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We present radiation effects test results and analysis produced by NASA JSC in 2021 for candidate electronic components and devices. Devices tested include integrated circuits, MOSFETs, DC-DC converters, and various commercial solutions.
Over the past decade, electronic, electrical, and electromechanical (EEE) parts for space applications have undergone significant changes, largely driven by CubeSat and commercial space developers pushing the boundaries on the utilization of commercial parts in space. Global product shortages and shipping delays are still impacting space flight project deadlines. Many projects have turned to automotive grade resistors as an alternate to their MILSPEC counterparts to fulfill requirements. In addition, automotive grade resistors may offer designers a wider range of parts to consider. A recent NASA study recommended the use of high-volume manufactured commercial components for space applications provided these components show evidence of stringent fabrication controls and thorough reliability monitoring practices. Automotive grade components have stringent qualification requirements per the Automotive Electronic Council (AEC). However, the end user usually does not have insight into the practices the manufacturer may use to reduce/eliminate infant mortality nor for compliance to all datasheet specifications. Screening, Life and Accelerated Life testing on a set of standard automotive-grade chip resistors is proposed to evaluate the reliability of these components. Requirements from both the AEC-Q (Automotive Electronic Council Qualification) and EEE-INST-002 (Instructions for EEE Parts Selection, Screening, Qualification, and Derating) for resistors is compared and discussed. The resistors have been tested by using a modified methodology from EEEINST-002 to evaluate their reliability for space flight projects. The findings of this study indicate that the underlying degradation mechanisms at rated temperature and power are best represented by power law models with a fitted exponent between 0 and 1. A linear model is more conservative which compensates for potential model uncertainty given the wide range of design and materials used in automotive resistors, while still providing useful long-term resistance drift estimates. No electrical anomalies or failures were observed throughout the 1000-hour Life Tests other than small in tolerance resistance drift aging. Degradation models were utilized to quantify and extrapolate the long-term resistance drift under operating conditions for the components. The models demonstrated that some automotive-grade resistors are likely to operate 10 years at nominal usage conditions while others might fail earlier.
Over the past decade, electronic, electrical, and electromechanical (EEE) parts for space applications have undergone significant changes, largely driven by CubeSat and commercial space developers pushing the boundaries on the utilization of commercial parts in space. Global product shortages and shipping delays are still impacting space flight project deadlines. Many projects have turned to automotive grade resistors as an alternate to their MIL-SPEC counterparts to fulfill requirements. In addition, automotive grade resistors may offer designers a wider range of parts to consider. A recent NASA study recommended the use of high-volume manufactured commercial components for space applications provided these components show evidence of stringent fabrication controls and thorough reliability monitoring practices [1]. Automotive grade components have stringent qualification requirements per the Automotive Electronic Council (AEC). However, the end user usually does not have insight into the practices the manufacturer may use to reduce/eliminate infant mortality nor for compliance to all datasheet specifications. Screening, Life and Accelerated Life testing on a set of standard automotive-grade chip resistors is proposed to evaluate the reliability of these components. Requirements from both the AEC-Q (Automotive Electronic Council Qualification) and EEE-INST-002 (Instructions for EEE Parts Selection, Screening, Qualification, and Derating) for resistors is compared and discussed. The resistors have been tested by using a modified methodology from EEE-INST-002 to evaluate their reliability for space flight projects. The findings of this study indicate that the underlying degradation mechanisms at rated temperature and power are best represented by power law models with a fitted exponent between 0 and 1. A linear model is more conservative which compensates for potential model uncertainty given the wide range of design and materials used in automotive resistors, while still providing useful long-term resistance drift estimates. No electrical anomalies or failures were observed throughout the 1,000-hour Life Tests other than small in tolerance resistance drift aging. Degradation models were utilized to quantify and extrapolate the long-term resistance drift under operating conditions for the components. The models demonstrated that some automotive-grade resistors are likely to operate 10 years at nominal usage conditions while others might fail earlier.
High-resolution submillimeter/terahertz spectroscopy is important for studying atmospheric and interstellar molecular gaseous species. It typically uses heterodyne receivers where an unknown (weak) signal is mixed with a strong signal from the local oscillator (LO) operating at a slightly different frequency. The non-linear mixer devices for this frequency range are unique and are not off-the-shelf commercial products. Three types of THz mixers are commonly used: Schottky diode, superconducting hot-electron bolometer (HEB), and superconductor-insulation-superconductor (SIS) junction. A HEB mixer based on the two-dimensional electron gas (2DEG) formed at the interface of two slightly dissimilar semiconductors was developed. This mixer can operate at temperatures between 100 and 300 K, and thus can be used with just passive radiative cooling available even on small spacecraft.
Technologies enabling long-term, wide-ranging measurement in hard-to-reach areas are a critical need for planetary science inquiry. Phenomena of interest include flows or variations in volatiles, gas composition or concentration, particulate density, or even simply temperature. Improved measurement of these processes enables understanding of exotic geologies and distributions or correlating indicators of trapped water or biological activity. However, such data is often needed in unsafe areas such as caves, lava tubes, or steep ravines not easily reached by current spacecraft and planetary robots. To address this capability gap, we have developed miniaturized, expendable sensors which can be ballistically lobbed from a robotic rover or static lander - or even dropped during a flyover. These projectiles can perform sensing during flight and after anchoring to terrain features. By augmenting exploration systems with these sensors, we can extend situational awareness, perform long-duration monitoring, and reduce utilization of primary mobility resources, all of which are crucial in surface missions. We call the integrated payload that includes a cold gas launcher, smart projectiles, planning software, network discovery, and science sensing: PHALANX. In this paper, we introduce the mission architecture for PHALANX and describe an exploration concept that pairs projectile sensors with a rover “mothership.” Science use cases explored include reconnaissance using ballistic cameras, volatiles detection, and building timelapse maps of temperature and illumination conditions. Strategies to autonomously coordinate constellations of deployed sensors to self-discover and localize with peer ranging (i.e. a “local GPS”) are summarized, thus providing communications infrastructure beyond-line-of-sight (BLOS) of the rover. Capabilities were demonstrated through both simulation and physical testing with a terrestrial prototype. The approach to developing a terrestrial prototype is discussed, including design of the launching mechanism, projectile optimization, micro-electronics fabrication, and sensor selection. Results from early testing and characterization of commercial-off-the-shelf (COTS) components are reported. Nodes were subjected to successful burn-in tests over 48 hours at full logging duty cycle. Integrated field tests were conducted in the Roverscape, a half-acre planetary analog environment at NASA Ames, where we tested up to 10 sensor nodes simultaneously coordinating with an exploration rover. Ranging accuracy has been demonstrated to be within +/-10cm over 20m using commodity radios when compared to high-resolution laser scanner ground truthing. Evolution of the design, including progressive miniaturization of the electronics and iterated modifications of the enclosure housing for streamlining and optimized radio performance are described. Finally, lessons learned to date, gaps toward eventual flight mission implementation, and continuing future development plans are discussed.
Multi-walled CNT yarns have been experimentally and commercially created to yield lightweight, high conductivity fibers with good tensile properties for application as electrical wiring and multifunctional tendons. Multifunctional tendons are needed as the cable structures in tensegrity robots for use in planetary exploration. These lightweight robust tendons can provide mechanical strength for movement of the robot in addition to power distribution and data transmission. In aerospace vehicles, such as Orion, electrical wiring and harnessing mass can approach half of the avionics mass. Use of CNT yarns as electrical power and data cables could reduce mass of the wiring by thirty to seventy percent. These fibers have been intercalated with mixed halogens to increase their specific electrical conductivity to that near copper. This conductivity, combined with the superior strength and fatigue resistance makes it an attractive alternative to copper for wiring and multifunctional tendon applications. Electron beam irradiation has been shown to increase mechanical strength in pristine CNT fibers through increased cross-linking. Both pristine and intercalated CNT yarns have been irradiated using a 5-megavolt electron beam for various durations and the conductivities and tensile properties will be discussed. Structural information obtained using a field emission scanning electron microscope, energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy will correlate microstructural details with bulk properties.
In this paper we review the discovery of cosmic ray effects on the performance and reliability of microelectronic systems as well as on human health and safety, as well as the development of the engineering and health science tools used to evaluate and mitigate cosmic ray effects in earth surface, atmospheric flight, and space flight environments. Three twentieth century technological developments, 1) high altitude commercial and military aircraft; 2) manned and unmanned spacecraft; and 3) increasingly complex and sensitive solid state micro-electronics systems, have driven an ongoing evolution of basic cosmic ray science into a set of practical engineering tools (e.g. ground based test methods as well as high energy particle transport and reaction codes) needed to design, test, and verify the safety and reliability of modern complex electronic systems as well as effects on human health and safety. The effects of primary cosmic ray particles, and secondary particle showers produced by nuclear reactions with spacecraft materials, can determine the design and verification processes (as well as the total dollar cost) for manned and unmanned spacecraft avionics systems. Similar considerations apply to commercial and military aircraft operating at high latitudes and altitudes near the atmospheric Pfotzer maximum. Even ground based computational and controls systems can be negatively affected by secondary particle showers at the Earth's surface, especially if the net target area of the sensitive electronic system components is large. Accumulation of both primary cosmic ray and secondary cosmic ray induced particle shower radiation dose is an important health and safety consideration for commercial or military air crews operating at high altitude/latitude and is also one of the most important factors presently limiting manned space flight operations beyond low-Earth orbit (LEO).
Silicon-carbide- (SiC-) based power devices could enable substantial aerospace electronics benefits over today's silicon-based electronics. However, present-day SiC wafers contain electrically harmful dislocations (including micropipes) that are unpredictably distributed in high densities across all commercial 4H- and 6H-SiC wafers. The NASA Glenn Research Center recently demonstrated a crystal growth process that moves SiC wafer dislocations to predetermined lateral positions in epitaxial layers so that they can be reproducibly avoided during subsequent SiC electronic device fabrication. The process starts by reactive ion etching mesa patterns with enclosed trench regions into commercial on-axis (0001) 4H- or 6H-SiC substrates. An example of a pregrowth mesa geometry with six enclosed triangular-shaped trench regions is shown. After the etch mask is stripped, homoepitaxial growth is carried out in pure stepflow conditions that enable thin cantilevers to grow laterally from the tops of mesas whose pregrowth top surfaces are not threaded by substrate screw dislocations. The image in the bottom figure shows the postgrowth structure that forms after the lateral cantilevers expand to coalesce and completely roof over each of the six triangular trench regions. Atomic force microscope (AFM) measurements of the roof revealed that three elementary screw dislocation growth spirals, each shown in the AFM insets of the bottom image on the previous page, formed in the film roof at three respective points of cantilever film coalescence. The image above shows the structure following an etch in molten potassium hydroxide (KOH) that produced surface etch pits at the dislocation defects. The larger KOH etch pits--S1, S2, and S3--shown in this image correspond to screw dislocations relocated to the final points of cantilever coalescence. The smaller KOH etch pits are consistent with epilayer threading edge dislocations from the pregrowth substrate mesa (P1, P3, and P4) and a final cantilever coalescence point (P2). No defects (i.e., no etch pits) are observed in other cantilevered portions of the film surface. On the basis of the principle of dislocation Burgers vector conservation, we hypothesize that all vertically propagating substrate dislocations in an enclosed trench region become combined into a single dislocation in the webbed film roof at the point of final roof coalescence. The point of final roof coalescence, and therefore the lateral location of a webbed roof dislocation, can be designed into the pregrowth mesa pattern. Screw dislocations with predetermined lateral positions can then be used to provide the new growth steps necessary for growing a 4H/6H-SiC epilayer with a lower dislocation density than the substrate. Devices fabricated on top of such films can be positioned to avoid the preplaced dislocations.
Information is given in viewgraph form on Wakeshield, a space experiment platform. The Wake Shield Facility (WSF) flight program objectives, product applications, commercial development approach, and cooperative experiments are listed. The program objectives are to produce new industry-driven electronic, magnetic, and superconducting thin-film materials and devices both in terrestrial laboratories and in space; utilize the ultra-vacuum of space for thin film epitaxial growth and materials processing; and develop commercial space hardware for research and development and enhanced access to space.
The performance of propulsion engine systems is sensitive to weight and volume considerations. This can severely constrain the configuration and complexity of the control system hardware. Distributed Engine Control technology is a response to these concerns by providing more flexibility in designing the control system, and by extension, more functionality leading to higher performing engine systems. Consequently, there can be a weight benefit to mounting modular electronic hardware on the engine core casing in a high temperature environment. This paper attempts to quantify the in-flight temperature constraints for engine casing mounted electronics. In addition, an attempt is made at studying heat soak back effects. The Commercial Modular Aero Propulsion System Simulation 40k (C-MAPSS40k) software is leveraged with real flight data as the inputs to the simulation. A two-dimensional (2-D) heat transfer model is integrated with the engine simulation to approximate the temperature along the length of the engine casing. This modification to the existing C-MAPSS40k software will provide tools and methodologies to develop a better understanding of the requirements for the embedded electronics hardware in future engine systems. Results of the simulations are presented and their implications on temperature constraints for engine casing mounted electronics is discussed.
The performance of propulsion engine systems is sensitive to weight and volume considerations. This can severely constrain the configuration and complexity of the control system hardware. Distributed Engine Control technology is a response to these concerns by providing more flexibility in designing the control system, and by extension, more functionality leading to higher performing engine systems. Consequently, there can be a weight benefit to mounting modular electronic hardware on the engine core casing in a high temperature environment. This paper attempts to quantify the in-flight temperature constraints for engine casing mounted electronics. In addition, an attempt is made at studying heat soak back effects. The Commercial Modular Aero Propulsion System Simulation 40k (C-MAPSS40k) software is leveraged with real flight data as the inputs to the simulation. A two-dimensional (2-D) heat transfer model is integrated with the engine simulation to approximate the temperature along the length of the engine casing. This modification to the existing C-MAPSS40k software will provide tools and methodologies to develop a better understanding of the requirements for the embedded electronics hardware in future engine systems. Results of the simulations are presented and their implications on temperature constraints for engine casing mounted electronics is discussed.
Electronics used in space missions encounter exposure to extreme temperatures and operation under wide thermal swings. Most commercial-off-the-shelf (COTS) devices are not designed to function under such extreme conditions and very little data exist on their performance outside their specified range of operation. Extending the temperature range at which electronic parts can operate reliably leads to potential benefits resulting in improving reliability, reducing mass/weight, and simplifying thermal design due to elimination of thermal control elements and fewer parts count. In this work, the performance of an isolated, precision gate driver for controlling power-level transistors, including gallium nitride (GaN) and silicon carbide (SiC) devices, was evaluated under extreme temperatures and thermal cycling. The investigations were carried out to assess performance for potential use of this device in space exploration missions under extreme temperature conditions.
The JPL Center for Space Microelectronics Technology (CSMT) is actively pursuing research in the neural network theory, algorithms, and electronics as well as optoelectronic neural net hardware implementations, to explore the strengths and application potential for a variety of NASA, DoD, as well as commercial application problems, where conventional computing techniques are extremely time-consuming, cumbersome, or simply non-existent. An overview of the JPL electronic neural network hardware development activities and some of the striking applications of the JPL electronic neuroprocessors are presented.
A twin-jet commercial transport equipped with digital navigation, guidance, and control systems and advanced electronic display system was used for airborne operational research. The results of flight tests which evaluated a second-order horizontal-path guidance control law and the autopilot and airplane response are presented. This evaluation was accomplished through analysis of recorded flight data and through pilot opinion of the airplane maneuvers during automatic path-capture scenarios and path tracking. Four different path captures were flown at a ground speed of approximately 160 knots and repeated at approximately 300 knots. Path tracking tracking error was measured in terms of cross track error along two paths: one pat at cruise speeds and one at airport-terminal-area speeds. The path tracking accuracy and the smoothness of the airplane maneuvers were judged satisfactory for high speeds; however, at lower speeds the control law design should be improved so that tracking will be more accurate for operations in the airport terminal area.
A detailed quantitative study of the microstructural variation of chemical composition of chemically vapor-deposited commercial SiC SCS-6 fiber is presented. Chemical etching and various electron-optical techniques including SEM, TEM, scanning Auger microscopy, AES, and parallel electron energy loss spectroscopy are used to analyze the chemical composition of the as-received fiber. In addition, some results on stereology of the high-temperature annealed fiber are presented. The results show that the carbon-to-silicon atom ratio in the SiC layers decreases in a stepwise fashion from about 3:2 to about 1:1 in going from the innermost layer to the outermost layer.
The Office of Space Communications (OSC) is tasked by NASA to conduct a planning process to meet NASA's science mission and other communications and data processing requirements. A set of technology trend studies was undertaken by Science Applications International Corporation (SAIC) for OSC to identify quantitative data that can be used to predict performance of electronic equipment in the future to assist in the planning process. Only commercially available, off-the-shelf technology was included. For each technology area considered, the current state of the technology is discussed, future applications that could benefit from use of the technology are identified, and likely future developments of the technology are described. The impact of each technology area on NASA operations is presented together with a discussion of the feasibility and risk associated with its development. An approximate timeline is given for the next 15 to 25 years to indicate the anticipated evolution of capabilities within each of the technology areas considered. This volume contains four chapters: one each on technology trends for database systems, computer software, neural and fuzzy systems, and artificial intelligence. The principal study results are summarized at the beginning of each chapter.
The ability to sense explosives residues in the marine environment is a critical tool for identification and classification of underwater unexploded ordnance (UXO). Trace explosives signatures of TNT and DNT have been extracted from multiple sediment samples adjacent to unexploded undersea ordnance at Halifax Harbor, Canada. The ordnance was hurled into the harbor during a massive explosion fifty years earlier, in 1945 after World War II had ended. Laboratory sediment extractions were made using the solid-phase microextraction (SPME) method in seawater, and detection using the Reversal Electron Attachment Detection (READ) technique and, in the case of DNT, a commercial gas-chromatography/mass spectrometer (GC/MS). Results show that, after more than 50 years in the environment, ordnance which appeared to be physically intact gave good explosives signatures at the parts-per-billion level, whereas ordnance which had been cracked open during the explosion gave no signatures at the 10 parts-per-trillion sensitivity level. These measurements appear to provide the first reported data of explosives signatures from undersea UXOs.
Trace explosives signatures of TNT and DNT have been extracted from multiple sediment samples adjacent to unexploded undersea ordnance at Halifax Harbor, Canada. The ordnance was hurled into the harbor during a massive explosion some 50 years earlier, in 1945 after World War II had ended. Laboratory sediment extractions were made using the solid-phase microextraction (SPME) method in seawater and detection using the Reversal Electron Attachment Detection (READ) technique and, in the case of DNT, a commercial gas chromatograph/mass spectrometer (GC/MS). Results show that, after more than 50 years in the environment, ordnance that appeared to be physically intact gave good explosives signatures at the parts per billion level, whereas ordnance that had been cracked open during the explosion gave no signatures at the 10 parts per trillion sensitivity level. These measurements appear to provide the first reported data of explosives signatures from undersea unexploded ordnance.