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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 NTRS2013

Space Power Facility-Capabilities for Space Environmental Testing Within a Single Facility

The purpose of this paper is to describe the current and near-term environmental test capabilities of the NASA Glenn Research Center's Space Power Facility (SPF) located at Sandusky, Ohio. The paper will present current and near-term capabilities for conducting electromagnetic interference and compatibility testing, base-shake sinusoidal vibration testing, reverberant acoustic testing, and thermal-vacuum testing. The paper will also present modes of transportation, handling, ambient environments, and operations within the facility to conduct those tests. The SPF is in the midst of completing and activating new or refurbished capabilities which, when completed, will provide the ability to conduct most or all required full-scale end-assembly space simulation tests at a single test location. It is envisioned that the capabilities will allow a customer to perform a wide range of space simulation tests in one facility at reasonable cost.

Sorge, Richard N.↗
NASA NTRS2018

International Space Station Spacecraft Charging Environments: Modeling, Measurement and Implications for Future Human Space Flight Programs

Spacecraft charging analysis and migration is an interdisciplinary subject combining aspects of electrostatics, plasma physics, ionizing radiation, and materials science, as well as electronic system electromagnetic interference and compatibility (EMI/EMC) effects. Spacecraft charging hazards are caused by the accumulation of electrical charge on spacecraft and spacecraft components produced by interactions with space plasmas, energetic charged particles, and solar UV photons as well as spacecraft electrical power and propulsion systems operations. Spacecraft charging hazard effects include both hard and soft avionics and electrical power system anomalies and have led to the partial or complete loss of numerous spacecraft. The International Space Station (ISS) orbital altitude and inclination (~400 km and 51.6o) determined the dominant natural environment factors affecting ISS spacecraft charging; high speed flight through the geomagnetic field and electrical power system interaction with the cold, high-density ionospheric plasma. In addition ISS is exposed to energetic auroral electrons at high latitude. In this paper we present the results of ISS spacecraft charging modeling and measurements and compare the measurements with numerical modeling of ISS charging processes. ISS is a large metallic structure and flight through the geomagnetic field at orbital speed dominates ISS charging. Collection of ionospheric electrons by the large 160V PV arrays is the next largest contributor. Charging by auroral electrons is detectable but makes a relatively minor contribution. Finally we report the observation of short duration (~ 1 sec) rapid charging peaks associated with shunt/un-shunt operations of the 160V PV arrays, a phenomena not predicted before flight. ISS spacecraft charging environments are radically different from those encountered at higher altitudes in Earth?s magnetosphere and in cis-Lunar space. We present a brief review of those charging environments and an assessment of the applicability of ISS spacecraft charging management and experience to future human spaceflight programs beyond LEO.

Koontz, Steven L.↗
NASA NTRS1994

Field of View Analysis of SeaWinds Reflector Antenna

Antennas are often mounted among many other instruments on the spacecraft platform. The electromagnetic interference (EMI) and compatibility (EMC) issues are of great concern to the antenna and spacecraft system design engineers. Considering the rotating reflector antenna of the NASA SeaWinds Scatterometer on the Japanes ADEOS II spacecraft, it is desirable to determine the antenna's field of view (FOV) performance. In other words, how far should the other boxes be kept away from the reflector antenna to minimize the blockage/diffraction effects on the antenna's performance requirements.

electromagnetic interference EMI↗
NASA NTRS2019

Ocean Color Instrument Integration and Testing

This paper describes the plans, flows, key facilities, components and equipment necessary to fully integrate, functionally test, qualify and calibrate the Ocean Color Instrument (OCI) on the Plankton, Aerosols, Clouds, and oceans Ecosystem (PACE) observatory. PACE is currently in the design phase of mission development. It is scheduled to launch in 2022, extending and improving NASA's twenty-year record of satellite observations of global ocean biology, aerosols and clouds. PACE will advance the assessment of ocean health by measuring the distribution of phytoplankton, which are small plants and algae that sustain the marine food web. It will also continue systematic records of key atmospheric variables associated with air quality and the Earth's climate. PACE's primary sensor, the OCI, is a highly advanced optical spectrometer that will be used to measure properties of light over portions of the electromagnetic spectrum. It will enable continuous measurement of light at finer wavelength resolution than previous NASA satellite sensors, extending key system ocean color data records for climate studies. The color of the ocean is determined by the interaction of sunlight with substances or particles present in seawater such as chlorophyll. By monitoring global phytoplankton distribution and abundance with unprecedented detail, the OCI will contribute to a better understanding of the complex systems that drive ocean ecology and it's impacts on global fisheries. This paper will focus on the Integration and Test (I&T) activities for OCI while it is at the NASA Goddard Space Flight Center. The OCI integration consists of assembly and alignment of the rotating telescope, electronics box integration, fixed deck assembly integration, thermal systems integration and the final assembly and testing. This I&T phase will be followed by the OCI calibration and characterization, environmental tests which include electromagnetic interference (EMI)/electromagnetic compatibility (EMC), vibration with sine sweep, acoustics, shock, thermal balance, thermal vacuum, mass properties and center of gravity. This paper will briefly discuss OCI shipment and delivery to the spacecraft vendor for observatory level I&T as well as some launch preparation activities.

Petro, Susanna↗
NASA NTRS2020

Plankton, Aerosol, Cloud, Ocean Ecosystem (PACE) Mission Integration and Testing

This paper describes the plans, flows, key facilities, components and equipment necessary to fully integrate, functionally test and qualify the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) Observatory. PACE is currently in the design phase of mission implementation. It is scheduled to launch in 2022, extending and improving NASA's twenty-year record of satellite observations of global ocean biology, aerosols and clouds. PACE will advance the assessment of ocean health by measuring the distribution of phytoplankton, which are small plants and algae that sustain the marine food web. It will also continue systematic records of key atmospheric variables associated with air quality and the Earth's climate. The PACE observatory is comprised of the spacecraft and three instruments, an Ocean Color Instrument (OCI) and two polarimeters, the Hyper-Angular Rainbow Polarimeter 2 (HARP2) and the Spectro-Polarimeter for Exploration (SPEXone). The spacecraft and the OCI, which is the primary instrument, are developed and integrated at the NASA Goddard Space Flight Center (GSFC). The OCI is a hyper-spectral scanning (HSS) radiometer designed to measure spectral radiances from the ultraviolet to shortwave infrared (SWIR) to enable advanced ocean color and heritage cloud and aerosol particle science. The HARP2 and SPEXone are secondary instruments on the PACE observatory, acquired outside of GSFC. The Hyper-Angular Rainbow Polarimeter instrument (HARP2) is a wide swath imaging polarimeter that is capable of characterizing atmospheric aerosols for purposes of sensor atmospheric correction as well as atmospheric science. The SPEXone provides atmospheric aerosol and cloud data at high temporal and spatial resolution. This paper will focus on the Integration and Test (I&T) activities for the PACE mission at NASA GSFC. This I&T phase consists of mechanical, electrical and thermal integration and test of all the spacecraft subsystems and the integration of the instruments with the spacecraft. The PACE observatory environmental tests include electromagnetic interference (EMI)/electromagnetic compatibility (EMC), vibration, acoustics, shock, thermal balance, thermal vacuum, mass properties and center of gravity. This paper will also discuss the observatory shipment to the launch site as well as the launch site processing.

Petro, Susanna↗
NASA NTRS2021

L’Ralph Integration and Testing

This paper describes the plans, flows, key facilities, components and equipment necessary to fully integrate, functionally test, qualify and calibrate the L’Ralph instrument on the Lucy observatory. Lucy is currently in the final design and fabrication phase (phase C) of mission development. It is scheduled to launch out of Cape Canaveral, Florida, in October 2021. Lucy will be the first space mission to study the Trojan asteroids associated with Jupiter, that are thought to be remnants of the primordial material that formed the outer planets. Lucy will fly by and carry out remote sensing on six different Trojan asteroids. The mission takes its name from the fossilized human ancestor (called “Lucy” by her discoverers) whose skeleton provided unique insight into humanity's evolution. Likewise, the Lucy mission will revolutionize our knowledge of planetary origins and the formation of the solar system. L’Ralph is one of the instruments on Lucy and it is provided by the NASA Goddard Space Flight Center (GSFC). L’Ralph is a combined multi-band visible imager (the Multi-spectral Visible Imaging Camera, MVIC, 0.4-0.85 microns) and wedge-filter infrared spectrometer (Linear Etalon Imaging Spectral Array, LEISA, 1-3.6 microns). LEISA will allow the team to look for the absorption lines that serve as the fingerprints for different silicates, ices and organics that likely will be on the surface of the Trojan asteroids. MVIC will take color images of the Trojan asteroid targets, and help determine how active they are. This paper will focus on the Integration and Test (I&T) activities for L’Ralph while it is at the NASA GSFC. L’Ralph has two assemblies, the telescope detector assembly (TDA) and main electronics box (MEB). The TDA is a single telescope feeding two focal planes, MVIC and LEISA. L’Ralph integration consists of assembly and alignment of the telescope, electronics box integration, thermal systems integration and the final assembly and testing. This I&T phase will be followed by the L’Ralph calibration and characterization, environmental tests which include electromagnetic interference (EMI)/electromagnetic compatibility (EMC), vibration with sine sweep, acoustics, shock, thermal balance, thermal vacuum, mass properties and center of gravity determination. This paper will briefly discuss L’Ralph shipment and delivery to the spacecraft vendor for observatory level I&T as well as some launch preparation activities.

Spaceflight Instruments↗
NASA NTRS1989

Strain and dynamic measurements using fiber optic sensors embedded into graphite/epoxy tubes

Graphite/epoxy tubes were fabricated with embedded optical fibers to evaluate the feasibility of monitoring strains with a fiber optic technique. Resistance strain gauges were attached to the tubes to measure strain at four locations along the tube for comparison with the fiber optic sensors. Both static and dynamic strain measurements were made with excellent agreement between the embedded fiber optic strain sensor and the strain gauges. Strain measurements of 10(exp -7) can be detected with the optical phase locked loop (OPLL) system using optical fiber. Because of their light weight, compatibility with composites, immunity to electromagnetic interference, and based on the static and dynamic results obtained, fiber optic sensors embedded in composites may be useful as the sensing component of smart structures.

Dehart, D. W.↗
DOE OSTI2025

Final design of outer poloidal field coils for COMPASS Upgrade

The paper aims to provide an overview of the final design of the outer poloidal field coils system for COMPASS Upgrade. Due to a relatively unique combination of design features of the new device (placement in high toroidal magnetic field, copper coils sub-cooled to liquid nitrogen temperature, hot vacuum vessel operation), the poloidal field coils design faced several interesting engineering challenges. Most notably high electromagnetic stress in the coil conductor, compatibility of the insulation to thermal and mechanical stress and design of coil supports with given spatial constraints while able to accommodate coil movements and withstand considerable mechanical stress. In conclusion, the paper describes solution to these challenges together with underlying analyses and mechanical tests.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
NASA NTRS1973

A study of the compatibility of science instruments with the solar electric propulsion space vehicle

Electromagnetic interference and field-of-view constraints are identified as the areas of most concern to science on solar electric propulsion space vehicles. Several areas are indicated which more detailed data on the space vehicle environment are needed. In addition, possible means to attain or demonstrate science/space vehicle compatibility are recommended for further iteration between space vehicle design and science payload considerations. The space vehicle design developed by the solar electric propulsion system integration technology effort is used. Two payload sets for comet Encke missions (a slow flyby and a rendezvous), as well as several instruments which are not included in the two payload sets, are analyzed to determine requirements on the space vehicle imposed by the instruments in order to meet their objectives. Environmental requirements for the sets of instruments are developed and compared to both the SEPSIT design criteria and the environment as it is presently understood.

Parker, R. H.↗
NASA NTRS1971

Investigation of space stable thermal control coating properties

A capability to study the nuclear magnetic resonance of spacecraft thermal control coating has been built utilizing an electromagnet and V-series and Wl-series electronics. The electronics associated with the electromagnet had to be modified to make it compatible with the resonance measuring system. Resonance measurements have been performed on ZnO, Zn2TiO4 and FEP Teflon. The failure to observe resonance in ZnO and Zn2TiO4 has been theoretically explained. The linewidth and second moment measurements on ultraviolet irradiated FEP Teflon showed that there was no measurable degradation of the material due to short term irradiation.

Mookherji, T.↗
NASA NTRS1974

Power processor for a 30cm ion thruster

A thermal vacuum power processor for the NASA Lewis 30cm Mercury Ion Engine was designed, fabricated and tested to determine compliance with electrical specifications. The power processor breadboard used the silicon controlled rectifier (SCR) series resonant inverter as the basic power stage to process all the power to an ion engine. The power processor includes a digital interface unit to process all input commands and internal telemetry signals so that operation is compatible with a central computer system. The breadboard was tested in a thermal vacuum environment. Integration tests were performed with the ion engine and demonstrate operational compatibility and reliable operation without any component failures. Electromagnetic interference data were also recorded on the design to provide information on the interaction with total spacecraft.

Biess, J. J.↗
NASA NTRS2006

Structurally Integrated Antenna Concepts for HALE UAVs

This technical memorandum describes work done in support of the Multifunctional Structures and Materials Team under the Vehicle Systems Program's ITAS (Integrated Tailored Aero Structures) Project during FY 2005. The Electromagnetics and Sensors Branch (ESB) developed three ultra lightweight antenna concepts compatible with HALE UAVs (High Altitude Long Endurance Unmanned Aerial Vehicles). ESB also developed antenna elements that minimize the interaction between elements and the vehicle to minimize the impact of wing flexure on the EM (electromagnetic) performance of the integrated array. In addition, computer models were developed to perform phase correction for antenna arrays whose elements are moving relative to each other due to wing deformations expected in HALE vehicle concepts. Development of lightweight, conformal or structurally integrated antenna elements and compensating for the impact of a lightweight, flexible structure on a large antenna array are important steps in the realization of HALE UAVs for microwave applications such as passive remote sensing and communications.

Cravey, Robin L.↗
NASA NTRS2001

Addressing EO-1 Spacecraft Pulsed Plasma Thruster EMI Concerns

The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing One (EO-1) spacecraft has been designed to demonstrate the capability of a new generation PPT to perform spacecraft attitude control. Results from PPT unit level radiated electromagnetic interference (EMI) tests led to concerns about potential interference problems with other spacecraft subsystems. Initial plans to address these concerns included firing the PPT at the spacecraft level both in atmosphere, with special ground support equipment. and in vacuum. During the spacecraft level tests, additional concerns where raised about potential harm to the Advanced Land Imager (ALI). The inadequacy of standard radiated emission test protocol to address pulsed electromagnetic discharges and the lack of resources required to perform compatibility tests between the PPT and an ALI test unit led to changes in the spacecraft level validation plan. An EMI shield box for the PPT was constructed and validated for spacecraft level ambient testing. Spacecraft level vacuum tests of the PPT were deleted. Implementation of the shield box allowed for successful spacecraft level testing of the PPT while eliminating any risk to the ALI. The ALI demonstration will precede the PPT demonstration to eliminate any possible risk of damage of ALI from PPT operation.

Zakrzwski, C. M.↗
NASA NTRS2011

Design and Development of an Equipotential Voltage Reference (Grounding) System for a Low-Cost Rapid-Development Modular Spacecraft Architecture

This work describes the design and development effort to adapt rapid-development space hardware by creating a ground system using solutions of low complexity, mass, & cost. The Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft is based on the modular common spacecraft bus architecture developed at NASA Ames Research Center. The challenge was building upon the existing modular common bus design and development work and improving the LADEE spacecraft design by adding an Equipotential Voltage Reference (EVeR) system, commonly referred to as a ground system. This would aid LADEE in meeting Electromagnetic Environmental Effects (E3) requirements, thereby making the spacecraft more compatible with itself and its space environment. The methods used to adapt existing hardware are presented, including provisions which may be used on future spacecraft.

Lukash, James A.↗
NASA NTRS2016

A Broadband Micro-Machined Far-Infrared Absorber

The experimental investigation of a broadband far-infrared meta-material absorber is described. The observed absorptance is greater than 0.95 from 1 to 20 terahertz (300-15 microns) over a temperature range spanning 5-300 degrees Kelvin. The meta-material, realized from an array of tapers approximately 100 microns in length, is largely insensitive to the detailed geometry of these elements and is cryogenically compatible with silicon-based micro-machined technologies. The electromagnetic response is in general agreement with a physically motivated transmission line model.

broadband far-infrared meta-material absorber↗
NASA NTRS1984

Study of new flight test techniques

The modification and testing of a small electromechanical vibrator are described. The vibrator was designed for the flutter testing of aircraft wings and was built to specifications that make it compatible with the X-29 experimental aircraft. The device uses alternating electromagnetic forces to move a magnetic mass and produce vibration. Its unconventional way of producing vibration avoids the need for complex mechanisms and makes efficient use of space and weight.

Deam, D.↗
NASA NTRS1995

Novel Techniques for Millimeter-Wave Packages

A new millimeter-wave package architecture with supporting electrical, mechanical and material science experiment and analysis is presented. This package is well suited for discrete devices, monolithic microwave integrated circuits (MMIC's) and multichip module (MCM) applications. It has low-loss wide-band RF transitions which are necessary to overcome manufacturing tolerances leading to lower per unit cost Potential applications of this new packaging architecture which go beyond the standard requirements of device protection include integration of antennas, compatibility to photonic networks and direct transitions to waveguide systems. Techniques for electromagnetic analysis, thermal control and hermetic sealing were explored. Three dimensional electromagnetic analysis was performed using a finite difference time-domain (FDTD) algorithm and experimentally verified for millimeter-wave package input and output transitions. New multi-material system concepts (AlN, Cu, and diamond thin films) which allow excellent surface finishes to be achieved with enhanced thermal management have been investigated. A new approach utilizing block copolymer coatings was employed to hermetically seal packages which met MIL STD-883.

Herman, Martin I.↗
NASA NTRS2005

Fast Laser Shutters With Low Vibratory Disturbances

A prototype vacuum-compatible, fast-acting, long-life shutter unit that generates very little vibratory disturbance during switching is reviewed. This is one of a number of shutters designed to satisfy requirements specific to an experiment, to be performed aboard a spacecraft in flight, in which laser beams must be blocked rapidly and completely, without generating a vibratory disturbance large enough to adversely affect the power and frequency stability of the lasers. Commercial off-the-shelf laboratory shutter units -- typically containing electromagnet-coil-driven mechanisms -- were found not to satisfy the requirements because they are not vacuum-compatible, their actuators engage in uncompensated motions that generate significant vibrations, and their operational lifetimes are too short. Going beyond the initial outerspace application, the present vacuum-compatible, fast-acting, long-life shutter units could also be used in terrestrial settings in which there are requirements for their special characteristics. In designing these shutter units, unbalanced, electromagnetically driven mechanisms were replaced with balanced mechanisms that include commercial piezoelectric bending actuators. In each shutter unit, the piezoelectric bending actuators are configured symmetrically as opposing cantilever beams within a housing that contains integral mounts for lenses that focus a laser beam to a waist at the shutter location. In operation, the laser beam is blocked by titanium blades bonded near the free ends of the piezoelectric benders. The benders are driven by shaped electrical pulses with a maximum voltage differential of less than 60 V. Preliminary measurements indicate that rise and fall times are less than 1 ms.

Brinza, David↗