- API data.nasa.gov | Last Updated 2018-07-19T18:48:10.000Z
Under this and several other programs, CTD has developed TEMBO<SUP>REG</SUP> deployable solid-surface reflectors (TEMBO<SUP>REG</SUP> Reflectors) to provide future NASA and Air Force missions and commercial communications satellites with large RF apertures that can operate at very high operational frequencies (Ka band and above). TEMBO<SUP>REG</SUP> Reflectors incorporate non-tensioned graphite composite membranes that are formed using conventional construction techniques and stiffened using CTD's TEMBO<SUP>REG</SUP> shape-memory composite panels to allow practical packaging and deployment without complex mechanisms. The simplicity of the design provides a significant cost advantage when compared to existing deployable reflector technologies, (4-fold cost reduction over mesh antenna and 2-fold reduction in manufacturing time) and the continuous graphite surface enables high frequency antenna operations at Ka band and above. CTD can stow either a Cassegrainian (center-fed) or Gregorian (offset-fed) 5m TEMBO<SUP>REG</SUP> Reflectors in a Falcon 1e launch vehicle. To moderate cost and fabrication time, the TEMBO<SUP>REG</SUP> reflector is supported by a deployable backing structure. In the proposed Phase II effort, CTD will further refine innovative backing structure developed in Phase I as well as to develop additional precision capability to enable both the high frequency (Ka band and above), large aperture (5 to 8 meters) performance required for near-term and future NASA programs.
- API data.nasa.gov | Last Updated 2018-07-19T10:45:44.000Z
Decomposing monopropellant hydrazine across a spontaneous catalyst bed is the gold standard for small propulsion systems responsible for attitude control on satellites and spacecraft. Such a propulsion system is both simple and reliable, and offers reasonable performance. However, the simplicity and reliability enjoyed today is the result of a nearly two-decade effort designed to identify and perfect a spontaneous catalyst. Modern hydrazine replacements generally do not work well with hydrazine catalysts, so the enormous costs associated with a new catalyst development effort have stalled the widespread acceptance of potential hydrazine replacements. Our proposed effort will explore the use of an alternative ignition source that eliminates the need for a catalyst bed entirely. It achieves the same simplicity enjoyed by traditional monopropellant propulsion systems, but dramatically increases thruster response time on both startup and especially shutdown. It requires low power because it exploits a unique property of most of the propellants often cited as the future replacement for hydrazine. It is also low cost because it requires a very low part count and development issues will be trivial.
- API data.nasa.gov | Last Updated 2019-04-29T15:22:30.000Z
NARSTO EPA Supersite in Pittsburgh Gac Conc and PM Physical Properties Data
Lightweight, High Strength Metals With Enhanced Radiation Shielding - Technology Advancing Partnerships Challengedata.nasa.gov | Last Updated 2018-07-19T08:02:20.000Z
<p>The Technology Advancing Partnership (TAP) Challenge will seek to foster innovation throughout the Center by allowing the KSC workforce to identify a specific technology idea that needs improvement and to then work with an external partner to develop that technology. This Challenge will enable competitive partnerships with outside entities that will increase the value by bringing leveraged resources. The selected proposal from the University of Florida will develop new lightweight technologies with radiation mitigation for spacecraft. </p> <p>The alloy of interest will be magnesium-based, which will make it 70% lighter than steel and 65% of the density of aluminum, giving it a potential to decrease fuel consumption dramatically. Magnesium (Mg) has been approved by Federal and Joint Aviation standards and NASA standards state that it can be used in areas that are not prone to corrosion. Thus, the proposed applications include the skin or cladding within structural members or on non-oxidizing environments such as Mars. The Europe Commission is investigation the general use of Mg alloys for aerospace applications under the AEROMAG project, which considers the use of Mg as a breakthrough technology.</p><p>The objectives of the research are to 1) develop high strength Mg-based alloys doped with thermal radiation mitigation (neutron-absorbing) elements, 2) characterize their microstructure and mechanical properties, and 3) characterize their radiation shielding efficiency. This work will be carried out at the University of Florida which houses state-of-the-art radiation testing facilities and light metals foundry capability of designing, fabricating, and testing any light weight structural material. The proposed work leverages existing programs supported by the University of Florida, National Science Foundation, and the Department of Energy.</p><p>The results of this work are not only expected to elucidate fundamental radiation shielding mechanisms inherent to doped Mg alloys but also explore the opportunity to integrate Mg into non-critical members, thus potentially creating a new area of research and center of excellence for NASA Kennedy Space Center.</p>
- API data.nasa.gov | Last Updated 2018-07-19T17:52:06.000Z
Distributed prognostics architecture design is an enabling step for efficient implementation of health management systems. A major challenge encountered in such design is formulation of optimal distributed prognostics algorithms. In this paper, we present a distributed GPR based prognostics algorithm whose target platform is a wireless sensor network. In addition to challenges encountered in a distributed implementation, a wireless network poses constraints on communication patterns, thereby making the problem more challenging. The prognostics application that was used to demonstrate our new algorithms is battery prognostics. In order to present trade-offs within different prognostic approaches, we present comparison with the distributed implementation of a particle filter based prognostics for the same battery data.
- API data.nasa.gov | Last Updated 2019-06-24T15:17:43.000Z
TES Level 2 data contain retrieved species (or temperature) profiles at the observation targets and the estimated errors. The geolocation, quality and other data (e.g., surface characteristics for nadir observations) are also provided. L2 modeled spectra are evaluated using radiative transfer modeling algorithms. The process, referred to as retrieval, compares observed spectra to the modeled spectra and iteratively updates the atmospheric parameters. L2 standard product files include information for one molecular species (or temperature) for an entire global survey or special observation run. A global survey consists of a maximum of 16 consecutive orbits. A Nadir sequence within the TES Global Survey is a fixed number of observations within an orbit for a Global Survey. Prior to April 24, 2005, it consisted of two low resolution scans over the same ground locations. After April 24, 2005, Global Survey data consisted of three low resolution scans. The Nadir standard product consists of four files, where each file is composed of the Global Survey Nadir observations from one of four focal planes for a single orbit, i.e. 72 orbit sequences. The Global Survey Nadir observations currently only use a single set of filter mix. A Global Survey consists of observations along 16 consecutive orbits at the start of a two day cycle, over which 3,200 retrievals are performed. Each observation is the input for retrievals of species Volume Mixing Ratios (VMR), temperature profiles, surface temperature and other data parameters with associated pressure levels, precision, total error, vertical resolution, total column density and other diagnostic quantities. Each TES Level 2 standard product reports information in a swath format conforming to the HDF-EOS Aura File Format Guidelines. Each Swath object is bounded by the number of observations in a global survey and a predefined set of pressure levels representing slices through the atmosphere. Each standard product can have a variable number of observations depending upon the Global Survey configuration and whether averaging is employed. Also, missing or bad retrievals are not reported. The organization of data within the Swath object is based on a superset of the UARS pressure levels used to report concentrations of trace atmospheric gases. The reporting grid is the same pressure grid used for modeling. There are 67 reporting levels from 1211.53 hPa, which allows for very high surface pressure conditions, to 0.1 hPa, about 65 km. In addition, the products will report values directly at the surface when possible or at the observed cloud top level. Thus in the Standard Product files each observation can potentially contain estimates for the concentration of a particular molecule at 67 different pressure levels within the atmosphere. However, for most retrieved profiles, the highest pressure levels are not observed due to a surface at lower pressure or cloud obscuration. For pressure levels corresponding to altitudes below the cloud top or surface, where measurements were not possible, a fill value will be applied. Details of the format of this product can be found in the TES Data Products Specifications (DPS) which is available from the LaRC ASDC site: https://eosweb.larc.nasa.gov/project/tes/DPS To minimize the duplication of information between the individual species standard products, data fields common to each species (such as spacecraft coordinates, emissivities, and other data fields) have been collected into a separate standard product, termed the TES L2 Ancillary Data product (ESDT short name: TL2ANC). Users of this product should also obtain the Ancillary Data product.
- API data.nasa.gov | Last Updated 2018-07-19T08:15:45.000Z
A Narloy-Z-diamond particulate composite providing increased thermal conductivity and light weight will be developed for use in liners for liquid rocket engine thrust chamber designs at similar cost to NarloyZ. Shortcomings of previous copper-diamond products have been poor resistance to thermal cycling and high cost. In the current work, attention will be given to developing a strong, chemically bonded metallurgical interface between the copper alloy and diamond phases to resist thermal cycle damage under operational conditions for the thrust chamber
- API data.nasa.gov | Last Updated 2018-07-19T18:23:13.000Z
Advanced bipropellant engines are needed for ARES/ORION vehicle maneuvering and future deep space science missions. Currently, an iridium-lined rhenium combustion chamber is the state-of-the-art for in-space propulsion applications. An example of an in-space engine that incorporates an iridium-lined rhenium thruster is Aerojet's HiPAT apogee engine. This engine uses monomethyl-hydrazine (MMH, CH3N2H3) as fuel and nitrogen tetroxide (N2O4, specifically MON-3) as oxidizer. To increase performance of bipropellant engines, improved chamber materials are needed that will allow higher operating conditions (pressure and temperature) and better resistance to oxidation. Therefore, Plasma Processes, Inc. and its partner, Aerojet, propose to develop hafnium oxide-iridium lined rhenium combustion chambers that will simplify engine design and allow higher operating conditions. As a result, a lower cost, higher performance bipropellant space engine will be produced.
- API data.nasa.gov | Last Updated 2018-07-19T07:18:17.000Z
<p>AMMOS provides multi-mission operations, navigation, design, and training tools for Planetary Science flight missions, and undertakes technology investments for improved communications and navigation technologies. A portion of the AMMOS budget supports AMMOS Technology, which funds "Focused Technology," defined as technology that has a high likelihood of being infused into the AMMOS System.<p/><p>AMMOS Technology tasks include: - Enhance mission planning and sequence generation tools with constraint based automated planning and scheduling techniques to enable greater levels of ground automation. - Demonstration of automated mission planning for tactical surface operations - Developing a multi-objective optimization tool for use in science planning for complex observatory scheduling. - An automated method to diagnose spacecraft systems from telemetry, generating models from standard test data and system documentation only - Develop Level 2 data product creation framework for producing atmospheric profiles. The framework will be multimission and will allow subsequent missions to leverage on the implementations of previous missions - Automatic analysis discovers near-invisible signals and rapidly drafts maps of surface materials Develop Orbital stability analysis algorithms, mean element orbit control/sizing algorithms - Develop flexible, reactive, multimission â€œsmartâ€ executive for AutoNav/AutoGNC - Develop algorithms to optimize the time of finite burns within a multi-body gravity field. - Develop tools and a handbook to quickly survey and generate low-energy transfers between the Earth and Moon, including transfers to low lunar orbits and three-body orbits. - Develop a strategy using an optimal sequence of flybys and observations to do rapid characterization (shape, gravity, and environment) of small bodies (including binaries) without entering orbit or placing the S/C into an unstable state</p>
- API data.nasa.gov | Last Updated 2018-07-18T19:51:19.000Z
High substrate costs, as well as weight, typically play a major role in the high costs of multijunction space solar cell production and deployment. III-V/Si multijunction structures provide a potential solution to this through the use of an exceptionally inexpensive (and lightweight) substrate that also serves as an active cell component, combined with a III-V semiconductor stack tailored to space PV needs to provide high efficiency. Already, GaP/Si has been demonstrated in MBE and MOCVD growth modes, with dual junction cells for terrestrial application under development. This proposed work seeks to generate optimized III-V/Si structures for space power generation. Using prior knowledge of terrestrial photovoltaics efforts in III-V/Si technology, my goal is to adapt these dual junction (and ultimately triple junction) devices for space deployment via tailoring the bandgaps of the III-V component(s) for optimized AM0 absorption, and addressing radiation hardness issues with silicon. With the right composition of GaAsyP1-y and (AlzGa1-z)xIn1-xP alloys on silicon, maximum efficiencies under AM0 are calculated to be ~41% and ~45% for the dual and triple junction cells respectively. A significant part of this optimization process will involve investigation of metamorphic materials required to join the GaP lattice constant to the targeted GaAsyP1-y and (AlzGa1-z)xIn1-xP alloys, enabling the optimum composition/bandgaps for dual junction and triple junction devices. Metamorphic materials encompass many forms of crystalline defects which, above certain levels, greatly hinder device performance and effectiveness. Aside from normal characterization methods, including: photoluminescence spectroscopy (PL), Hall mobility, high-resolution triple-axis X-ray diffraction (XRD), and transport measurements (I-V, C-V, etc.), I will use a novel characterization technique, electron channeling contrast imaging (ECCI), to quantify defect populations and behaviors within these metamorphic materials. This work, being traditionally performed in plan-view TEM, will be significantly expedited due to the use of ECCI, which requires minimal sample preparation and avoids destroying a device. Thus, it will allow a less hindered development of defect mitigated metamorphic materials, allowing devices to more closely approach their theoretical efficiencies. A supporting task of this research will also be to optimize the GaP/Si bottom cell for space deployment. Radiation hardness remains an issue, though I will investigate the potential benefits and demerits of utilizing thin-Si to mitigate these issues. Radiation studies will be used to understand how to design the Si bottom cell around these potential problems. Another part of this research will be focused on device growth via MBE and MOCVD, first demonstrating space-optimized dual junction III-V/Si cells, and later developing triple junction cells. Holistic device design will be guided by physics-based modeling using technology computer aided design (TCAD) software. Individual components and entire devices will be modeled using up-to-date empirical materials properties data, dislocation aspects garnered from the metamorphic material characterization, and full testing results (e.g. DIV, LIV, QE, etc.) in an iterative developmental cycle, resulting in the realization of dual and triple junction III-V/Si photovoltaics optimized to efficiently generate solar power in space, while keeping costs of production and deployment low.