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- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:30:45.000Z
In the proposed Phase I program, Busek Co. will demonstrate an innovative methodology for clustering Hall thrusters into a high performance, very high power propulsion system. The concept uses multiple thruster discharge assemblies with a common (shared) magnetic structure. The concept combines the benefits of clustering that include modularity, reliability, reduced beam divergence and throttleability with the cost, mass savings and power loss reduction of a shared magnetic structure. In Phase I, Busek will conduct a sub-scale demonstration of a shared magnetics cluster based on our existing BHT-600 (nominally 600 W input power) Hall thruster. A methodology for shared magnetics clustering will be developed that can be applied to the full range of Hall thruster power requirements (100 kW ? 1 MW) envisioned by NASA for obit insertion, planetary transfers and manned exploration. In Phase II a 200 ? 400 kW shared magnetics thruster based on NASA's existing high power Hall thruster technology will be designed and built. Busek is uniquely positioned to implement the proposed program having expertise in both the clustering of Hall thrusters and shared magnetics thruster development.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:44:06.000Z
Software is an integral part of many complex embedded systems, such as avionics, scientific exploration, and on-board systems. However, poor software reliability is a major impediment to the success of these mission-critical systems. Testing, formal verification, and code synthesis techniques have been proposed to achieve more reliable software, with automated code synthesis being the most promising method. But synthesizing a complex system from scratch is costly. A more practical approach is to synthesize systems from existing components, i.e., component-based system synthesis (CBSS). Existing research in CBSS focuses on synthesizing systems bottom-up, which has severe limitations. We propose to achieve CBSS by combining the top-down and bottom-up approaches. Specifically, we develop techniques to achieve automated system decomposition and semi-automated system architecture synthesis. The IDEAL decomposition technique decomposes a system into ``IDEAL'' units that are mathematically composable and can be developed and evolved independently. Consequently, the technique assures system reliability and enables on-the-fly feature/technology upgrades. The QoS-based architecture synthesis technique seeks to assure system QoS properties by synthesizing an architecture that optimizes QoS objectives. It also facilitates on-board system adaptation due to resource and power constraints. Combined with bottom-up techniques, such as Amphion and pattern-based code synthesis, a dramatic leap in automated CBSS capability can be achieved. The proposed research will lead to sophisticated automation for synthesizing highly reliable, multi-mission capable avionics and exploration systems.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:31:39.000Z
Many of NASA's exploration scenarios include important roles for autonomous or partially autonomous robots. It is desirable for them to utilize human tools when possible, rather than needing to build custom tools for each robot. Control of robotic manipulators for tool usage generally requires a very precise Cartesian-space trajectory of the tool tip (e.g., moving a marker along the surface of a whiteboard or rotating a screwdriver about an axis). Well-known techniques exist for manipulator control in Cartesian space, most of which necessitate solving a series of Inverse Kinematics (IK) problems. Closed-form IK solvers work well for 7-degree-of-freedom (DOF) arms with rigid tool attachments, but cannot handle non-rigid tools that slip in the robot's hands. Numerical IK approaches are more generic and can handle non-rigid links to tools, but can be slow to converge. More importantly, if any joints fail or become limited in their range of motion, the robot arm essentially becomes 6-DOF or lower. IK solvers often fail in these lower DOF spaces because the configuration space becomes non-continuous and full of "holes". As a result, a 7-DOF robotic arm in space might be rendered largely useless if a single joint fails or even loses mobility until it can be serviced. TRACLabs proposes to investigate an alternative approach to traditional Cartesian control approaches, which rely on complex IK solvers that go from Cartesian space backwards to joint space. We propose to leverage cheap memory and modern processing speeds to instead perform simple computations that go from joint space forwards to Cartesian space. Such techniques should overcome common changes to a manipulation chain caused by tool slippage or the grasping of a new tool and to overcome uncommon changes to a chain caused by joint failures, reduced joint mobility, changes in joint geometry or range of motion, or added joints.
Nimbus-5 Electrically Scanning Microwave Radiometer (ESMR) Imagery of Brightness Temperature on 70 mm Film V001nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T04:56:30.000Z
The ESMRN5IM data product consists of daily brightness temperature images on 70-mm photofacsimile film. Each frame contains a geographic grid and two groups of three parallel strips of imagery, each containing one-half the orbital data. The spatial coverage is identical in each group, but each strip has a different dynamic range for its gray scale: 100-200 K, 190-270 K, and 250-300 K, respectively. The spatial resolution is 25 x 25 km near nadir, degrading to 160 km cross-track by 45 km down-track at the ends of the scan. The images are saved as JPEG 2000 digital files. About 2 weeks of images are archived into a TAR file. Additional information can be found in "The Nimbus 5 User's Guide." The primary objectives of the Nimbus 5 Electrically Scanning Microwave Radiometer (ESMR) were: (1) to derive the liquid water content of clouds from brightness temperatures over oceans, (2) to observe differences between sea ice and the open sea over the polar caps, and (3) to test the feasibility of inferring surface composition and soil moisture. To accomplish these objectives, the ESMR was capable of continuous global mapping of the 1.55-cm (19.36 GHz) microwave radiation emitted by the earth/atmosphere system, and could function even in the presence of cloud conditions that block conventional satellite infrared sensors. The ESMR experiment made measurements from Dec. 11, 1972 until May 16, 1977.These images can be used to supplement the radiance data files from the ESMRN5L2 data product.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T08:49:10.000Z
These data are the Goddard Satellite-based Surface Turbulent Fluxes Version-2c (GSSTF2c) Dataset recently produced through a MEaSUREs funded project led by Dr. Chung-Lin Shie (UMBC/GEST, NASA/GSFC), converted to HDF-EOS5 format. The stewardship of this HDF-EOS5 dataset is part of the MEaSUREs project, http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects/surface-turbulent-fluxes-esdr http://earthdata.nasa.gov/our-community/community-data-system-programs/measures-projects GSSTF version 2b (Shie et al. 2010, Shie et al. 2009) generally agreed better with available ship measurements obtained from several field experiments in 1999 than GSSTF2 (Chou et al. 2003) did in all three flux components, i.e., latent heat flux [LHF], sensible heat flux [SHF], and wind stress [WST] (Shie 2010a,b). GSSTF2b was also found favorable, particularly for LHF and SHF, in an intercomparison study that accessed eleven products of ocean surface turbulent fluxes, in which GSSTF2 and GSSTF2b were also included (Brunke et al. 2011). However, a temporal trend appeared in the globally averaged LHF of GSSTF2b, particularly post year 2000. Shie (2010a,b) attributed the LHF trend to the trends originally found in the globally averaged SSM/I Tb's, i.e., Tb(19v), Tb(19h), Tb(22v) and Tb(37v), which were used to retrieve the GSSTF2b bottom-layer (the lowest atmospheric 500 meter layer) precipitable water [WB], then the surface specific humidity [Qa], and subsequently LHF. The SSM/I Tb's trends were recently found mainly due to the variations/trends of Earth incidence angle (EIA) in the SSM/I satellites (Hilburn and Shie 2011a,b). They have further developed an algorithm properly resolving the EIA problem and successfully reproducing the corrected Tb's by genuinely removing the "artifactitious" trends. An upgraded production of GSSTF2c (Shie et al. 2011) using the corrected Tb's has been completed very recently. GSSTF2c shows a significant improvement in the resultant WB, and subsequently the retrieved LHF - the temporal trends of WB and LHF are greatly reduced after the proper adjustments/treatments in the SSM/I Tb's (Shie and Hilburn 2011). In closing, we believe that the insightful "Rice Cooker Theory" by Shie (2010a,b), i.e., "To produce a good and trustworthy 'output product' (delicious 'cooked rice') depends not only on a well-functioned 'model/algorithm' ('rice cooker'), but also on a genuine and reliable 'input data' ('raw rice') with good quality" should help us better comprehend the impact of the improved Tb on the subsequently retrieved LHF of GSSTF2c. This is the Daily (24-hour) product; data are projected to equidistant Grid that covers the globe at 1x1 degree cell size, resulting in data arrays of 360x180 size. A finer resolution, 0.25 deg, of this product has been released as Version 3. The GSSTF, Version 2c, daily fluxes have first been produced for each individual available SSM/I satellite tapes (e.g., F08, F10, F11, F13, F14 and F15). Then, the Combined daily fluxes are produced by averaging (equally weighted) over available flux data/files from various satellites. These Combined daily flux data are considered as the "final" GSSTF, Version 2c, and are stored in this HDF-EOS5 collection. There are only one set of GSSTF, Version 2c, Combined data, "Set1" It contains 9 variables: "E" 'latent heat flux' (W/m**2), "STu" 'zonal wind stress' (N/m**2), "STv" 'meridional wind stress' (N/m**2), "H" 'sensible heat flux' (W/m**2), "Qair" 'surface air (~10-m) specific humidity' (g/kg), "WB" 'lowest 500-m precipitable water' (g/cm**2), "U" '10-m wind speed' (m/s), "DQ" 'sea-air humidity difference' (g/kg) "Tot_Precip_Water" 'total precipitable water' (g/cm**2) The double-quoted labels are the short names of the data fields in the HDF-EOS5 files. The "individual" daily flux data files, produced for each individual satellite, are also available in HDF-EOS5, although from differe...
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-19T07:33:35.000Z
Contains the hydraulic properties of the soil at each tower flux site determined by the HYD-01 science team.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:38:32.000Z
<p>The Nuclear Systems Project demonstrates nuclear power technology readiness to support the goals of NASA&rsquo;s Space Technology Mission Directorate. To this end, the project will:</p><ul><li>Demonstrate subsystem-level technology readiness in a relevant environment (Technology Readiness Level (TRL) 5)</li><li>Establish a hardware-based technical foundation for fission power system (FPS) design concepts and reduce risk</li><li>Validate a FPS concept that meets exploration power requirements at reasonable cost with added benefits over competitive options</li><li>Reduce the cost uncertainties for FPS and establish greater credibility for flight system cost estimates</li><li>Generate the key gate products that will allow Agency decision-makers to consider fission power as a viable option to proceed to flight development</li></ul><p>The Nuclear Systems Project is aligned with STMD&rsquo;s Roadmap on Space Power and Energy Storage (TA-03) and addresses a key milestone for a non-nuclear subsystem demonstration of a &ldquo;workhorse&rdquo; 10-100 kWe fission system.&nbsp; The National Research Council&rsquo;s review of the STMD Roadmap identifies Fission Power Generation as one of the top 16 NASA technology development priorities.&nbsp; The STMD Roadmap clearly recognizes the importance of the planned non-nuclear demonstration as a crucial step in deploying an initial space fission system and a foundation for follow-on fission power system technology development.&nbsp; While the 10-100 kWe class system is ideally suited for lunar and Mars surface power, the component technologies are readily adaptable to larger megawatt-class systems for Nuclear Electric Propulsion (NEP) missions.&nbsp; Further, the analytical tools and non-nuclear testing strategies that will be exercised in this project can be applied to the megawatt systems as well as lower power (kilowatt-class) systems that may be needed for space science missions that exceed current Radioisotope Power System (RPS) capabilities.</p>
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:13:42.000Z
Next generation Earth Science Satellites ORCA and CLARREO are designed to measure our planet's ocean and climate health. Using hyper-spectral imaging at wavelengths ranging from the UV through NIR, these instruments will record the levels of the earth's temperature rise over the course of a decade. To make such detailed measurements, polarization effects at various wavelengths due to multiple factors must be eliminated using an optical device known as a "de-polarizer". For the CLARREO de-polarizer, four quartz windows are needed to randomize the polarization state of the observed reflected light spectrum. Multiple reflections from 4 surfaces produce losses up to 14% of the incident light, a level high enough to produce "ghost" effects superimposed on the desired earth images resulting in reduced image contrast and greater measurement error. An anti-reflection (AR) treatment is needed that can withstand the radiation and temperature effects caused by the mission environment while reducing reflection losses to levels of fractions of one percent. A new type of AR treatment, being developed for many military and commercial applications, is based on surface relief microstructures fabricated directly in a window, optic, or sensor material. AR microstructures (ARMs) can suppress internal reflections to levels unattainable by conventional thin-film AR coating technology. To extend the performance benefits of ARMs to hyper-spectral imaging systems, it is proposed that the fabrication processes developed for fused silica, glass, silicon, and many other optical materials be adapted for use with the quartz and magnesium fluoride depolarizers planned for the ORCA and CLARREO missions. In addition, an investigation of innovative surface microstructure technology is proposed for the fabrication of a new type of non-scattering, micro-textured depolarizer with inherent AR properties that can be applied to multiple optical elements within a spectrometer system.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:09:41.000Z
Building on our successful Phase I Tactile Data Entry program, Barron Associates proposes development of a Glove-Enabled Computer Operations (GECO) system to permit suited crewmembers to perform virtual keyboard/mouse interactions using an instrumented EVA glove. The Phase II system will use two-hand motion tracking, multi-finger gesture recognition, and vibrotactile feedback to create an intuitive human-computer interface that mirrors familiar desktop data entry modalities. The program will deliver demonstration hardware and software compatible with laboratory, field, and on-orbit testing of crewmember performance in relevant data entry tasks. The prototype will include functional EVA gloves with integrated motion sensing and vibrotactile transducers that couple to existing NASA suits via a quick-connect fitting. We will produce right and left hand gloves, lower arm suit sections, and a specialized two-port acrylic glove box to enable human subject evaluations in a realistic pressurized environment. Initial trials at Barron Associates will permit refinement of design concepts, followed by more extensive usability, comfort, and durability testing at NASA.
- API nasa-test-0.demo.socrata.com | Last Updated 2015-07-20T05:17:06.000Z
New & innovative technologies are needed to support exploration of remote & presently inaccessible terrain features on Mars & enable surface & subsurface material sampling. Key among those new technologies is the ability to measure & control force & torque loads on robotic arms, tether play-out & directional systems & subsurface boring systems. Presently available multi-axis sensors do not support all of these mission requirements, particularly with respect to small size, low mass & low-temperature survivability & operation. This innovative development will produce a force/moment feedback sensor that can reliably operate in spaceflight/Mars environments that would fully support this planetary mission. FUTEK Advanced Sensor Technology, Inc. has the Mars hardware development experience & industry know-how to design & develop the required compact, low mass, 6-axis multi-component cryogenic transducer.