Electronics & Computers

Methods for Mitigating Space Radiation Effects, Fault Detection and Correction, and Processing Sensor Data

A combination of three innovations enables increased efficiency, stability, and flexibility of data management and systems functionality. The Integrated Modular Avionics (IMA) architecture being developed for space applications requires that sensor data be autonomously sampled and transmitted to the system network. This transmission needs to occur on a predetermined, fixed schedule to avoid conflicts on the network. It needs to be capable of building packets of sensor data for individual application partitions (i.e., environmental control, propulsion, and vehicle management). It must be easily configured for flexibility in system scheduling.

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Quad First Stage Processor: A Four-Channel Digitizer and Digital Beam-Forming Processor

A 4-channel digitizer was designed, built, and tested. The very large, complex board enables SweepSAR. The proposed Deformation, Eco-Systems, and Dynamics of Ice Radar (DESDynl-R) Lband SAR instrument employs multiple digital channels to optimize resolution while keeping a large swath on a single pass. High-speed digitization with very fine synchronization and digital beam forming are necessary in order to facilitate this new technique.

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Compact Ka-Band Antenna Feed with Double Circularly Polarized Capability

This design could be used for the feed component in highgain antennas. NASA has an interest in utilizing the Ka-band frequency allocation. One of the main reasons for migrating to Kaband is the need for higher frequency bandwidth to enable higher data rates. A dual circular polarized wideband antenna for Ka-band communications applications was designed leveraging a novel Ka-band polarizer design used in Lunar Reconnaissance Orbiter/Solar Dynamics Observatory (LRO/SDO). The proposed design merges two components (polarizer and antenna) into one unit, reducing its overall size. Its simulated bandwidth extends beyond the allocated bandwidth for NASA at Ka-band. This novel design could be used as well for the feed component in high-gain antennas (HGAs).

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Reworked CCGA-624 Interconnect Package Reliability for Extreme Thermal Environments

The effect of the number of reworks is examined on the reliability of this technology for harsh, extreme thermal environments. During the past two decades, large, high-density, high-input/output (I/O) electronic interconnect SMT (surface mount technology) packages such as ceramic column grid arrays (CCGAs) have increased usage in avionics hardware of NASA projects. The test boards built with CCGA packages are expensive and often require rework to replace reflowed, reprogrammed, failed, or redesigned CCGA packages. Theoretically, a good rework process should have a similar temperature- time profile as that used for the original manufacturing process of solder reflow. A multiple rework process may be implemented with CCGA packaging technology to understand the effect of the number of reworks on the reliability of this technology for harsh, extreme, thermal environments.

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Ultra-Wideband, Dual-Polarized, Beam- Steering P-Band Array Antenna

The novel design geometry can be scaled with minor modifications. A dual-polarized, wide-bandwidth (200 MHz for one polarization, 100 MHz for the orthogonal polarization) antenna array at P-band was designed to be driven by NASA’s EcoSAR digital beam former. EcoSAR requires two wide P-band antenna arrays mounted on the wings of an aircraft, each capable of steering its main beam up to 35° off-boresight, allowing the twin radar beams to be steered at angles to the flight path. The science requirements are mainly for dual-polarization capability and a wide bandwidth of operation of up to 200 MHz if possible, but at least 100 MHz with high polarization port isolation and low cross-polarization. The novel design geometry can be scaled with minor modifications up to about four times higher or down to about half the current design frequencies for any application requiring a dual-polarized, wide-bandwidth steerable antenna array.

Posted in: Electronics & Computers, Briefs, TSP

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Centering a DDR Strobe in the Middle of a Data Packet

The Orion CEV Northstar ASIC (application-specific integrated circuit) project required a DDR (double data rate) memory bus driver/receiver (DDR PHY block) to interface with external DDR memory. The DDR interface (JESD79C) is based on a source synchronous strobe (DQS\) that is sent along with each packet of data (DQ). New data is provided concurrently with each edge of strobe and is sent irregularly. In order to capture this data, the strobe needs to be delayed and used to latch the data into a register.

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Submerged AUV Charging Station

Potential uses include studying ocean climate change, pollution, salinity, and currents. Autonomous Underwater Vehicles (AUVs) are becoming increasingly important for military surveillance and mine detection. Most AUVs are battery powered and have limited lifetimes of a few days to a few weeks. This greatly limits the distance that AUVs can travel underwater. Using a series of submerged AUV charging stations, AUVs could travel a limited distance to the next charging station, recharge its batteries, and continue to the next charging station, thus traveling great distances in a relatively short time, similar to the Old West “Pony Express.”

Posted in: Electronics & Computers, Briefs, TSP

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