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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS2022

Quasi-Periodic Whistler Mode Emission in the Plasmasphere as Observed By the DSX Spacecraft

We describe the quasi-periodic (QP) whistler-mode emissions found in the plasmasphere as detected by electric and magnetic instrumentation onboard the Demonstration and Science Experiments (DSX) spacecraft in medium Earth orbit. Over the course of the nearly 2-year mission, at least 45 episodes of whistler mode QP emissions were detected by the Broad Band Receiver (BBR) onboard DSX. Episodes of QP emissions were identified by discrete events having a clear unambiguous periodic nature as detected by both the electric antennae and search coil magnetic sensor in the BBR survey data at 30 second temporal resolution. Most of the QP episodes occurred in a frequency range between 1- 4 kHz, in a band previously identified by Van Allen Probes and Cluster investigators. However, episodes were also detected by DSX at higher frequencies - events in these episodes extending all the way to 15 kHz. We present our findings on these unusual high frequency events in the presentation herein. Specifically, these high frequency QP episodes tended to be observed near dawn/dusk when the spacecraft was at relatively high magnetic latitudes and on magnetic L-shells between 3-5. Another unusual feature of these episodes is that individual up-drifting events making up the episode were found to sometimes occur concurrently in time: The high frequency portion of one up-drifting ‘polliwog-shaped’ event overlapped in time with the low frequency portion of the subsequent event. This behavior of the QP emissions has not been previously emphasized and we consider how this temporal concurrence relates to the source processes.

Quasi-periodic↗
NASA NTRS1993

The cosmic-ray He-3/He-4 ratio from 100 to 1600 MeV/amu

The Superconducting Magnet Instrument for Light Isotopes (SMILI) flew for 19 hours on September 1, 1989, with a residual overburden of 5 g/sq cm. It measured the charge, rigidity, and velocity of 30,000 cosmic-ray helium nuclei, with velocity determined by time-of-flight and Cerenkov techniques. Using these data, the flux and isotopic composition of helium as a function of energy were determined. The observed isotopic composition is consistent with that expected from interstellar propagation models inferred from the secondaries of CNO, in contrast to earlier observations which indicated an overabundance of He-3. We discuss constraints that this result places on cosmic-ray transport and solar modulation models.

Beatty, J. J.↗
NASA NTRS1999

Low-Temperature Electronic Components Being Developed

In many future NASA missions, such as deep space planetary exploration and the Next Generation Space Telescope, electrical components and systems must operate reliably and efficiently in extremely low temperature environments. Most modern electronic components cannot operate below moderately low operating temperatures (-40 to -55 C). The low-temperature electronics program at the NASA Lewis Research Center is focusing on the development and characterization of low-temperature components and the integration of the developed devices into demonstrable very low-temperature (-200 C) power systems such as dc-dc converters. Such low-temperature electronics will not only tolerate hostile environments but also will reduce system size and weight by eliminating radioisotope heating units, thereby reducing launch cost, improving reliability and lifetime, and increasing energy densities. Low-temperature electronic components will also have a great influence on terrestrial applications such as medical instrumentation, magnetic levitation transportation systems, and arctic and antarctic exploration. Lewis researchers are now performing extensive evaluations of commercially available as well as custom-made devices. These include various types of energy storage and signal capacitors, power switching devices, magnetic and superconducting materials, and primary lithium batteries, to name a few.

Patterson, Richard L.↗
NASA NTRS2005

Reliability of Electronics for Cryogenic Space Applications Being Assessed

Many future NASA missions will require electronic parts and circuits that can operate reliably and efficiently in extreme temperature environments below typical device specification temperatures. These missions include the Mars Exploration Laboratory, the James Webb Space Telescope, the Europa Orbiter, surface rovers, and deep-space probes. In addition to NASA, the aerospace and commercial sectors require cryogenic electronics in applications that include advanced satellites, military hardware, medical instrumentation, magnetic levitation, superconducting energy management and distribution, particle confinement and acceleration, and arctic missions. Besides surviving hostile space environments, electronics capable of low-temperature operation would enhance circuit performance, improve system reliability, extend lifetime, and reduce development and launch costs. In addition, cryogenic electronics are expected to result in more efficient systems than those at room temperature.

Patterson, Richard L.↗
NASA NTRS1993

The Cluster magnetic field investigation: Scientific objectives and instrumentation

The Cluster magnetic field investigation is presented. Cluster represents a qualitatively new type of space mission which will provide, for the first time, a three dimensional view of small scale plasma processes and structures in the different regions in and around the Earth's magnetosphere. Concepts of data analysis needed to interpret the four spacecraft magnetic field data in terms of magnetospheric processes and structures are outlined. The instrument itself, a vital component of the scientific payload, follows a long tradition of fluxgate magnetometers on space missions, yet represents an evolution in terms of built in functions and reliability. A detailed description of the instrument is given with emphasis on those aspects that are unique to the mission.

Balogh, A.↗
DOE OSTI2024

Design and instrumentation for permanent magnet samples exposed to a radiation environment

This work is part of a larger program to study the effects of radiation on permanent magnets in an accelerator environment. In order to be sure that the permanent magnet samples are accurately placed, measured, and catalogued we have developed a system of sample racks, holders and measuring apparatuses. We have combined these holders and measurement racks with electronics to allow a single computer to catalogue the position and intensity of the magnet measurements. We outline the design of the apparatus, the collection software, and the methodology we will use to collect the data.

Accelerator Physics↗
NASA NTRS1980

The Magsat magnetometer boom

A lightweight extendable structure that can precisely position magnetically sensitive instruments safe distances from magnetic sources in a spacecraft is described as well as the major areas of concern that played dominant roles in its development. Weight, packaging volume, thermal distortion, mechanical misalignments, dimensional instability, launch environments, and low temperature functioning were areas that presented some formidable obstacles. The ways in which these obstacles were dealt with are examined for those involving the development of similar aerospace mechanisms with equally restrictive requirements.

Smola, J. F.↗
NASA NTRS1992

Development of an advanced spacecraft tandem mass spectrometer

The purpose of this research was to apply current advanced technology in electronics and materials to the development of a miniaturized Tandem Mass Spectrometer that would have the potential for future development into a package suitable for spacecraft use. The mass spectrometer to be used as a basis for the tandem instrument would be a magnetic sector instrument, of Nier-Johnson configuration, as used on the Viking Mars Lander mission. This instrument configuration would then be matched with a suitable second stage MS to provide the benefits of tandem MS operation for rapid identification of unknown organic compounds. This tandem instrument is configured with a newly designed GC system to aid in separation of complex mixtures prior to MS analysis. A number of important results were achieved in the course of this project. Among them were the development of a miniaturized GC subsystem, with a unique desorber-injector, fully temperature feedback controlled oven with powered cooling for rapid reset to ambient conditions, a unique combination inlet system to the MS that provides for both membrane sampling and direct capillary column sample transfer, a compact and ruggedized alignment configuration for the MS, an improved ion source design for increased sensitivity, and a simple, rugged tandem MS configuration that is particularly adaptable to spacecraft use because of its low power and low vacuum pumping requirements. The potential applications of this research include use in manned spacecraft like the space station as a real-time detection and warning device for the presence of potentially harmful trace contaminants of the spacecraft atmosphere, use as an analytical device for evaluating samples collected on the Moon or a planetary surface, or even use in connection with monitoring potentially hazardous conditions that may exist in terrestrial locations such as launch pads, environmental test chambers or other sensitive areas. Commercial development of the technology could lead to a new family of environmental test instruments that would be small and portable, yet would give quick analyses of complex samples.

Drew, Russell C.↗
NASA NTRS2017

The Juno Magnetic Field Investigation

The Juno Magnetic Field investigation (MAG) characterizes Jupiter's planetary magnetic field and magnetosphere, providing the first globally distributed and proximate measurements of the magnetic field of Jupiter. The magnetic field instrumentation consists of two independent magnetometer sensor suites, each consisting of a tri-axial Fluxgate Magnetometer (FGM) sensor and a pair of co-located imaging sensors mounted on an ultra-stable optical bench. The imaging system sensors are part of a subsystem that provides accurate attitude information (to approx. 20 arcsec on a spinning spacecraft) near the point of measurement of the magnetic field. The two sensor suites are accommodated at 10 and 12 m from the body of the spacecraft on a 4 m long magnetometer boom affixed to the outer end of one of 's three solar array assemblies. The magnetometer sensors are controlled by independent and functionally identical electronics boards within the magnetometer electronics package mounted inside Juno's massive radiation shielded vault. The imaging sensors are controlled by a fully hardware redundant electronics package also mounted within the radiation vault. Each magnetometer sensor measures the vector magnetic field with 100 ppm absolute vector accuracy over a wide dynamic range (to 16 Gauss = 1.6 x 10(exp. 6) nT per axis) with a resolution of approx. 0.05 nT in the most sensitive dynamic range (+/-1600 nT per axis). Both magnetometers sample the magnetic field simultaneously at an intrinsic sample rate of 64 vector samples per second. The magnetic field instrumentation may be reconfigured in flight to meet unanticipated needs and is fully hardware redundant. The attitude determination system compares images with an on-board star catalog to provide attitude solutions (quaternions) at a rate of up to 4 solutions per second, and may be configured to acquire images of selected targets for science and engineering analysis. The system tracks and catalogs objects that pass through the imager field of view and also provides a continuous record of radiation exposure. A spacecraft magnetic control program was implemented to provide a magnetically clean environment for the magnetic sensors, and residual spacecraft fields andor sensor offsets are monitored in flight taking advantage of Juno's spin (nominally 2 rpm) to separate environmental fields from those that rotate with the spacecraft.

Juno spacecraft↗
NASA NTRS2009

A First Look at Carbon and Oxygen Stable Isotope Measurements of Martian Atmospheric C02 by the Phoenix Lander

Precise stable isotope measurements of the CO2 in the martian atmosphere have the potential to provide important constraints for our understanding of the history of volatiles, the carbon cycle, current atmospheric processes, and the degree of water/rock interaction on Mars. The isotopic composition of the martian atmosphere has been measured using a number of different methods (Table 1), however a precise value (<1%) has yet to be achieved. Given the elevated 13C values measured in carbonates in martian meteorites it has been supposed that the martian atmosphere was enriched in delta(sup 13)C. This was supported by measurements of trapped CO2 gas in EETA 79001[2] which showed elevated delta(sup 13)C values (Table 1). More recently, Earth-based spectroscopic measurements of the martian atmosphere have measured the martian CO2 to be depleted in delta(sup 13)C relative to CO2 in the terrestrial atmosphere. The spectroscopic measurements performed by Krasnopolsky et al. were reported with approx.2% uncertainties which are much smaller than the Viking measurements, but still remain very large in comparison to the magnitude of carbon and oxygen isotope fractionations under martian surface conditions. The Thermal Evolved Gas Analyzer (TEGA) instrument on the Mars Phoenix Lander included a magnetic sector mass spectrometer (EGA) which had the goal of measuring the isotopic composition of martian atmospheric CO2 to within 0.5%. The mass spectrometer is a miniature magnetic sector instrument intended to measure both the martian atmosphere as well as gases evolved from heating martian soils. Ions produced in the ion source are drawn out by a high voltage and focused by a magnetic field onto a set of collector slits. Four specific trajectories are selected to cover the mass ranges, 0.7 - 4, 7 - 35, 14 - 70, and 28 - 140 Da. Using four channels reduces the magnitude of the mass scan and provides simultaneous coverage of the mass ranges. Channel electron multiplier (CEM) detectors that operate in the pulse counting mode detect the ion beams.

Niles, P.B.↗
NASA NTRS1993

Structure and properties of the subsolar magnetopause for northward interplanetary magnetic field - Multiple-instrument particle observations

The paper examines the structure and properties of the subsolar magnetopause for northward IMF on the basis of measurements from 10 different instrument for three ISEE crossings. It is shown that the overall structure and properties are similar for the three crossings, indicating that the magnetopause is relatively well determined in the subsolar region for strongly northward IMF. The combined data set suggests that the magnetopause region is best organized by defining a sheath transition layer and steplike boundary layers. The electron flux enhancements in the lowest energies in the boundary layers and magnetosphere are found to be ionospheric electrons and not photoelectrons from the spacecraft. For northward IMF, they are photoelectrons, but for southward IMF they may be secondary electrons. The density measurements from differential and integral techniques are similar, leaving no room for a significant 'invisible' population.

Song, P.↗
NASA NTRS2012

The Process of Developing a Multi-Cell KEMS Instrument

Multi-cell KEMS offers many advantages over single cell instruments in regard to in-situ temperature calibration and studies on high temperature alloys and oxides of interest to NASA. The instrument at NASA Glenn is a 90 deg magnetic sector instrument originally designed for single cell operation. The conversion of this instrument to a multi-cell instrument with restricted collimation is discussed. For restricted collimation, the 'field aperture' is in the copper plate separating the Knudsen Cell region and the ionizer and the 'source aperture' is adjacent to the ionizer box. A computer controlled x-y table allows positioning of one of the three cells into the sampling region. Heating is accomplished via a Ta sheet element and temperature is measured via an automatic pyrometer from the bottom of the cells. The computer control and data system have been custom developed for this instrument and are discussed. Future improvements are also discussed.

Copland, E. H.↗