- API data.nasa.gov | Last Updated 2020-01-29T04:19:52.000Z
Advanced Cooling Technologies, Inc. (ACT) proposes to develop a low-cost Loop Heat Pipe (LHP) evaporator using a technique known as Direct Metal Laser Sintering (DMLS), otherwise known as 3D printing, to produce low-cost LHPs to be used in CubeSat and SmallSat applications. The wick structure in an LHP assumes the role of a pump in a standard loop, pumping liquid from the lower pressure condenser to the higher pressure evaporator by capillary forces. The overall thermal performance of the system is therefore highly dependent on the in-situ characteristics of the wick structure. Current LHP wick manufacturing and installation processes are cumbersome, labor intensive, and suffer from a low yield rate. Specifically, the primary wick's hydrodynamic characteristics and sealing integrity to the envelope are critical to heat transport, start-up, shut down and overall reliability. It is estimated that the cost to produce an LHP evaporator, including the attachment of the bayonet, secondary wick and compensation chamber, accounts for approximately 75% of the total system's manufacturing cost. By 3D printing an evaporator envelope with an integral porous primary wick structure, the overall complexity and cost of the design can be significantly reduced.
- API data.nasa.gov | Last Updated 2020-01-29T04:59:06.000Z
Gradient metal alloy structures possess multi-functional properties that conventional monolithic metal counterparts do not have. Such structures can potentially change the paradigm of material selections and mechanical designs to enable more efficient space vehicles to be built. Existing laser-based additive manufacturing techniques for gradient metal alloy fabrication suffer from the following two major drawbacks: high system cost and slow printing speed. In this proposal, AlphaSense details the development of a novel 3D printer for the fabrications of gradient metal alloy structures. Key innovations of this proposal include the following: a) The fabrication of gradient metal alloy parts using low-cost resin as starting materials, b) The development of novel printing suspensions containing micro-/nano- sized metal particles and photo-curable resins to fabricate the green parts, and c) The application of a Digital Light Processing (DLP) projector for simultaneous layer exposure. With such innovations, the merits of the proposed 3D printing method for metal part fabrication include the following: a) Low fabrication cost, b) High printing speed, c) Superior printing quality, d) Easy to scale up and e) Easy and well-controlled process.
- API data.nasa.gov | Last Updated 2020-01-29T02:13:09.000Z
Fault to Failure Progression (FFP) signature modeling and processing is a new method for applying condition-based signal data to detect degradation, to identify fault modes, and to produce system estimates for State of Health (SoH) and Remaining Useful Life (RUL). The base technology has been applied for prognostic purposes for various government-sponsored programs, but FFP signature modeling and processing has not been applied for the area of Fault Management, nor does it include such features as fault dictionaries, lookup tables, and management algorithms. The technology includes Ridgetop-designed and developed algorithms to do the following: (1) perform Kalman Filtering to reduce noise; (2) transform sensor signal data to reveal underlying (hidden) FFP signatures; (3) normalize units-of-measure dependent signal data into dimensionless FFP signatures to facilitate re-use and reduce the time to characterize and define new FFP signatures; (4) define and use model definitions that reduce memory requirements and support fast and accurate processing and calculations; (5) two forms of trajectory curve characterization, both straight-line and curvilinear; (6) a fast yet accurate, graphics-based mathematical routine to adapt an FFP model to received data; (7) amplitude and time updates similar to Extended Kalman Filtering to estimate how long it will take an adapted FFP model to reach a defined failure threshold; and (8) produce SoH and RUL estimates that rapidly converge to the estimated time-to-failure (TTF) solution. The FFP signature modeling and processing will include additional innovation to support FM to minimize application-specific programming, those include algorithms to simplify fault identification and isolation.
- API data.nasa.gov | Last Updated 2019-12-12T23:59:40.000Z
The Cloud Properties Level-3 gridded product is designed to facilitate continuity in cloud property statistics between the MODIS on the Aqua and Terra platforms and the common continuity products generated for the VIIRS (Visible Infrared Imaging Radiometer Suite) and the MODIS Aqua instruments. CLDPROP Level-3 statistical routines include scalar and histograms (1-D and 2-D) that are calculated identically to statistical datasets in the MODIS standard Level-3 product (MOD08 and MYD08 for MODIS Terra and Aqua, respectively). In addition, the same dataset names are used for all common datasets provided in both the continuity and standard Level-3 files.
- API data.nasa.gov | Last Updated 2020-01-29T01:54:30.000Z
<p>The Global Aerosol Measurement System (GAMS) project is developing a new, low cost satellite capability for measuring the properties and distributions of particles in the upper troposphere and lower stratosphere (collectively, the UTLS). This altitude region is important because there have been observed increases in the amount of particles in the UTLS. These particles typically reflect sunlight back into space and cool the Earth. GAMS will measure the altitudes and amounts of these particles by looking to the side of the spacecraft, through the thickness of Earth’s atmosphere, and provide detailed information about how particles are changing in the UTLS.</p><p>The goal of the Global Aerosol Measurement System (GAMS) project is to develop needed technologies and observation strategies to optimally measure the distributions and properties of particles in the upper troposphere and lower stratosphere (UTLS). The GAMS concept is based on the limb-scattering measurement techniques used on past sensors, most directly from the heritage of the Ozone Mapping and Profiling Suite (OMPS) Limb Profiler (LP) currently flying on board the Suomi National Polar-orbiting Partnership (NPP) spacecraft. OMPS-LP was launched on Suomi NPP in 2011, with the next planned launch of this instrument in 2022 on the next generation Joint Polar Satellite System-2 (JPSS-2). Because of the length of time between the NPP and JPSS-2 launches there is the potential for a significant data gap for these important measurements. The GAMS concept is intended to be a simple and low cost measurement system that could be ready to fill such a gap.</p><p> </p><p>The current OMPS-LP system measures light reflected by particles in the UTLS by looking behind the Suomi NPP path, looking through the thickness of Earth’s atmosphere (i.e., the limb). Although OMPS-LP has proven capable of detecting the presence of background particles in the UTLS, as well as particles from volcanic eruptions and meteorites entering Earth’s atmosphere from space, it has very limited spatial coverage and suffers from sensitivity issues since it preferentially sees particles in one direct with respect to the sun. GAMS seeks to overcome both limitations by making measurements of reflected light In two or more directions relative to the spacecraft flight. Because GAMS focuses only on the limb profiling capabilities (versus the more comprehensive but more complicated OMPS system) it can be contained in a relatively smaller spacecraft, which will reduce deployment costs. Additional increased spatial coverage can be realized by flying multiple copies of the GAMS instrument in different orbits.</p><p> </p><p>In this stage of the GAMS project we are working to develop capabilities for adding additional spectral channels to our detector system. We initially targeting 350 nm for altitude registration and 675 nm for aerosol detection. We are now developing an extension to include an additional channel at 1020 nm for aerosol detection. This channel will provide additional sensitivity to aerosol in the lower stratosphere, provides heritage overlap with other sensors (e.g., SAGE), and paired with the 675 nm channel provides additional information to recover other aspects of the aerosol distribution (e.g., particle size). We are additionally developing an observation simulator based on model output from the NASA Goddard Earth Observing System (GEOS-5) atmospheric model. This will allow us to prototype assimilation methodologies to ingest the eventual GAMS observations into aerosol prediction models.</p>
Voluntary Consensus Organization Standards for Nondestructive Evaluation of Aerospace Materials (including Additive Manufactured Parts)data.nasa.gov | Last Updated 2020-01-29T03:14:48.000Z
<p>This NASA-industry effort accomplishes the following:</p><p>1) Lead collaboration between NASA Centers, other government agencies, industry, academia, and voluntary census organizations (ASTM Committees E07 on Nondestructive Testing, F42 on Additive Manufacturing (AM) Technologies, and ISO Technical Committee (TC) 261) to develop national standards for NDE of aerospace materials used in NASA/aerospace applications.</p><p>2) Lead a leveraged interlaboratory study (ILS) to develop NDE for qualification and certification of AM parts.</p><p>3) Lead ASTM E07 development and periodic revision of flat panel polymer matrix composite (PMC) standards: ASTM E2533 (Guide) , E2580 (ultrasonic testing (UT) , E2581 (shearography) , E2582 (flash thermography) , E2661 (acoustic emission) , E2662 (radiographic testing (RT)) , and draft work item WK40707 (active thermography).</p><p>4) Lead periodic revision of composite overwrapped pressure vessel (COPV) standards: E2981 (overwrap)  and ASTM E2982 (liner) .</p><p>5) Develop a new NDE of AM Guide (ASTM WK47031) .</p><p>6) Develop a new eddy current test (ECT)-UT-profilometer standard practice or test method for fracture control of metal parts using 90/95 Probability of Detection (POD) of critical initial flaws sizes in metal parts (TBD).</p><p>7) Respond to NASA Office of Safety and Mission Assurance (OSMA) and NASA Space Technology Mission Directorate (STMD) requests as needed (e.g., AM, advanced manufacturing, counterfeit parts and ESA/JAXA collaboration).</p><p>The historical standards development time line (Items 3 through 6) is shown in <strong>Figure 1</strong>. The WK47031 effort (Item 5) constitutes the bulk of the present focus and capitalizes on momentum created by the release of the FY14 <em>Nondestructive Evaluation of Additive Manufacturing</em> <em>State-of-the-Discipline Report </em>(NASA-TM-218560) . The ultimate goal vis-à-vis WK47031 is to determine the effect-of-defect of specific seeded flaw types while determining detection thresholds using controlled embedded features. A portion of this effort also dovetails with the NASA Engineering and Safety Center (NESC) Universal ECT-UT-Profilometer Scanner project.</p> <p><strong>Background:</strong> One of the main obstacles slowing the acceptance and use of advanced materials (e.g., PMCs, COPVs and AM parts) in NASA and commercial space applications is the lack of a broadly accepted materials and process quality systems, including sensitive NDE procedures with well-defined accept-reject criteria. Matching VCO standards are also needed to ensure process and equipment control, finished part quality and consistent inspection methodologies for finished parts after manufacturing and after installation of parts in service. In AM, the possibility to ‘design to constraint’ offers a paradigm shift opening the door to make parts with shorter production lead times, less waste, improved cost, maximized properties, and reduced weight. However, to fully realize the merits of this and other advanced processing technologies, and to ensure parts of the highest quality end up in NASA/aerospace applications, new approaches to for in-situ monitoring NDE used during manufacturing, post-process NDE used on as-build and finished parts are needed. In AM, for example, NDE procedures must be able to detect flaw types (<strong>Figure 2</strong>), many of which are not found in cast, wrought or conventionally welded parts (<strong>Figure 3</strong>). Deeply embedded porosity, complex part geometry, and intricate internal features (e.g., lattice structures) impose additional challenges on conventional NDE.</p><p> </p><p><strong>Technical Approach: </strong> In the WK47031 effort (<strong>Figure 4</strong>), a NASA-led interlaboratory study (ILS) is currently being conducted to identify and refine NDE for inspection of AM aerospace parts. This effort is spread across g
- API data.nasa.gov | Last Updated 2020-01-29T02:13:20.000Z
Given that SysML is becoming a standard for model-based systems engineering and Integration (SE&I), system health management (SHM)-related models will either be done in SysML, or be done outside of SysML but enabled by conversion, mapping, and traceability of information across SysML and SHM models. Given that current implementations of SysML are not particularly useful to perform analyses, and that SHM analyses are not identical to typical SE&I-related analyses, there will need to be connectivity between SysML representations and SHM models that perform SHM-related analyses. Qualtech Systems, Inc. (QSI), with Dr. Stephen Johnson as a consultant intends to explore and develop the integration of model-based systems engineering and Integration (SE&I) using SysML with system health management (SHM) modeling and analysis using QSI's Testability Engineering and Maintenance System (TEAMS). An overarching objective of this proposal is to reduce the duplicative and disjoint effort by NASA's subject matter experts in the development of systems engineering and design models as well as systems health management/fault management models. The intent is to leverage the success space or intent based system design models and transform them for developing fault management models and ensuring changes in design have a natural flow-through to the FM domain, thereby keeping FM models in sync with the design through a semi-automated process. This is one step in the larger set of issues that will need to be addressed in the development of the model-based Discipline of Systems Engineering and its concurrent integration with SHM to achieve higher-quality designs while reducing the costs of SE&I.
- API data.nasa.gov | Last Updated 2020-01-29T02:03:18.000Z
Galileo Orbiter Magnetometer (MAG) calibrated high-resolution data from the Earth-1 flyby in spacecraft, GSE, and GSM coordinates. These data cover the interval 1990-11-05 to 1990-12-31.
- API data.nasa.gov | Last Updated 2020-01-29T03:49:18.000Z
High-power electric propulsion with Hall thrusters has been proposed as a strong candidate for Electric Path missions, but conventional power processing units (PPUs) are complicated and the mass of the discharge power converters needs to be reduced. Direct Discharge Power Processing Units (DDUs) have been proposed as an alternative due to their simplicity and low mass, but the achievable operating range of thrust and ISP is significantly limited because power regulation for DDUs is only achieved through gas flow control, array offpointing or shunting. This proposal presents a compromise between PPUs and DDUs called a Hybrid Direct Drive Power Processing Unit (HDDU) that provides a wider operating range than DDUs while reducing the mass and increasing the efficiency compared to conventional PPUs. An HDDU provides filtering like a DDU, but it can additionally raise or lower the discharge voltage over a limited range. An HDDU only processes the power necessary to raise or lower the discharge voltage. We propose using a soft switching non-inverting interleaved buck-boost circuit similar to what was built for Phase I, but with improved control circuitry and a modular chassis. Straight-through direct drive operation is possible by leaving the buck switches on continually while having the boost switches off. The proposed HDDU would operate from an input voltage of 150 V to 300 V, and would provide 15 kW output power from approximately 200 V to 500 V. The HDDU approach is readily scalable to higher power levels by connecting modules in parallel because the proposed circuit naturally shares output currents. The HDDU will also include a digital control interface unit (DCIU), heater, keeper and magnet supply modules and driving circuits for a VACCO gas flow controller. The DCIU will be controlled through a Windows GUI and a MIL-STD-1553 communication to USB adapter. The modular approach and enhanced operating range promote design re-use and reduce life-cycle costs.
CERES and GEO-Enhanced TOA, Within-Atmosphere and Surface Fluxes, Clouds and Aerosols Monthly-Averaged 1-Hourly Terra-Aqua Edition4Adata.nasa.gov | Last Updated 2019-12-12T23:51:39.000Z
The CERES SYN1deg products provide CERES-observed temporally interpolated top-of-atmosphere (TOA) radiative fluxes and coincident MODIS-derived cloud and aerosol properties and include geostationary-derived cloud properties and broadband fluxes that have been carefully normalized with CERES fluxes in order to maintain the CERES calibration. They also contain computed initial TOA, in-atmosphere, and surface fluxes and computed fluxes that have been adjusted or constrained to the CERES-observed TOA fluxes. The computed fluxes are produced using the Langley Fu-Liou radiative transfer model. Computations use MODIS and geostationary satellite cloud properties along with atmospheric profiles provided by GMAO. The adjustments to clouds and atmospheric properties are also provided. The computations are made for all-sky, clear-sky, pristine (clear-sky without aerosols), and all-sky without aerosol conditions. This product provides parameters on a monthly-averaged one-hourly temporal resolution and 1°-regional spatial scales. Fluxes are provided for clear-sky and all-sky conditions in the longwave (LW), shortwave (SW), and window (WN) regions. The CERES SYN1deg products use 1-hourly radiances and cloud property data from geostationary (GEO) imagers to more accurately model variability between CERES observations. To use GEO data to enhance diurnal sampling, several steps are involved. First, GEO radiances are cross-calibrated with the MODIS imager using only data that is coincident in time and ray-matched in angle. Next, the GEO cloud retrievals are inferred from the calibrated GEO radiances. The GEO radiances are converted from narrowband to broadband using empirical regressions and then to broadband GEO TOA fluxes using ADMs and directional models. To ensure GEO and CERES TOA fluxes are consistent, a normalization technique is used. Instantaneous matched gridded fluxes from CERES and GEO are regressed against one another over a month from 5°x5 ° latitude-longitude regions. The regression relation is then applied to all GEO fluxes to remove biases that depend upon cloud amount, solar and view zenith angles, and regional dependencies. The regional means are determined for 1° equal-angle grid boxes calculated by first interpolating each parameter for any missing times of the CERES/GEO observations to produce a complete 1-hourly time series for the month. Monthly means are calculated using the combination of observed and interpolated parameters from all days containing at least one CERES observation. Clouds and the Earth's Radiant Energy Systems (CERES) is a key component of the Earth Observing System (EOS) program. The CERES instruments provide radiometric measurements of the Earth's atmosphere from three broadband channels. The CERES missions are a follow-on to the successful Earth Radiation Budget Experiment (ERBE) mission. The first CERES instrument (PFM) was launched on November 27, 1997 as part of the Tropical Rainfall Measuring Mission (TRMM). Two CERES instruments (FM1 and FM2) were launched into polar orbit on board the EOS flagship Terra on December 18, 1999. Two additional CERES instruments (FM3 and FM4) were launched on board EOS Aqua on May 4, 2002. The newest CERES instrument (FM5) was launched on board the Suomi National Polar-orbiting Partnership (NPP) satellite on October 28, 2011.