (NTRS)

    Vessot, R. F. C.; Levine, M. W.

    1979-01-01

    A Scout D rocket was launched from Wallops Island, Virginia, carrying an atomic hydrogen maser oscillator system as the payload. The frequency of signals from the oscillator was monitored on the ground at Merritt Island, Florida, by using two hydrogen masers as comparison oscillators. The first-order Doppler shift in the signals was eliminated by a go-return transponder link to the payload, and the resulting data, representing the relativistic shifts, were recovered and recorded. The objective was to measure directly the effect of gravitational potential on the frequency of an atomic hydrogen maser assuming it to be a 'proper' clock. A gravitational effect amounting to some 4.5 parts in 10 to the 10th power was measured with an oscillator having a stability better than 1 part in 10 to the 14th power. Therefore, to make the best possible use of the oscillator, all frequency shifts at the 2 to 5 X 10 to the -15 power level in delta f/f in the system must be accounted for. This includes all the phase variations that can cause such a shift to appear. The experiment, the data available and the manner in which they were processed, and the results are described.

  13. Pioneer Saturn Encounter. [Pioneer 11 space probe

    NASA Technical Reports Server (NTRS)

    1979-01-01

    The Pioneer Saturn Spacecraft, which began its journey as Pioneer 11, provided the first close view of the rings of Saturn as well as its system of moons. Its payload of 11 operating instruments obtained or confirmed data about the mass, temperature, composition, radiation belts, and atmosphere of the planet and its larger satellite, Titan. It made photometric and polarization measurements of lapetus, Rhea, Dione, and Tethys, as well as discovered additional rings. Scientific highlights of the mission are summarized. Color imagery provided by the photopolarimeter is included along with illustrations of the planet's magnetic field and radiation belts.

  14. MARINER 10 SPACE PROBE UNDERGOES ENCAPSULATION

    NASA Technical Reports Server (NTRS)

    1973-01-01

    After complete check out, technicians prepare to encapsulate Mariner 10, the spacecraft that will be launched toward the planets Venus and Mercury in early November. The Mariner 10 project includes two first: First use of one planet's (Venus') gravitational field to propel a spacecraft onto another; and first exploration of Mercury. The spacecraft weighs 1,100 pounds, including 170 pounds of scientific equipment. Two television cameras aboard Mariner 10 are expected to take 8,000 pictures of the two planets, and six scientific experiments will return information on solar wind, magnetic fields, charged particles, temperature emissions, radio signals, and atmospheric conditions. Mariner will be launched atop Atlas/Centaur 34, from NASA Complex 36B at Cape Kennedy, Fla.

  15. Heat transfer probe

    DOEpatents

    Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

    2006-10-10

    Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

  16. NASA Smart Surgical Probe Project

    NASA Technical Reports Server (NTRS)

    Mah, Robert W.; Andrews, Russell J.; Jeffrey, Stefanie S.; Guerrero, Michael; Papasin, Richard; Koga, Dennis (Technical Monitor)

    2002-01-01

    Information Technologies being developed by NASA to assist astronaut-physician in responding to medical emergencies during long space flights are being employed for the improvement of women's health in the form of "smart surgical probe". This technology, initially developed for neurosurgery applications, not only has enormous potential for the diagnosis and treatment of breast cancer, but broad applicability to a wide range of medical challenges. For the breast cancer application, the smart surgical probe is being designed to "see" a suspicious lump, determine by its features if it is cancerous, and ultimately predict how the disease may progress. A revolutionary early breast cancer detection tool based on this technology has been developed by a commercial company and is being tested in human clinical trials at the University of California at Davis, School of Medicine. The smart surgical probe technology makes use of adaptive intelligent software (hybrid neural networks/fuzzy logic algorithms) with the most advanced physiologic sensors to provide real-time in vivo tissue characterization for the detection, diagnosis and treatment of tumors, including determination of tumor microenvironment and evaluation of tumor margins. The software solutions and tools from these medical applications will lead to the development of better real-time minimally-invasive smart surgical probes for emergency medical care and treatment of astronauts on long space flights.

  17. Astronaut James Lovell checks body temperature with oral temperature probe

    NASA Technical Reports Server (NTRS)

    1965-01-01

    Gemini 7 pilot Astronaut James A. Lovell Jr. has temperature check with oral temperature probe attached to his space suit during final preflight preparations for the Gemini 7 space mission. The temperature probe allows doctors to monitor astronauts body temperature at any time during the mission.

  18. Hydrodynamic ultrasonic probe

    DOEpatents

    Day, Robert A.; Conti, Armond E.

    1980-01-01

    An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

  19. Methylation at the PW71 locus on chromosome 15 in DNA derived from CVS and from amniocytes; implications for the use of the PW71 probe in prenatal diagnosis of the Prader-Willi and Angleman syndromes

    SciTech Connect

    Telleria, P.; Yu, C.C.; Brown, S.

    1994-09-01

    The probe PW71 spans a HpaII site in the Prader-Willi/Angleman Syndrome critical region on chromosome 15. A single Southern blot with this probe can be used to detect deletion and uniparental disomy. We attempted to determine the methylation state of the PW71 locus in DNA derived from prenatal sources. Southern blots of HindIII and HindIII/HpaII double digests of DNA from cultured amniocytes and CVS specimens were prepared and probed with the PW71 probe. The results from 6 cultured CVS specimens indicate that several HPAII sites recognized by the PW71 probe are not methylated in trophoblast. Four amniotic fluid cultures gave results which were not different from lymphocyte-derived DNA; however, in several cases, amniotic fluid cultures resulted in Southern blots identical to those from CVS. Since we did not have verified prenatal cases of chromosome 15 uniparental disomy, we were unable to determine whether the parent-of-origin specific methylation present in lymphocyte DNA is also present in amniocyte DNA. We conclude that prenatal determination of chromosome 15 uniparental disomy with this probe will be unreliable.

  20. A study of the properties of the Grand Solar Minima throughout the past 13,000 years and the implications for Space Weather.

    NASA Astrophysics Data System (ADS)

    McCracken, Ken; Beer, Juerg

    2016-04-01

    The intensity of the cosmic radiation reaching the orbit of Earth is primarily controlled by the strength of the heliomagnetic field, which itself is largely determined by the level of solar activity. The paleo-cosmic ray (PCR) record therefore provides the output from a "cosmic magnetometer", and a proxy for solar activity in the past. Using 10Be (ice-cores) and 14C (tree rings) data we investigate the wide variations in the PCR and solar activity that have occurred during the past 13,000 years. In particular, we study the occurrence and properties of "Grand Minima"- the periods of very low solar activity similar to the Maunder Minimum (1645-1715) for which solar and geophysical data are available. There was a sequence of five GM between 950-1830CE; there were three similar sequences of similar duration in the preceding millennia; interspersed with intervals of ~1000 year essentially devoid of GM. The four sequences of GM correspond to the minima of the 2300 y Hallstatt periodicity. The PCR increases by ~50% during "Grand Solar Minima" and we use the PCR intensity to quantify the relative significance of the Grand Minima in the past. On the basis that the terrestrial and heliospheric consequences of a GM will depend on both the amplitude of the change in PCR intensity, and its duration, we have defined a parameter, the GM index, as the product of the amplitude and duration of a GM. We conclude that there have been 22 GM of geophysical significance equal to, or greater than that of the Wolf GM (1230-1350CE). The Sun is in a "Grand Minimum" condition for ~45% of the time during a GM sequence; and for only ~5% of the time in the intervening 1000y intervals of high solar activity. We discuss the implications of these observations in respect of space weather and climate. In conclusion, we speculate that the sun may now be entering one of its extended periods of high activity which will persist for ~1000 y.

  1. Effects of "Hot Fingers" on the Thermal Structure and Mantle Wedge Flow Pattern in Subduction Zones: Implications for Seismic Anisotropy and Volcanic Spacing in Northeast Japan

    NASA Astrophysics Data System (ADS)

    Lee, C.; Wada, I.

    2015-12-01

    Geophysical observations in Northeast Japan indicate its complex mantle wedge dynamics: in particular, 1) narrow low-seismic-velocity regions extending from the back-arc into the sub-arc mantle, so called "hot fingers" [Tamura et al., 2002], and 2) abrupt rotation of the seismically fast polarization direction from trench-normal to trench-parallel beneath the arc [Nakajima and Hasegawa, 2004]. Although the origin of hot fingers is not well understood, its strong spatial correlation with volcanic clustering at surface indicates that they play an important role in controlling arc volcanism. The cause of trench-parallel fast direction in the fore-arc mantle is also unclear; it has been attributed to a range of mechanisms, such as trench-normal mantle wedge flow, the presence of B-type olivine and trench-parallel alignment of melt pockets in the mantle wedge, and hydration along trench-parallel deep-cutting faults in the subducting slab. In this study, we examine the effects of hot fingers on the mantle wedge flow pattern and thermal structure beneath the arc and forearc through three-dimensional numerical experiments and investigate its implications for volcanic spacing and seismic anisotropy in Northeast Japan. In the model, the effects of hot fingers are implemented by imposing thermal anomalies on the back-arc-side vertical boundary. We found that the presence of hot fingers results in 3-D dynamic pressure gradients, which induce local along-arc mantle flow between hot fingers beneath the fore-arc, consistent with the observed pattern of seismic anisotropy in the mantle wedge. Between hot fingers, the along-arc mantle flow in the fore-arc suppresses corner flow, causing lower temperatures in the mantle wedge and in the upper portion of the subducting slab. The cooler condition is likely to hinder the dehydration of the subducting slab and flux melting in the mantle wedge, and this can explain the paucity of Quaternary arc volcanism between hot fingers in Northeast

  2. Ecology of micro-organisms in a small closed system - Potential benefits and problems for Space Station

    NASA Technical Reports Server (NTRS)

    Rodgers, E. B.; Seale, D. B.; Boraas, M. E.; Sommer, C. V.

    1989-01-01

    The probable sources and implications of microbial contamination on the proposed Space Station are discussed. Because of the limited availability of material, facilities and time on the Space Station, we are exploring the feasibility of replacing traditional incubation methods for assessing microbial contamination with rapid, automated methods. Some possibilities include: ATP measurement, microscopy and telecommunications, and molecular techniques such as DNA probes or monoclonal antibodies. Some of the important ecological factors that could alter microbes in space include microgravity, exposure to radiation, and antibiotic resistance.

  3. Engine spectrometer probe and method of use

    NASA Technical Reports Server (NTRS)

    Barkhoudarian, Sarkis (Inventor); Kittinger, Scott A. (Inventor)

    2006-01-01

    The engine spectrometer probe and method of using the same of the present invention provides a simple engine spectrometer probe which is both lightweight and rugged, allowing an exhaust plume monitoring system to be attached to a vehicle, such as the space shuttle. The engine spectrometer probe can be mounted to limit exposure to the heat and debris of the exhaust plume. The spectrometer probe 50 comprises a housing 52 having an aperture 55 and a fiber optic cable 60 having a fiber optic tip 65. The fiber optic tip 65 has an acceptance angle 87 and is coupled to the aperture 55 so that the acceptance angle 87 intersects the exhaust plume 30. The spectrometer probe can generate a spectrum signal from light in the acceptance angle 506 and the spectrum signal can be provided to a spectrometer 508.

  4. Making space for nonlocality

    NASA Astrophysics Data System (ADS)

    Millen, James

    2016-04-01

    George Musser's book Spooky Action at a Distance focuses on one of quantum physics' more challenging concepts, nonlocality, and its multitude of implications, particularly its assault on space itself.

  5. A review of the economic implications of the National Academy of Engineering 1974 study of the potential application of space systems

    NASA Technical Reports Server (NTRS)

    1975-01-01

    User benefits resulting from the application of space systems to previously described application areas were identified, and methods to assign priorities to application areas and to quantify the benefits were described. The following areas were selected for in-depth review: communications, materials processing in space, weather and climate, and institutional arrangements for space applications. Recommendations concerning studies that should be undertaken to develop a more precise understanding of the source and magnitude of the realizable economic benefits were also presented.

  6. Galileo Probe Battery System

    NASA Technical Reports Server (NTRS)

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

    1997-01-01

    The conclusions of the Galileo probe battery system are: the battery performance met mission requirements with margin; extensive ground-based and flight tests of batteries prior to probe separation from orbiter provided good prediction of actual entry performance at Jupiter; and the Li-SO2 battery was an important choice for the probe's main power.

  7. The Interstellar Ethics of Self-Replicating Probes

    NASA Astrophysics Data System (ADS)

    Cooper, K.

    Robotic spacecraft have been our primary means of exploring the Universe for over 50 years. Should interstellar travel become reality it seems unlikely that humankind will stop using robotic probes. These probes will be able to replicate themselves ad infinitum by extracting raw materials from the space resources around them and reconfiguring them into replicas of themselves, using technology such as 3D printing. This will create a colonising wave of probes across the Galaxy. However, such probes could have negative as well as positive consequences and it is incumbent upon us to factor self-replicating probes into our interstellar philosophies and to take responsibility for their actions.

  8. Monitoring Physiological Variables with Membrane Probes

    NASA Technical Reports Server (NTRS)

    Janle, Elsa M.

    1997-01-01

    This project has demonstrated the possibility of using membrane probes in rodents to monitor physiological variables for extended periods of time. The utility of these probes in physiological studies of microgravity has been demonstrated. The feasibility of developing on-line sensors has also been demonstrated and allows for the possibility of developing real-time automated monitoring systems which can be used in ground-base physiological research as well as in research and medical monitoring in space. In addition to space applications these techniques can be extended to medical monitoring in critical care situations on earth as well as facilitating research in many human and animal diseases.

  9. Monoclonals and DNA probes in diagnostic and preventative medicine

    SciTech Connect

    Gallo, R.C.; Della Povta, G.; Albertini, A.

    1987-01-01

    This book contains 24 selections. Some of the titles are: Use of DNA Probes for Prenatal and Carrier Diagnosis of Hemophilia and Fragile X Mental Retardation; The Application of DNA Probes to Diagnosis and Research of Duchenne Muscular Dystrophy: Clinical Trial, New Probes and Deletion Mapping; Molecular Genetics of the Human Collagens; Molecular Genetics of Human Steroid 21-Hydroxylase Genes; Detection of Hepatitis B Virus DNA and Hepatitis Delta Virus RNA: Implications in Diagnosis and Pathogenesis; and DNA Probes to Evaluate the Possible Association of Papovaviruses with Human Tumors.

  10. Theory of a cylindrical probe in a collisionless magnetoplasma

    NASA Technical Reports Server (NTRS)

    Laframboise, J. G.; Rubinstein, J.

    1976-01-01

    A theory is presented for a cylindrical electrostatic probe in a collisionless plasma in the case where the probe axis is inclined at an angle to a uniform magnetic field. The theory is applicable to electron collection, and under more restrictive conditions, to ion collection. For a probe at space potential, the theory is exact in the limit where probe radius is much less than Debye length. At attracting probe potentials, the theory yields an upper bound and an adiabatic limit for current collection. At repelling probe potentials, it provides a lower bound. The theory is valid if the ratios of probe radius to Debye length and probe radius to mean gyroradius are not simultaneously large enough to produce extrema in the probe sheath potential. The numerical current calculations are based on the approximation that particle orbits are helices near the probe, together with the use of kinetic theory to relate velocity distributions near the probe to those far from it. Probe characteristics are presented for inclination angles from 0 to 90 deg and for probe-radius mean-gyroradius ratios from 0.1 to infinity. For an angle of 0 deg, the end-effect current is calculated separately.

  11. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, Shimon; Chemla, Daniel S.; Ogletree, D. Frank; Botkin, David

    1995-01-01

    An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

  12. Traversing probe system

    DOEpatents

    Mashburn, Douglas N.; Stevens, Richard H.; Woodall, Harold C.

    1977-01-01

    This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride.

  13. Ultrafast scanning probe microscopy

    DOEpatents

    Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

    1995-05-16

    An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

  14. Information gains from cosmological probes

    NASA Astrophysics Data System (ADS)

    Grandis, S.; Seehars, S.; Refregier, A.; Amara, A.; Nicola, A.

    2016-05-01

    In light of the growing number of cosmological observations, it is important to develop versatile tools to quantify the constraining power and consistency of cosmological probes. Originally motivated from information theory, we use the relative entropy to compute the information gained by Bayesian updates in units of bits. This measure quantifies both the improvement in precision and the `surprise', i.e. the tension arising from shifts in central values. Our starting point is a WMAP9 prior which we update with observations of the distance ladder, supernovae (SNe), baryon acoustic oscillations (BAO), and weak lensing as well as the 2015 Planck release. We consider the parameters of the flat ΛCDM concordance model and some of its extensions which include curvature and Dark Energy equation of state parameter w. We find that, relative to WMAP9 and within these model spaces, the probes that have provided the greatest gains are Planck (10 bits), followed by BAO surveys (5.1 bits) and SNe experiments (3.1 bits). The other cosmological probes, including weak lensing (1.7 bits) and {H0} measures (1.7 bits), have contributed information but at a lower level. Furthermore, we do not find any significant surprise when updating the constraints of WMAP9 with any of the other experiments, meaning that they are consistent with WMAP9. However, when we choose Planck15 as the prior, we find that, accounting for the full multi-dimensionality of the parameter space, the weak lensing measurements of CFHTLenS produce a large surprise of 4.4 bits which is statistically significant at the 8 σ level. We discuss how the relative entropy provides a versatile and robust framework to compare cosmological probes in the context of current and future surveys.

  15. The role of probe oxide in local surface conductivity measurements

    SciTech Connect

    Barnett, C. J.; Kryvchenkova, O.; Wilson, L. S. J.; Maffeis, T. G. G.; Cobley, R. J.; Kalna, K.

    2015-05-07

    Local probe methods can be used to measure nanoscale surface conductivity, but some techniques including nanoscale four point probe rely on at least two of the probes forming the same low resistivity non-rectifying contact to the sample. Here, the role of probe shank oxide has been examined by carrying out contact and non-contact I V measurements on GaAs when the probe oxide has been controllably reduced, both experimentally and in simulation. In contact, the barrier height is pinned but the barrier shape changes with probe shank oxide dimensions. In non-contact measurements, the oxide modifies the electrostatic interaction inducing a quantum dot that alters the tunneling behavior. For both, the contact resistance change is dependent on polarity, which violates the assumption required for four point probe to remove probe contact resistance from the measured conductivity. This has implications for all nanoscale surface probe measurements and macroscopic four point probe, both in air and vacuum, where the role of probe oxide contamination is not well understood.

  16. Space station executive summary

    NASA Technical Reports Server (NTRS)

    1972-01-01

    An executive summary of the modular space station study is presented. The subjects discussed are: (1) design characteristics, (2) experiment program, (3) operations, (4) program description, and (5) research implications. The modular space station is considered a candidate payload for the low cost shuttle transportation system.

  17. Space Studies Board, 1994

    NASA Technical Reports Server (NTRS)

    1995-01-01

    This 1994 report of the Space Studies Board of the National Research Council summarizes the charter and organization of the board, activities and membership, major and short reports, and congressional testimony. A cumulative bibliography of the Space Studies (formerly Space Science) Board and its committees is provided. An appendix contains reports of the panel to review Earth Observing System Data and Information System (EOSDIS) plans. Major reports cover scientific opportunities in the human exploration of space, the dichotomy between funding and effectiveness in space physics, an integrated strategy for the planetary sciences for the years 1995-2010, and Office of Naval Research (ONR) research opportunities in upper atmospheric sciences. Short reports cover utilization of the space station, life and microgravity sciences and the space station program, Space Infrared Telescope Facility and the Stratospheric Observatory for Infrared Astronomy, and the Advanced X-ray Astrophysics Facility and Cassini Saturn Probe.

  18. Conductivity Probe after Trench-Bottom Placement

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Needles of the thermal and conductivity probe on NASA's Phoenix Mars Lander were positioned into the bottom of a trench called 'Upper Cupboard' during Sol 86 (Aug. 21, 2008), or 86th Martian day after landing. This image of the conductivity probe after it was raised back out of the trench was taken by Phoenix's Robotic Arm Camera. The conductivity probe is at the wrist of the robotic arm's scoop.

    The probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The 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.

  19. Gravity and on-shell probe actions

    NASA Astrophysics Data System (ADS)

    Ferrari, Frank; Rovai, Antonin

    2016-08-01

    In any gravitational theory and in a wide class of background space-times, we argue that there exists a simple, yet profound, relation between the on-shell Euclidean gravitational action and the on-shell Euclidean action of probes. The probes can be, for instance, charged particles or branes. The relation is tightly related to the thermodynamic nature of gravity. We provide precise checks of the relation in several examples, which include both asymptotically flat and asymptotically AdS space-times, with particle, D-brane and M-brane probes. Perfect consistency is found in all cases, including in a highly non-trivial example including α'-corrections.

  20. Mechanics of evenly spaced strike-slip faults and its implications for the formation of tiger-stripe fractures on Saturn's moon Enceladus

    NASA Astrophysics Data System (ADS)

    Yin, An; Zuza, Andrew V.; Pappalardo, Robert T.

    2016-03-01

    We present the first mechanical analysis based on realistic rheology and boundary conditions on the formation of evenly spaced strike-slip faults. Two quantitative models employing the stress-shadow concept, widely used for explaining extensional-joint spacing, are proposed in this study: (1) an empirically based stress-rise-function model that simulates the brittle-deformation process during the formation of evenly spaced parallel strike-slip faults, and (2) an elastic plate model that relates fault spacing to the thickness of the fault-hosting elastic medium. When applying the models for the initiation and development of the tiger-stripe fractures (TSF) in the South Polar Terrain (SPT) of Enceladus, the mutually consistent solutions of the two models, as constrained by the mean spacing of the TSF at ∼35 km, requires that the brittle ice-shell thickness be ∼30 km, the elastic thickness be ∼0.7 km, and the cohesive strength of the SPT ice shell be ∼30 kPa. However, if the brittle and elastic models are decoupled and if the ice-shell cohesive strength is on the order of ∼1 MPa, the brittle ice shell would be on the order of ∼10 km.

  1. Functional probes for scanning probe microscopy

    NASA Astrophysics Data System (ADS)

    Hasegawa, Yukio; Akiyama, Kotone; Hamada, Masayuki; Eguchi, Toyoaki; An, Toshu; Fujikawa, Yasunori; Sakurai, Toshio

    2008-03-01

    Inspite of importance of the probe in scanning probe microscopy (SPM), little attention was paid for the SPM probes for most of the measurements of SPM. We developed sharp metal-tip cantilevers with a typical curvature radius better than 5nm using focused ion beam (FIB) suitable for Kelvin probe force microscopy (KFM)^1. We obtained atomically resolved KFM images with an energy resolution less than 3meV with the probe^2. We also developed a glass-coated tungsten tip for synchrotron radiation-scanning tunneling microscopy with the FIB method^3 and obtained elementally resolved images in a resolution less than 20nm^4. We are now developing a precise atomic force microscope (AFM) lithography^5 with the FIB-milled tip attached to a quartz tuning fork controlled by noncontact AFM. We will present recent results of our AFM lithography, such as an Au line with a width of 20˜30 nm and characters drawn with Au nano dots on a Si surface. 1 K. Akiyama et al., RSI 76, 033705 (2005) 2 T. Eguchi, K. Akiyama et al., PRL 93, 266102 (2004) 3 K. Akiyama et al., RSI 76, 083711 (2005) 4 T. Eguchi, K. Akiyama et al., APL 89, 243119 (2006) 5 K. Akiyama et al., JP 61, 22 (2007).

  2. Periodontal probing: a review.

    PubMed

    Al Shayeb, Kwthar Nassar A; Turner, Wendy; Gillam, David G

    2014-08-01

    Periodontal probes are the main instruments that are used to assess the status of the periodontium, either for screening purposes or to evaluate periodontal changes throughout the treatment process. With increased knowledge and understanding of periodontal disease, the probes have evolved from a unidimensional manual shape into a more sophisticated computerised instrument. This is due to the need to increase the accuracy and reproducibility of readings and to improve efficiency (time, effort, money). Each probe has characteristic features that makes it unique and, in some cases, specific and limited to use. The aim of this paper is to present a brief introduction to periodontal disease and the methodology of measuring it, followed by probing limitations. The paper will also discuss the methodology of reducing probing error, examiner calibration and probing reproducibility. PMID:25198634

  3. High temperature probe

    DOEpatents

    Swan, Raymond A.

    1994-01-01

    A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

  4. The Experimental Verdict on Spacetime from Gravity Probe B

    NASA Astrophysics Data System (ADS)

    Overduin, James

    Concepts of space and time have been closely connected with matter since the time of the ancient Greeks. The history of these ideas is briefly reviewed, focusing on the debate between "absolute" and "relational" views of space and time and their influence on Einstein's theory of general relativity, as formulated in the language of four-dimensional spacetime by Minkowski in 1908. After a brief detour through Minkowski's modern-day legacy in higher dimensions, an overview is given of the current experimental status of general relativity. Gravity Probe B is the first test of this theory to focus on spin, and the first to produce direct and unambiguous detections of the geodetic effect (warped spacetime tugs on a spinning gyroscope) and the frame-dragging effect (the spinning earth pulls spacetime around with it). These effects have important implications for astrophysics, cosmology and the origin of inertia. Philosophically, they might also be viewed as tests of the propositions that spacetime acts on matter (geodetic effect) and that matter acts back on spacetime (frame-dragging effect).

  5. Metastable atom probe for measuring electron beam density profiles

    NASA Technical Reports Server (NTRS)

    Lockhart, J. M.; Zorn, J. C.

    1972-01-01

    Metastable atom probe was developed for measuring current density in electron beam as function of two arbitrary coordinates, with spatial resolution better than 0.5 mm. Probe shows effects of space charge, magnetic fields, and other factors which influence electron current density, but operates with such low beam densities that introduced perturbation is very small.

  6. Gravity Probe B spacecraft description

    NASA Astrophysics Data System (ADS)

    Bennett, Norman R.; Burns, Kevin; Katz, Russell; Kirschenbaum, Jon; Mason, Gary; Shehata, Shawky

    2015-11-01

    The Gravity Probe B spacecraft, developed, integrated, and tested by Lockheed Missiles & Space Company and later Lockheed Martin Corporation, consisted of structures, mechanisms, command and data handling, attitude and translation control, electrical power, thermal control, flight software, and communications. When integrated with the payload elements, the integrated system became the space vehicle. Key requirements shaping the design of the spacecraft were: (1) the tight mission timeline (17 months, 9 days of on-orbit operation), (2) precise attitude and translational control, (3) thermal protection of science hardware, (4) minimizing aerodynamic, magnetic, and eddy current effects, and (5) the need to provide a robust, low risk spacecraft. The spacecraft met all mission requirements, as demonstrated by dewar lifetime meeting specification, positive power and thermal margins, precision attitude control and drag-free performance, reliable communications, and the collection of more than 97% of the available science data.

  7. The Gravity Probe B Payload Hoisted by Crane

    NASA Technical Reports Server (NTRS)

    2001-01-01

    The Gravity Probe B (GP-B) payload was hoisted by crane to the transportation truck in the W.W. Hansen Experimental Physics Laboratory in Stanford, California for shipment to 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. Launched April 20, 2004, the GP-B program was managed for NASA by the Marshall Space Flight Center. Development of the GP-B is the responsibility of Stanford University, along with major subcontractor Lockheed Martin Corporation. (Photo Credit: Stanford University)

  8. Inherit Space

    NASA Technical Reports Server (NTRS)

    Giarratano, Joseph C.; Jenks, K. C.

    1997-01-01

    The objective of the proposed research was to begin development of a unique educational tool targeted at educating and inspiring young people 12-16 years old about NASA and the Space Program. Since these young people are the future engineers, scientists and space pioneers, the nurturing of their enthusiasm and interest is of critical importance to the Nation. This summer the basic infrastructure of the tool was developed in the context of an educational game paradigm. The game paradigm has achieved remarkable success in maintaining the interest of young people in a self-paced, student-directed learning environment. This type of environment encourages student exploration and curiosity which are exactly the traits that future space pioneers need to develop to prepare for the unexpected. The Inherit Space Educational Tool is an open-ended learning environment consisting of a finite-state machine classic adventure game paradigm. As the young person explores this world, different obstacles must be overcome. Rewards will be offered such as using the flight simulator to fly around and explore Titan. This simulator was modeled on conventional Earth flight simulators but has been considerably enhanced to add texture mapping of Titan's atmosphere utilizing the latest information from the NASA Galileo Space Probe. Additional scenery was added to provide color VGA graphics of a futuristic research station on Titan as well as an interesting story to keep the youngster's attention. This summer the game infrastructure has been developed as well as the Titan Flight Simulator. A number of other enhancements are planned.

  9. CONSULTATION ON IMPLICATIONS OF THE RESULTS OF THE INSTITUTE OF MEDICINE'S REPORT ON DAMP INDOOR SPACES AND HEALTH FOR THE INDOOR ENVIRONMENTS DIVISION'S INDOOR AIR QUALITY PROGRAM.

    EPA Science Inventory

    The National Academy of Sciences (NAS) Institute of Medicine (IOM) expects to publish a report on Damp Indoor Spaces and Health. The IOM has conducted a comprehensive review of the scientific literature regarding the relationship between damp or moldy indoor environments and the...

  10. Radio frequency-compensated Langmuir probe with auxiliary double probes

    SciTech Connect

    Oh, Se-Jin; Oh, Seung-Ju; Chung, Chin-Wook

    2010-09-15

    A radio frequency (rf) compensation design using auxiliary double probes connected in parallel with a main measurement probe was developed for Langmuir probe diagnostics. This probe structure can reduce the sheath impedance of the main probe. In our probe design, the sheath capacitance of the probe can be increased and its sheath resistance can be decreased with increasing dc bias differential voltage between the auxiliary double probes. The I-V characteristic curve and electron energy distribution functions measured by our probe system had sufficient rf compensation performance in inductively coupled plasmas.

  11. Radio frequency-compensated Langmuir probe with auxiliary double probes.

    PubMed

    Oh, Se-Jin; Oh, Seung-Ju; Chung, Chin-Wook

    2010-09-01

    A radio frequency (rf) compensation design using auxiliary double probes connected in parallel with a main measurement probe was developed for Langmuir probe diagnostics. This probe structure can reduce the sheath impedance of the main probe. In our probe design, the sheath capacitance of the probe can be increased and its sheath resistance can be decreased with increasing dc bias differential voltage between the auxiliary double probes. The I-V characteristic curve and electron energy distribution functions measured by our probe system had sufficient rf compensation performance in inductively coupled plasmas. PMID:20886976

  12. Neptune Polar Orbiter with Probes

    NASA Technical Reports Server (NTRS)

    Bienstock, Bernard; Atkinson, David; Baines, Kevin; Mahaffy, Paul; Steffes, Paul; Atreya, Sushil; Stern, Alan; Wright, Michael; Willenberg, Harvey; Smith, David; Frampton, Robert; Sichi, Steve; Peltz, Leora; Masciarelli, James; VanCleve, Jeffey

    2005-01-01

    The giant planets of the outer solar system divide into two distinct classes: the gas giants Jupiter and Saturn, which consist mainly of hydrogen and helium; and the ice giants Uranus and Neptune, which are believed to contain significant amounts of the heavier elements oxygen, nitrogen, and carbon and sulfur. Detailed comparisons of the internal structures and compositions of the gas giants with those of the ice giants will yield valuable insights into the processes that formed the solar system and, perhaps, other planetary systems. By 2012, Galileo, Cassini and possibly a Jupiter Orbiter mission with microwave radiometers, Juno, in the New Frontiers program, will have yielded significant information on the chemical and physical properties of Jupiter and Saturn. A Neptune Orbiter with Probes (NOP) mission would deliver the corresponding key data for an ice giant planet. Such a mission would ideally study the deep Neptune atmosphere to pressures approaching and possibly exceeding 1000 bars, as well as the rings, Triton, Nereid, and Neptune s other icy satellites. A potential source of power would be nuclear electric propulsion (NEP). Such an ambitious mission requires that a number of technical issues be investigated, however, including: (1) atmospheric entry probe thermal protection system (TPS) design, (2) probe structural design including seals, windows, penetrations and pressure vessel, (3) digital, RF subsystem, and overall communication link design for long term operation in the very extreme environment of Neptune's deep atmosphere, (4) trajectory design allowing probe release on a trajectory to impact Neptune while allowing the spacecraft to achieve a polar orbit of Neptune, (5) and finally the suite of science instruments enabled by the probe technology to explore the depths of the Neptune atmosphere. Another driving factor in the design of the Orbiter and Probes is the necessity to maintain a fully operational flight system during the lengthy transit time

  13. Formative Assessment Probes

    ERIC Educational Resources Information Center

    Eberle, Francis; Keeley, Page

    2008-01-01

    Formative assessment probes can be effective tools to help teachers build a bridge between students' initial ideas and scientific ones. In this article, the authors describe how using two formative assessment probes can help teachers determine the extent to which students make similar connections between developing a concept of matter and a…

  14. Magnetically driven filament probe.

    PubMed

    Schmid, A; Herrmann, A; Rohde, V; Maraschek, M; Müller, H W

    2007-05-01

    A radially movable probe has been developed for studies of filamentary transport in ASDEX Upgrade during edge localized modes (ELMs) by means of Langmuir tips and magnetic pickup coils. The probe is permanently installed at the low field side in the ASDEX Upgrade vacuum vessel and is not subject to limitations in probe size, as, for example, probes on a shared manipulator are. The probe is moved by a magnetic drive, which allows for easy installation in the vessel, and has moderate machine requirements, as it will only require an electric feedthrough and an external power supply. The drive gives a linear motion with a radial range of 5 cm within 50 ms, where range and velocity can be largely scaled according to experimental requirements. The probe has been installed in the outer midplane of the ASDEX Upgrade vessel, where ELM filaments are expected to have their maximum amplitude. Filaments are coherent substructures within an ELM, carrying a fraction of the ELM released energy towards the wall. The new probe allows to measure the structure of these filaments, in particular, parameters such as filament rotation (by time delay measurements) and size (by peak width analysis). Activating the drive moves the probe from a safe position behind the limiter to a position in front of the limiters, i.e., exposes the Langmuir pins to the scrape-off layer plasma. PMID:17552815

  15. PDV Probe Alignment Technique

    SciTech Connect

    Whitworth, T L; May, C M; Strand, O T

    2007-10-26

    This alignment technique was developed while performing heterodyne velocimetry measurements at LLNL. There are a few minor items needed, such as a white card with aperture in center, visible alignment laser, IR back reflection meter, and a microscope to view the bridge surface. The work was performed on KCP flyers that were 6 and 8 mils wide. The probes used were Oz Optics manufactured with focal distances of 42mm and 26mm. Both probes provide a spot size of approximately 80?m at 1550nm. The 42mm probes were specified to provide an internal back reflection of -35 to -40dB, and the probe back reflections were measured to be -37dB and -33dB. The 26mm probes were specified as -30dB and both measured -30.5dB. The probe is initially aligned normal to the flyer/bridge surface. This provides a very high return signal, up to -2dB, due to the bridge reflectivity. A white card with a hole in the center as an aperture can be used to check the reflected beam position relative to the probe and launch beam, and the alignment laser spot centered on the bridge, see Figure 1 and Figure 2. The IR back reflection meter is used to measure the dB return from the probe and surface, and a white card or similar object is inserted between the probe and surface to block surface reflection. It may take several iterations between the visible alignment laser and the IR back reflection meter to complete this alignment procedure. Once aligned normal to the surface, the probe should be tilted to position the visible alignment beam as shown in Figure 3, and the flyer should be translated in the X and Y axis to reposition the alignment beam onto the flyer as shown in Figure 4. This tilting of the probe minimizes the amount of light from the bridge reflection into the fiber within the probe while maintaining the alignment as near normal to the flyer surface as possible. When the back reflection is measured after the tilt adjustment, the level should be about -3dB to -6dB higher than the probes

  16. Circumferential pressure probe

    NASA Technical Reports Server (NTRS)

    Holmes, Harlan K. (Inventor); Moore, Thomas C. (Inventor); Fantl, Andrew J. (Inventor)

    1989-01-01

    A probe for measuring circumferential pressure inside a body cavity is disclosed. In the preferred embodiment, a urodynamic pressure measurement probe for evaluating human urinary sphincter function is disclosed. Along the length of the probe are disposed a multiplicity of deformable wall sensors which typically comprise support tube sections with flexible side wall areas. These are arranged along the length of the probe in two areas, one just proximal to the tip for the sensing of fluid pressure inside the bladder, and five in the sensing section which is positioned within the urethra at the point at which the urinary sphincter constricts to control the flow of urine. The remainder of the length of the probe comprises multiple rigid support tube sections interspersed with flexible support tube sections in the form of bellows to provide flexibility.

  17. Economics of Automation in Space: Implications of Automated Versus Manned Operations on the High Cost of On-Orbit Assembly, Control and Servicing of Spacecraft

    NASA Technical Reports Server (NTRS)

    Zimmerman, W. F.

    1994-01-01

    The continued high cost and risk of placing astronauts in space has placed considerable burden on NASA to cut costs and consider other means of achieving mission goals both effectively and safely. Additionally, future science missions which might place a tremendous burden on Shuttle availability, or require extended vehicle duty cycles on the Lunar surface and Mars surface, might preclude the presence of astronauts altogether.

  18. Phase-Space Reconstruction: a Path Towards the Next Generation of Nonlinear Differential Equation Based Models and Its Implications Towards Non-Uniform Sampling Theory

    SciTech Connect

    Charles R. Tolle; Mark Pengitore

    2009-08-01

    This paper explores the overlaps between the Control community’s work on System Identification (SysID) and the Physics, Mathematics, Chaos, and Complexity communities’ work on phase-space reconstruction via time-delay embedding. There are numerous overlaps between the goals of each community. Nevertheless, the Controls community can gain new insight as well as some new very powerful tools for SysID from the latest developments within the Physics, Mathematics, Chaos, and Complexity communities. These insights are gained via the work on phase-space reconstruction of non-linear dynamics. New methods for discovering non-linear differential based equations that evolved from embedding operations can shed new light on hybrid-systems theory, Nyquest-Shannon’s Theories, and network based control theory. This paper strives to guide the Controls community towards a closer inspection of the tools and additional insights being developed within the Physics, Mathematics, Chaos, and Complexity communities for discovery of system dynamics, the first step in control system development. The paper introduces the concepts of phase-space reconstruction via time-delay embedding (made famous byWhitney, Takens, and Sauer’s Thoreoms), intergrate-and-fire embedding, and non-linear differential equation discovery based on Perona’s method.

  19. Radition belt dynamics : Recent results from van Allen Probes and future observations from CeREs

    NASA Astrophysics Data System (ADS)

    Kanekal, Shrikanth; O'Brien, Paul; Baker, Daniel N.; Ogasawara, Keiichi; Fennell, Joseph; Christian, Eric; Claudepierre, Seth; Livi, Stefano; Desai, Mihir; Li, Xinlin; Jaynes, Allison; Turner, Drew; Jones, Ashley; Schiller, Quintin

    2016-07-01

    We describe recent observations of the Earth's radiation belts made by instruments on board the Van Allen Probes mission, particularly the Relativistic Electron Proton Telescope (REPT) and the Magnetic Electron Ion spectrometer (MagEIS). These observations have significantly advanced our understanding of terrestrial radiation belt dynamics. The Van Allen Probes mission comprises two identically instrumented spacecraft which were launched 31 August, 2012 into low-inclination lapping equatorial orbits. The orbit periods are about 9 hours, with perigees and apogees of of ~600 km and 5.8 RE respectively. We discuss the new scientific findings of the Van Allen Probes mission regarding the physics of energization and loss of relativistic electrons and their implications for future low-cost missions, especially CubeSats. We describe the CeREs (a Compact Radiation belt Explorer) CubeSat mission currently being built at the Goddard Space Flight Center, and carrying on board, an innovative instrument, the Miniaturized Electron Proton Telescope (MERiT). The MERiT is a compact low-mass low-power instrument measuring electrons from a few keV to tens of MeV in multiple differential channels. MERiT is optimized to measure electron microbursts with a high time resolution of a few milliseconds. We present and discuss possible future scientific contributions from CeREs.

  20. Pioneer Jupiter orbiter probe mission 1980, probe description

    NASA Technical Reports Server (NTRS)

    Defrees, R. E.

    1974-01-01

    The adaptation of the Saturn-Uranus Atmospheric Entry Probe (SUAEP) to a Jupiter entry probe is summarized. This report is extracted from a comprehensive study of Jovian missions, atmospheric model definitions and probe subsystem alternatives.

  1. Shock wave diagnostics using fluorescent dye probes

    NASA Astrophysics Data System (ADS)

    Banishev, Alexandr; Christensen, James; Dlott, Dana

    2015-06-01

    Fluorescent probes are highly developed, and have found increasing use in a wide variety of applications. We have studied shock compression of various materials with embedded dye probes used as high speed probes of pressure and temperature. Under the right conditions, dye emission can be used to make a map of the pressure distribution in shocked microstructured materials with high time (1 ns) and space (1 micrometer) resolution. In order to accomplish this goal, we started by studying shock compression of PMMA polymer with rhodamine 6G dye (R6G), as a function of shock pressure and shock duration. We observed the shock-induced spectral redshift and the shock-induced intensity loss. We investigated the fundamental mechanisms of R6G response to pressure. We showed that the time response of a dye probe is limited by its photophysical behavior under shock. We developed superemissive ultrafast dye probes by embedding R6G in a silica nanoparticle. More recently, we have searched for dye probes that have better responses. For instance, we have found that the dye Nile Red embedded in the right polymer matrix has 1.7 times larger pressure-induced redshift than R6G.

  2. Phoenix Conductivity Probe with Shadow and Toothmark

    NASA Technical Reports Server (NTRS)

    2008-01-01

    NASA's Phoenix Mars Lander inserted the four needles of its thermal and conductivity probe into Martian soil during the 98th Martian day, or sol, of the mission and left it in place until Sol 99 (Sept. 4, 2008).

    The Robotic Arm Camera on Phoenix took this image on the morning of Sol 99 after the probe was lifted away from the soil. The imprint left by the insertion is visible below the probe, and a shadow showing the probe's four needles is cast on a rock to the left.

    The thermal and conductivity probe measures how fast heat and electricity move from one needle to an adjacent one through the soil or air between the needles. Conductivity readings can be indicators about water vapor, water ice and liquid water.

    The probe is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments.

    The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  3. The Hubble Space Telescope UV Legacy Survey of Galactic Globular Clusters. VII. Implications from the Nearly Universal Nature of Horizontal Branch Discontinuities

    NASA Astrophysics Data System (ADS)

    Brown, T. M.; Cassisi, S.; D’Antona, F.; Salaris, M.; Milone, A. P.; Dalessandro, E.; Piotto, G.; Renzini, A.; Sweigart, A. V.; Bellini, A.; Ortolani, S.; Sarajedini, A.; Aparicio, A.; Bedin, L. R.; Anderson, J.; Pietrinferni, A.; Nardiello, D.

    2016-05-01

    The UV-initiative Hubble Space Telescope Treasury survey of Galactic globular clusters provides a new window into the phenomena that shape the morphological features of the horizontal branch (HB). Using this large and homogeneous catalog of UV and blue photometry, we demonstrate that the HB exhibits discontinuities that are remarkably consistent in color (effective temperature). This consistency is apparent even among some of the most massive clusters hosting multiple distinct sub-populations (such as NGC 2808, ω Cen, and NGC 6715), demonstrating that these phenomena are primarily driven by atmospheric physics that is independent of the underlying population properties. However, inconsistencies arise in the metal-rich clusters NGC 6388 and NGC 6441, where the discontinuity within the blue HB (BHB) distribution shifts ˜1000–2000 K hotter. We demonstrate that this shift is likely due to a large helium enhancement in the BHB stars of these clusters, which in turn affects the surface convection and evolution of such stars. Our survey also increases the number of Galactic globular clusters known to host blue-hook stars (also known as late hot flashers) from 6 to 23 clusters. These clusters are biased toward the bright end of the globular cluster luminosity function, confirming that blue-hook stars tend to form in the most massive clusters with significant self-enrichment. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-13297.

  4. Study of entry and landing probes for exploration of Titan

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Saturn's largest moon, Titan, is a totally unique planetary body which is certain to yield exciting new phenomena. Current information is lacking in detail to distinguish between a thin methane rich atmosphere and a thick nitrogen rich atmosphere. Therefore, both the thin and thick atmospheric models were used for the study of various Titan probe classes described in this report. The technical requirements, conceptual design, science return, schedule, cost and mission implications of three probe classes that could be used for exploration of Titan are defined. The three probe classes were based on a wide range of exploration mission possibilities.

  5. Hands-Free Transcranial Color Doppler Probe

    NASA Technical Reports Server (NTRS)

    Chin, Robert; Madala, Srihdar; Sattler, Graham

    2012-01-01

    Current transcranial color Doppler (TCD) transducer probes are bulky and difficult to move in tiny increments to search and optimize TCD signals. This invention provides miniature motions of a TCD transducer probe to optimize TCD signals. The mechanical probe uses a spherical bearing in guiding and locating the tilting crystal face. The lateral motion of the crystal face as it tilts across the full range of motion was achieved by minimizing the distance between the pivot location and the crystal face. The smallest commonly available metal spherical bearing was used with an outer diameter of 12 mm, a 3-mm tall retaining ring, and 5-mm overall height. Small geared motors were used that would provide sufficient power in a very compact package. After confirming the validity of the basic positioning concept, optimization design loops were completed to yield the final design. A parallel motor configuration was used to minimize the amount of space wasted inside the probe case while minimizing the overall case dimensions. The distance from the front edge of the crystal to the edge of the case was also minimized to allow positioning of the probe very close to the ear on the temporal lobe. The mechanical probe is able to achieve a +/-20deg tip and tilt with smooth repeatable action in a very compact package. The enclosed probe is about 7 cm long, 4 cm wide, and 1.8 cm tall. The device is compact, hands-free, and can be adjusted via an innovative touchscreen. Positioning of the probe to the head is performed via conventional transducer gels and pillows. This device is amendable to having advanced software, which could intelligently focus and optimize the TCD signal.

  6. Focus: DNA probes

    SciTech Connect

    Not Available

    1986-11-01

    Progress in the development of DNA probes for the identification and quantitation of specific genetic sequences in biological samples is reviewed. Current research efforts in the development of DNA probes for the diagnosis of a wide variety of bacterial, viral, and other infectious diseases, such as herpes simplex and cytomegalovirus, and inherited genetic diseases such as cystic fibrosis and sickle cell anemia are discussed. Progress in development of DNA probe assays for cancer diagnosis, detection of Salmonella food poisoning, tissue typing (detection of histocompatibility antigens), mutagen screening, and animal diseases, among other applications is included.

  7. Foldable polymers as probes

    DOEpatents

    Li, Alexander D. Q.; Wang, Wei

    2007-07-03

    Disclosed herein are novel probes, which can be used to detect and identify target molecules of interest in a sample. The disclosed probes can be used to monitor conformational changes induced by molecular recognition events in addition to providing signaling the presence and/or identity of a target molecule. Methods, including solid phase synthesis techniques, for making probe molecules that exhibit changes in their optical properties upon target molecule binding are described in the disclosure. Also disclosed herein are novel chromophore moieties, which have tailored fluorescent emission spectra.

  8. Foldable polymers as probes

    DOEpatents

    Li, Alexander D. Q.; Wang, Wei

    2009-07-07

    Disclosed herein are novel probes, which can be used to detect and identify target molecules of interest in a sample. The disclosed probes can be used to monitor conformational changes induced by molecular recognition events in addition to providing signaling the presence and/or identity of a target molecule. Methods, including solid phase synthesis techniques, for making probe molecules that exhibit changes in their optical properties upon target molecule binding are described in the disclosure. Also disclosed herein are novel chromophore moieties, which have tailored fluorescent emission spectra.

  9. Chemical sensing flow probe

    DOEpatents

    Laguna, George R.; Peter, Frank J.; Butler, Michael A.

    1999-01-01

    A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir.

  10. Chemical sensing flow probe

    DOEpatents

    Laguna, G.R.; Peter, F.J.; Butler, M.A.

    1999-02-16

    A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir. 7 figs.

  11. BEAM CONTROL PROBE

    DOEpatents

    Chesterman, A.W.

    1959-03-17

    A probe is described for intercepting a desired portion of a beam of charged particles and for indicating the spatial disposition of the beam. The disclosed probe assembly includes a pair of pivotally mounted vanes moveable into a single plane with adjacent edges joining and a calibrated mechanical arrangement for pivoting the vancs apart. When the probe is disposed in the path of a charged particle beam, the vanes may be adjusted according to the beam current received in each vane to ascertain the dimension of the beam.

  12. Single nucleotide polymorphism analysis using different colored dye dimer probes

    NASA Astrophysics Data System (ADS)

    Marmé, Nicole; Friedrich, Achim; Denapaite, Dalia; Hakenbeck, Regine; Knemeyer, Jens-Peter

    2006-09-01

    Fluorescence quenching by dye dimer formation has been utilized to develop hairpin-structured DNA probes for the detection of a single nucleotide polymorphism (SNP) in the penicillin target gene pbp2x, which is implicated in the penicillin resistance of Streptococcus pneumoniae. We designed two specific DNA probes for the identification of the pbp2x genes from a penicillin susceptible strain R6 and a resistant strain Streptococcus mitis 661 using green-fluorescent tetramethylrhodamine (TMR) and red-fluorescent DY-636, respectively. Hybridization of each of the probes to its respective target DNA sequence opened the DNA hairpin probes, consequently breaking the nonfluorescent dye dimers into fluorescent species. This hybridization of the target with the hairpin probe achieved single nucleotide specific detection at nanomolar concentrations via increased fluorescence.

  13. Planetary Resources and Astroecology. Planetary Microcosm Models of Asteroid and Meteorite Interiors: Electrolyte Solutions and Microbial Growth- Implications for Space Populations and Panspermia

    NASA Astrophysics Data System (ADS)

    Mautner, Michael N.

    2002-03-01

    Planetary microcosms were constructed using extracts from meteorites that simulate solutions in the pores of carbonaceous chondrites. The microcosms were found to support the growth of complex algal and microbial populations. Such astroecology experiments demonstrate how a diverse ecosystem could exist in fluids within asteroids, and in meteorites that land on aqueous planets. The microcosm solutions were obtained by extracting nutrient electrolytes under natural conditions from powders of the Allende (CV3) and Murchison (CM2) meteorites at low (0.02 g/ml) and high (10.0 g/ml) solid/solution ratios. The latter solutions contain >3 mol/L electrolytes and about 10 g/L organics, that simulate natural fluids in asteroids during aqueous alteration and in the pores of meteorites, which can help prebiotic synthesis and the survival of early microorganisms. These solutions and wet solids were in fact found to support complex self-sustaining microbial communities with populations of 4 × 105 algae and 6 × 106 bacteria and fungi for long periods (>8 months). The results show that planetary microcosms based on meteorites can: assay the fertilities of planetary materials; identify space bioresources; target astrobiology exploration; and model past and future space-based ecosystems. The results show that bioresources in the carbonaceous asteroids can sustain a biomass of 1018 kg, comprising 1032 microorganisms and a human population of 1014. The results also suggest that protoplanetary nebulae can support and disperse microorganisms and can be therefore effective environments for natural and directed panspermia.

  14. Experimental hypervelocity impacts: Implication for the analysis of material retrieved after exposure to space environment. Part I. Impacts on aluminium targets

    NASA Astrophysics Data System (ADS)

    Mandeville, Jean-Claude; Perrin, Jean-Marie; Vidal, Loïc

    2012-12-01

    During the last three decades a wide variety of surfaces have been brought back to Earth after being exposed to space environment. The impact features found on these surfaces are used to evaluate the damages caused to spacecraft and can give clues to the characteristics of the orbital debris and meteoroids that created them. In order to derive more precisely the particle parameters and to improve the analysis of projectile remnants, we have performed an extensive analysis of craters caused by the impact of high velocity particles on thick ductile targets, using a micro-particle accelerator. We show that from the geometry of the craters and from the analysis of the remnants it is possible to derive the main characteristics of the projectiles. In particular, using up-to-date instrumentation, scanning electron microscope (SEM) and Energy Dispersive X-ray (EDX) spectrometer, we found that even small residues inside craters can be identified. However, this study shows that a velocity resolution better than 1 km/s would be appropriate to obtain a fair calibration of the impact processes on a ductile target. This would allow to decipher with precision impact features on ductile surfaces exposed to space environment.

  15. Micrometeoroid and orbital debris impact inspection of the Hubble Space Telescope Wide Field Planetary Camera 2 radiator and the implications for the near-Earth small particle environment

    NASA Astrophysics Data System (ADS)

    Liou, J.-C.; Anz-Meador, P.; Opiela, J.; Christiansen, E.; Cowardin, H.; Davidson, W.; Ed-Wards, D.; Hedman, T.; Herrin, J.; Hyde, J.; Juarez, Q.; Lear, D.; McNamara, K.; Moser, D.; Ross, D.; Stansbery, E.

    The STS-125 Atlantis astronauts retrieved the Hubble Space Telescope (HST) Wide Field Planetary Camera 2 (WFPC2) during a very successful servicing mission to the HST in May 2009. The radiator attached to WFPC2 has dimensions of 2.2 m by 0.8 m. Its outermost layer is a 4-mm thick aluminum plate covered with a white thermal control coating. This radiator had been exposed to space since the deployment of WFPC2 in 1993. Due to its large surface area and long exposure time, the radiator serves as a unique witness plate for the micrometeoroid and orbital debris (MMOD) environment between 560 and 620 km altitude. The NASA Orbital Debris Program Office is leading an effort, with full support from the HST Program at GSFC, NASA Curation Office at JSC, NASA Hypervelocity Impact Technology Facility at JSC, and NASA Meteoroid Environment Office at MSFC, to inspect the exposed radiator surface. The objective is to measure and analyze the MMOD impact damage on the radiator, and then apply the data to validate or improve the near-Earth MMOD environment definition. The initial inspection was completed in September 2009. A total of 685 MMOD impact features (larger than about 0.3 mm) were identified and documented. This paper will provide an overview of the inspection, the analysis of the data, and the initial effort to use the data to model the MMOD environment.

  16. Functional Probes for Scanning Probe Microscopy

    NASA Astrophysics Data System (ADS)

    Akiyama, Kotone; Eguchi, Toyoaki; An, Toshu; Fujikawa, Yasunori; Hasegawa, Yukio; Sakurai, Toshio

    2007-03-01

    For superior performance of scanning probe microscopy, we are working to fabricate functional probes. For Kelvin probe force microscopy, we fabricated a metal-tip cantilever by attaching a thin metal wire to a regular Si cantilever and milling it by focused ion beam (FIB)^1. By using the W tip with a curvature radius of 3.5 nm, we obtained the potential profile of Ge/Si(105) surface in atomic resolution with the energy resolution better than 3 meV^2. For synchrotron-radiation-light-irradiated scanning tunneling microscopy which aims at atomically resolved elemental analysis, we fabricated a glass-coated W tip using FIB^3. It is found that the glass coating blocks the unwanted secondary electrons, which come from large area of the sample, by a factor of 40 with respect to the case no coating. Using the tip to detect the electrons emitted just below the tip, we obtained element specific images with a spatial resolution better than 20 nm under the photo irradiation whose energy is just above the adsorption edge of the element^4. 1 K. Akiyama et al., RSI 76, 033705 (2005) 2 T. Eguchi, K. Akiyama et al., PRL 93, 266102 (2004) 3 K. Akiyama et al., RSI 76, 083711 (2005) 4 T. Eguchi, K. Akiyama et al., APL, in press

  17. Periodic Spacing of Channel-Spanning Potholes in Navajo Sandstone, Henry Mountains Utah: Implications for Propagation of Incision Pulses across Tributary Junctions

    NASA Astrophysics Data System (ADS)

    Barnes, C. M.; Sklar, L. S.; Whipple, K. X.; Johnson, J. P.

    2004-12-01

    Incision of the Colorado River at Glen Canyon over the past ~1 Ma triggered pulses of incision that have migrated upstream through tributary drainages. The rate of incision of small tributaries often lags behind that of trunk streams, creatng over-steepened reaches at the tributary junction. In the arid Colorado Plateau, many of these low-order tributaries in massive lithologies have developed sequences of channel-spanning, periodically-spaced pothole bedforms. Although the dynamics of pothole formation and evolution are poorly understood, the occurrence of potholes correlates with super-critical flow and tools-limited conditions. We are exploring the hypothesis that pothole spacing and other profile attributes can be used to reconstruct the propagation of waves of incision through a drainage network. Here we report preliminary results of a field study of potholed reaches in steep, low-order channels draining Navajo Sandstone in the Henry Mountains, Utah. Our survey focused on channels where overlying sedimentary units and pediment deposits have largely been removed from the Navajo Sandstone. We surveyed six tributaries of the middle fork of Trail Canyon, and one tributary of Milk Creek, which are, in turn, minor tributaries of the Colorado River. We surveyed the long profile of each channel using a 5-m rod, 100-m tape, and a clinometer. In bedrock reaches, we focused on quantifying the spacing of alternating pothole steps and bedrock chutes, and the elevation change within and between potholes steps. We also characterized individual potholes by width, depth, maximum sediment size captured, and direction of flow recirculation. In alluviated reaches, we measured the bankfull width and depth to estimate relative differences in bankfull discharge. We also measured channel geometry in higher-order trunk streams at the junctions with the surveyed tributaries. Our preliminary results include the successful prediction of locations where potholed channels were found, by

  18. A new probe for measuring small electric fields in plasmas

    NASA Technical Reports Server (NTRS)

    Stenzel, R. L.

    1991-01-01

    A dipolar double probe has been developed for in situ measurements of small electric fields in laboratory plasmas. The probe measures dc to ac electric fields (f values between 0 and 20 MHz) with high sensitivity (Emin about 10 microV/cm) and responds to both space charge electric fields and inductive electric fields. Using voltage-to-frequency conversion, the probe signal is obtained free of errors and loading effects by a transmission line. Various examples of useful applications for the new probe are presented, such as measurements of dc ambipolar fields, ac space-charge fields of ion acoustic waves, ac inductive fields of whistler waves, and mixed inductive and space-charge electric fields in current-carrying magnetoplasmas.

  19. The meaning of space science

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The development of aerospace sciences through the first decade of NASA's existence was reviewed. Those scientific investigations made possible or significantly aided by rockets, satellites, and space probes are discussed along with the resulting space techniques that developed by way of those investigations.

  20. Technology for Entry Probes

    NASA Technical Reports Server (NTRS)

    Cutts, James A.; Arnold, James; Venkatapathy, Ethiraj; Kolawa, Elizabeth; Munk, Michelle; Wercinski, Paul; Laub, Bernard

    2005-01-01

    A viewgraph describing technologies for entry probes is presented. The topics include: 1) Entry Phase; 2) Descent Phase; 3) Long duration atmospheric observations; 4) Survivability at high temperatures; and 5) Summary.

  1. An Ultrasonographic Periodontal Probe

    NASA Astrophysics Data System (ADS)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  2. Implications of RFI at L-Band on Passive Microwave Remote Sensing of Soil Moisture from Space: Experience with ESTAR During SGP97

    NASA Technical Reports Server (NTRS)

    LeVine, David M.

    2000-01-01

    Passive microwave remote sensing in the protected band at 1.413 GHz (L-band) is important for monitoring parameters of the ocean and land surface such as soil moisture and sea surface salinity. These parameters are needed for understanding energy exchange between the surface and atmosphere and therefore are important for improving our understanding of weather and climate change. Although the band at 1.413 GHz is protected for passive use, airborne radiometers experience problems with RFI. For example, during the Southern Great Plains Experiment (1997) the ESTAR radiometer experienced significant RFI associated with airports, presumably air traffic control radar. This is a potential problem for future sensors in space planned for remote sensing of the earth surface in this frequency band.

  3. Effect of Glucose on the Fatty Acid Composition of Cupriavidus necator JMP134 during 2,4-Dichlorophenoxyacetic Acid Degradation: Implications for Lipid-Based Stable Isotope Probing Methods▿†

    PubMed Central

    Lerch, Thomas Z.; Dignac, Marie-France; Barriuso, Enrique; Mariotti, André

    2011-01-01

    Combining lipid biomarker profiling with stable isotope probing (SIP) is a powerful technique for studying specific microbial populations responsible for the degradation of organic pollutants in various natural environments. However, the presence of other easily degradable substrates may induce significant physiological changes by altering both the rate of incorporation of the target compound into the biomass and the microbial lipid profiles. In order to test this hypothesis, Cupriavidus necator JMP134, a 2,4-dichlorophenoxyacetic acid (2,4-D)-degrading bacterium, was incubated with [13C]2,4-D, [13C]glucose, or mixtures of both substrates alternatively labeled with 13C. C. necator JMP134 exhibited a preferential use of 2,4-D over glucose. The isotopic analysis showed that glucose had only a small effect on the incorporation of the acetic chain of 2,4-D into the biomass (at days 2 and 3) and no effect on that of the benzenic ring. The addition of glucose did change the fatty acid methyl ester (FAME) composition. However, the overall FAME isotopic signature reflected that of the entire biomass. Compound-specific individual isotopic analyses of FAME composition showed that the 13C-enriched FAME profiles were slightly or not affected when tracing the 2,4-D acetic chain or 2,4-D benzenic ring, respectively. This batch study is a necessary step for validating the use of lipid-based SIP methods in complex environments. PMID:21856833

  4. Planetary resources and astroecology. Planetary microcosm models of asteroid and meteorite interiors: electrolyte solutions and microbial growth--implications for space populations and panspermia.

    PubMed

    Mautner, Michael N

    2002-01-01

    Planetary microcosms were constructed using extracts from meteorites that simulate solutions in the pores of carbonaceous chondrites. The microcosms were found to support the growth of complex algal and microbial populations. Such astroecology experiments demonstrate how a diverse ecosystem could exist in fluids within asteroids, and in meteorites that land on aqueous planets. The microcosm solutions were obtained by extracting nutrient electrolytes under natural conditions from powders of the Allende (CV3) and Murchison (CM2) meteorites at low (0.02 g/ml) and high (10.0 g/ml) solid/solution ratios. The latter solutions contain > 3 mol/L electrolytes and about 10 g/L organics, that simulate natural fluids in asteroids during aqueous alteration and in the pores of meteorites, which can help prebiotic synthesis and the survival of early microorganisms. These solutions and wet solids were in fact found to support complex self-sustaining microbial communities with populations of 4 x 10(5) algae and 6 x 10(6) bacteria and fungi for long periods (> 8 months). The results show that planetary microcosms based on meteorites can: assay the fertilities of planetary materials; identify space bioresources; target astrobiology exploration; and model past and future space-based ecosystems. The results show that bioresources in the carbonaceous asteroids can sustain a biomass of 10(18) kg, comprising 10(32) microorganisms and a human population of 10(14). The results also suggest that protoplanetary nebulae can support and disperse microorganisms and can be therefore effective environments for natural and directed panspermia. PMID:12449855

  5. Asteroid 6 Hebe: Spectral Evaluation of the Prime Large Mainbelt Ordinary Chondrite Parent Body Candidate with Implications from Space Weathering of Gaspra and the Ida-Dactyl System

    NASA Astrophysics Data System (ADS)

    Gaffey, M. J.

    1996-03-01

    No large mainbelt asteroid has yet been confirmed as an ordinary chondrite parent body. A number of plausible candidates have been identified based on dynamical considerations and/or spectral evidence. The fifth largest S-asteroid, 6 Hebe, is the best current candidate for one of the long sought large mainbelt ordinary chondrite parent bodies. Its proximity to the chaotic zones associated with both the 3:1 proper motion and the nu(sub)6 (or g=g(sub)6) secular resonance "escape hatches" should make Hebe a major mainbelt contributor to the terrestrial meteorite flux. Hebe also exhibits a surface assemblage (subtype S(IV), the only subgroup among the S-asteroids that might include ordinary chondrite parent bodies) which allows (or more precisely, does not exclude) an ordinary chondrite affinity. An analysis of the rotational variations of spectra obtained in June 1979 and February 1989 provide a sophisticated test of whether or not Hebe is a viable ordinary chondrite parent body. If the rotational spectral variations of Hebe are consistent with an undifferentiated silicate assemblage, there still remains the mismatch in the overall spectral slope and band intensities. It has been suggested that the Gaspra and Ida-Dactyl encounters establish that space weathering causes this discrepancy. However, there are several inconsistencies in this simple picture which suggest that while the presence of a space weathering process on Ida and Gaspra appears well established, there still remains considerable uncertainty concerning its nature and ability to spectrally modify ordinary chondrites to match the slope and band depths of S-asteroids.

  6. Probing Stellar Populations in the Virgo and Fornax Clusters with Infrared Surface Brightness Fluctuations

    NASA Astrophysics Data System (ADS)

    Jensen, Joseph B.; Gibson, Zachary J; Lee, Hyun-chul; Blakeslee, John

    2014-06-01

    Surface brightness fluctuations (SBF) are a useful tool for measuring extragalactic distances. At infrared wavelengths, SBF break the age-metallicity degeneracy and are useful for probing the properties of the most luminous stars in a galaxy, even when individual stars are not resolved. We present a detailed comparison of F110W and F160W SBF measurements made using the Hubble Space Telescope WFC3/IR camera to a variety of stellar population models, including those with solar-scaled and alpha-enhanced compositions and models incorporating convective core overshoot for younger populations. We use these model comparisons to assess the star formation histories of 16 galaxies spanning a wide range in color and luminosity in the Virgo and Fornax clusters, measured as a function of distance from the galaxy center in elliptical apertures. We discuss the implications of population variations on the fluctuation magnitudes and distance measurements.

  7. Mapping the Heavens: Probing Cosmology with the Sloan Digital Sky Survey

    SciTech Connect

    Frieman, Josh

    2006-12-04

    This talk will provide an overview of results from the on-going Sloan Digital Sky Survey (SDSS), the most ambitious mapping of the Universe yet undertaken, focusing on those with implications for cosmology. It will include a virtual fly-through of the survey that reveals the 3-dimensional large-scale structure of the galaxy distribution. Recent measurements of this large-scale structure, in combination with observations of the cosmic microwave background, have provided independent evidence for a Universe dominated by dark matter and dark energy as well as insights into how galaxies and larger-scale structures formed. I will also describe early results from the SDSS Supernova Survey, which aims to provide more precise constraints on the nature of dark energy. Future planned surveys from the ground and from space will build on these foundations to probe the history of the cosmic expansion--and thereby the dark energy--with even greater precision.

  8. Workshop summary. Biomedical and Space-Related Research with Heavy Ions at the BEVALAC

    NASA Technical Reports Server (NTRS)

    Schimmerling, W.; Curtis, S. B.

    1989-01-01

    The authors provide an overview of papers presented at a workshop on Biomedical and Space-Related Research with Heavy Ions at the BEVALAC at Lawrence Berkeley Laboratory. Goals of the meeting were to determine the critical experiments using heavy ions as probes in radiation physics, radiation chemistry, macromolecular and cellular biology, evolution science, basic neurophysiology, and medical therapies; how beam lines and facilities at Lawrence Berkeley Laboratory can be improved for these experiments; and implications in priorities and funding for national policy. Workshop topics included physics and facilities, cellular and molecular biology, tissue radiobiology, and the future of heavy ion research.

  9. Workshop summary. Biomedical and Space-Related Research with Heavy Ions at the BEVALAC.

    PubMed

    Schimmerling, W; Curtis, S B

    1989-08-01

    The authors provide an overview of papers presented at a workshop on Biomedical and Space-Related Research with Heavy Ions at the BEVALAC at Lawrence Berkeley Laboratory. Goals of the meeting were to determine the critical experiments using heavy ions as probes in radiation physics, radiation chemistry, macromolecular and cellular biology, evolution science, basic neurophysiology, and medical therapies; how beam lines and facilities at Lawrence Berkeley Laboratory can be improved for these experiments; and implications in priorities and funding for national policy. Workshop topics included physics and facilities, cellular and molecular biology, tissue radiobiology, and the future of heavy ion research. PMID:11536613

  10. Exercise Countermeasures for Bone Loss During Space Flight: A Method for the Study of Ground Reaction Forces and their Implications for Bone Strain

    NASA Technical Reports Server (NTRS)

    Peterman, M.; McCrory, J. L.; Sharkey, N. A.; Piazza, S.; Cavanagh, P. R.

    1999-01-01

    Effective countermeasures to prevent loss of bone mineral during long duration space flight remain elusive. Despite an exercise program on MIR flights, the data from LeBlanc et al. (1996) indicated that there was still a mean rate of loss of bone mineral density in the proximal femur of 1.58% per month (n=18, flight duration 4 - 14.4 months). The specific mechanisms regulating bone mass are not known, but most investigators agree that bone maintenance is largely dependent upon mechanical demand and the resultant local bone strains. A plausible hypothesis is that bone loss during space flight, such as that reported by LeBlanc et al. (1996), may result from failure to effectively load the skeleton in order to generate localized bone strains of sufficient magnitude to prevent disuse osteoporosis. A variety of methods have been proposed to simulate locomotor exercise in reduced gravity. In such simulations, and in an actual microgravity environment, a gravity replacement load (GRL) must always be added to return the exercising subject to the support surface and the resulting skeletal load is critically dependent upon the magnitude of the GRL. To our knowledge, GRLs during orbital flight have only been measured once (on STS 81) and it is likely that most or all prior treadmill exercise in space has used GRLs that were less than one body weight. McCrory (1997) has shown that subjects walking and running in simulated zero-G can tolerate GRLs of 1 if an appropriate harness is used. Several investigators have attempted to measure in vivo strains and forces in the bones of humans, but have faced ethical and technical limitations. The anteromedial aspect of the tibial midshaft has been a common site for the placement of strain gauges; one reason to measure strains in the anterior tibia is that this region is surgically accessible. Aamodt et al. (1997) were able to measure strains on the lateral surface of the proximal femur only because their experimental subjects were

  11. Review of Gravity Probe B

    NASA Technical Reports Server (NTRS)

    1995-01-01

    In response to a request by the NASA Administrator, the National Research Council (NRC) has conducted an accelerated scientific review of NASA's Gravity Probe B (GP-B) mission. The review was carried out by the Task Group on Gravity Probe B, under the auspices of the NRC's Space Studies Board and Board on Physics and Astronomy. The specific charge to the task group was to review the GP-B mission with respect to the following terms of reference: (1) scientific importance - including a current assessment of the value of the project in the context of recent progress in gravitational physics and relevant technology; (2) technical feasibility - the technical approach will be evaluated for likelihood of success, both in terms of achievement of flight mission objectives but also in terms of scientific conclusiveness of the various possible outcomes for the measurements to be made; and (3) competitive value - if possible, GP-B science will be assessed qualitatively against the objectives and accomplishments of one or more fundamental physics projects of similar cost (e.g., the Cosmic Background Explorer, COBE).

  12. The Gravity Probe B Experiment

    NASA Technical Reports Server (NTRS)

    Kolodziejczak, Jeffrey

    2008-01-01

    This presentation briefly describes the Gravity Probe B (GP-B) Experiment which is designed to measure parts of Einstein's general theory of relativity by monitoring gyroscope orientation relative to a distant guide star. To measure the miniscule angles predicted by Einstein's theory, it was necessary to build near-perfect gyroscopes that were approximately 50 million times more precise than the best navigational gyroscopes. A telescope mounted along the central axis of the dewar and spacecraft provided the experiment's pointing reference to a guide star. The telescope's image divide precisely split the star's beam into x-axis and y-axis components whose brightness could be compared. GP-B's 650-gallon dewar, kept the science instrument inside the probe at a cryogenic temperature for 17.3 months and also provided the thruster propellant for precision attitude and translation control. Built around the dewar, the GP-B spacecraft was a total-integrated system, comprising both the space vehicle and payload, dedicated as a single entity to experimentally testing predictions of Einstein's theory.

  13. Probing Inflation with CMB Polarization

    SciTech Connect

    Baumann, Daniel; Jackson, Mark G.; Adshead, Peter; Easther, Richard; Amblard, Alexandre; Cooray, Asantha; Ashoorioon, Amjad; Watson, Scott; Bartolo, Nicola; Matarrese, Sabino; Bean, Rachel; Beltran, Maria; Dvorkin, Cora; Bernardis, Francesco de; Melchiorri, Alessandro; Pagano, Luca; Bird, Simeon; Peiris, Hiranya V.; Chen Xingang; Hertzberg, Mark P.

    2009-06-09

    We summarize the utility of precise cosmic microwave background (CMB) polarization measurements as probes of the physics of inflation. We focus on the prospects for using CMB measurements to differentiate various inflationary mechanisms. In particular, a detection of primordial B-mode polarization would demonstrate that inflation occurred at a very high energy scale, and that the inflaton traversed a super-Planckian distance in field space. We explain how such a detection or constraint would illuminate aspects of physics at the Planck scale. Moreover, CMB measurements can constrain the scale-dependence and non-Gaussianity of the primordial fluctuations and limit the possibility of a significant isocurvature contribution. Each such limit provides crucial information on the underlying inflationary dynamics. Finally, we quantify these considerations by presenting forecasts for the sensitivities of a future satellite experiment to the inflationary parameters.

  14. Atomic Resolution Imaging with a sub-50 pm Electron Probe

    SciTech Connect

    Erni, Rolf P.; Rossell, Marta D.; Kisielowski, Christian; Dahmen, Ulrich

    2009-03-02

    Using a highly coherent focused electron probe in a 5th order aberration-corrected transmission electron microscope, we report on resolving a crystal spacing less than 50 pm. Based on the geometrical source size and residual coherent and incoherent axial lens aberrations, an electron probe is calculated, which is theoretically capable of resolving an ideal 47 pm spacing with 29percent contrast. Our experimental data show the 47 pm spacing of a Ge 114 crystal imaged with 11-18percent contrast at a 60-95percent confidence level, providing the first direct evidence for sub 50-pm resolution in ADF STEM imaging.

  15. Holocene vertical deformation along the coastal sector of Mt. Etna volcano (eastern Sicily, Italy): Implications on the time-space constrains of the volcano lateral sliding

    NASA Astrophysics Data System (ADS)

    Branca, Stefano; De Guidi, Giorgio; Lanzafame, Gianni; Monaco, Carmelo

    2014-12-01

    A detailed survey of morphological and biological markers of paleo-shorelines has been carried out along the coastal sector of Mt. Etna volcano (eastern Sicily, Italy), in order to better define causes and timing of vertical deformation. We have mapped markers of raised Holocene shorelines, which are represented by beach rocks, wave-cut platforms, balanid, vermetid and algal rims. The timing of coastal uplift has been determined by radiocarbon dating of shells collected from the raised paleo-shorelines and, to correctly assess the total amount of tectonic uplift of the coast during the Late Holocene, we have compared the elevation-age data of sampled shells to the local curve of Holocene sea-level rise. Taking into account the nominal elevation of the associated paleo-shorelines, an uplift rate of 2.5-3.0 mm/year has been estimated for the last 6-7 ka. This general process of uplifting is only locally interrupted by subsidence related to flank sliding of the volcanic edifice, measured at docks and other manmade structures, and by acceleration along the hinge of an active anticline and at the footwall of an active fault. Based on this new data we suggest more precise time-space constraints for the dynamics of the lower eastern flank of Mt. Etna volcano.

  16. Optimizing the antenna system of a microwave space power station: Implications for the selection of operating power, frequency and antenna size

    NASA Technical Reports Server (NTRS)

    Manning, Robert M.

    1987-01-01

    A design for a space power station that is to transmit power to the surface of a planet via high powered microwaves should commence with the optimum design of the transmitting and receiving antenna combination to be employed. Once one has assured that the desired amount of power has been transferred (which, after all, is the prupose of any power transmission system), one can, from the constraints imposed by such a design, taylor other parameters of the system such as antenna sizes and weights, power density in the planet's atmosphere (e.g., to avoid electrical breakdown), and frequency of operation. It is the purpose of this brief analysis to provide the working equations of such an optimized antenna system, and to give examples of their use. Related problems that should be analyzed in the future will then be discussed and a flow chart of the indicated order of priority presented. The analysis given here differs from previous work on this subject in that the development given will allow analytical expressions to be obtained for the relevant parameters. This is made possible by employing an approximation procedure to be given during the exposition.

  17. Gently dipping normal faults identified with Space Shuttle radar topography data in central Sulawesi, Indonesia, and some implications for fault mechanics

    USGS Publications Warehouse

    Spencer, J.E.

    2011-01-01

    Space-shuttle radar topography data from central Sulawesi, Indonesia, reveal two corrugated, domal landforms, covering hundreds to thousands of square kilometers, that are bounded to the north by an abrupt transition to typical hilly to mountainous topography. These domal landforms are readily interpreted as metamorphic core complexes, an interpretation consistent with a single previous field study, and the abrupt northward transition in topographic style is interpreted as marking the trace of two extensional detachment faults that are active or were recently active. Fault dip, as determined by the slope of exhumed fault footwalls, ranges from 4?? to 18??. Application of critical-taper theory to fault dip and hanging-wall surface slope, and to similar data from several other active or recently active core complexes, suggests a theoretical limit of three degrees for detachment-fault dip. This result appears to conflict with the dearth of seismological evidence for slip on faults dipping less than ~. 30??. The convex-upward form of the gently dipping fault footwalls, however, allows for greater fault dip at depths of earthquake initiation and dominant energy release. Thus, there may be no conflict between seismological and mapping studies for this class of faults. ?? 2011 Elsevier B.V.

  18. Model for resonant plasma probe.

    SciTech Connect

    Warne, Larry Kevin; Johnson, William Arthur; Hebner, Gregory Albert; Jorgenson, Roy E.; Coats, Rebecca Sue

    2007-04-01

    This report constructs simple circuit models for a hairpin shaped resonant plasma probe. Effects of the plasma sheath region surrounding the wires making up the probe are determined. Electromagnetic simulations of the probe are compared to the circuit model results. The perturbing effects of the disc cavity in which the probe operates are also found.

  19. Dual active surface heat flux gage probe

    NASA Astrophysics Data System (ADS)

    Liebert, Curt H.; Kolodziej, Paul

    1995-02-01

    A unique plug-type heat flux gage probe was tested in the NASA Ames Research Center 2x9 turbulent flow duct facility. The probe was fabricated by welding a miniature dual active surface heat flux gage body to the end of a hollow metal cylindrical bolt containing a metal inner tube. Cooling air flows through the inner tube, impinges onto the back of the gage body and then flows out through the annulus formed between the inner tube and the hollow bolt wall. Heat flux was generated in the duct facility with a Huels arc heater. The duct had a rectangular cross section and one wall was fabricated from 2.54 centimeter thick thermal insulation rigid surface material mounted onto an aluminum plate. To measure heat flux, the probe was inserted through the plate and insulating materials with the from of the gage located flush with the hot gas-side insulation surface. Absorbed heat fluxes measured with the probe were compared with absorbed heat fluxes measured with six water-cooled reference calorimeters. These calorimeters were located in a water-cooled metal duct wall which was located across from the probe position. Correspondence of transient and steady heat fluxes measured with the reference calorimeters and heat flux gage probe was generally within a satisfactory plus or minus 10 percent. This good correspondence was achieved even though the much cooler probe caused a large surface temperature disruption of 1000K between the metal gage and the insulation. However, this temperature disruption did not seriously effect the accuracy of the heat flux measurement. A current application for dual active surface heat flux gages is for transient and steady absorbed heat flux, surface temperature and heat transfer coefficient measurements on the surface of an oxidizer turbine inlet deflector operating in a space shuttle test bed engine.

  20. Computational simulation of Faraday probe measurements

    NASA Astrophysics Data System (ADS)

    Boerner, Jeremiah J.

    Electric propulsion devices, including ion thrusters and Hall thrusters, are becoming increasingly popular for long duration space missions. Ground-based experimental testing of such devices is performed in vacuum chambers, which develop an unavoidable background gas due to pumping limitations and facility leakage. Besides directly altering the operating environment, the background gas may indirectly affect the performance of immersed plasma probe diagnostics. This work focuses on computational modeling research conducted to evaluate the performance of a current-collecting Faraday probe. Initial findings from one dimensional analytical models of plasma sheaths are used as reference cases for subsequent modeling. A two dimensional, axisymmetric, hybrid electron fluid and Particle In Cell computational code is used for extensive simulation of the plasma flow around a representative Faraday probe geometry. The hybrid fluid PIC code is used to simulate a range of inflowing plasma conditions, from a simple ion beam consistent with one dimensional models to a multiple component plasma representative of a low-power Hall thruster plume. These simulations produce profiles of plasma properties and simulated current measurements at the probe surface. Interpretation of the simulation results leads to recommendations for probe design and experimental techniques. Significant contributions of this work include the development and use of two new non-neutral detailed electron fluid models and the recent incorporation of multi grid capabilities.