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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2000

Performance Characterization of Digital Optical Data Transfer Systems for Use in the Space Radiation Environment

Radiation effects in photonic and microelectronic components can impact the performance of high-speed digital optical data link in a variety of ways. This segment of the short course focuses on radiation effects in digital optical data links operating in the MHz to GHz regime. (Some of the information is applicable to frequencies above and below this regime) The three basic component level effects that should be considered are Total Ionizing Dose (TID), Displacement Damage Dose (DDD) and Single Event Effects (SEE). In some cases the system performance degradation can be quantified from component level tests, while in others a more holistic characterization approach must be taken. In Section 2.0 of this segment of the Short Course we will give a brief overview of the space radiation environment follow by a summary of the basic space radiation effects important for microelectronics and photonics listed above. The last part of this section will give an example of a typical mission radiation environment requirements. Section 3.0 gives an overview of intra-satellite digital optical data link systems. It contains a discussion of the digital optical data link and it's components. Also, we discuss some of the important system performance metrics that are impacted by radiation effects degradation of optical and optoelectronic component performance. Section 4.0 discusses radiation effects in optical and optoelectronic components. While each component effect will be discussed, the focus of this section is on degradation of passive optical components and SEE in photodiodes (other mechanisms are covered in segment II of this short course entitled "Photonic Devices with Complex and Multiple Failure Modes"). Section 5.0 will focus on optical data link system response to the space radiation environment. System level SEE ground testing will be discussed. Then we give a discussion of system level assessment of data link performance when operating in the space radiation environment.

Reed, Robert A.↗
NASA NTRS1998

RHETT/EPDM Performance Characterization

The 0.6 kW Electric Propulsion Demonstration Module (EPDM) flight thruster system was tested in a large vacuum facility for performance measurements and functional checkout. The thruster was operated at a xenon flow rate of 3.01 mg/s, which was supplied through a self-contained propellant system. All power was provided through a flight-packaged power processing unit, which was mounted in vacuum on a cold plate. The thruster was cycled through 34 individual startup and shutdown sequences. Operating periods ranged from 3 to 3600 seconds. The system responded promptly to each command sequence and there were no involuntary shutdowns. Direct thrust measurements indicated that steady state thrust was temperature sensitive, and varied from a high of 41.7 mN at 16 C, to a low of 34.8 mN at 110 C. Short duration thruster firings showed rapid response and good repeatability.

Haag, T.↗
NASA NTRS2009

Global Performance Characterization of the Three Burn Trans-Earth Injection Maneuver Sequence over the Lunar Nodal Cycle

The Orion spacecraft will be required to perform a three-burn trans-Earth injection (TEI) maneuver sequence to return to Earth from low lunar orbit. The origin of this approach lies in the Constellation Program requirements for access to any lunar landing site location combined with anytime lunar departure. This paper documents the development of optimized databases used to rapidly model the performance requirements of the TEI three-burn sequence for an extremely large number of mission cases. It also discusses performance results for lunar departures covering a complete 18.6 year lunar nodal cycle as well as general characteristics of the optimized three-burn TEI sequence.

Williams, Jacob↗
NASA NTRS2012

Automated Performance Characterization of DSN System Frequency Stability Using Spacecraft Tracking Data

This software provides an automated capability to measure and qualify the frequency stability performance of the Deep Space Network (DSN) ground system, using daily spacecraft tracking data. The results help to verify if the DSN performance is meeting its specification, therefore ensuring commitments to flight missions; in particular, the radio science investigations. The rich set of data also helps the DSN Operations and Maintenance team to identify the trends and patterns, allowing them to identify the antennas of lower performance and implement corrective action in a timely manner. Unlike the traditional approach where the performance can only be obtained from special calibration sessions that are both time-consuming and require manual setup, the new method taps into the daily spacecraft tracking data. This new approach significantly increases the amount of data available for analysis, roughly by two orders of magnitude, making it possible to conduct trend analysis with good confidence. The software is built with automation in mind for end-to-end processing. From the inputs gathering to computation analysis and later data visualization of the results, all steps are done automatically, making the data production at near zero cost. This allows the limited engineering resource to focus on high-level assessment and to follow up with the exceptions/deviations. To make it possible to process the continual stream of daily incoming data without much effort, and to understand the results quickly, the processing needs to be automated and the data summarized at a high level. Special attention needs to be given to data gathering, input validation, handling anomalous conditions, computation, and presenting the results in a visual form that makes it easy to spot items of exception/ deviation so that further analysis can be directed and corrective actions followed.

Pham, Timothy T.↗
NASA NTRS2012

Automated Performance Characterization of DSN System Frequency Stability Using Spacecraft Tracking Data

This software provides an automated capability to measure and qualify the frequency stability performance of the Deep Space Network (DSN) ground system, using daily spacecraft tracking data. The results help to verify if the DSN performance is meeting its specification, therefore ensuring commitments to flight missions; in particular, the radio science investigations. The rich set of data also helps the DSN Operations and Maintenance team to identify the trends and patterns, allowing them to identify the antennas of lower performance and implement corrective action in a timely manner. Unlike the traditional approach where the performance can only be obtained from special calibration sessions that are both time-consuming and require manual setup, the new method taps into the daily spacecraft tracking data. This new approach significantly increases the amount of data available for analysis, roughly by two orders of magnitude, making it possible to conduct trend analysis with good confidence. The software is built with automation in mind for end-to-end processing. From the inputs gathering to computation analysis and later data visualization of the results, all steps are done automatically, making the data production at near zero cost. This allows the limited engineering resource to focus on high-level assessment and to follow up with the exceptions/deviations. To make it possible to process the continual stream of daily incoming data without much effort, and to understand the results quickly, the processing needs to be automated and the data summarized at a high level. Special attention needs to be given to data gathering, input validation, handling anomalous conditions, computation, and presenting the results in a visual form that makes it easy to spot items of exception/deviation so that further analysis can be directed and corrective actions followed.

Pham, Timothy T.↗
NASA NTRSDate not supplied

Extended Performance Characterization of the 12.5-kW Advanced Electric Propulsion System Engineering Test Unit Hall Thruster

This work presents a summary of the first detailed performance assessment of the Advanced Electric Propulsion System (AEPS) Engineering Test Unit 2 (ETU-2) thruster produced by Aerojet Rocketdyne at the throttle conditions most relevant for AEPS application on the Gateway Power and Propulsion Element (PPE). First, an assessment was performed of ETU-2 performance and backpressure sensitivity at the previously-tested throttle points of 300 V/6.25 kW, 400 V/8.33 kW, 500 V/10.42 kW, and 600 V/12.5 kW that confirmed ETU-2 and the test facility were both operating nominally and consistent with historical baselines. ETU-2 performance and stability were then assessed throughout the PPE throttle range of 2.6-12 kW and shown to be in-family with predictions based on the scaling of previous results. Taken together, these results will help inform application of AEPS on PPE as the AEPS design progresses towards its Critical Design Review.

Jason D Frieman↗
NASA NTRSDate not supplied

Extended Performance Characterization of the 12.5-kW Advanced Electric Propulsion System Engineering Test Unit Hall Thruster

This work presents a summary of the first detailed performance assessment of the Advanced Electric Propulsion System (AEPS) Engineering Test Unit 2 (ETU-2) thruster produced by Aerojet Rocketdyne at the throttle conditions most relevant for AEPS application on the Gateway Power and Propulsion Element (PPE). First, an assessment was performed of ETU-2 performance and backpressure sensitivity at the previously-tested throttle points of 300 V/6.25 kW, 400 V/8.33 kW, 500 V/10.42 kW, and 600 V/12.5 kW that confirmed ETU-2 and the test facility were both operating nominally and consistent with historical baselines. ETU-2 performance and stability were then assessed throughout the PPE throttle range of 2.6-12 kW and shown to be in-family with predictions based on the scaling of previous results. Taken together, these results will help inform application of AEPS on PPE as the AEPS design progresses towards its Critical Design Review.

HERMeS↗
NASA NTRS2019

LANDSAT 9: Mission Status and Prelaunch Instrument Performance Characterization and Calibration

Landsat 9 is currently under development as a joint effort between NASA and the United States Geological Survey (USGS). Landsat 9 is largely a rebuild of Landsat 8 and has the same two sensors, an Operational Land Imager (OLI) and a Thermal InfraRed Sensor(TIRS). The OLI-2 on Landsat 9, being built by Ball Aerospace, has completed its pre-launch characterization and calibration and is scheduled to be delivered in the summer of 2019. The TIRS-2, with improved stray light performance and increased redundancy for improved reliability, is being built by Goddard Space Flight Center. TIRS-2is undergoing testing through Spring 2019 and is also scheduled for summer2019 delivery. Several improvements to the characterization of both instruments have been incorporated into the testing plan, including improved spectral and radiometric characterization. The instruments will then be integrated onto the spacecraft being built by Northrop Grumman Innovation Systems (NGIS). The mission is targeted to launch as early as December 2020 on an Atlas V.

Landsat↗
NASA NTRS2017

Mars Organic Molecule Analyzer (MOMA) Laser Desorption/Ionization Source Design and Performance Characterization

The Mars Organic Molecule Analyzer (MOMA), a dual-source, ion trap-based instrument capable of both pyrolysis-gas chromatography mass spectrometry (pyr/GC-MS) and laser desorption/ionization mass spectrometry (LDI-MS), is the core astrobiology investigation on the ExoMars rover. The MOMA instrument will be the first spaceflight mass analyzer to exploit the LDI technique to detect refractory organic compounds and characterize host mineralogy; this mode of analysis will be conducted at Mars ambient conditions. In order to achieve high performance in the Martian environment while keeping the instrument compact and low power, a number of innovative designs and components have been implemented for MOMA. These include a miniaturized linear ion trap (LIT), a fast actuating aperture valve with ion inlet tube, and a Microelectromechanical System (MEMS) Pirani sensor. Advanced analytical capabilities like Stored Waveform Inverse Fourier Transform (SWIFT) for selected ion ejection and tandem mass spectrometry (MS/MS) are realized in LDI-MS mode, and enable the isolation and enhancement of specific mass ranges and structural analysis, respectively. We report here the technical details of these instrument components as well as system-level analytical capabilities, and we review the applications of this technology to Mars and other high-priority targets of planetary exploration.

Xiang Li↗
NASA NTRS1990

Performance characterization of a segmented anode arcjet thruster

A modular, 1 to 2 kW class arcjet thruster incorporating a segmented anode/nozzle was operated on a thrust stand to obtain performance characteristics of the device and further study its operating characteristics under a number of experimental conditions. The nozzle was composed of five axial conducting segments isolated from one another by boron nitride spacers. The electrical configuration allowed the current delivered to the arcjet to be collected at any combination of segments. Both the current collected by each segment, and the potential difference between the cathode and each segment were monitored throughout the test period. As in previous tests a similar device, current appeared to attach diffusely in the anode when all of the segments were allowed to conduct. Improvements to the device allowed long term (4 to 8 hour) operation at steady-state and operating characteristics were repeatable over extended periods. Performance characteristics indicated that the segmented anode reasonably simulates the behavior of solid anodes of similar geometry. Current distribution depended on flow rate as the arc attachment moved downstream in the nozzle with increases in the mass flow rate. The current level had little effect on current distribution on the anode segments. Thrust measurements indicated that the current distribution in the nozzle did not significantly affect performance of the device.

Curran, Francis M.↗
NASA NTRS2011

Cryogenic Thermal Distortion Performance Characterization for the JWST ISIM Structure

The James Webb Space Telescope (JWST) Integrated Science Instrument Module (ISIM) Structure is a precision optical metering structure for the JWST science instruments. Optomechanical performance requirements place stringent limits on the allowable thermal distortion of the metering structure between ambient and cryogenic operating temperature (~35 K). This paper focuses on thermal distortion testing and successful verification of performance requirements for the flight ISIM Structure. The ISIM Structure Cryoset Test was completed in Spring 2010 at NASA Goddard Space Flight Center in the Space Environment Simulator Chamber. During the test, the ISIM Structure was thermal cycled twice between ambient and cryogenic (~35 K) temperatures. Photogrammetry was used to measure the Structure in the ambient and cryogenic states for each cycle to assess both cooldown thermal distortion and repeatability. This paper will provide details on the post-processing of the metrology datasets completed to compare measurements with performance requirements.

Johnston, John D.↗
NASA NTRS2016

GOES-16 On-Orbit Dual Isolation Performance Characterization Results

The Geostationary Operational Environmental Satellite-R Series (GOES-R) is the first of the next generation geostationary weather satellites. GOES-R successfully launched on November19, 2016 and renamed GOES-16 upon entering geostationary orbit. Subsequently, GOES-16post-launch testing began. This paper presents the GOES-16 Satellite Dynamic Interaction Characterization results for the Earth Pointed Platform (EPP) stowed, referred to as the Reaction Wheel Assembly (RWA) Isolation Only configuration, and deployed, referred to as the Dual Isolation configuration. GOES-R represents a quantum increase in Earth and solar weather observation capabilities, with 4 times the resolution, 5 times the observation rate, and 3 times the number of spectral bands for Earth observations. With the improved resolution, comes the instrument suites increased sensitivity to disturbances over a broad spectrum 0-512Hz. Sources of disturbance include reaction wheels, thruster firings for station keeping and momentum management, gimbal motion, and internal instrument disturbances. To minimize the impact of these disturbances, the baseline design included an EPP, a stiff optical bench to which the two nadir pointed instruments are collocated together with the Guidance Navigation Control (GNC) star trackers and Inertial Measurement Units (IMUs). The EPP is passively isolated from the spacecraft bus with Honeywell D-Strut isolators providing attenuation for frequencies above 5 Hz in all six degrees-of-freedom. To reduce the risk of wheel disturbances impacting performance, a secondary passive isolation system manufactured by Moog CSA Engineering was incorporated under each of the six 160 Nms reaction wheels, tuned to provide attenuation at frequencies above 50 Hz. Integrated wheel and isolator testing was performed on a Kistler table at NASA Goddard Space Flight Center. Pre-launch Satellite Dynamic Interaction Characterization high-fidelity simulations and ground testing were conducted to evaluate jitter performance for two cases: 1) deployed EPP and reaction wheel (Dual Isolation) and 2) EPP hard mounted (RWA Isolation Only) to the spacecraft. A comparison of pre-launch to post-launch Satellite Dynamic Interaction Characterization results are also presented in this paper.

Carter, Delano↗
NASA NTRS1990

Performance characterization of a segmented anode arcjet thruster

Results are presented from a continuing experimental program aimed at providing insight into arc energy deposition in the nozzle, the nature of the arc attachment, and its effects on performance characteristics of the device. A modular, 1-2 kW class arcjet thruster incorporating a segmented anode/nozzle was run on a thrust stand to determine performance characteristics under a number of experimental conditions. The nozzle comprised five axial conducting segments isolated from each other by boron nitride spacers. The electrical configuration permitted the current delivered to the arcjet to be collected at any combination of segments. It is concluded that the changes in the electric field in the nozzle that occur as a result of the changes in the current distribution do not significantly affect the momentum transfer or loss mechanisms in the type of nozzle investigated. Performance characteristics show that the segmented anode reasonably simulates the behavior of solid anodes of similar geometry.

Curran, Francis M.↗
NASA NTRS2005

An Application-Based Performance Characterization of the Columbia Supercluster

Columbia is a 10,240-processor supercluster consisting of 20 Altix nodes with 512 processors each, and currently ranked as the second-fastest computer in the world. In this paper, we present the performance characteristics of Columbia obtained on up to four computing nodes interconnected via the InfiniBand and/or NUMAlink4 communication fabrics. We evaluate floating-point performance, memory bandwidth, message passing communication speeds, and compilers using a subset of the HPC Challenge benchmarks, and some of the NAS Parallel Benchmarks including the multi-zone versions. We present detailed performance results for three scientific applications of interest to NASA, one from molecular dynamics, and two from computational fluid dynamics. Our results show that both the NUMAlink4 and the InfiniBand hold promise for application scaling to a large number of processors.

Biswas, Rupak↗
NASA NTRS1987

Preliminary performance characterizations of an engineering model multipropellant resistojet for space station application

Presented are the results of a program to describe the operational characteristics of an engineering model multipropellant resistojet for application as an auxiliary propulsion system for the space station. Performance was measured on hydrogen, helium, methane, water (steam), nitrogen, air, argon, and carbon dioxide. Thrust levels ranged form 109 to 355 mN, power levels ranged from 167 to 506 W, and specific impulse values ranged from 93 to 385 sec, depending on the propellant, chamber pressure, and heater current level selected. Detailed thermal maps of the heater and heat exchanger were also obtained for operation with carbon dioxide.

Morren, W. Earl↗