Optical multi-context scrubbing operation on a redundant system

This paper presents a proposal of the world-first optical multi-context scrubbing operation on a redundant system that can maintain the state of a sequential circuit and the operation continuously without any interruption on a radiation-hardened optically reconfigurable gate array even after a permanent failure suddenly happens on the sequential circuit or a flip-flop by radiation. Up to now, a high-speed optical scrubbing operation has been demonstrated on a radiation-hardened optically reconfigurable gate array. In addition, a multi-context scrubbing operation based on the high-speed optical scrubbing operation has already been demonstrated. Although the multi-context scrubbing operation presents the benefit that it can treat both soft errors and permanent failures caused by radiation simultaneously, the conventional contributions have never presented how to maintain the state of a sequential circuit after a permanent failure occurs on flip-flops. Therefore, in the conventional multi-context scrubbing operation, all the operations must be restarted from the initial condition each time a permanent failure occurs on a programmable gate array. As a result, conventional multi-context scrubbing operations could not be applied for real-time systems. The proposed optical multi-context scrubbing method that can solve the issue has been experimentally evaluated on a radiation-hardened optically reconfigurable gate array

Assessing the performance of Digital Micromirror Devices for use in space-based multi-object spectrometers

A current need in space-based instrumentation is a reconfigurable slit mask. Several techniques for slit masks have been employed for ground-based astronomical spectrographs. These ground-based instruments have used large discrete components, which are impractical for remote operation in space-based deployment. The Texas Instruments\u27 Digital Micromirror Device (DMD) was originally conceived purely for display purposes, but is a viable candidate to be use as a slit mask in a space-based multi-object spectrograph (MOS). The Integrated Circuit (IC) manufacturing industry has enabled the robust integration of both silicon transistors and Micro-Electrical Mechanical Systems (MEMS) optical components into a very reliable monolithic chip (the DMD). The focus of this work was in three areas that addressed the suitability of proposing DMDs for future space missions. The DMDs were optically characterized to assess their utility in a spectrograph. The DMDs were also cooled in a liquid nitrogen dewar to determine their minimum operating temperature. The low temperature tests indicated that the DMD can operate to temperatures as low as 130 K. In addition, several DMDs were irradiated with high-energy protons at the LBNL 88 Cyclotron to determine how robust the devices are to ionizing radiation (protons). The radiation testing results indicate that DMDs would survive medium to long duration space missions with full operability. Based on preliminary tests in these three areas, the DMD should be considered as an excellent candidate for deployment in future space missions

SINGLE EVENT UPSET DETECTION IN FIELD PROGRAMMABLE GATE ARRAYS

The high-radiation environment in space can lead to anomalies in normal satellite operation. A major cause of concern to spacecraft-designers is the single event upset (SEU). SEUs can result in deviations from expected component behavior and are capable of causing irreversible damage to hardware. In particular, Field Programmable Gate Arrays (FPGAs) are known to be highly susceptible to SEUs. Radiation-hardened versions of such devices are associated with an increase in power consumption and cost in addition to being technologically inferior when compared to contemporary commercial-off-the-shelf (COTS) parts. This thesis consequently aims at exploring the option of using COTS FPGAs in satellite payloads. A framework is developed, allowing the SEU susceptibility of such a device to be studied. SEU testing is carried out in a software-simulated fault environment using a set of Java classes called JBits. A radiation detector module, to measure the radiation backdrop of the device, is also envisioned as part of the final design implementation

Analysis, Implementation and Considerations for Liquid Crystals as a Reconfigurable Antennas Solution (LiCRAS) for Space

The space industry has predominantly relied on high gain reflector dish antenna apertures for performing communications, but is constantly investing in phase array antenna concepts to provide increased signal flexibility at reduced system costs in terms of finances and system resources. The problem with traditional phased arrays remains the significantly greater program cost and complexity added to the satellite by integrating arrays of antenna elements with dedicated amplifier and phase shifters to perform adaptive beam forming. Liquid Crystal Reflectarrays (LiCRas) offer some of the electrical beam forming capability of a phased array system with the component and design complexity in lines with a traditional reflector antenna aperture but without the risks associated with mechanical steering systems. The final solution is believed to be a hybrid approach that performs in between the boundaries set by the two current disparate approaches. Practical reflectarrays have been developed since the 90s as a means to control reflection of incident radiation off a flat structure that is electrically curved based on radiating elements and their reflection characteristics with tailored element phase delay. In the last decade several methods have been proposed to enable tunable reflectarrays where the electrical shape of the reflector can be steered by controlling the resonating properties of the elements on the reflector using a DC bias. These approaches range from complex fast switching MEMS and ferroelectric devices, to more robust but slower chemical changes. The aim of this work is to investigate the feasibility of a molecular transition approach in the form of liquid crystals which change permittivity based on the electrical field they are subjected to. In this work, particular attention will be paid to the impact of space environment on liquid crystal reflectarray materials and reflector architectures. Of particular interest are the effects on performance induced by the temperature extremes of space and the electromagnetic particle environment. These two items tend to drive much of the research and development for various space technologies and based on these physical influences, assertions can be made toward the space worthiness of such a material approach and can layout future R&D needs to make certain LC RF devices feasible for space use. Moreover, in this work the performance metrics of such a technology will be addressed along with methods of construction from a space perspective where specific design considerations must be made based on the extreme environment that a typical space asset must endure.\u2

NASA Tech Briefs, April 2011

Topics covered include: Amperometric Solid Electrolyte Oxygen Microsensors with Easy Batch Fabrication; Two-Axis Direct Fluid Shear Stress Sensor for Aerodynamic Applications; Target Assembly to Check Boresight Alignment of Active Sensors; Virtual Sensor Test Instrumentation; Evaluation of the Reflection Coefficient of Microstrip Elements for Reflectarray Antennas; Miniaturized Ka-Band Dual-Channel Radar; Continuous-Integration Laser Energy Lidar Monitor; Miniaturized Airborne Imaging Central Server System; Radiation-Tolerant, SpaceWire-Compatible Switching Fabric; Small Microprocessor for ASIC or FPGA Implementation; Source-Coupled, N-Channel, JFET-Based Digital Logic Gate Structure Using Resistive Level Shifters; High-Voltage-Input Level Translator Using Standard CMOS; Monitoring Digital Closed-Loop Feedback Systems; MASCOT - MATLAB Stability and Control Toolbox; MIRO Continuum Calibration for Asteroid Mode; GOATS Image Projection Component; Coded Modulation in C and MATLAB; Low-Dead-Volume Inlet for Vacuum Chamber; Thermal Control Method for High-Current Wire Bundles by Injecting a Thermally Conductive Filler; Method for Selective Cleaning of Mold Release from Composite Honeycomb Surfaces; Infrared-Bolometer Arrays with Reflective Backshorts; Commercialization of LARC (trade mark) -SI Polyimide Technology; Novel Low-Density Ablators Containing Hyperbranched Poly(azomethine)s; Carbon Nanotubes on Titanium Substrates for Stray Light Suppression; Monolithic, High-Speed Fiber-Optic Switching Array for Lidar; Grid-Tied Photovoltaic Power System; Spectroelectrochemical Instrument Measures TOC; A Miniaturized Video System for Monitoring Drosophila Behavior; Hydrofocusing Bioreactor Produces Anti-Cancer Alkaloids; Creep Measurement Video Extensometer; Radius of Curvature Measurement of Large Optics Using Interferometry and Laser Tracker n-B-pi-p Superlattice Infrared Detector; Safe Onboard Guidance and Control Under Probabilistic Uncertainty; General Tool for Evaluating High-Contrast Coronagraphic Telescope Performance Error Budgets; Hidden Statistics of Schroedinger Equation; Optimal Padding for the Two-Dimensional Fast Fourier Transform; Spatial Query for Planetary Data; Higher Order Mode Coupling in Feed Waveguide of a Planar Slot Array Antenna; Evolutionary Computational Methods for Identifying Emergent Behavior in Autonomous Systems; Sampling Theorem in Terms of the Bandwidth and Sampling Interval; Meteoroid/Orbital Debris Shield Engineering Development Practice and Procedure; Self-Balancing, Optical-Center-Pivot, Fast-Steering Mirror; Wireless Orbiter Hang-Angle Inclinometer System; and Internal Electrostatic Discharge Monitor - IESDM

The NASA SBIR product catalog

The purpose of this catalog is to assist small business firms in making the community aware of products emerging from their efforts in the Small Business Innovation Research (SBIR) program. It contains descriptions of some products that have advanced into Phase 3 and others that are identified as prospective products. Both lists of products in this catalog are based on information supplied by NASA SBIR contractors in responding to an invitation to be represented in this document. Generally, all products suggested by the small firms were included in order to meet the goals of information exchange for SBIR results. Of the 444 SBIR contractors NASA queried, 137 provided information on 219 products. The catalog presents the product information in the technology areas listed in the table of contents. Within each area, the products are listed in alphabetical order by product name and are given identifying numbers. Also included is an alphabetical listing of the companies that have products described. This listing cross-references the product list and provides information on the business activity of each firm. In addition, there are three indexes: one a list of firms by states, one that lists the products according to NASA Centers that managed the SBIR projects, and one that lists the products by the relevant Technical Topics utilized in NASA's annual program solicitation under which each SBIR project was selected

The integration of active silicon components in polymer microfluidic devices

Early microfluidic devices borrowed technology from established CMOS microfabrication, and were therefore structurally similar to silicon computer chips. In the late 1990s, George Whitesides' group pioneered a cheaper, mass producible polymer device fabrication technique called 'soft lithography' that revolutionized modern microfluidics. This dissertative work has been focused on re-introducing silicon as a common material in microfluidic devices, but as an active component instead of a structural one. These active components exploit the optical properties, electronic properties, and optoelectronic properties of silicon. The optical properties of silicon are utilized in the integration of silicon nanophotonic ring resonators as refractive index sensors embedded in microfluidic channels. The electronic properties of silicon are utilized in the fabrication of an ultra-thin Schottky diode for use as a transmission radiation particle detector for focused ion-beams. Finally, the optoelectronic properties of silicon are used as a photoconductive layer in light-induced dielectrophoretic manipulation of cells. These three projects are combined to investigate optofluidic sensing and manipulation, with potential radiobiological applications

Air Force Institute of Technology Research Report 2010

This report summarizes the research activities of the Air Force Institute of Technology’s Graduate School of Engineering and Management. It describes research interests and faculty expertise; lists student theses/dissertations; identifies research sponsors and contributions; and outlines the procedures for contacting the school. Included in the report are: faculty publications, conference presentations, consultations, and funded research projects. Research was conducted in the areas of Aeronautical and Astronautical Engineering, Electrical Engineering and Electro-Optics, Computer Engineering and Computer Science, Systems and Engineering Management, Operational Sciences, Mathematics, Statistics and Engineering Physic

Center for space microelectronics technology

The 1992 Technical Report of the Jet Propulsion Laboratory Center for Space Microelectronics Technology summarizes the technical accomplishments, publications, presentations, and patents of the center during the past year. The report lists 187 publications, 253 presentations, and 111 new technology reports and patents in the areas of solid-state devices, photonics, advanced computing, and custom microcircuits

Resilience of an embedded architecture using hardware redundancy

In the last decade the dominance of the general computing systems market has being replaced by embedded systems with billions of units manufactured every year. Embedded systems appear in contexts where continuous operation is of utmost importance and failure can be profound. Nowadays, radiation poses a serious threat to the reliable operation of safety-critical systems. Fault avoidance techniques, such as radiation hardening, have been commonly used in space applications. However, these components are expensive, lag behind commercial components with regards to performance and do not provide 100% fault elimination. Without fault tolerant mechanisms, many of these faults can become errors at the application or system level, which in turn, can result in catastrophic failures. In this work we study the concepts of fault tolerance and dependability and extend these concepts providing our own definition of resilience. We analyse the physics of radiation-induced faults, the damage mechanisms of particles and the process that leads to computing failures. We provide extensive taxonomies of 1) existing fault tolerant techniques and of 2) the effects of radiation in state-of-the-art electronics, analysing and comparing their characteristics. We propose a detailed model of faults and provide a classification of the different types of faults at various levels. We introduce an algorithm of fault tolerance and define the system states and actions necessary to implement it. We introduce novel hardware and system software techniques that provide a more efficient combination of reliability, performance and power consumption than existing techniques. We propose a new element of the system called syndrome that is the core of a resilient architecture whose software and hardware can adapt to reliable and unreliable environments. We implement a software simulator and disassembler and introduce a testing framework in combination with ERA’s assembler and commercial hardware simulators