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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1981

Very low frequency waves stimulated by an electron accelerator in the auroral ionosphere

The sounding rocket, Polar 5, carrying a 10 keV electron accelerator in a mother-daughter configuration and other diagnostic instruments, was launched into a slightly disturbed ionosphere with weak auroral activity on February 1, 1976 from Northern Norway to study VLF wave phenomena. The rocket trajectory crossed two auroral regions: one, between 86 and 111 s flight time, and a secondary region between 230 and 330 s. The daughter, carrying the accelerator, was separated axially from the mother in a forward direction at an altitude of 90 km. The VLF experiment, carried by the mother payload, recorded both electromagnetic and electrostatic waves. The receiving antenna was an electric dipole, 0.3 m tip-to-tip, oriented 90 degrees to the rocket spin axis. The onboard particle detector recorded increased electron fluxes in the two auroral regions. A double peaked structure was observed in the fluxes of 4-5 and 12-27 keV electrons within the northern auroral form. The number density of thermal plasma varied during the flight, with maximum density within the main auroral region. To the north of this aurora a slow, steady decrease in the density was observed, with no enhancement in the region of the second aurora.

Holtet, J. A.↗
NASA NTRS1971

Satellite auxiliary-propulsion selection techniques. Addendum: A survey of auxiliary electric propulsion systems

A review of electric thrusters for satellite auxiliary propulsion was conducted at JPL during the past year. Comparisons of the various thrusters for attitude propulsion and east-west and north-south stationkeeping were made based upon performance, mass, power, and demonstrated life. Reliability and cost are also discussed. The method of electrical acceleration of propellant served to divide the thruster systems into two groups: electrostatic and electromagnetic. Ion and colloid thrusters fall within the electrostatically accelerated group while MPD and pulsed plasma thrusters comprise the electromagnetically accelerated group. The survey was confined to research in the United States with accent on flight and flight prototype systems.

Holcomb, L. B.↗
NASA NTRS2000

High Undercooling of Ni59Nb41 Alloy in a Containerless Electrostatic Levitation Facility

Utilizing the containerless electrostatic levitation facility at NASA/MSFC, we were able to undercool the Ni59Nb41 (atomic) alloy by 210 K which was 160 degrees farther than the results of previous flight experiments. Undercoolings were clustered around 200 K during the repeated melting-freezing cycles on a single sample. Prior to this work, a metastable liquid separation had been presumed to limit the undercooling of this alloy. However, microstructural observations have revealed that undercooling was limited by crystal nucleation.

Robinson, M. B.↗
NASA NTRS1992

The Ulysses solar wind plasma investigation - Experiment description and initial in-ecliptic results

During the in-ecliptic flight of Ulysses from the Earth toward its encounter with Jupiter, the Los Alamos solar wind plasma experiment has performed well. Briefly described, the instrumentation contains two independent electrostatic analyzers, one for ions and one for electrons. Initial analysis of solar wind electron core temperatures obtained between 1.15 and 3.76 AU yields a gradient of T (proportional to) R(exp -0.7) which is flatter than expected for adiabatic expansion of a single-temperature Maxwellian velocity distribution and steeper than that obtained from Mariner-Voyager.

Bame, S. J.↗
NASA NTRS1994

Assessment of velocity/trajectory measurement technologies during a particle capture event

Since the early 1960s, the means to measure the time of flight (TOF) of dust grain within a mechanical detection array has existed, first in the laboratory and then in space experiments. Laboratory hypervelocity dust particle accelerators have used electrostatic detection of charge on accelerated particles for TOF and particle mass detections. These laboratory studies have led to the development of ultra-thin-film sensors that have been used for TOF measurements in dust particle space experiments. The prototypes for such devices were ultra-thin-film capacitors that were used in the OGO series of satellites. The main goal of the experimental work to be described is the development of the capability to determine the velocity vector or trajectory of a dust grain traversing an integrated dust detection array. The results of these studies have shown that the capability of detecting the charge liberated by hypervelocity dust grains with diameters in the micrometer range can be detected. Based on these results, detection systems have been designed to provide a precise analysis of the physical and dynamic properties of micrometer and submicrometer dust grains, namely the design verification unit (DVU). Through unique combinations of in situ detection systems, direct measurements of particle surface charge, velocity, momentum, kinetic energy, and trajectory have been achieved. From these measurements, the remaining physical parameters of mass, size, and density can be determined.

Tanner, William G.↗
NASA NTRS2021

Charged Particle Dynamics in Lunar Environment

Current state-of-the-art (SOA) granular gas dynamics models used to explain rocket plume impingement physics have not taken into account the natural or induced electrostatic environment of the lunar surface, nor the effect of charged regolith grains being present in the plume plasma. This work improved upon the SOA by adding long-range and contact inter-particle electrostatic interactions to a granular mechanics discrete element method (DEM) modeling software package. Experiments have been tentatively selected to fly on a lunar gravity Blue Origin New Shepard flight through the Flight Opportunities Program (FOP). These experiments will directly provide inputs into the models discussed in this report to provide validation from a more relevant environment than may be produced in the lab.

James Phillips↗
NASA NTRS2017

Conceptual Design of an Electric Sail Technology Demonstration Mission Spacecraft

There is great interest in examining the outer planets of our solar system and Heliopause region (edge of Solar System) and beyond regions of interstellar space by both the Planetary and Heliophysics communities. These needs are well docu-mented in the recent National Academy of Sciences Decadal Surveys. There is significant interest in developing revolutionary propulsion techniques that will enable such Heliopause scientific missions to be completed within 10 to15 years of the launch date. One such enabling propulsion technique commonly known as Electric Sail (E-Sail) propulsion employs positively charged bare wire tethers that extend radially outward from a rotating spacecraft spinning at a rate of one revolution per hour. Around the positively charged bare-wire tethers, a Debye Sheath is created once positive voltage is applied. This sheath stands off of the bare wire tether at a sheath diameter that is proportional to the voltage in the wire coupled with the flux density of solar wind ions within the solar system (or the location of spacecraft in the solar system. The protons that are expended from the sun (solar wind) at 400 to 800 km/sec are electrostatically repelled away from these positively charged Debye sheaths and propulsive thrust is produced via the resulting momentum transfer. The amount of thrust produced is directly proportional to the total wire length. The Marshall Space Flight Center (MSFC) Electric Sail team is currently funded via a two year Phase II NASA Innovative Advanced Concepts (NIAC) awarded in July 2015. The team's current activities are: 1) Developing a Particle in Cell (PIC) numeric engineering model from the experimental data collected at MSFC's Solar Wind Facility on the interaction between simulated solar wind interaction with a charged bare wire that can be applied to a variety of missions, 2) The development of the necessary tether deployers and tethers to enable successful de-ployment of multiple, multi km length bare tethers, 3) Controllability of the space-craft via a voltage bias to steer itself through the solar system to destinations of discovery. These activities once demonstrated analytically, will require a technology demonstration mission (TDM) around the year2020 to demonstrate that all systems work together seamlessly before a Heliophysics Electrostatic Rapid Transit System (HERTS) mission could be initiated. A notional TDM spacecraft that meets the requirements of such a mission will be showcased in this paper.

Wiegmann, Bruce M.↗
NASA NTRS1975

The prevention of electronical breakdown and electrostatic voltage problems in the space shuttle and its payloads. Part 2: Design guides and operations considerations

The specific electrical discharge problems that can directly affect the shuttle vehicle and its payloads are addressed. General design guidelines are provided to assist flight hardware managers in minimizing these kinds of problems. Specific data are included on workmanship practices and system testing while in low pressure environments. Certain electrical discharge problems that may be unique to the design of the shuttle vehicle itself and to its various mission operational models are discussed.

Whitson, D. W.↗
NASA NTRS2000

Thermophysical Property Measurement and Materials Research in the NASA/MSFC Electrostatic Levitator

Containerless processing is an important tool for thermophysical property measurements and materials research. The freedom from a crucible allows processing of liquid materials in a metastable undercooled state, as well as allowing processing of high temperature and highly reactive melts. Electrostatic levitation (ESL) is a containerless method which provides a number of unique advantages, including the decoupling of positioning force from sample heating, the ability to operate in ultra-high vacuum or at moderate gas pressure (approximately 3 atm), and the ability to process non-conducting materials. ESL also has the potential to reduce internal flow velocities below those possible with electromagnetic, acoustic, or aero-acoustic techniques. The ESL facility at NASA's Marshall Space Flight Center (MSFC) is in use for thermophysical property measurements and materials research by a number of different internal and external investigators. The methods for obtaining access to the facility, as well as a summary of current capabilities and some future directions will be discussed. In electrostatic levitation, the acceleration of gravity (or residual acceleration in reduced gravity) is opposed by the action of an applied electric field on a charged sample. This positioning method is applicable to any material which can be electrically charged, whether solid or liquid, conducting, or insulating. Because the position of the sample is unstable, a 3-dimensional active control loop rapidly adjusts the applied field to maintain levitation and minimize motion of the sample. Heating lasers melt the sample, and may be adjusted to maintain specified thermal profiles. Microgravity allows electrostatic levitation to work even more effectively. With the need to cancel less than 1 milli-g, the applied field required is reduced from approximately 10 MV/m to approximately 10 kV/m. Alternatively, a microgravity ESL can position larger samples than is possible on the ground, or it can position samples which maintain their charge poorly. Microgravity also reduces the effects of buoyant convection and sedimentation. In the MSFC ESL, many different classes of experiments and measurements have been demonstrated in collaboration with many investigators. These capabilities include heat capacity measurement, phase diagram determination, and nucleation and growth experiments including nucleation rate, TTT curves, and phase selection. We have demonstrated the capability of triggering recalescence of an undercooled liquid sample without loss of levitation. Currently under development are techniques for measuring the surface tension, viscosity, and density of levitated samples, as well as other thermophysical properties. Expanded levitation capabilities including various gas environments for sample processing, sample rotation control and management of thermal gradients are under development for the MSFC ESL. Containerless processing allows research on materials which may not be processed any other way. Electrostatic levitation extends the range of containerless processing to include many materials and classes of materials which cannot be processed by conventional electromagnetic, acoustic, or aerodynamic levitation techniques.

Rogers, Jan↗
NASA NTRS2008

Contamination Sources Effects Analysis (CSEA) - A Tool to Balance Cost/Schedule While Managing Facility Availability

A CSEA is similar to a Failure Modes Effects Analysis (FMEA). A CSEA tracks risk, deterrence, and occurrence of sources of contamination and their mitigation plans. Documentation is provided spanning mechanical and electrical assembly, precision cleaning, thermal vacuum bake-out, and thermal vacuum testing. These facilities all may play a role in contamination budgeting and reduction ultimately affecting test and flight. With a CSEA, visibility can be given to availability of these facilities, test sequencing and trade-offs. A cross-functional team including specialty engineering, contamination control, electrostatic dissipation, manufacturing, testing, and material engineering participate in an exercise that identifies contaminants and minimizes the complexity of scheduling these facilities considering their volatile schedules. Care can be taken in an efficient manner to insure correct cleaning processes are employed. The result is reduction in cycle time ("schedule hits"), reduced cost due to rework, reduced risk and improved communication and quality while achieving adherence to the Contamination Control Plan.

Wilcox, Margaret↗
NASA NTRS1985

Shuttle electrical environment

Part of an AFGL payload flown on the STS-4 mission consisted of experiments to measure in-situ electric fields, electron densities, and vehicle charging. During this flight some 11 hours of data were acquired ranging from 5 minute snapshots up to continuous half-orbits. These experiments are described and results presented for such vehicle induced events as a main engine burn, thruster firings and water dumps in addition to undisturbed periods. The main characteristic of all the vehicle induced events is shown to be an enhancement in the low frequency noise (less than 2 kHz), in both the electrostatic and electron irregularity (delta N/N) spectra. The non-event results indicate that the electrostatic broadband emissions show a white noise characteristic in the low frequency range up to 2 kHz at an amplitude of 10 db above the shuttle design specification limit, falling below that limit above 10 kHz. The vehicle potential remained within the range of -3 to +1 volt throughout the flight which exhibits normal behavior for a satellite in a low equatorial orbit.

Smiddy, M.↗
NASA NTRS2013

LVGEMS Time-of-Flight Mass Spectrometry on Satellites

NASA fs investigations of the upper atmosphere and ionosphere require measurements of composition of the neutral air and ions. NASA is able to undertake these observations, but the instruments currently in use have their limitations. NASA has extended the scope of its research in the atmosphere and now requires more measurements covering more of the atmosphere. Out of this need, NASA developed multipoint measurements using miniaturized satellites, also called nanosatellites (e.g., CubeSats), that require a new generation of spectrometers that can fit into a 4 ~4 in. (.10 ~10 cm) cross-section in the upgraded satellites. Overall, the new mass spectrometer required for the new depth of atmospheric research must fulfill a new level of low-voltage/low-power requirements, smaller size, and less risk of magnetic contamination. The Low-Voltage Gated Electrostatic Mass Spectrometer (LVGEMS) was developed to fulfill these requirements. The LVGEMS offers a new spectrometer that eliminates magnetic field issues associated with magnetic sector mass spectrometers, reduces power, and is about 1/10 the size of previous instruments. LVGEMS employs the time of flight (TOF) technique in the GEMS mass spectrometer previously developed. However, like any TOF mass spectrometer, GEMS requires a rectangular waveform of large voltage amplitude, exceeding 100 V -- that means that the voltage applied to one of the GEMS electrodes has to change from 0 to 100 V in a time of only a few nanoseconds. Such electronic speed requires more power than can be provided in a CubeSat. In the LVGEMS, the amplitude of the rectangular waveform is reduced to about 1 V, compatible with digital electronics supplies and requiring little power.

Herrero, Federico↗
NASA NTRS2000

High Undercooling of Ni59Nb41 Alloy in a Containerless Electrostatic Levitation Facility

Utilizing the containerless electrostatic levitation facility at NASA/MSFC, we were able to undercool the Ni-59Nb-41 (atomic) alloy by 210 K which was 160 deg. farther than the results of previous flight experiments. Undercoolings were clustered around 200 K during the repeated melting-freezing cycles on a single sample. Prior to this work, a metastable liquid separation had been presumed to limit the undercooling of this alloy. However, microstructural observations have revealed that undercooling was limited by crystal nucleation.

Robinson, M. B.↗
DOE OSTI2023

Ion emission from warm dense matter produced by irradiation with a soft x-ray free-electron laser

Here we report on an experiment performed at the FLASH2 free-electron laser (FEL) aimed at producing warm dense matter via soft x-ray isochoric heating. In the experiment, we focus on study of the ions emitted during the soft x-ray ablation process using time-of-flight electron multipliers and a shifted Maxwell–Boltzmann velocity distribution model. We find that most emitted ions are thermal, but that some impurities chemisorbed on the target surface, such as protons, are accelerated by the electrostatic field created in the plasma by escaped electrons. The morphology of the complex crater structure indicates the presence of several ion groups with varying temperatures. We find that the ion sound velocity is controlled by the ion temperature and show how the ion yield depends on the FEL radiation attenuation length in different materials.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS2016

Fast Plasma Investigation for Magnetospheric Multiscale

The Fast Plasma Investigation (FPI) was developed for flight on the Magnetospheric Multiscale (MMS) mission to measure the differential directional flux of magnetospheric electrons and ions with unprecedented time resolution to resolve kinetic-scale plasma dynamics. This increased resolution has been accomplished by placing four dual 180-degree top hat spectrometers for electrons and four dual 180-degree top hat spectrometers for ions around the periphery of each of four MMS spacecraft. Using electrostatic field-of-view deflection, the eight spectrometers for each species together provide 4pi-sr-field-of-view with, at worst, 11.25-degree sample spacing. Energy/charge sampling is provided by swept electrostatic energy/charge selection over the range from 10 eVq to 30000 eVq. The eight dual spectrometers on each spacecraft are controlled and interrogated by a single block redundant Instrument Data Processing Unit, which in turn interfaces to the observatory's Instrument Suite Central Instrument Data processor. This paper described the design of FPI, its ground and in-flight calibration, its operational concept, and its data products.

Pollock, C.↗
NASA NTRS1972

Planetary exploration with electrically propelled vehicles.

The characteristics of propulsion systems required for carrying out flight missions within the solar system, as desired by planetary physicists and astronomers, are reviewed. It is shown that an encouraging answer to these requirements is available in the form of electrostatic or ion propulsion systems. The design and performance characteristics of an electrostatic thrustor employing an ion source, accelerating electrode, beam neutralizer, and power source are discussed, together with those of the Kaufmann engine (electrostatic thrustor employing bombardment type ionization). More demanding missions which will become feasible with the advent of nuclear-electric power sources (such as the incore thermionic reactor) may include close orbiters around all the planets, and asteroid and cometary missions.

Stuhlinger, E.↗
NASA NTRS1992

The plasma instrumentation for the Galileo Mission

The Galileo Mission's plasma instrumentation package encompasses a nested set of four spherical-plate electrostatic analyzers and three miniature magnetic mass spectrometers which identify the composition of the positive ion plasmas; the spectrometers' energy range is species-dependent. Two instrument microprocessors allow in-flight implementation of operational modes by ground command that are tailored for such specific regimes as the magnetosheath and the plasma sheet of the environs of Jupiter. Observational objectives include field-aligned currents, 3D ion bulk flows, Galilean satellite pickup ions, and the spatial distributions of plasmas.

Frank, L. A.↗
NASA NTRS2022

Rocket Measurements of Electron Energy Spectra From Earth's Photoelectron Production Layer

Photoelectrons are crucial to atmospheric physics. They heat the atmosphere, strengthen planetary ambipolar electric fields, and enhance the outflow of ions to space. However, there exist only a handful of measurements of their energy spectrum near the peak of photoproduction. We present calibrated energy spectra of pristine photoelectrons at their source by a prototype Dual Electrostatic Analyzer (DESA) instrument flown on 11 July 2021 aboard the Dynamo-2 sounding rocket (NASA № 36.357). Photopeaks arising from 30.4 nm He-II spectral line were observed throughout the flight above 120 km. DESA also successfully resolved the rarely observed N2 absorption feature. Below 10 eV observations were in good agreement with the GLOW suprathermal electron. Above 10 eV fluxes substantially deviated from the model by as much as an order of magnitude.

Glyn A. Collinson↗