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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 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Local halide heterogeneity drives surface wrinkling in mixed-halide wide-bandgap perovskites

Compositional heterogeneity in wide-bandgap (1.8 - 2.1 eV) mixed-halide perovskites is a key bottleneck in the processing of high-quality solution-processed thin films and prevents their application in efficient multijunction solar cells. Notably, mixed-cation (formamidinium-methylammonium) wide-bandgap perovskite films are prone to form micrometer-scale wrinkles which can interfere with the smooth surfaces ideal for multijunction devices. Here, we study the formation dynamics of wrinkled mixed-halide perovskite films and its impact on the local composition and optoelectronic properties. We use in situ X-ray scattering during perovskite film formation to show that crystallization of bromide-rich perovskites precedes that of mixed-halide phases in wrinkled films cast using an antisolvent-based process. Using nanoscopic X­-ray fluorescence and hyperspectral photoluminescence imaging, we also demonstrate the formation of iodide- and bromide-rich phases in the wrinkled domains. This intrinsic spatial halide segregation results in an increased local bandgap variation and Urbach energy. Morphological disorder and compositional heterogeneity also aggravate the formation of sub-bandgap electronic defects, reducing photostability and accelerating light-induced segregation of iodide and bromide ions in thin films and solar cells.

36 MATERIALS SCIENCE↗
NASA NTRS1988

Insitu measurement and control of processing properties of composite resins in a production tool

An in situ measuring technique for use in automated composite processing and quality control is discussed. Frequency dependent electromagnetic sensors are used to measure processing parameters at four ply positions inside a thick section 192-ply graphite-epoxy composite during cure in an 8 x 4 in. autoclave. Viscosity measurements obtained using the sensors are compared with the viscosities calculated using the Loos-Springer cure process model. Good overall agreement is obtained. In a subsequent autoclave run, the output from the four sensors was used to control the autoclave temperature. Using the 'closed loop' sensor controlled autoclave temperature resulted in a more uniform and more rapid cure cycle.

Kranbuehl, D.↗
NASA NTRS1988

Testing and checkout experiences in the National Transonic Facility since becoming operational

The U.S. National Transonic Facility, constructed by NASA to meet the national needs for High Reynolds Number Testing, has been operational in a checkout and test mode since the operational readiness review (ORR) in late 1984. During this time, there have been problems centered around the effect of large temperature excursions on the mechanical movement of large components, the reliable performance of instrumentation systems, and an unexpected moisture problem with dry insulation. The more significant efforts since the ORR are reviewed and NTF status concerning hardware, instrumentation and process controls systems, operating constraints imposed by the cryogenic environment, and data quality and process controls is summarized.

Bruce, W. E., Jr.↗
NASA NTRS2010

Ambiguity of Quality in Remote Sensing Data

This slide presentation reviews some of the issues in quality of remote sensing data. Data "quality" is used in several different contexts in remote sensing data, with quite different meanings. At the pixel level, quality typically refers to a quality control process exercised by the processing algorithm, not an explicit declaration of accuracy or precision. File level quality is usually a statistical summary of the pixel-level quality but is of doubtful use for scenes covering large areal extents. Quality at the dataset or product level, on the other hand, usually refers to how accurately the dataset is believed to represent the physical quantities it purports to measure. This assessment often bears but an indirect relationship at best to pixel level quality. In addition to ambiguity at different levels of granularity, ambiguity is endemic within levels. Pixel-level quality terms vary widely, as do recommendations for use of these flags. At the dataset/product level, quality for low-resolution gridded products is often extrapolated from validation campaigns using high spatial resolution swath data, a suspect practice at best. Making use of quality at all levels is complicated by the dependence on application needs. We will present examples of the various meanings of quality in remote sensing data and possible ways forward toward a more unified and usable quality framework.

Lynnes, Christopher↗
DOE OSTI2024

PV Performance Modeling and Stakeholder Engagement (Final Technical Report)

This core capability project’s objective is to increase the value of photovoltaic (PV) performance models by improving their functionality, demonstrating, and quantifying their validity, and offering a wide range of stakeholder engagement opportunities. In FY22-24, we developed new and improved modeling algorithms and functions to represent PV performance more accurately in a variety of environments and conditions. The “Model parameter toolkit” was developed and includes functions to translate between different module temperature models, incidence angle modifier models, and single-diode models. A new modeling capability named “PV Atlas” was also developed leveraging Sandia’s High Performance Computing resources. This capability allows us to investigate several questions and provide climate-specific best practices and geographic data files; all these are hosted on an interactive website on Sandia’s GitHub and can be used for training, system optimization, or to provide best practices for uncertainty reduction. For model validation, we published high-quality PV performance, and weather data; these data are well documented, filtered, and processed for quality and include examples on how to run PV simulations. We also developed well documented, standardized methods for validating PV models and ran independent model validation and 2 blind modeling intercomparisons engaging with 49 organizations from 17 countries. We co-led and contributed to a growing, well documented and maintained suite of open-source functions for PV modeling (i.e., the pvlib-python) and we outreached to the PV modeling stakeholders via the PVPMC workshops and web resources. In addition, this project supported US representation and leadership for the International Energy Agency (IEA) PVPS Task 13; specifically, members of our team led and supported 3 subtasks on: 1) Best practices for the optimization of bifacial photovoltaic tracking, 2) Extreme weather events and their multiple impact on PV power plants: Risks, failure mechanisms and mitigation strategies, and 3) Best practice guidelines for the use of economic and technical Key Performance Indicators (KPIs). This project resulted in the publications of 14 peer reviewed journal papers, 37 conference presentations, 6 SAND reports, 5 public datasets and 6 new webpages on the PVPMC website. It supported the release of 13 pvlib-python versions where 28 enhancements were from this PV Performance Modeling project. We co-organized 5 PVPMC workshops in FY22-24 with the participation of 214 unique institutions and around 700 participants. The PVPMC website was redesigned, and its reliability was improved; it receives over 50,000 visitors/year from 202 unique countries.

14 SOLAR ENERGY↗
NASA NTRS1976

Image processing system performance prediction and product quality evaluation

The author has identified the following significant results. A new technique for image processing system performance prediction and product quality evaluation was developed. It was entirely objective, quantitative, and general, and should prove useful in system design and quality control. The technique and its application to determination of quality control procedures for the Earth Resources Technology Satellite NASA Data Processing Facility are described.

Stein, E. K.↗
NASA NTRS2002

An interfaces approach to TES ground data system processing design with the Science Investigator-led Processing System (SIPS)

Developing production-quality software to process the large volumes of scientific data is the responsibility of the TES Ground Data System, which is being developed at the Jet Propulsion Laboratory together with support contractor Raytheon/ITSS. The large data volume and processing requirements of the TES pose significant challenges to the design.

TES TES SIPS↗
NASA NTRS2016

The Quality Control Algorithms Used in the Process of Creating the NASA Kennedy Space Center Lightning Protection System Towers Meteorological Database

The methodology and the results of the quality control (QC) process of the meteorological data from the Lightning Protection System (LPS) towers located at Kennedy Space Center (KSC) launch complex 39B (LC-39B) are documented in this paper. Meteorological data are used to design a launch vehicle, determine operational constraints, and to apply defined constraints on day-of-launch (DOL). In order to properly accomplish these tasks, a representative climatological database of meteorological records is needed because the database needs to represent the climate the vehicle will encounter. Numerous meteorological measurement towers exist at KSC; however, the engineering tasks need measurements at specific heights, some of which can only be provided by a few towers. Other than the LPS towers, Tower 313 is the only tower that provides observations up to 150 m. This tower is located approximately 3.5 km from LC-39B. In addition, data need to be QC'ed to remove erroneous reports that could pollute the results of an engineering analysis, mislead the development of operational constraints, or provide a false image of the atmosphere at the tower's location.

Orcutt, John M.↗
NASA NTRS1988

Continuous Production Of Refractory Microballoons

Continuous process has economic and quality advantages over batch processes. Expected to produce high-quality microballoons at relatively low cost. Continuous hollow-jet process produces microballoons of refractory metal. Microballoon products made by continuous process includes inertial-confinement fusion targets, thermal insulators, lightweight composites, impact absorbers, and containers for hazardous materials.

Schilling, Christopher H.↗
NASA NTRS2006

Role of Process Control in Improving Space Vehicle Safety A Space Shuttle External Tank Example

Developing a safe and reliable space vehicle requires good design and good manufacturing, or in other words "design it right and build it right". A great design can be hard to build or manufacture mainly due to difficulties related to quality. Specifically, process control can be a challenge. As a result, the system suffers from low quality which leads to low reliability and high system risk. The Space Shuttle has experienced some of those cases, but has overcome these difficulties through extensive redesign efforts and process enhancements. One example is the design of the hot gas temperature sensor on the Space Shuttle Main Engine (SSME), which resulted in failure of the sensor in flight and led to a redesign of the sensor. The most recent example is the Space Shuttle External Tank (ET) Thermal Protection System (TPS) reliability issues that contributed to the Columbia accident. As a result, extensive redesign and process enhancement activities have been performed over the last two years to minimize the sensitivities and difficulties of the manual TPS application process.

Safie, Fayssal M.↗
NASA NTRS1971

A graphite/epoxy compression panel for the space shuttle.

Martin Marietta fabricated a hat-section-stiffened compression panel of graphite/epoxy composite that was analyzed to optimize the structural configuration and material distribution. The fabrication processes developed were modified following the appearance of several problems associated with the unique physical properties of the material. Quality control processes were developed, with emphasis in the areas of ultrasonics and X-ray.

Meredith, O. D.↗
NASA NTRS2006

Control of Technology Transfer at JPL

Controlled Technology: 1) Design: preliminary or critical design data, schematics, technical flow charts, SNV code/diagnostics, logic flow diagrams, wirelist, ICDs, detailed specifications or requirements. 2) Development: constraints, computations, configurations, technical analyses, acceptance criteria, anomaly resolution, detailed test plans, detailed technical proposals. 3) Production: process or how-to: assemble, operated, repair, maintain, modify. 4) Manufacturing: technical instructions, specific parts, specific materials, specific qualities, specific processes, specific flow. 5) Operations: how-to operate, contingency or standard operating plans, Ops handbooks. 6) Repair: repair instructions, troubleshooting schemes, detailed schematics. 7) Test: specific procedures, data, analysis, detailed test plan and retest plans, detailed anomaly resolutions, detailed failure causes and corrective actions, troubleshooting, trended test data, flight readiness data. 8) Maintenance: maintenance schedules and plans, methods for regular upkeep, overhaul instructions. 9) Modification: modification instructions, upgrades kit parts, including software

Jet Propulsion Laboratory (JPL)↗
NASA NTRSDate not supplied

Mission Status, On-Orbit Performance, and Lessons Learned of the Global Ecosystem Dynamics Investigation (GEDI) Lidar Laser Transmitters

The Global Ecosystems Dynamics Investigation (GEDI) Lidar, is a global 3-dimensional biomass lidar instrument aboard the International Space Station (ISS) and the Japanese Experiment Module (JEM). Its core mission is to measure the global carbon balance of Earth’s forests with 3 laser transmitters using multi-beam waveform-capture methods. GEDI’s laser transmitter concept was originally funded by NASA Goddard’s Earth Science Technology Office (ESTO) for future Earth Altimetry and Lidar missions ~ 20 years ago, and after a long road of development, the first flight-ready unit was a 10 mJ-class system for GEDI’s ISS-based specifications. Furthermore, no adjustment in drive parameters has been required nor significant decay detected after 4 years of near continuous operation of 3 on-board lasers, which were designed for a 2-year mission. We report on the GEDI laser design process, their on-orbit performance, the major lessons learned, and some critical insight into our in-house flight quality development process that enabled their delivery within budget, schedule, and low risk extended mission life capability.

D. Barry Coyle↗
NASA NTRS2000

Atmospheric Boundary Layer Wind Data During the Period January 1, 1998 Through January 21, 1999 at the Dallas-Fort Worth Airport: Data and Processing - Volume 2

The NASA Langley Research Center's Aircraft Vortex Spacing System (AVOSS) requires accurate winds and turbulence to determine aircraft wake vortex behavior near the ground. Volume 1 described the wind input and quality analysis process. This volume documents the data available during the period January 1998 through January 1999 and the partitioning and concatenation of files for time of day, turbulence, non duplication, cross wind profile quality and ceiling and visibility. It provides the resultant filtered files for the first three partitions as well as identification of ceiling/visibility conditions when they were below 5000 feet and 5 miles respectively. It also includes the wind profile quality flags to permit automatic selection of files for AVOSS application using selected ceiling/visibility and wind profile quality values and flags (or no flags).

Zak, J. Allen↗
NASA NTRS1994

Environmental process improvement feasibility study and demonstration program

This report is the final product of an environmental study conducted by Western Commercial Space Center, Inc. under contract to Tennessee-Calspan Center for Space Transportation and Applied Research. The purpose of this investigation is to accurately document the current environmental and permitting processes associated with commercial space launch activity at Vandenberg AFB, and make recommendations to streamline those processes. The particular areas of interest focus on: identifying applicable Federal, state, and local laws, Department of Defense directives, and Air force regulations; defining the environmental process on Vandenberg AFB and how it relates with other agencies, including Federal and state regulatory agencies; and defining the air quality permit process. Study investigation results are applied to an example Pilot Space Launch Vehicle (PSLV) planning to launch from Vandenberg AFB. The PSLV space hardware is analyzed with respect to environmental and permitting issues associated with vehicle processing, facilities required (existing or new), and launch. The PSLV verified the earlier findings of the study and gave insight into streamlining recommendations.

Martin, Rodger L.↗
NASA NTRS2020

Development of a Display Tool to Quality Control Weather Balloon Data for Space Launch Vehicles Using Python

Continuous atmospheric data analysis is an important factor for space launch vehicle design and operations. The balloon quality control tool was developed by NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NEB) for monitoring quality control processes and verifying the automated flags created on the balloon data sets analyzed. The data sets currently analyzed are comprised of high-resolution and low-resolution balloon data from NASA Kennedy Space Center (KSC), co-located on the United States Air Force’s Eastern range (ER) at the Cape Canaveral Air Force Station. The NEB was tasked to perform a quality assessment of these data sets and needed a tool to confirm the quality control (QC) flags produced from an automated process and add additional QC flags if necessary. This Graphical User Interface (GUI) was developed to visualize all of the data from these balloon sets, display any flags from the automated QC process, and add additional flags to variables if necessary. The GUI was developed in Python 3.6 utilizing different packages available such as pandas for data analysis and manipulation, NumPy for high-performance multidimensional array and tools to compute with and manipulate arrays, Matplotlib for plotting data and Tkinter to build the GUI.

Jessica K Headley↗
NASA NTRS2020

Development of a Display Tool to Quality Control Weather Balloon Data for Space Launch Vehicles

Continuous atmospheric data analysis is an important factor for space launch vehicle design and operations. The balloon quality control tool was developed by NASA’s Marshall Space Flight Center (MSFC) Natural Environments Branch (NEB) for monitoring quality control processes and verifying the automated flags created on the balloon data sets analyzed. The data sets currently analyzed are comprised of high-resolution and low-resolution balloon data from NASA Kennedy Space Center (KSC), co-located on the United States Air Force’s Eastern range (ER) at the Cape Canaveral Air Force Station. The NEB was tasked to perform a quality assessment of these data sets and needed a tool to confirm the quality control (QC) flags produced from an automated process and add additional QC flags if necessary. This Graphical User Interface (GUI) was developed to visualize all of the data from these balloon sets, display any flags from the automated QC process, and add additional flags to variables if necessary. The GUI was developed in Python 3.6 utilizing different packages available such as pandas for data analysis and manipulation, NumPy for high-performance multidimensional array and tools to compute with and manipulate arrays, Matplotlib for plotting data and Tkinter to build the GUI.

Jessica K Headley↗