- API data.nasa.gov | Last Updated 2018-07-19T07:41:48.000Z
Missions to Solar System bodies must meet increasingly ambitious objectives requiring highly reliable capabilities in ranging and mapping for soft and precision landing to avoid hazardous sites. A compact and light weight LiDAR instrument is needed for topography mapping, position sensing, laser altimetry, and autonomous rendezvous of satellites. Missions to small bodies such as asteroids, comets, and moons require precision rendezvous and accurate identification of landing or sampling sites. Precision range data significantly improves spacecraft control in close-approach and landing scenarios. Range data is most critical in the final descent phase where the spacecraft is within a few kilometers of the target surface. These missions require improved precision from previously flown lidar technologies as well as significant reductions in size, weight, and power (SWaP) given the resource-constrained class of missions likely to utilize this capability. Q-Peak, in partnership with Sigma Space Corp., is proposing a low-SWaP laser integrated into a compact laser LiDAR instrument that can achieve the desired ranging accuracy and precision with minimum resource from spacecraft bus. In Phase I, Q-Peak proposes the development of an ultra-compact, passively Q-switched laser, < 4 cm3 in volume that will produce > 0.1 mJ pulse energies and < 2 ns-duration pulses at 523 nm at pulse repetition rates of 10-30 kHz. This laser will be specifically designed for integration and testing in the newly developed LiDAR instrument at Sigma Space. In Phase II, Q-Peak will bond the passive Q-switch to the laser gain medium to make it monolithic and essentially alignment free. We will harden the laser and integrate it into the LiDAR instrument to advance the TRL level by subjecting them to a space-like environment.
- API data.nasa.gov | Last Updated 2018-07-19T08:42:09.000Z
<p>To provide economical, reliable and safe access to space, design weaknesses should be identified earlier in the engineering life cycle, using model-based systems engineering. The slow manual approach to performing Failure Modes and Effects Analysis (FMEA) is a barrier to early identification of weaknesses. To semi-automate the identification of failure modes and causes use a prototype FMEA Assistant, including a library with standard terminology, to classify components associated with failure modes and automatically identify candidate functions, infrastructure and failure modes. This automation will reduce cost and increase coverage, standardization and reuse. Early identification of design weaknesses can substantially reduce rework costs later in the life cycle, which are all too common in the testing phase. Use of SysML will closely link safety analysis with the overall engineering process, resulting in smoother collaboration and safer vehicles and missions. The resulting reusable model would become part of the model-based system engineering process.<p/><p>This project was a small proof-of-concept case study, generating SysML model information as a side effect of safety analysis. A prototype FMEA Assistant was used to semi-automate safety analysis that identifies failure modes and causes, using a library with standard SysML-compatible terminology to classify components associated with failure modes and to automatically identify candidate functions, infrastructure and failure modes. FMEA analysts select from standard functions and failures to systematically narrow down failure mode selection (presented in automatically created pick lists). Standard terminology from an existing Aerospace Ontology is used to classify components and automatically identify candidate functions and failure modes. With automatically created pick lists, analysts can easily and correctly select standard functions and failures for a SysML architecture model as a side effect of using FMEA Assistant. A white paper reports on a concept for using SysML profiles for safety analysis, to standardize FMEA-related terminology for reuse in several types of safety analysis (hazard analyses, fault trees, reliability block diagrams). See related project: Failure Modes and Effects Analysis (FMEA) Simulation Tool</p>
- API data.nasa.gov | Last Updated 2019-06-03T15:19:03.000Z
This data set (NmIDCS3G) consists of daily, global image composites constructed from Nimbus 3 and Nimbus 4 Image Dissector Camera System (IDCS) imagery for the region between 60 N and 60 S. Images were acquired between 23 April, 1969 - 04 January, 1971. Data are available as GeoTIFFs and browse images. For HDF5 formatted version of these data, see <a href="http://dx.doi.org/10.5067/NIMBUS/NmIDCS3H">Nimbus Image Dissector Camera System Remapped Visible Imagery Daily L3, HDF5</a>.
- API data.nasa.gov | Last Updated 2019-04-22T03:02:32.000Z
The UARS Correlative assimilation data from NOAA's National Meteorological Center (NMC) consists of daily model runs at 12 GMT as a means of providing an independent analysis for comparison with data from the UARS instruments. The NMC data product includes temperature (Kelvin), humidity (%), geopotential height (m), and zonal and meridional wind components (m/s). Geopotential height and atmospheric temperature data are derived from two analysis systems: 1) tropospheric fields from 1000 to 100 mb, and 2) stratospheric analyses from 70 to 0.4 mb. The tropospheric fields are the 12 GMT gridded fields which are part of the Global Daily Assimilation System (GDAS), where data from radiosondes, aircraft, satellites, ships, bouys, or any other conventional means are assimilated and merged into meteorological fields (heights, temperature, winds). The stratospheric analyses are 12 GMT operational analyses at the 70 - 0.4 mb pressure levels produced from satellite temperature retrievals and RAOBS via a modified Cressman analysis. Tropospheric temperature analyses use combined NOAA-10 and NOAA-11 data. Moisture (northern hemisphere only) and Winds data are obtained from the NMC GDAS. The gridded fields are on the standard 65 x 65 NMC polar stereographic grid oriented 80W (grid increment 381 km at 60N), and 100E (grid increment 381 km at 60S); Pole at (33,33). The NMC uses 18 standard pressure levels for data at 1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 10, 5, 2, 1, 0.4 millibars. Height and temperature data are produced at all 18 pressure levels from 1000 mb to 0.4 mb. Moisture data are only produced in the northern hemisphere for the 6 lowest altitude pressure levels. Wind data are produced for the 12 lowest altitude levels in the northern hemisphere, and at the 4 levels 1000, 500, 300, and 250 mb in the southern hemisphere. There are four data files representing each subtype per day. Included in the NMC correlative data set will be a geographical data richness file. This file is used by the NMC access routines, and indicates the radiosonde coverage for each point on the NMC grid. The data files are available in a binary record oriented format.
- API data.nasa.gov | Last Updated 2018-07-19T20:13:45.000Z
Radiation shielding is a requirement to protect humans from the hazards of space radiation during NASA missions. Multifunctional materials have the potential to provide both non-parasitic radiation protection and structural requirements. Because of the radiation only low atomic number materials can be used. Boron and carbon meet the radiation requirement and in fibrous form meet the structural requirement. In Phase I it was demonstrated feasible to produce boron fibers on graphite fiber tow substrates. Composites produced with the boron fibers showed modulus increase and high strength compared to graphite fiber composites. Phase II will optimize the processing to maximize the boron fiber properties and the composite properties fabricated from the boron fibers. Continuous production of boron fiber processing and prepregging of the fibers will be demonstrated. The boron fibers produced will be utilized to demonstrate the fabrication of large size composites and delivery of both fibers and composites to NASA.
- API data.nasa.gov | Last Updated 2018-07-19T07:46:51.000Z
CoolCAD Electronics, LLC, proposes to design and fabricate a SiC UV detector array with a 10μm pixel pitch, sensitive to EUV, VUV and Deep UV. SiC is a visible-blind material with very low intrinsic dark current, able to operate at >350C. Expanding from our past successful demonstration of UV sensors and MOSFET circuits on the same substrate, we will develop fabrication processes and capabilities to design and integrate SiC pn-junction photodiodes and low-voltage MOSFET devices with the required small dimensions. To our knowledge, this represents the first program to scale SiC optoelectronic circuits to such feature size restrictions; particularly, a 1μm MOSFET gate length and submicron margins for layer overlaps. Scaling monolithically-integrated sensors and transistors to submicron feature sizes advances the SiC technology state-of-the-art. We plan to extend our process flow and device designs to use a semiconductor reduction stepper during fabrication to enable submicron features. We will demonstrate single pn-junction photodiodes, photodiodes with MOSFETs in the 3-transistor pixel architecture, and arrays of both these structures. We will deliver a 32 x 32 passive array and a 4 x 4 active array that contains SiC MOSFETs as well as photodiodes. This effort lays the groundwork for developing a megapixel array in a future Phase II or related program. We will further design planar SiC avalanche photodiodes and planar APD arrays, as the initial step to monolithically integrating APDs with their readout electronics and therefore obtain a high-temperature-operation-capable detector, sensitive to extremely low illumination levels. The entire design and fabrication will be performed in the United States, and using CoolCAD's patent pending fabrication processes.
- API data.nasa.gov | Last Updated 2018-07-19T08:11:39.000Z
The innovation is a new Stretched Lens Array (SLA) with a thinner, lighter, more robust Fresnel lens (with thin glass or polymer superstrate or embedded aluminum mesh). The new lens enables a blanket-level specific power > 1,000 W/kg, including lenses, PV cell circuit (including cells, encapsulation, high-voltage insulation, and heavy radiation shielding), and waste heat rejection radiator. The new SLA array is cost-effective, with the most expensive array cost element, the IMM solar cell, contributing only $50/W to the array cost. The new lens is novel in configuration, enabling single-axis tracking for the array even in the presence of large beta angles (e.g., 50 degrees) between the array and the sun. For future high-power arrays (e.g., > 100 kW), including Solar Electric Propulsion (SEP) missions, the new SLA will offer a unique combination of high efficiency (e.g., >35%), ultra-low mass, high-operating voltage (e.g., >300 V), and low cost. SLA technology is a direct descendant of the SCARLET array used to power NASA's Deep Space 1 SEP mission in 1998-2001. SLA recently completed a flight test on TacSat 4 in a very high radiation orbit, and the lessons learned from TacSat 4 led to the new SLA, the subject of this proposal. The new SLA is scalable to multi-hundred-kW array sizes using blanket deployment and support platforms such as DSS's Roll-Out Solar Array (ROSA). The new SLA will typically operate at 4X concentration, saving substantially on solar cell area, cost, radiation shielding mass, and dielectric isolation mass. The new SLA will enable the early use of state-of-the-art cells, such as inverted metamorphic (IMM) cells with 4 or 6 junctions, and will enhance the production capacity of cell vendors (e.g., 100 kW per year of 1 sun cells = 400 kW per year of 4X cells). The feasibility of the new SLA was firmly established in Phase I, and fully functional prototype hardware will be developed and tested by MOLLC, DSS, SolAero-Emcore, and CFE in Phase II.
- API data.nasa.gov | Last Updated 2018-07-19T11:06:30.000Z
We will develop an efficient tool for formal verification of PowerPC 750 executables. The PowerPC 750 architecture is used in the radiation-hardened RAD750 flight-control computers that are utilized in many space missions. The resulting tool will be capable of formally checking: 1) the equivalence of two instruction sequences; and 2) properties of a given instruction sequence. The tool will automatically introduce symbolic state for state variables that are not initialized and for external inputs. We bring a tremendous expertise in formal verification of complex microprocessors, formal definition of instruction semantics, and efficient translation of formulas from formal verification to Boolean Satisfiability (SAT). We will also produce formally verified definitions of the PowerPC 750 instructions used in the project, expressed in synthesizable Verilog; these definitions could be utilized for formal verification and testing of PowerPC 750 compatible processors, for FPGA-based emulation of PowerPC 750 executables, as well as in other formal verification tools to be implemented in the future.
Interferometric Correlator for Acoustic Radiation & Underlying Structural Vibration (ICARUSV), Phase IIdata.nasa.gov | Last Updated 2018-07-19T08:11:57.000Z
Current methods for identification of aircraft noise sources, such as near-field acoustical holography and beam forming techniques, involve the use of pressure probes or microphone arrays to measure the radiated sound field. However, those techniques are intrusive, bandwidth limited, time consuming to implement, require extensive data processing and the resulting data may ultimately generate false results in the form of pseudo (noise) sources. Advanced Systems & Technologies Inc. proposes an optical non-contact sensor fusion concept which, for the first time, enables direct capture and observation of full-field non-stationary dynamic structural vibrations (SV) and unsteady radiated sound fields or transient flow fields around the structure of interest. SV depict the flow of energy in a structure and provides an unambiguous identification of structural noise sources and sinks. Additionally, the ability to capture and correlate the acoustic/flow field data with the structure borne intensity, offers an unprecedented and rapid diagnostic capability for noise source characterization and evaluation of noise abatement systems. In addition to being non-intrusive the measurements are fast, can be made at operationally relevant bandwidths, which extend to the ultrasonic domain, and provide deeper insight into the complex structural dynamics which are the root cause of noise emission.
- API data.nasa.gov | Last Updated 2018-07-20T07:20:59.000Z
This grouping contains the incompressible-flow cases from the 1980-81 Data Library.