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This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.
Results of an experiment providing initial validation of the use of charge collection spectroscopy to measure the over-layer and epitaxial thickness and substrate diffusion length are given for several CMOIS SRAM test devices.
In support of the Constellation Program, a space-suit architecture was envisioned for support of Launch, Entry, Abort, Micro-g EVA, Post Landing crew operations, and under emergency conditions, survival. This space suit architecture is unique in comparison to previous launch, entry, and abort (LEA) suit architectures in that it utilized rigid mobility elements in the scye and the upper arm regions. The suit architecture also employed rigid thigh disconnect elements to allow for quick disconnect functionality above the knee which allowed for commonality of the lower portion of the suit across two suit configurations. This suit architecture was designed to interface with the Orion seat subsystem, which includes seat components, lateral supports, and restraints. Due to this unique configuration of spacesuit mobility elements, combined with the need to provide occupant protection during dynamic landing events, risks were identified with potential injury due to the suit characteristics described above. To address the risk concerns, a test series was developed to evaluate the likelihood and consequences of these potential issues. Testing included use of Anthropomorphic Test Devices (ATDs), Post Mortem Human Subjects (PMHS), and representative seat/suit hardware in combination with high linear acceleration events. The ensuing treatment focuses o detailed results of the testing that has ben conducted under this test series thus far.
In support of the NASA Constellation Program, a space-suit architecture was envisioned for support of Launch, Entry, Abort, Micro-g EVA, Post Landing crew operations, and under emergency conditions, survival. This space suit architecture is unique in comparison to previous launch, entry, and abort (LEA) suit architectures in that it utilized rigid mobility elements in the scye and the upper arm regions. The suit architecture also employed rigid thigh disconnect elements to allow for quick disconnect functionality above the knee which allowed for commonality of the lower portion of the suit across two suit configurations. This suit architecture was designed to interface with the Orion seat subsystem, which includes seat components, lateral supports, and restraints. Due to this unique configuration of spacesuit mobility elements, combined with the need to provide occupant protection during dynamic landing events, risks were identified with potential injury due to the suit characteristics described above. To address the risk concerns, a test series was developed to evaluate the likelihood and consequences of these potential issues. Testing included use of Anthropomorphic Test Devices (ATDs), Post Mortem Human Subjects (PMHS), and representative seat/suit hardware in combination with high linear acceleration events. The ensuing treatment focuses on detailed results of the testing that has been conducted under this test series thus far.
Spaceflight requires tremendous amounts of energy to achieve Earth orbit and to attain escape velocity for interplanetary missions. Although the majority of the energy is managed in such a way as to limit the accelerations on the crew, several mission phases may result in crew exposure to dynamic loads. In the automotive industry, risk of serious injury can be tolerated because the probability of a crash is remote each time a person enters a vehicle, resulting in a low total risk of injury. For spaceflight, the level of acceptable injury risk must be lower to achieve a low total risk of injury because the dynamic loads are expected on each flight. To mitigate the risk of injury due to dynamic loads, the NASA Human Research Program has developed a research plan to inform the knowledge gaps and develop relevant tools for assessing injury risk. The risk of injury due to dynamic loads can be further subdivided into extrinsic and intrinsic risk factors. Extrinsic risk factors include the vehicle dynamic profile, seat and restraint design, and spacesuit design. Human tolerance to loads varies considerably depending on the direction, amplitude, and rise-time of acceleration therefore the orientation of the body to the dynamic vector is critical to determining crew risk of injury. Although a particular vehicle dynamic profile may be safe for a particular design, the seat, restraint, and suit designs can affect the risk of injury due to localized effects. In addition, characteristics intrinsic to the crewmember may also contribute to the risk of injury, such as crewmember sex, age, anthropometry, and deconditioning due to spaceflight, and each astronaut may have a different risk profile because of these factors. The purpose of the research plan is to address any knowledge gaps in the risk factors to mitigate injury risk. Methods for assessing injury risk have been well documented in other analogous industries and include human volunteer testing, human exposure to dynamic environments, post-mortem human subject (PMHS) testing, animal testing, anthropomorphic test devices (ATD), dynamic models of the human, numerical models of ATDs, and numerical models of the human. Each has inherent strengths and limitations. For example, human volunteer testing is advantageous because a population can be selected that is similar to the astronaut corps; however, because of the inherent ethical limitations, only sub-injurious conditions can be tested. PMHSs can be tested in a variety of conditions including injurious levels, but the responses are not completely analogous to living human subjects. In addition, it is exceedingly difficult to select a PMHS population that is similar to the astronaut corps. ATDs are currently widely used in the automotive industry and military because they are highly repeatable and durable. Unfortunately, because they are mechanical models of the human body, the biofidelity of the responses are limited to dynamic conditions used to validate the ATD. Numerical models of the ATD, in addition to the strengths and limitations for ATDs, are easy to use for a variety of designs before a design is fabricated, but also have additional limitations for ATDs, are easy to use for a variety of designs before a design is fabricated, but also have additional uncertainty. Dynamic models are simple and easy to use, but do not account for localized effects of the seat and suit. Finally, numerical models of the human have the potential to have the most advantages; however, the current models are not validated for the conditions expected during spaceflight. To properly assess spaceflight conditions with numerical human models, human data would be needed to optimize the model responses for those conditions. Using the appropriate assessment method with the knowledge gained for each risk factor, an appropriate approach for mitigating the risk of injury due to dynamic loads can be developed ensuring crew safety in future NASA vehicles.
As one of the very few people in the world to give the “go/no go” decision to detonate a nuclear device, Austin “Mac” McGuire holds a very special place in the history of both the Los Alamos National Laboratory and the world. As Commander of Joint Task Force Unit 8.1.1, on Christmas Island in the spring and summer of 1962, Mac directed the Los Alamos data collection efforts for twelve of the last atmospheric nuclear detonations conducted by the United States. Since data collection was at the heart of nuclear weapon testing, it fell to Mac to make the ultimate decision to detonate each test device. He calls his experience THE LAST BIG BANG, since these tests, part of Operation Dominic, were characterized by the dramatic displays of the heat, light, and sounds unique to atmospheric nuclear detonations – never, perhaps, to be witnessed again.
Rapid improvement of the stability of metal halide perovskite materials is required to enable their adoption for energy production at Terawatt scale. To understand the role of the active layer stability in these devices we use operando x-ray diffraction to observe the evolution in structural stability across APbI3 alloys where A is a combination of formamidinium, Cs, and/or methylammonium. During device operation we observe spatial de-alloying and phase segregation into the alloy’s constituent phases. Using complementary first-principles calculations of halide perovskite alloys a hypothesized framework explaining the experimentally observed mixing and demixing of these systems is presented and then validated using in-situ X-ray diffraction and time of flight secondary ion mass spectrometry. Taken together these results indicate that stability is not only a function of device architecture or chemical formulation, but that the processing strategy is critically important in synthesizing the most energetically favorable state and therefore the most stable device systems. This study reconciles disparate reports within the literature and also highlights the limitations of shelf life studies to ascertain stability as well as the importance of testing devices under operational conditions.
There is a strong need to decrease the amount of Pt electrocatalyst used in fuel cells and increase its durability for transportation application. Conventional strategies include Pt nanocrystals and Pt alloy with well-controlled structures, durable carbon support, non-carbon support, etc. We have developed the so-called “metal-metal oxide-carbon” triple junction concept to stabilize Pt and protect carbon from corrosion. It also improved the activity of Pt. The good performance was not achieved in fuel cell test mainly because of the transport issue due to the use of 2D graphene. In this project, our main goal is to demonstrate the concept in fuel cell device test using 3D porous graphene as support so that the transport issue could be addressed.
Topics include: Test Waveform Applications for JPL STRS Operating Environment; Pneumatic Proboscis Heat-Flow Probe; Method to Measure Total Noise Temperature of a Wireless Receiver During Operation; Cursor Control Device Test Battery; Functional Near-Infrared Spectroscopy Signals Measure Neuronal Activity in the Cortex; ESD Test Apparatus for Soldering Irons; FPGA-Based X-Ray Detection and Measurement for an X-Ray Polarimeter; Sequential Probability Ratio Test for Spacecraft Collision Avoidance Maneuver Decisions; Silicon/Carbon Nanotube Photocathode for Splitting Water; Advanced Materials and Fabrication Techniques for the Orion Attitude Control Motor; Flight Hardware Packaging Design for Stringent EMC Radiated Emission Requirements; RF Reference Switch for Spaceflight Radiometer Calibration; An Offload NIC for NASA, NLR, and Grid Computing; Multi-Scale CNT-Based Reinforcing Polymer Matrix Composites for Lightweight Structures; Ceramic Adhesive and Methods for On-Orbit Repair of Re-Entry Vehicles; Self-Healing Nanocomposites for Reusable Composite Cryotanks; Pt-Ni and Pt-Co Catalyst Synthesis Route for Fuel Cell Applications; Aerogel-Based Multilayer Insulation with Micrometeoroid Protection; Manufacturing of Nanocomposite Carbon Fibers and Composite Cylinders; Optimized Radiator Geometries for Hot Lunar Thermal Environments; A Mission Concept: Re-Entry Hopper-Aero-Space-Craft System on-Mars (REARM-Mars); New Class of Flow Batteries for Terrestrial and Aerospace Energy Storage Applications; Reliability of CCGA 1152 and CCGA 1272 Interconnect Packages for Extreme Thermal Environments; Using a Blender to Assess the Microbial Density of Encapsulated Organisms; Mixed Integer Programming and Heuristic Scheduling for Space Communication; Video Altimeter and Obstruction Detector for an Aircraft; Control Software for Piezo Stepping Actuators; Galactic Cosmic Ray Event-Based Risk Model (GERM) Code; Sasquatch Footprint Tool; and Multi-User Space Link Extension (SLE) System.
Photoelectrochemical (PEC) water splitting, which utilizes sunlight and water to produce hydrogen fuel, is potentially one of the most sustainable routes to clean energy. One challenge to success is that, to date, similar materials and devices measured in different labs or by different operators lead to quantitatively different results, due to the lack of accepted standard operating procedures and established protocols for PEC efficiency testing. With the aim of disseminating good practices within the PEC community, we provide a vetted protocol that describes how to prepare integrated components and accurately measure their solar-to-hydrogen (STH) efficiency (η STH ). This protocol provides details on electrode fabrication, η STH test device assembly, light source calibration, hydrogen evolution measurement, and initial material qualification by photocurrent measurements under monochromatic and broadband illumination. Common pitfalls in translating experimental results from any lab to an accurate STH efficiency under an AM1.5G reference spectrum are discussed. A III–V tandem photocathode is used to exemplify the process, though with small modifications, the protocol can be applied to photoanodes as well. Dissemination of PEC best practices will help those approaching the field and provide guidance for comparing the results obtained at different lab sites by different groups.
This paper presents data taken in the 80- by 120-Foot Wind Tunnel in 1992 to data taken in the 40- by 80-Foot Wind Tunnel in 2016 at the NFAC. In both sets of data, the RTA was equipped with an identical set of S-76 helicopter blades. These data sets were compared to determine the repeatability of the RTA as a testing device, and to quantify differences in 40- by 80-Foot Wind Tunnel vs. 80- by 120-Foot Wind Tunnel results. The contents include an overview of the RTA and test facility, as well as a discussion of the methodology used. Vibratory load data is presented for a variety of wind and RPM conditions in various test section configurations. Data presented in this report quantifies the repeatability of the RTA.
This paper presents ongoing work to create a dataset for low-flying autonomous medical UAS operations, focused on human stance recognition. This is an exploration of the viability of airborne classification for the Drone as a First Responder (DFR) concept in which a UAS arrives at the scene of an incident before emergency response personnel can get there and provides some level of situational awareness for the personnel arriving to the scene. Future incarnations could also see the UAS administer some level of care to injured parties at the scene. The data set, focused on detecting human stance, being developed here is the result of 30 test flights at NASA Langley Research Center in early 2024. In addition to flights where the participant (an anthropomorphic testing device or human) is alone in the viewing area holding a particular stance, two emergency scenes have been fabricated and collected through video - ``bike crash'' and ``difficult camping''. These test flights include four human participants. The contribution of this work upon completion will be a publicly available data set for the development of classification engines focused on human stance, and in the future, even triage.
The following results were accomplished in the development of charge coupled infrared imaging devices: (1) a four-phase overlapping gate with 9 transfers (2-bits) and 1.0-mil gate lengths was successfully operated, (2) the measured transfer efficiency of 0.975 for this device is in excellent agreement with predictions for the reduced gate length device, (3) mask revisions of the channel stop metal on the 8582 mask have been carried out with the result being a large increase in the dc yield of the tested devices, (4) partial optical sensitivity to chopped blackbody radiation was observed for an 8582 9-bit imager, (5) analytical consideration of the modulation transfer function degradation caused by transfer inefficiency in the CCD registers was presented, and (6) for larger array lengths or for the insertion of isolated bits between sensors, improvements in InSb fabrication technology with corresponding decrease in the interface state density are required.
Availability of nuclear power plant is highly dependent on the quality of major control systems including NSSS Control Systems. It has been experienced that a small flaw hidden among the control functions resulted in large operational transient or even reactor trip. The proactive quality control of these systems is not easy because of the dynamical characteristics of control algorithms. In a stand-alone or open loop state, it is not possible to perform integral system tests because they need control loads to form an appropriate closed control loop. In the construction plant, Power Ascension Test (PAT) is the first chance to witness the overall performance of the control systems. Because the PAT is the last activity of plant construction schedule, the cost of corrective actions is very high if any functional defect is found in this stage. To minimize risk caused by late detection of control system defects, we developed a validation tool as a proactive test device for the NSSS Process Control System (NPCS) for the SKN Unit 3 which is the first APR1400 plant in Korea. In this paper, the features of the dynamic performance test tool, test methodology, and the test results are described.
A 128 x 128 element CID imager was operated in a simulated stellar trackling environment and evaluated for temporal and pattern noise and spectral response over a temperature range of -40 C to +25 C. The test devices were fabricated on long-lifetime bulk silicon material and utilized very thin upper-level polysilicon electrodes for enhanced spectral response. A standard microcomputer was used to generate all control signals and to collect and process performance data. The results of this program were used to predict the performance of a 400 x 400 CID array designed specifically for stellar-tracking.
An assessment was conducted on multiple wireless local area network (WLAN) devices using the three wireless standards for spurious radiated emissions to determine their threat to aircraft radio navigation systems. The measurement process, data and analysis are provided for devices tested using IEEE 802.11a, IEEE 802.11b, and Bluetooth as well as data from portable laptops/tablet PCs and PDAs (grouping known as PEDs). A comparison was made between wireless LAN devices and portable electronic devices. Spurious radiated emissions were investigated in the radio frequency bands for the following aircraft systems: Instrument Landing System Localizer and Glideslope, Very High Frequency (VHF) Communication, VHF Omnidirectional Range, Traffic Collision Avoidance System, Air Traffic Control Radar Beacon System, Microwave Landing System and Global Positioning System. Since several of the contiguous navigation systems were grouped under one encompassing measurement frequency band, there were five measurement frequency bands where spurious radiated emissions data were collected for the PEDs and WLAN devices. The report also provides a comparison between emissions data and regulatory emission limit.
A full-scale crash test was successfully conducted in March 2010 of an MD-500 helicopter at NASA Langley Research Center s Landing and Impact Research Facility. The reasons for conducting this test were threefold: 1 To generate data to be used with finite element computer modeling efforts, 2 To study the crashworthiness features typically associated with a small representative helicopter, and 3 To compare aircraft response to data collected from a previously conducted MD-500 crash test, which included an externally deployable energy absorbing (DEA) concept. Instrumentation on the airframe included accelerometers on various structural components of the airframe; and strain gages on keel beams, skid gear and portions of the skin. Three Anthropomorphic Test Devices and a specialized Human Surrogate Torso Model were also onboard to collect occupant loads for evaluation with common injury risk criteria. This paper presents background and results from this crash test conducted without the DEA concept. These results showed accelerations of approximately 30 to 50 g on the airframe at various locations, little energy attenuation through the airframe, and moderate to high probability of occupant injury for a variety of injury criteria.
We are developing small pitch transition-edge sensor (TES) X-ray detectors optimized for solar astronomy. These devices are fabricated on thick Si substrates with embedded Cu heat-sink layer. We use 35 x 35 square micrometers Mo/Au TESs with 4.5 micrometer thick Au absorbers. We have tested devices with different geometric absorber stem contact areas with the TES and surrounding substrate area. This allows us to investigate the loss of athermal phonons to the substrate. Results show a correlation between thc stem contact area and a broadening in the spectral line shape indicative of athermal phonon loss. When the contact area is minimized we have obtained exceptional broadband spectral resolution of 1.28 plus or minus 0.03 eV at an energy of 1.5 keV, 1.58 plus or minus 0.07 eV at 5.9 keV and 1.96 plus or minus 0.08 eV at 8 keV. The linearity in the measured gain scale is understood in the context of the longitudinal proximity effect from the electrical bias leads resulting in transition characteristics that are strongly dependent upon TES size.