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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS1947

An Investigation of the Aerodynamic Characteristics of an 0.08-Scale Model of the Chance Vought XF7U-1 Airplane in the Langley High-Speed 7- by 10-Foot Tunnel. Part V - Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage TED No. NACA DE308: Wing-Alone Tests and Effect of Modifications to the Vertical Fins, Speed Brakes, and Fuselage, TED No. NACA DE308 - Part V

Tests have been conducted in the Langley high-speed 7- by 10-foot tunnel over a Mach number range from 0.40 to 0.91 to determine the stability and control characteristics of an 0.08-scale model of the Chance Vought XF7U-1 airplane. The wing-alone tests and the effect of the various vertical-fin modifications, speed-brake modifications, and fuselage modifications on the aerodynamic characteristics in pitch and yaw are presented in the present paper with a limited analysis of the results. Also included are tuft studies of the flow for some of the modifications tested.

Kuhri, Richard E.↗
NASA NTRS2002

Test and Analysis Capabilities of the Space Environment Effects Team at Marshall Space Flight Center

Marshall Space Flight Center has developed world-class space environmental effects testing facilities to simulate the space environment. The combined environmental effects test system exposes temperature-controlled samples to simultaneous protons, high- and low-energy electrons, vacuum ultraviolet (VUV) radiation, and near-ultraviolet (NUV) radiation. Separate chambers for studying the effects of NUV and VUV at elevated temperatures are also available. The Atomic Oxygen Beam Facility exposes samples to atomic oxygen of 5 eV energy to simulate low-Earth orbit (LEO). The LEO space plasma simulators are used to study current collection to biased spacecraft surfaces, arcing from insulators and electrical conductivity of materials. Plasma propulsion techniques are analyzed using the Marshall magnetic mirror system. The micro light gas gun simulates micrometeoroid and space debris impacts. Candidate materials and hardware for spacecraft can be evaluated for durability in the space environment with a variety of analytical techniques. Mass, solar absorptance, infrared emittance, transmission, reflectance, bidirectional reflectance distribution function, and surface morphology characterization can be performed. The data from the space environmental effects testing facilities, combined with analytical results from flight experiments, enable the Environmental Effects Group to determine optimum materials for use on spacecraft.

Finckenor, M. M.↗
NASA NTRS1999

Propulsion Induced Effects (PIE) Test Program

The Propulsion Induced Effects (PIE) test program is being lead by NASA Ames for Configuration Aerodynamics (CA). Representatives from CA, Technology Integration (TI), Inlet, and the Nozzle ITD's are working with Ames in defining and executing this test program. The objective of the CA 4-14 milestone is to assess the propulsion/airframe integration characteristics of the Technology Concept Airplane (TCA) and design variations using computational and experimental methods. The experimental aspect includes static calibrations, transonic and supersonic wind tunnel testing. The test program will generate a comprehensive database that will include all appropriate wind tunnel corrections, with emphasis placed on establishing the propulsion induced effects on the flight performance of the TCA.

Cappuccio, Gelsomina↗
NASA NTRS1999

Proton Effects and Test Issues for Satellite Designers: Ionization Effects - Section 4

This portion of the Short Course is divided into two segments to separately address the two major proton-related effects confronting satellite designers: ionization effects and displacement damage effects. While both of these topics are deeply rooted in "traditional" descriptions of space radiation effects, there are several factors at play to cause renewed concern for satellite systems being designed today. For example, emphasis on Commercial Off-The-Shelf (COTS) technologies in both commercial and government systems increases both Total Ionizing Dose (TID) and Single Event Effect (SEE) concerns. Scaling trends exacerbate the problems, especially with regard to SEEs where protons can dominate soft error rates and even cause destructive failure. In addition, proton-induced displacement damage at fluences encountered in natural space environments can cause degradation in modern bipolar circuitry as well as in many emerging electronic and opto-electronic technologies. A crude, but nevertheless telling, indication of the level of concern for proton effects follows from surveying the themes treated in papers presented at this conference. The table lists themes found in the IEEE Transaction on Nuclear Science (TNS) December issue from the past year and compares them with the December issue's content a decade earlier. Ten years ago there were nine papers, or about 10% of the total, dealing with the four indicated topics. At that time, single event effects from protons were the primary concern, and these were thought to be possible only when a nuclear reaction initiated energetic recoil atoms. This is shown in the table as the 'traditional" SEE subject. A decade later, submissions addressing this topic had doubled, while papers devoted to displacement damage studies had increased from one to nine! More importantly, displacement damage effects in the natural space environments have become a concern for degradation in modern devices (other than solar cells), and this was not so ten years earlier.

Marshall, Paul W.↗
NASA NTRS1999

Proton Effects and Test Issues for Satellite Designers: Displacement Effects - Section 4

Microelectronic and photonic systems in the natural space environment are bombarded by a variety of charged particles including electrons, trapped protons, cosmic rays, and solar particles (protons and other heavy ions). These incident particles cause both ionizing and non-ionizing effects when traversing a device, and the effects can be either transient or permanent. The vast majority of the kinetic energy of an incident proton is lost to ionization, creating the single event effects (SEES) and total ionizing dose (TID) effects described in section IVA. However, the small portion of energy lost in non-ionizing processes causes atoms to be removed from their lattice sites and form permanent electrically active defects in semiconductor materials. These defects, i.e., "displacement damage," can significantly degrade device performance. In general, most of the displacement damage effects in the natural space environment can be attributed to protons since they are plentiful and extremely energetic (and therefore not readily shielded against). For this reason, we consider only proton induced displacement damage in this course. (Nevertheless, we identify solar cells as an important example of a case where both electron and proton damage can be important since only very light shielding is feasible.) The interested reader is encouraged to explore the three previous NSREC and RADECS short courses [Srou88a, Summ92, Hopk97] which also treat displacement damage issues for satellite applications. Part A of this segment of the short course introduces the space environment, proton shielding issues, and requirements specifications for proton-rich environments. In order to exercise the displacement damage analysis tools for on-orbit performance predictions, the requirements document must provide the relevant proton spectra in addition to the usual total ionizing dose-depth curves.

Marshall, Cheryl J.↗
NASA NTRS1999

1999 NSREC Short Course: Proton Effects and Test Issues for Satellite Designers: Displacement Effects

This portion of the Short Course is divided into two segments to separately address the two major proton-related effects confronting satellite designers: ionization effects and displacement damage effects. While both of these topics are deeply rooted in "traditional" descriptions of space radiation effects, there are several factors at play to cause renewed concern for satellite systems being designed today. For example, emphasis on Commercial Off-The-Shelf (COTS) technologies in both commercial and government systems increases both Total Ionizing Dose (TID) and Single Event Effect (SEE) concerns. Scaling trends exacerbate the problems, especially with regard to SEEs where protons can dominate soft error rates and even cause destructive failure. In addition, proton-induced displacement damage at fluences encountered in natural space environments can cause degradation in modern bipolar circuitry as well as in many emerging electronic and opto-electronic technologies.

Marshall, Cheryl J.↗
NASA NTRS1987

V/STOL and STOL ground effects and testing techniques

The ground effects associated with V/STOL operation were examined and an effort was made to develop the equipment and testing techniques needed for that understanding. Primary emphasis was on future experimental programs in the 40 x 80 and the 80 x 120 foot test sections and in the outdoor static test stand associated with these facilities. The commonly used experimental techniques are reviewed and data obtained by various techniques are compared with each other and with available estimating methods. These reviews and comparisons provide insight into the limitations of past studies and the testing techniques used and identify areas where additional work is needed. The understanding of the flow mechanics involved in hovering and in transition in and out of ground effect is discussed. The basic flow fields associated with hovering, transition and STOL operation of jet powered V/STOL aircraft are depicted.

Kuhn, R. E.↗
NASA NTRSDate not supplied

A Facility Effect Characterization Test of the BHT6000 Hall Thruster

During the development of the BHT-6000 Hall thruster for flight on NASA’s Power and Propulsion Element, a facility effect test campaign was performed on an engineering unit of the thruster. Testing occurred in Vacuum Facility 5 at NASA Glenn Research Center. The goal of the test campaign was to characterize the behavior of the BHT-6000 Hall thruster as functions of facility effects such that the thruster’s in-flight behavior can be reasonably bounded. In particular, the behavior of the thruster with regard to the background pressure and electrical environment was tested. The background pressure was controlled by injecting supplemental propellant flow into the environment, while the electrical environment was controlled by biasing the facility beam dump. Thrust was found to remain constant over the tested range of pressures while specific impulse was found to increase slightly (1 to 1.5% over a range of up to 20 μTorr, depending on operating point). Plasma plume properties, particularly of ions exiting the side of the thruster, were found to be highly sensitive to pressure and may require pressures of less than a few μTorr for accurate measurements. The thruster was found to operate identically with changing beam dump bias voltage to within measurement uncertainties.

Electric propulsion↗
NASA NTRSDate not supplied

A Facility Effect Characterization Test of the BHT-6000 Hall Thruster

During the development of the BHT-6000 Hall thruster for flight on NASA’s Power and Propulsion Element, a facility effect test campaign was performed on an engineering unit of the thruster. Testing occurred in Vacuum Facility 5 at NASA Glenn Research Center. The goal of the test campaign was to characterize the behavior of the BHT-6000 Hall thruster as functions of facility effects such that the thruster’s in-flight behavior can be reasonably bounded. In particular, the behavior of the thruster with regard to the background pressure and electrical environment was tested. The background pressure was controlled by injecting supplemental propellant flow into the environment, while the electrical environment was controlled by biasing the facility beam dump. Thrust was found to remain constant over the tested range of pressures while specific impulse was found to increase slightly (1 to 1.5% over a range of up to 20 μTorr, depending on operating point). Plasma plume properties, particularly of ions exiting the side of the thruster, were found to be highly sensitive to pressure and may require pressures of less than a few μTorr for accurate measurements. The thruster was found to operate identically with changing beam dump bias voltage to within measurement uncertainties.

Electric propulsion↗
NASA NTRS1995

Test-Derived Effective Emittance for Cassini MLI Blankets and Heat Loss Characteristics in the Vicinity of Seams

Thermal performance of Cassini MLI blankets was characterized in thermal vacuum tests. Effective emittance was derived for the standard and high-temperature layups, with or without micrometeoroid protection standoffs, and for a high-performance duo-layup with staggered seams. The all-Kapton layup wa shown to have a 19% higher effective emittance than the hybrid Kapton-Mylar layup, and the duo-layup exhibited a dramatic capability of reducing heat dissipation by 2.6 fold. Several different definitions of effective emittance are discussed, and their relations to distinct hardware-MLI configurations and corresponding modeling techniques clarified. Large temperature differences (up to 70 C) were observed between the center and seam of a blanket. Heat losses in the vicinity of seams are qualified, and a major MLI heat loss mechanism elucidated.

Cassini↗
NASA NTRS2020

Medical Proton Test Facilities (MPTFs) Lessons Learned on the Unique Aspects for Single Event Effects (SEE) Testing of Electronics in the 200 MeV Regime

Ever since the closure of the Indiana University Cyclotron Facility (IUCF) in 2014, there has been an increasing use of medical proton therapy facilities (MPTF) for SEE testing with protons in the 200 MeV or greater regime. This talk covers some of the unique features and considerations for utilizing MPTFs including both logistical and technical aspects. This presentation provides an overview of lessons learned for SEE testing at MPTFs.

Medical Proton Test Facilities (MPTFs)↗
NASA NTRS1975

Results of test 0A82 in the NASA/LRC 31 inch CFHT on an 0.010-scale model (32-0) of the space shuttle configuration 3 to determine RCS jet flow field interaction and to investigate RT real gas effects

Tests were conducted in the NASA Langley Research Center 31-inch Continuous Flow Hypersonic Wind Tunnel to determine RCS jet interaction effects on hypersonic aerodynamic characteristics and to investigate RT (gas constant times temperature) scaling effects on the RCS similitude. The model was an 0.010-scale replica of the Space Shuttle Orbiter Configuration 3. Hypersonic aerodynamic data were obtained from tests at Mach 10.3 and dynamic pressures of 200, 150, 125, and 100 psf. The RCS modes of pitch, yaw, and roll at free flight dynamic pressure simulation of 20 psf were investigated.

Thornton, D. E.↗
NASA NTRS2018

Guideline for Single-Event Effect (SEE) Testing of System on a Chip (SOC) Devices

The use of complex single and multicore processors with significant cache memory, on-chip peripherals, memory controllers, and high speed input/output (IO) that integrate many of the parts of a traditional computer system is becoming more common in space applications. Such devices are often referred to as system on a chip devices (SOCs), even though the term is used somewhat inaccurately due to the lack of analog and mixed signal subcircuits. These devices are complex combinations of single- or multi-core processors with memory controllers, high-speed input/output (IO), and other peripheral structures that formerly would have been handled by off-chip resources. In the past the processors were tested for single event effects (SEE) separately, and the peripherals were often put into custom application-specific integrated circuits (ASICs) along with other resources required by the user. Performance and cost pressures have pushed commercial devices to incorporate many of the functional blocks into a single chip, an SOC. The NASA Electronic Parts and Packaging Program (NEPP) has been examining ways to perform SEE radiation hardness assurance (RHA) testing of these processor-centric SOCs to achieve reasonable understanding of their performance in space missions.

Guertin, Steven M.↗
NASA NTRS2016

Facility Effect Characterization Test of NASA's HERMeS Hall Thruster

A test to characterize the effect of varying background pressure on NASA's 12.5-kW Hall Effect Rocket with Magnetic Shielding had being completed. This thruster is the baseline propulsion system for the Solar Electric Propulsion Technology Demonstration Mission (SEP TDM). Potential differences in thruster performance and oscillation characteristics when in ground facilities versus on-orbit are considered a primary risk for the propulsion system of the Asteroid Redirect Robotic Mission, which is a candidate for SEP TDM. The first primary objective of this test was to demonstrate that the tools being developed to predict the zero-background-pressure behavior of the thruster can provide self-consistent results. The second primary objective of this test was to provide data for refining a physics-based model of the thruster plume that will be used in spacecraft interaction studies. Diagnostics deployed included a thrust stand, Faraday probe, Langmuir probe, retarding potential analyzer, Wien filter spectrometer, and high-speed camera. From the data, a physics-based plume model was refined. Comparisons of empirical data to modeling results are shown.

Electric Propulsion↗