Tech Briefs

Fourier Transform Spectrometer on Autonomous Self-Healing Hardware Platform

This liquid crystal waveguide-based platform provides self-healing for electronics in dangerous or hard-to-reach locations. NASA’s Jet Propulsion Laboratory, Pasadena, California The autonomous self-healing (eDNA) hardware platform is a reconfigurable field-programmable gate-array (FPGA)-type platform developed by Technical University of Denmark (patent: WO/2010/060923). It is capable of autonomously reconfiguring itself in case a fault is detected and, thusly, restoring functionality at a fault-free location on the chip.

Posted in: Electronics & Computers, Briefs

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Low-Temperature-Compatible Electronics for a Miniature Nuclear Magnetic Resonance Spectrometer

The electronics have been demonstrated to function down to 77 K. NASA’s Jet Propulsion Laboratory, Pasadena, California Missions to Titan are severely limited in available mass and power because spacecraft have to travel over a billion miles to get there, consuming large masses of propellants. Thus low-mass, low-power instruments are a high priority need for Titan missions. A miniature, liquid-phase, high-resolution, pulsed proton-NMR (1H-NMR) spectrometer was developed with low mass (1.5 kg), requiring low power, that can be operated cryogenically on the surface of Titan. This work focuses on new pulsed electronic circuits, optimized for a nuclear magnetic resonance (NMR) spectrometer for analysis of hydrocarbon liquids on Titan.

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Ionospheric Delay Compensation Using a Scale Factor Based on an Altitude of a Receiver

Lyndon B. Johnson Space Center, Houston, Texas GPS receivers must compensate for the delay a GPS signal experiences as it passes through the ionosphere in order to accurately determine the position of the receiver. Receivers limited to terrestrial operation may utilize the Klobuchar parameters transmitted by the GPS satellites to model the ionosphere and remove much of this delay. However, as a GPS receiver passes through the ionosphere, such as in a spacecraft or low-Earth orbit space station, the Klobuchar model no longer adequately approximates the correction to be applied. Other models exist, particularly the IRI 2007 model created by NASA et al., but these are too computationally complex to be performed in real time by common hardware available for space implementations. Moreover, although the IRI model provides extensive insight into the historical characteristics of the ionosphere, it is purely predictive for times beyond the publication date of the model. Still other models exist that can be used during post-processing but are also not available in real time.

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Microelectronic Repair Techniques for Wafer-Level Integration

Goddard Space Flight Center, Greenbelt, Maryland Wafer-level integration was employed to mount the microshutter array for the James Webb Space Telescope (JWST) and the detector-read-out hybrid for TIRS (Thermal Infrared Sensor). In the case of the JWST substrate, two conductors (polysilicon and aluminum) separated by a silicon oxide insulating layer were fabricated on a roughly 85-mm-square silicon wafer. The size of the substrate, the density and length of the conductive traces, and the requirement of zero shorts and zero opens on the finished device necessitated nearly impossible cleanroom requirements. Techniques were developed to repair the inevitable shorts and opens created during the wafer fabrication process. The wafers were repaired to zero shorts and zero opens without degradation of device performance.

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Multi-Gigabit-Rate Radiation Hard Bus

Goddard Space Flight Center, Greenbelt, Maryland A concept was developed for a multi-gigabit-rate, radiation-hardened (RH) bus that would support open-system architecture and provide a cost-effective, high-speed interconnect. This concept is based on Advanced Science and Novel Technology Company’s SerDes system, which supports a variety of interfaces, and operates at frequencies from DC to more than 15 GHz. The design of the improved SerDes is based on the company’s proprietary library of RH cells and functional blocks using annular FETs (field-effect transistors) that are available in commercial CMOS (complementary metal-oxide-semiconductor) technologies. Bus architecture and preliminary SerDes circuit design have been accomplished during this phase. At the time of this reporting, the complete chip was to be designed and fabricated in the next phase.

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Hovercraft Landing System

Ames Research Center, Moffett Field, California A concept for recovering reusable spacecraft or capsules, or reusable rocket boosters, has them land on an airbag-based, cushioned platform positioned on a highly maneuverable hovercraft. This landing method would have performance advantages over conventional approaches to reusability by placing most of the landing function on the hovercraft while maintaining the safety benefit of an open ocean landing away from populated areas; however, it would be similar to a dry landing as the spacecraft or booster would not enter the water.

Posted in: Mechanical Components, Briefs

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Novel Catalytic Reactor System for CO2 Reduction via Sabatier Process

Marshall Space Flight Center, Alabama A novel, short-contact-time Microlith Sabatier reactor system for CO2 reduction offers a significant advance in support of manned spaceflight. Compared to the current and prospective alternatives (including microchannels), the reactor is much smaller and lighter, more energy and resource efficient, and more durable. In the spacecraft cabin atmosphere revitalization system (ARS), the utilization of CO2 to produce life support consumables such as O2 and H2O, via the Sabatier process as part of the CO2 Reduction Assembly (CRA), is an important function. This innovation is an integrated, stand-alone system consisting of a Microlith-based CO2 methanation reactor, water separation and recovery system, and automatic control software for ground demonstration. The system efficiently achieves high CO2 conversion and high CH4 selectivity for optimum water generation. The apparatus is capable of operating at high throughput while maintaining targeted performance of close-to-equilibrium CO2 conversion. The specific mass and volume of the reactor are much lower compared to the state-of-the-art metrics. H2 and CO2 (reactants) enter the system, and their flow rates are automatically controlled. The catalyst within the reactor promotes the conversion of the reactants to H2O and CH4. Since the reaction is exothermic, a thermal management approach is implemented to maintain reactor operating temperature and to avoid catalyst deactivation. The product H2O is separated from the CH4 via a condenser and separator system to provide two single-phase product streams. This innovation utilizes a novel thermal management approach to enable self-sustained operation without additional power requirements. A full support system including mass flow controllers, valves, heat exchanger, and water condensation and separation system was developed. The reactor and system were integrated with a newly developed automatic control system that enables single pushbutton start and steady-state operation with minimal user interface. This work was performed by Christian Junaedi and Kyle Hawley of Precision Combustion, Inc. for Marshall Space Flight Center. For more information, contact Ronald C. Darty, Licensing Executive in the MSFC Technology Transfer Office, at Ronald.C.Darty@nasa.gov. Refer to MFS-33063-1.

Posted in: Mechanical Components, Briefs

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