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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 235 records · Page 13
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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 NTRS1992

On-orbit coldwelding: Fact or friction?

A study into the potential of on-orbit coldwelding occurring was completed. No instances of cold welding were found during deintegration and subsequent testing and analysis of LDEF hardware. This finding generated wide interest and indicated the need to review previous on-orbit coldwelding experiments and on-orbit spacecraft anomalies to determine whether the absence of coldwelding on LDEF was to be expected. Results show that even though there have been no documented cases of significant on-orbit coldwelding events occurring, precautions should be taken to ensure that neither coldwelding nor galling occurs in the space or prelaunch environment.

Dursch, Harry↗
NASA NTRSDate not supplied

TriTruss Packaging and Deployment Trade Study

A trade study was conducted that evaluated viable concepts of operation for the packaging and deployment (P&D) of novel deployable modular truss modules, called TriTruss modules, that can be assembled to form a large aperture In-Space Assembled Telescopes (iSAT). In this first phase of an ongoing more comprehensive trade study, concepts were proposed and then evaluated based on initial metrics representing features of an ideal P&D concept. The ideal TriTruss P&D concept is defined as one that: allows for efficient packaging, has sufficient geometric versatility to be launch vehicle independent, provides a stiff and lightweight structure, has low mechanical complexity, and has component modularity. The P&D concept should allow for prelaunch subsystem or utility integration if required. The concept should be kinematically simple and be robotically deployed using a minimum number of specialized tools. The P&D concepts evaluated are categorized as: core collapse, face collapse, and erectable structures. Sub-scale models were constructed to help understand the kinematics and mechanical complexity required to enable P&D. Based on a weighting scale, the most promising candidate P&D concepts have been selected and will undergo more rigorous structural design, analysis, and testing in the study’s next phase. The ultimate goal of the comprehensive trade study will be to recommend a single TriTruss design and associated P&D concept that will be built and evaluated at NASA Langley Research Center’s In-Space Assembly Laboratory.

in-space assembly (ISA)↗
NASA NTRS1976

The Viking Orbiter Visual Imaging Subsystem

Two Viking spacecraft each consisting of an Orbiter and a Lander are on trajectories toward Mars with arrival dates in June and August 1976. A Visual Imaging Subsystem consisting of two slow-scan television cameras forms part of the scientific payload of each Orbiter. These cameras will be used to evaluate the potential landing sites on Mars and to conduct other scientific investigations of the planet. The camera system described in this paper was subjected to an extensive test and calibration program prior to launch. Based on this calibration and subsequent analyses, absolute photometric accuracies of 8.0% may be achieved. Surface resolution exceeding 100 meters will be achieved from the periapsis portion of the Viking orbits. The inherent geometric accuracies of the Orbiter cameras supersede those of previous planetary missions. The analyses of images acquired during the cruise phase of the mission confirms that the cameras have survived the rigors of launch and are performing in a manner consistent with the prelaunch calibrations.

Wellman, J. B.↗
NASA NTRS1993

The impact of LDEF results on the space application of metal matrix composites

Over 200 graphite/aluminum and graphite/magnesium composites were flown on the leading and trailing edges of LDEF on the Advanced Composites Experiment. The performance of these composites was evaluated by performing scanning electron microscopy and x-ray photoelectron spectroscopy of exposed surfaces, optical microscopy of cross sections, and on-orbit and postflight thermal expansion measurements. Graphite/aluminum and graphite/magnesium were found to be superior to graphite/polymer matrix composites in that they are inherently resistant to atomic oxygen and are less susceptible to thermal cycling induced microcracking. The surface foils on graphite/aluminum and graphite/magnesium protect the graphite fibers from atomic oxygen and from impact damage from small micrometeoroid or space debris particles. However, the surface foils were found to be susceptible to thermal fatigue cracking arising from contamination embrittlement, surface oxidation, or stress risers. Thus, the experiment reinforced requirements for carefully protecting these composites from prelaunch oxidation or corrosion, avoiding spacecraft contamination, and designing composite structures to minimize stress concentrations. On-orbit strain measurements demonstrated the importance of through-thickness thermal conductivity in composites to minimize thermal distortions arising from thermal gradients. Because of the high thermal conductivity of aluminum, thermal distortions were greatly reduced in the LDEF thermal environment for graphite/aluminum as compared to graphite/magnesium and graphite/polymer composites. The thermal expansion behavior of graphite/aluminum and graphite/magnesium was stabilized by on-orbit thermal cycling in the same manner as observed in laboratory tests.

Steckel, Gary L.↗
NASA NTRSDate not supplied

Investigating Biological Responses to Space-like Radiation using the yeast Saccharomyces cerevisiae

As we plan crewed missions to the Moon, Mars, and beyond, it is essential to understand how persistent exposure to space radiation affects biology. Unlike on the International Space Station, where crew support and sample return are possible, experiments for long-duration missions require autonomous systems with no sample return. Human cells would be ideal biosensors, but limitations in culture methods, extended prelaunch storage, and long flight durations make it very difficult to keep human cells alive. Unlike other model systems, yeast can survive the constraints of long-duration spaceflight. Despite a billion years of evolution separating yeast from humans, we share homology in hundreds of genes important for basic cell function, including responses to DNA damage. Thus, yeast are excellent biosensors for detecting types/extent of damage induced by space radiation. BioSentinel is NASA’s latest biological CubeSat, and first interplanetary space bioscience mission. BioSentinel is manifested on Artemis 1, the first test flight of NASA’s Space Launch System, in the coming year. The BioSensor payload within BioSentinel contains two yeast strains. The wild type serves as a control for health and “normal” DNA damage repair (DDR). The rad51 deletion mutant is defective for DDR and will undergo alterations to growth and metabolism as it accumulates radiation damage. Changes in growth and metabolic activity will be measured using a 3-color LED detection system and the metabolic redox dye alamarBlue®. Preliminary tests indicate a significant change in alamarBlue response to space-like, low-dose ionizing radiation. We will discuss these findings in four parts – Introduction to biological CubeSats and the BioSentinel mission (presented by Sergio Santa Maria), preliminary responses to space-like ionizing radiation (presented here), a deeper dive into tracking metabolic changes after exposure to ionizing radiation (presented by Diana Gentry), and a look into methods for correcting flight optical data (presented by Abbey Kim). This work is funded by NASA’s Advanced Exploration Systems.

CubeSat↗
NASA NTRS1988

Dypas: A dynamic payload scheduler for shuttle missions

Decision and analysis systems have had broad and very practical application areas in the human decision making process. These software systems range from the help sections in simple accounting packages, to the more complex computer configuration programs. Dypas is a decision and analysis system that aids prelaunch shutlle scheduling, and has added functionality to aid the rescheduling done in flight. Dypas is written in Common Lisp on a Symbolics Lisp machine. Dypas differs from other scheduling programs in that it can draw its knowledge from different rule bases and apply them to different rule interpretation schemes. The system has been coded with Flavors, an object oriented extension to Common Lisp on the Symbolics hardware. This allows implementation of objects (experiments) to better match the problem definition, and allows a more coherent solution space to be developed. Dypas was originally developed to test a programmer's aptitude toward Common Lisp and the Symbolics software environment. Since then the system has grown into a large software effort with several programmers and researchers thrown into the effort. Dypas is currently using two expert systems and three inferencing procedures to generate a many object schedule. The paper will review the abilities of Dypas and comment on its functionality.

Davis, Stephen↗
NASA NTRS2023

JPSS J2 Spectralon Performance Prelaunch

Spectralon® is a high reflectance excellent diffuser used to reflect sunlight for use as a calibrator for on-orbit and ground instruments. Radiometric calibration of the reflective bands in the 0.4 to 2.5μm wavelength range is performed by measuring the sunlight reflected from Spectralon®. Reflected sunlight is directly proportional to the Bidirectional Reflectance Distribution Function (BRDF) of the Spectralon®. On-orbit exposure to sunlight results in solarization due to solar UV and the presence of residual contamination. Spectralon® quality is checked at start of build by measuring the change in reflectance on exposing a witness sample to 100 hours Solar UV as an indication of on orbit performance. For JPSS J2, the witness samples accompanied the sensor till 30 days before launch. Measuring the reflectance change on exposure to Solar UV of the witness samples accompanying the sensor through build and test is a better indication of on orbit performance as this includes any additional contamination during the build and test phase.

spectral reflectance↗
NASA NTRS2018

Landsat 9 Thermal Infrared Sensor 2 Pre-Launch Characterization: Initial Imaging and Spectral Performance Results

The Thermal Infrared Sensor-2 (TIRS-2) scheduled to launch in December 2020 aboard Landsat 9 will continue Landsat's four decade-long legacy of providing moderate resolution thermal imagery from low earth orbit (at 705 km) for environmental applications. Like the Thermal Infrared Sensor aboard Landsat 8, it is a pushbroom sensor with a cross-track field of view of 15 and provides two spectral channels at 10.8 and 12 micrometers. To ensure radiometric, spatial, and spectral performance, a comprehensive pre-launch testing program is being conducted at NASA Goddard Space Flight Center at the component, subsystem, and instrument level. This effort will focus on the results from the subsystem level testing to assess TIRS-2 imaging performance including focus, spatial performance, and stray light rejection. It is also used to provide a preliminary assessment of spectral performance. The TIRS-2 subsystem is placed in a thermal vacuum chamber with the calibration ground support equipment, which provides a flexible blackbody illumination source and optics to assess imaging performance. Spectral performance is tested using a spectral response test setup with its own illumination source outside the chamber that propagates through the calibration ground support equipment in an optical configuration designed for this purpose. The results show that TIRS-2 performance is expected to meet all of its performance requirements with few waivers and deviations.

Landsat 9↗
NASA NTRS2018

Landsat 9 Thermal Infrared Sensor 2 Pre-Launch Characterization: Initial Imaging & Spectral Performance Results

The Thermal Infrared Sensor-2 (TIRS-2) scheduled to launch in December 2020 aboard Landsat 9 will continue Landsat's four decade-long legacy of providing moderate resolution thermal imagery from low earth orbit (at 705 km) for environmental applications. Like the Thermal Infrared Sensor aboard Landsat 8, it is a pushbroom sensor with a cross-track field of view of 15 and provides two spectral channels at 10.8 and 12 um. To ensure radiometric, spatial, and spectral performance, a comprehensive pre-launch testing program is being conducted at NASA Goddard Space Flight Center at the component, subsystem, and instrument level. This effort will focus on the results from the subsystem level testing to assess TIRS-2 imaging performance including focus, spatial performance, and stray light rejection. It is also used to provide a preliminary assessment of spectral performance. The TIRS-2 subsystem is placed in a thermal vacuum chamber with the calibration ground support equipment, which provides a flexible blackbody illumination source and optics to assess imaging performance. Spectral performance is tested using a spectral response test setup with its own illumination source outside the chamber that propagates through the calibration ground support equipment in an optical configuration designed for this purpose. The results show that TIRS-2 performance is expected to meet all of its performance requirements with few waivers and deviations.

scatter↗
NASA NTRS1998

STS-95 Post Flight Presentation

The STS-95 flight crew, Cmdr. Curtis L. Brown, Pilot Steven W. Lindsey, Mission Specialists Scott E. Parazynski, Stephen K. Robinson, and Pedro Duque, and Payload Specialists Chiaki Mukai and John H. Glenn present a video mission over-view of their space flight. Images include prelaunch activities such as eating the traditional breakfast, crew suit-up, and the ride out to the launch pad. Also, included are various panoramic views of the shuttle on the pad. The crew can be seen being readied in the "whiteroom" for their mission. After the closing of the hatch and arm retraction, launch activities are shown including countdown, engine ignition, launch, and the separation of the Solid Rocket Boosters. The primary objectives, which include the conducting of a variety of science experiments in the pressurized SPACEHAB module, the deployment and retrieval of the Spartan free-flyer payload, and operations with the HST Orbiting Systems Test (HOST) and the International Extreme Ultraviolet Hitchhiker (IEH) payloads are discussed in both the video and still photo presentation.

Source record↗
NASA NTRSDate not supplied

TriTruss Packaging and Deployment Trade Study

An architecture and feasibility study of next generation In-Space Assembled Telescopes (iSAT) concluded that robotic in-space assembly of modular components is necessary to enable large (>15-meter diameter) primary apertures. The iSAT study recommended that the foundational structure be assembled from modular TriTruss modules that are packaged for launch, deployed on-orbit and robotically assembled into the final configuration. This paper will describe and summarize the results of a trade study that investigated viable concept of operations (ConOps) for the packaging and deployment (P&D) of individual planar TriTruss modules that could be assembled to form a large aperture iSAT. The ideal TriTruss P&D concept is defined as one that: allows for efficient packaging; has sufficient geometric versatility to be launch vehicle independent; provides a stiff and lightweight structure; has low mechanical complexity; and has component modularity. The P&D concept should allow for prelaunch subsystem or utility integration if required. The concept would be kinematically simple and be robotically deployed using a minimum number of specialized tools. In this first phase of an ongoing more comprehensive trade study, concepts were proposed and then evaluated based on initial metrics representing features of an ideal P&D concept. The P&D concepts evaluated are categorized as: core collapse, face collapse, and erectable structures. Sub-scale models were constructed to help understand the kinematics and mechanical complexity required to enable P&D. Based on a weighting scale, the most promising candidate P&D concepts have selected and will undergo more rigorous structural design, analysis, and testing in the study’s next phase. The ultimate goal of the comprehensive trade study will be to recommend a single TriTruss design and associated P&D concept that will be built and evaluated at NASA Langley Research Center’s In-Space Assembly Laboratory.

in-space assembly (ISA)↗
NASA NTRS2013

SNPP VIIRS Spectral Bands Co-Registration and Spatial Response Characterization

The Visible Infrared Imager Radiometer Suite (VIIRS) instrument onboard the Suomi National Polar‐orbiting Partnership (SNPP) satellite was launched on 28 October 2011. The VIIRS has 5 imagery spectral bands (I-bands), 16 moderate resolution spectral bands (M-bands) and a panchromatic day/night band (DNB). Performance of the VIIRS spatial response and band-to-band co-registration (BBR) was measured through intensive pre-launch tests. These measurements were made in the non-aggregated zones near the start (or end) of scan for the I-bands and M-bands and for a limited number of aggregation modes for the DNB in order to test requirement compliance. This paper presents results based on a recently re-processed pre-launch test data. Sensor (detector) spatial impulse responses in the scan direction are parameterized in terms of ground dynamic field of view (GDFOV), horizontal spatial resolution (HSR), modulation transfer function (MTF), ensquared energy (EE) and integrated out-of-pixel (IOOP) spatial response. Results are presented for the non-aggregation, 2-sample and 3-sample aggregation zones for the I-bands and M-bands, and for a limited number of aggregation modes for the DNB. On-orbit GDFOVs measured for the 5 I-bands in the scan direction using a straight bridge are also presented. Band-to-band co-registration (BBR) is quantified using the prelaunch measured band-to-band offsets. These offsets may be expressed as fractions of horizontal sampling intervals (HSIs), detector spatial response parameters GDFOV or HSR. BBR bases on HSIs in the non-aggregation, 2-sample and 3-sample aggregation zones are presented. BBR matrices based on scan direction GDFOV and HSR are compared to the BBR matrix based on HSI in the non-aggregation zone. We demonstrate that BBR based on GDFOV is a better representation of footprint overlap and so this definition should be used in BBR requirement specifications. We propose that HSR not be used as the primary image quality indicator, since we show that it is neither an adequate representation of the size of sensor spatial response nor an adequate measure of imaging quality.

Suomi NPP VIIRS↗
NASA NTRS2012

Characterization of NPP Visible/Infrared Imager Radiometer Suite (VIIRS) Reflective Solar Bands Dual Gain Anomaly

The Visible/Infrared Imager Radiometer Suite (VIIRS) contains six dual gain bands in the reflective solar spectrum. The dual gain bands are designed to switch gain mode at pre-defined thresholds to achieve high resolution at low radiances while maintaining the required dynamic range for science. During pre-launch testing, an anomaly in the electronic response before transitioning from high to low gain was discovered and characterized. On-orbit, the anomaly was confirmed using MODIS data collected during Simultaneous Nadir Overpasses (SNOs). The analysis of the Earth scene data shows that dual gain anomaly can be determined at the orbital basis. To characterize the dual gain anomaly, the anomaly region and electronic offsets were tracked per week during the first 8 month of VIIRS operation. The temporal analysis shows the anomaly region can drift ~20 DN and is impacted by detectors DC Restore. The estimated anomaly flagging regions cover ~2.5 % of the high gain dynamic range and are consistent with prelaunch and on-orbit LUT. The prelaunch results had a smaller anomaly range (30-50 DN) and are likely the results of more stable electronics from the shorter data collection time. Finally, this study suggests future calibration efforts to focus on the anomaly's impact on science products and possible correction method to reduce uncertainties.

Lee, Shihyan↗
NASA NTRS2002

Prelaunch Instrument Calibration in the Real World: The GOES Example

The pre-launch ground infrared calibration of the Geostationary Operational Environmental Satellite (GOES) N-Q Imager and Sounder is presented. Ground calibration provides information necessary to the accurate on-orbit calibration of these radiometers. Infrared channels are calibrated in a thermal vacuum environment, under minimum and maximum mission operation temperatures, using a variable-temperature warm target to simulate the Earth scene and a cold target to simulate the space scene. Brightness temperatures derived from observation of the instrument internal calibration target, used for on-orbit calibration, are compared to brightness temperatures of the external calibration target as a check of relative accuracy using these two sources. Changes to the GOES N-Q specification from GOES I-M are highlighted, as well as results of noise, relative calibration accuracy, and spectral response performance to date. For completeness, results of spatial and pointing performance will be presented. Enhancements to test methodology and data processing techniques are highlighted throughout.

Murphy-Morris, J.↗
NASA NTRS1989

Flight Motor Set 360L003 (STS-29R)

The redesigned solid rocket motor (RSRM) flight set 360L003 was launched on March 13, 1989 as part of NASA space shuttle mission STS-29R. As was the case with flight sets 360L001 and 360L002 (STS-26R and STS-27R), both motors (360L003A and 360L003B) performed in an excellent manner. Evaluation of the ground environment instrumentation measurements verified thermal model analysis data and showed agreement with predicted environmental effects. The right-hand aft field joint primary heater failed during the countdown; the secondary heater was activated and performed as designed. All other field joint heaters and aft skirt thermal conditioning systems had no anomalies. Shuttle thermal imager infrared readings compared favorably with measured ground environment instrumentation data. No thermal launch commit criteria violations occurred at any time. Evaluation of the development flight instrumentation showed exceptional propulsion performance. All ballistic parameters closely matched the predicted values and were well within the required specification levels. Girth and biaxial strain gage measurements compared closely with corresponding gages on previous flight motors, static tests, and with preflight predictions. Adequate safety factors were verified. (Some ignition transient spiking was noted in a few girth gages; the spiking was determined not to be representative of actual case behavior, but an instrumentation phenomena.) The accelerometers again measured high vibration amplitude levels during the ignition transient and the reentry Max Q phases. Postflight inspection showed that all combustion gas was contained by the insulation in the field and case-to-nozzle joints. No anomalous insulation erosion patterns were found, and the seals that did directly contain motor pressure showed no heat effects, erosion, or blowby. All anomalies identified were a result of splashdown damage, with the exception of fretting in the case field joint interference (nonsealing) surfaces and a prelaunch field joint heater failure. The disposition of all anomalies and the complete results are reported.

Riehr, Glen A.↗
NASA NTRS2020

Pre-launch Radiometric Calibration and Uncertainty Analysis of Landsat Thermal Infrared Sensor 2

The Thermal Infrared Sensor-2 that will be on-board Landsat 9 has undergone a pre-launch testing campaign to characterize its radiometric, spectral, and spatial performance and demonstrate compliance to its requirements. This work reviews key elements of the instrument-level radiometric testing using an SI traceable source to derive its uncertainties. Those arising from on-orbit calibration using the TIRS-2 on-board blackbody are also discussed. We use a Monte Carlo approach to propagate the uncertainties through a non-linear calibration equation and address both random and systematic uncertainty terms. Achieving the required performance demonstrates the instrument’s potential for enhancing our understanding of the Earth’s environment.

Landsat↗
NASA NTRS1996

GOME Calibration and Validation Using Backscatter UV Techniques

GOME radiance, irradiance, and ozone products were validated by NASA Goddard Space Flight Center through three tasks which included, pre-launch calibration comparisons with SBUV and TOMS radiometric standards, validation of GOME Level-1 irradiance and radiance and Level 2 total ozone data products using SBUV/2 and TOMS algorithms and data, and studies of GOME data using the Goddard radiative transfer code. The prelaunch calibration using the NASA large aperture integrating sphere was checked against that provided by TPD. Agreement in the calibration constants, derived in air, between the Goddard and TPD system were better than 3%. Validation of Level-1 irradiance data included comparison of GOME and SSBUV and the UARS solar irradiances measurements. Large wavelength dependent differences, as high as 10%, were noted between GOME and the US instruments. This discrepancy has now been attributed to radiometric sensitivity changes experienced by GOME when operating in a vacuum. GOME Earth radiance data were then compared to the NOAA-14 SBUV/2 radiances. These results show that between 340 and 400 nm the differences in GOME and SBUV/2 data are less than 5% with some wavelength dependence. At wavelengths shorter than 300 nm, differences are of the order of 10% or more where the GOME radiances are larger. To test GOME DOAS retrieved total ozone values, these values were compared with ozone amounts retrieved using GOME radiances in the TOMS version-7 algorithm. The differences showed a solar zenith angle dependence ranging from 0 to 10% where the TOMS algorithm values were higher. GOME radiances below 300 nm were further validated by selecting radiances at wavelengths normally used by SBUV and processing them through the SBUV ozone profile algorithm and then compared to climatological values. The GOME ozone profiles ranged from 10-30% lower over altitude compared to climatological values. This is consistent with the offsets detected in the SBUV/2 radiance comparisons at wavelengths shorter than 300 nm.

Hilsenrath, E.↗