Progress simulating equatorial spread F (ESF) in pursuit of a space-weather forecast capability is summarized. ESF is the main manifestation of space weather at low magnetic latitudes in the ionosphere and is responsible for disrupting communication, navigation, imaging, and surveillance systems important to the Air Force and other federal agencies. A 3D numerical simulation of the plasma instabilities responsible for ESF written at Cornell has been developed and upgraded under this award....
Topics: DTIC Archive, Hysell,David L, CORNELL UNIV ITHACA NY ITHACA United States, space weather,...
The M2P2 concept is based on the transfer of momentum from the solar wind to an artificial magnetic field structure like that naturally occurs at all magnetized planets in the Solar System, called the magnetosphere. The objectives of this program include the following: (1) Demonstrate artificial magnetospheric inflation through cold plasma filling in vacuum; (2) Demonstrate deflection of a surrogate solar wind by an artificial magnetosphere in the laboratory vacuum chamber; (3) Compare...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD CONFIGURATIONS, PLASMA PROPULSION, SPACE...
The principal features that might exist in the terrestrial paleoionosphere, if the geomagnetic field were to assume a quadrupole form during a polarity reversal are discussed. Complicated phenomena would be expected to occur at magnetic equators and magnetospherically-driven plasma convection might occur at latitudes where the magnetic field is steeply inclined. The influence of magnetic field strength on ionospheric structure is considered in general terms.
Topics: NASA Technical Reports Server (NTRS), EARTH IONOSPHERE, GEOMAGNETISM, MAGNETIC FIELD...
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299
May 22, 2011
05/11
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Berlin, Graydon Lenni
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L-band radar images from the two NASA Shuttle Imaging Radar missions in 1981 and 1984 delineate and characterize a number of different geologic terrains in Saudi Arabia that are completely or partially buried beneath relatively thin deposits of eolian sand. The sand mantle was essentially made transparent because the propagated radar beams were able to penetrate through the fine-grained, loose, and very dry sand deposits and be diffusely reflected from various radar-rough substrates. These...
Topics: CONTACTORS, TEMPERATURE PROFILES, HEATING EQUIPMENT, HOLLOW CATHODES, INTERNATIONAL SPACE STATION,...
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459
Jul 23, 2010
07/10
by
Knoll, Richard H.; Macneil, Peter N.; England, James E
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The thermal protection systems for the shuttle/Centaur would have had to provide fail-safe thermal protection during prelaunch, launch ascent, and on-orbit operations as well as during potential abort. The thermal protection systems selected used a helium-purged polyimide foam beneath three rediation shields for the liquid-hydrogen tank and radiation shields only for the liquid-oxygen tank (three shields on the tank sidewall and four on the aft bulkhead). A double-walled vacuum bulkhead...
Topics: BRIGHTNESS, ION TEMPERATURE, SULFUR, IMAGING TECHNIQUES, IO, PLASMA HEATING, SPACE PLASMAS,...
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285
May 23, 2011
05/11
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Wood, Brian E.; Alexander, William R.; Linsky, Jeffrey L
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We present new observations of the Ly alpha lines of Epsilon Indi (K5 5) and A Andromedae (G8 4-3 ) These data were obtained by the Goddard High Resolution Spectrograph (GHRS) on the Hubble Space Telescope. Analysis of the interstellar H 1 and D 1 absorption lines reveals that the velocities and temperatures inferred from the H 1 lines are inconsistent with the parameters inferred from the D 1 lines, unless the H 1 absorption is assumed to be produced by two absorption components. One...
Topics: PHOTOVOLTAIC CELLS, PLASMA INTERACTIONS, SOLAR ARRAYS, SPACE PLASMAS, INTERNATIONAL SPACE STATION,...
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May 23, 2011
05/11
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Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G
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We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 15-20 Sept. 1993 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on 20 Sept. A total of 1804 bright points were...
Topics: PHOTOELECTRONS, POSITION (LOCATION), EXCITATION, SUNLIGHT, TIME DEPENDENCE, MAGNETIC FLUX,...
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450
May 23, 2011
05/11
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Schenk, Paul M.; Moore, Jeffrey M
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The morphology of volcanic features on Ganymede differs significantly from that on the terrestrial planets. Few if any major volcanic landforms, such as thick flows or shield volcanoes, have been identified to date. Using new stereo Voyager images, we have searched Ganymede for relief-generating volcanic constructs. We observed seven major types of volcanic structures, including several not previously recognized. The oldest are broad flat-topped domes partially filling many older craters in...
Topics: PLASMASPHERE, DIURNAL VARIATIONS, MAGNETIC FLUX, ELECTRIC FIELDS, DIFFUSIVITY, SPACE PLASMAS,...
We examined the various likely processes for creating the cavities and found that the mirror force acting on the transversely heated ions is the most likely mechanism. The pondermotive force causing the wave collapse was found to be a much weaker force than the mirror force on the transversely heated ions observed inside the cavities along with the lower hybrid waves. Using a hydrodynamic model for the polar wind we modeled the cavity formation and found that for the heating rate obtained from...
Topics: NASA Technical Reports Server (NTRS), EARTH IONOSPHERE, IONOSPHERIC HEATING, IONS, PLASMA HEATING,...
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.
Topics: NASA Technical Reports Server (NTRS), ELECTRIC POTENTIAL, REMOTE SENSORS, INTERNATIONAL SPACE...
The following describes a list of errata in our paper, "A simple, analytical model of collisionless magnetic reconnection in a pair plasma." It supersedes an earlier erratum. We recently discovered an error in the derivation of the outflow-to-inflow density ratio.
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD RECONNECTION, MATHEMATICAL MODELS, CORRECTION,...
It was predicted (Carlson, 1987; 1993) that once HF radio waves achieved ionospheric energy densities comparable to that from the solar EUV, they could produce their own ionosphere. That work estimated a GW ERP of rf energy would produce an ionosphere half that from an overhead sun, assuming 15 efficiency conversion of rf energy to accelerated electron energy. [Until 2009 only one experimental estimate existed, 15 from Carlson, 1982.] The production mechanism proposed was impact ionization, by...
Topics: DTIC Archive, Carlson,Herbert C, Utah State University Logan United States, Ionosphere, SPACE...
The availability of a data set of IMP-J (IMP 8) field and plasma data is announced. Magnetic field data and plasma data from a Faraday cup experiment are provided.
Topics: NASA Technical Reports Server (NTRS), INTERPLANETARY MAGNETIC FIELDS, INTERPLANETARY MEDIUM, SPACE...
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349
Jul 25, 2010
07/10
by
Gibson, J. S.; Adamian, A
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An approximation theory is presented for the LQG (Linear-Quadratic-Gaussian) optimal control problem for flexible structures whose distributed models have bounded input and output operators. The main purpose of the theory is to guide the design of finite dimensional compensators that approximate closely the optimal compensator. The optimal LQG problem separates into an optimal linear-quadratic regulator problem and an optimal state estimation problem. The solution of the former problem lies in...
Topics: INTERPLANETARY MAGNETIC FIELDS, INTERPLANETARY MEDIUM, SOLAR WIND, SPACE PLASMAS, EXPLORER 50...
The goal of theory is to understand how the fundamental laws of physics laws of physics and chemistry give rise to the features of the universe. It is recommended that NASA establish independent theoretical research programs in planetary sciences and in astrophysics similar to the solar-system plasma-physics theory program, which is characterized by stable, long-term support for theorists in university departments, NASA centers, and other organizations engaged in research in topics relevant to...
Topics: NASA Technical Reports Server (NTRS), ASTROPHYSICS, NASA PROGRAMS, PLANETOLOGY, SPACE PLASMAS,...
We have achieved all the goals stated in our grant proposal. Specifically, these include: 1. The understanding of the complexity induced nonlinear spatiotemporal coherent structures and the coexisting propagating modes. 2. The understanding of the intermittent turbulence and energization process of the observed Bursty Bulk Flows (BBF's) in the Earth s magnetotail. 3. The development of "anisotropic three-dimensional complexity" in the plasma sheet due to localized merging and...
Topics: NASA Technical Reports Server (NTRS), SPACE PLASMAS, NONLINEARITY, MAGNETIC FIELD CONFIGURATIONS,...
Progress in research to understand the three-dimensional nature of the Europagenic plasma torus is summarized. Efforts to improve the plasma torus description near Europa's orbit have included a better understanding of Europa's orbit and an improved description of the planetary magnetic field. New plasma torus chemistry for molecular and atomic species has been introduced and implemented in Europa neutral cloud models. Preliminary three-dimensional model calculations for Europa's neutral clouds...
Topics: NASA Technical Reports Server (NTRS), JUPITER (PLANET), PLANETARY MAGNETOSPHERES, EUROPA, SPACE...
Our research program is designed to carry out state-of-the-art atomic physics calculations crucial to advancing our understanding of fundamental astrophysical problems. We redress the present inadequacies in the atomic data base along two important areas: dielectronic recombination and inner-shell photoionization and multiple electron ejection/Auger fluorescence therefrom. All of these data are disseminated to the astrophysical community in the proper format for implementation in spectral...
Topics: NASA Technical Reports Server (NTRS), SPACE PLASMAS, ASTRONOMICAL MODELS, ATOMIC SPECTRA,...
Arcing and other types of electrical discharges are likely to occur in high-voltage subsystems of the Space Station. Results from ground and space experiments on the arcing of solar cell arrays are briefly reviewed, showing that the arcing occurs when the conducting interconnects in the arrays are at negative potential above a threshold, which decreases with the increasing plasma density. Furthermore, above the threshold voltages the arcing rate increases with the plasma density. At the...
Topics: NASA Technical Reports Server (NTRS), AEROSPACE ENVIRONMENTS, ARC DISCHARGES, ELECTRIC DISCHARGES,...
Contamination of spacecraft in the aerospace environment is examined. The optical systems, thermal control systems and solar power systems were deemed to be most vulnerable to particle damage. It was decided that all orbits should be considered. Specific issues concern whether there are changes in transmittance of optics and the radiative properties of protective coatings.
Topics: NASA Technical Reports Server (NTRS), OPTICAL MEASURING INSTRUMENTS, SPACE PLASMAS, SPACECRAFT...
The possible use of Chamber A for the replication or simulation of space plasma physics processes which occur in the geosynchronous Earth orbit (GEO) environment is considered. It is shown that replication is not possible and that scaling of the environmental conditions is required for study of the important instability processes. Rules for such experimental scaling are given. At the present time, it does not appear technologically feasible to satisfy these requirements in Chamber A. It is,...
Topics: NASA Technical Reports Server (NTRS), GEOSYNCHRONOUS ORBITS, PLASMA PHYSICS, SPACE ENVIRONMENT...
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442
May 23, 2011
05/11
by
Schelman, David A.; Jenkins, Phillip P.; Brinker, David J.; Appelbaum, Josep
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Past NASA missions to Mars, Jupiter and the outer planets were powered by radioisotope thermal generators (RTG's). Although these devices proved to be reliable, their high cost and highly toxic radioactive heat source has made them far less desirable for future planetary missions. This has resulted in a renewed search for alternate energy sources, some of them being photovoltaics (PV) and thermo-photovoltaics (TPV). Both of these alternate energy sources convert light/thermal energy directly...
Topics: SOLAR WIND, IONS, INNER RADIATION BELT, GEOMAGNETIC TAIL, SATELLITE INSTRUMENTS, MAGNETICALLY...
The theoretical interpretation of observed interplanetary resonance luminescence patterns is used as one of the must promising methods to determine the state of the local interstellar medium (LISM). However, these methods lead to discrepant results that would be hard to understand in the framework of any physical LISM scenario. Assuming that the observational data are reliable, two possibilities which could help to resolve these discrepancies are discussed: (1) the current modeling of resonance...
Topics: NASA Technical Reports Server (NTRS), INTERSTELLAR GAS, NEUTRAL GASES, PLASMA DIAGNOSTICS, PLASMA...
Fast magnetic reconnection refers to annihilation or topological rearrangement of magnetic fields on a timescale that is independent (or nearly independent) of the plasma resistivity. The resistivity of astrophysical plasmas is so low that reconnection is of little practical interest unless it is fast. Yet, the theory of fast magnetic reconnection is on uncertain ground, as models must avoid the tendency of magnetic fields to pile up at the reconnection layer, slowing down the flow. In this...
Topics: NASA Technical Reports Server (NTRS), MAGNETIC FIELD RECONNECTION, MATHEMATICAL MODELS, SPACE...
An important modification was made in the method for computing ion densities from DE1/RIMS observations, based on the observed relationship between total plasma density and spacecraft potential. An iterative technique was developed to require that this relationship be preserved in all individual observations, not just in the average sense observed. Results of employing this technique were examined closely and are found to generally improve the final densities in terms of agreement with...
Topics: NASA Technical Reports Server (NTRS), ION DENSITY (CONCENTRATION), MATHEMATICAL MODELS, SPACE...
Lower hybrid solitary structures (LHSS) have been observed by sounding rockets in the auroral ionosphere for over a decade and a half. LHSS are spatial structures embedded in space plasmas containing ambient whistler mode hiss. They are characterized by a density depletion of a few percent to several tens of percent in which electric fields near, both above and below, the lower hybrid resonance are more intense than the background fields by a factor of three to five. LHSS have dimensions across...
Topics: NASA Technical Reports Server (NTRS), CYLINDRICAL BODIES, ELECTRIC FIELDS, HYBRID STRUCTURES,...
This final report describes activities under NASA contract NAS5-31213 to Lockheed Missiles and Space Company. The report covers the entire contract period from 8 May 1991 to 7 Jun. 1994. This is a contract under the NASA Guest Investigator Program for the analysis and interpretation of the combined scientific data from the Hot Plasma Composition Experiment (HPCE) and the Charge Energy Mass (CHEM) spectrometer on the AMPTE/Charge Composition Explorer (CCE) spacecraft. These combined data sets...
Topics: NASA Technical Reports Server (NTRS), HIGH TEMPERATURE PLASMAS, IONS, MAGNETOPAUSE, MAGNETOSHEATH,...
The 8th Spacecraft Charging Technology Conference was held in Huntsville, Alabama, October 20-24, 2003. Hosted by NASA s Space Environments and Effects (SEE) Program and co-sponsored by the Air Force Research Laboratory (AFRL) and the European Space Agency (ESA), the 2003 conference saw attendance from eleven countries with over 65 oral papers and 18 poster papers. Presentation topics highlighted the latest in spacecraft charging mitigation techniques and on-orbit investigations, including:...
Topics: NASA Technical Reports Server (NTRS), SPACECRAFT CHARGING, EXTERNAL SURFACE CURRENTS, CONFERENCES,...
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412
May 23, 2011
05/11
by
Breininger, D. R.; Larson, V. L.; Schaub, R.; Duncan, B. W.; Schmalzer, P. A.; Oddy, D. M.; Smith, R. B.; Adrian, F.; Hill, H., Jr
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The Florida Scrub-Jay (Aphelocoma coerulescens) is an indicator of ecosystem integrity of Florida scrub, an endangered ecosystem that requires frequent fire. One of the largest populations of this federally threatened species occurs on John F. Kennedy Space Center/Merritt Island National Wildlife Refuge. Population trends were predicted using population modeling and field data on reproduction and survival of Florida Scrub-Jays collected from 1988 - 1995. Analyses of historical photography...
Topics: AURORAL ZONES, HARMONICS, SOLAR ACTIVITY, SOLAR PLANETARY INTERACTIONS, CYCLOTRON RADIATION,...
This report summarizes results obtained through the support of NASA Grant NAGW-1936. The objective of this report is to conduct large scale simulations of electron beams injected into space. The topics covered include the following: (1) simulation of radial expansion of an injected electron beam; (2) simulations of the active injections of electron beams; (3) parameter study of electron beam injection into an ionospheric plasma; and (4) magnetosheath-ionospheric plasma interactions in the cusp.
Topics: NASA Technical Reports Server (NTRS), BEAM INJECTION, BEAM INTERACTIONS, EARTH IONOSPHERE, ELECTRON...
In this paper we report early results from the Floating Potential Probe (FPP) recently installed on the International Space Station (ISS). The data show that FPP properly measures the electrical potential of ISS structure with respect to the plasma it is flying through. FPP Langmuir probe data seem to give accurate measurements of the ambient plasma density, and are generally consistent with the IRI-90 model. FPP data are used to judge the performance of the ISS Plasma Contacting Units (PCUs),...
Topics: NASA Technical Reports Server (NTRS), ELECTROSTATIC PROBES, INTERNATIONAL SPACE STATION, SPACE...
The interaction of a high-voltage solar array with the space plasma environment is investigated in a laboratory simulation experiment. Discharges are observed to occur when the solar array is at a sufficiently high negative bias with respect to the plasma. The frequency of occurrence of discharge is found to depend critically on the plasma density and on the geometry of the array. The electromagnetic interference (EMI) associated with a discharge is also measured. The amplitude of EMI increases...
Topics: NASA Technical Reports Server (NTRS), HIGH VOLTAGES, PLASMA INTERACTIONS, SOLAR ARRAYS, SPACE...
Turbulence in fluids and plasmas is a scale-dependent process that generates fluctuations towards ever-smaller scales until dissipation occurs. Recent Cluster observations in the solar wind demonstrate the existence of a cascade of magnetic energy from the scale of the proton Larmor radius, where kinetic properties of ions invalidate fluid approximations, down to the electron Larmor radius, where electrons become demagnetized. The cascade is quasi-two-dimensional and has been interpreted as...
Topics: NASA Technical Reports Server (NTRS), DISSIPATION, SOLAR WIND, CLUSTER MISSION, ASTROPHYSICS,...
The high density of the plasma at shuttle altitude is likely to increase greatly the possibility of arcing and shorting of exposed high voltage surfaces. For military missions over the polar caps and through the auoroal zones, the added hazards of high energy auroral particle fluxes or solar flares will further increase the hazard to shuttle, its crew, and its mission. A review of the role that the auroral and polar cap environment play in causing these interactions was conducted. A simple,...
Topics: NASA Technical Reports Server (NTRS), GEOMAGNETISM, MODELS, POLAR ORBITS, SOLAR ACTIVITY, SPACE...
The role plasma contactors play in effective electrodynamic tether operation is discussed. Hollow cathodes and hollow cathode-based plasma sources have been identified as leading candidates for the electrodynamic tether plasma contactor. Present experimental efforts to evaluate the suitability of these devices as plasma contactors, conducted concurrently at NASA Lewis Research Center and Colorado State University, are reviewed. These research programs include the definition of preliminary...
Topics: NASA Technical Reports Server (NTRS), CONTACTORS, ELECTRODYNAMICS, PLASMA CONTROL, ELECTRON...
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234
May 27, 2011
05/11
by
Stokes, George M
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This report describes the mechanical and aerodynamic features of a two-foot hypersonic facility at the Langley Research Center. The facility provides for the testing of aerodynamic models in the Mach number range between 3 and 7 at approximate Reynolds numbers between 0.5 x 10(exp 6) and 1.0 x 10(exp 6). The facility was designed to obtain the needed pressure ratio through the use of ejector nozzles. Compressors driving the ejectors operate continuously at a pressure ratio of 4 and thus give...
Topics: MEASURING INSTRUMENTS, ENERGY DISTRIBUTION, ELECTROSTATIC PROBES, DATA REDUCTION, SOLAR CELLS,...
No abstract available
Topics: NASA Technical Reports Server (NTRS), LUNAR ROCKS, ILMENITE, AMORPHOUS MATERIALS, SPACE WEATHERING,...
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May 28, 2011
05/11
by
Rutledge, Sharon K.; Banks, Bruce A.; Chichernea, Virgil A
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A noncontact method is described which uses atomic oxygen to remove soot and char from the surface of a painting. The atomic oxygen was generated by the dissociation of oxygen in low pressure air using radio frequency energy. The treatment, which is an oxidation process, allows control of the amount of material to be removed. The effectiveness of char removal from half of a fire-damaged oil painting was studied using reflected light measurements from selected areas of the painting and by visual...
Topics: EXTRATERRESTRIAL RADIATION, SPACE OBSERVATIONS (FROM EARTH), MAGNETIC DISTURBANCES, INTERPLANETARY...
The generation of either electrical power or propulsive thrust with an electrodynamic tether system necessarily depends on driving a return current through the system's ambient space plasma environment. An electrical connection is, therefore, required between the plasma and each end of the tether. The voltage required to drive current through the system is derived either from the orbital motion of the conducting tether through the magnetic field of the Earth, or from a high-voltage power supply...
Topics: NASA Technical Reports Server (NTRS), ELECTRODES, TETHERLINES, SPACECRAFT PROPULSION, INFLATABLE...
Progress under this grant has included identifying certain new radio emission components and determining the source location of both these and the two major Uranian radio emission (the SHF and bursty components) by a unique new statistical minimization technique. This new source location technique has subsequently also been applied at Neptune, with considerable success. New radio spectrograms have been prepared to clarify the behavior of such emissions, using both the usual 48-second,...
Topics: NASA Technical Reports Server (NTRS), NEPTUNE (PLANET), PLANETARY RADIATION, RADIO EMISSION, URANUS...
The emission of secondary electrons from surfaces exposed to the space plasma and radiation environment is a process of great importance to space system engineering design and operations. A spacecraft will collect charge until it reaches an equilibrium potential gov,erned by the balance of incoming electron and ion currents from the space environment with outgoing secondary, backscattered, and photoelectron currents. Laboratory measurements of secondary electron yields are an important...
Topics: NASA Technical Reports Server (NTRS), ELECTRON EMISSION, SPACE EXPLORATION, ION CURRENTS, SPACE...
The research performed in this project is divided in two main investigations: (1) the synthesis and analysis of a collection of independent observations for Io's sodium corona, its sodium extended atmosphere, and the sodium cloud, and (2) the analysis of a (System III longitude correlated) space-time 'bite-out' near western elongation in the 1981 sodium cloud images from the JPL Table Mountain Sodium Cloud Data Set. For the first investigation, modeling analysis of the collective observed...
Topics: NASA Technical Reports Server (NTRS), CORONAS, IO, JUPITER ATMOSPHERE, PLANETARY MAGNETOSPHERES,...
Highlights from the IMP 7 plasma wave experiment are briefly outlined. The measurements in the tail revealed great complexities involving substorms and fireballs and provided insight into the overall dynamics of the magnetosphere. The low levels of magnetic turbulence may be of significance with respect to the development of tearing mode dissipation for reconnection events. The IMP wave observations in the distant magnetosphere boundary region showed that the boundaries were quite diffuse and...
Topics: NASA Technical Reports Server (NTRS), DATA REDUCTION, EXPLORER 47 SATELLITE, PLASMA WAVES, SPACE...
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449
Jun 26, 2011
06/11
by
NON
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Passive or active networks responsive to changes in motor drive current alter the motor drive voltage or phase to damp hunting of the motor.
Topics: LUNAR RADIATION, EXTRAVEHICULAR ACTIVITY, NUCLEAR INTERACTIONS, SPACE PLASMAS, RADIATION...
Traditionally the views on the cosmic environent have been based on observations in the visual octave of the electromagnetic spectrum, during the last half-century supplemented by infrared and radio observations. Space research has opened the full spectrum. Of special importance are the X-ray-gamma-ray regions, in which a number of unexpected phenomena have been discovered. Radiations in these regions are likely to originate mainly from magnetised cosmic plasmas. Such a medium may also emit...
Topics: NASA Technical Reports Server (NTRS), COSMIC PLASMA, COSMOLOGY, PLASMA INTERACTIONS, SYNCHROTRON...
The IMAGE Mission extreme ultraviolet imager (EUY) observes He+ plasmaspheric ions throughout the inner magnetosphere. Limited by ionizing radiation and viewing close to the Sun, images of the He+ distribution are available every 10 minutes for many hours as the spacecraft passes through apogee in its highly elliptical orbit. As a consistent constituent at about 15%, He+ is an excellent surrogate for monitoring all of the processes that control the dynamics of plasmaspheric plasma. In...
Topics: NASA Technical Reports Server (NTRS), PLASMAS (PHYSICS), SPACE PLASMAS, EXTREME ULTRAVIOLET...
An examination of the interactions between proposed "solar sail" propulsion systems with photovoltaic energy generation capabilities and the space plasma environments. Major areas of interactions ere: Acting from high voltage arrays, ram and wake effects, V and B current loops and EMI. Preliminary analysis indicates that arcing will be a major risk factor for voltages greater than 300V. Electron temperature enhancement in the wake will be produce noise that can be transmitted via the...
Topics: NASA Technical Reports Server (NTRS), SOLAR ARRAYS, SPACE PLASMAS, ENVIRONMENT EFFECTS, SAILS,...
This serves as a final report entitled Energization and Transport of Ions of Ionospheric Origin in the Terrestrial Magnetosphere. The work has been predominantly focused on ion outflows identified in two data sets: (1) Prognoz 7; and (2) Dynamics Explorer. The study analyzed ion densities, temperatures, and flow velocities in the magnetotail. The work performed under this contract consisted of developing a program to load the raw data, compute the background subtraction of a strong sun pulse,...
Topics: NASA Technical Reports Server (NTRS), FLOW VELOCITY, ION EMISSION, IONOSPHERIC COMPOSITION,...
The latest version of the NASCAP/LEO digital computer code used to simulate the PIX 2 experiment is discussed. NASCAP is a finite-element code and previous versions were restricted to a single fixed mesh size. As a consequence the resolution was dictated by the largest physical dimension to be modeled. The latest version of NASCAP/LEO can subdivide selected regions. This permitted the modeling of the overall Delta launch vehicle in the primary computational grid at a coarse resolution, with...
Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, COMPUTERIZED SIMULATION, PLASMA DENSITY,...
A large amount of experimental and analytical effort has been directed toward understanding the plasma sheath growth and discharge phenomena which lead to high voltage solar array-space plasma interactions. An important question which has not been addressed is how the surface voltage gradient on such an array may affect these interactions. The results of this study indicate that under certain conditions, the voltage gradient should be taken into account when evaluating the effect on a solar...
Topics: NASA Technical Reports Server (NTRS), ELECTRIC POTENTIAL, SOLAR ARRAYS, SPACE PLASMAS, SPACECRAFT...
