SEARCH · Engineering Papers

Results for “hardware failure”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 901 records · Page 50

All sources NASA NTRS DOE OSTI

NASA NTRS1967

Investigation of Solder Cracking Problems on Printed Circuit Boards

A Solder Committee designated to investigate a solder cracking phenomena occurring on the SATURN electrical/electronic hardware found the cause to be induced stress in the soldered connections rather than faulty soldering techniques. The design of the printed circuit (PC) board assemblies did not allow for thermal expansion of the boards that occurred during normal operation. The difference between the thermal expansion properties of the boards and component lead materials caused stress and cracking in the soldered connections. The failure mechanism and various PC boards component mounting configurations are examined in this report. Effective rework techniques using flanged tubelets, copper tubelets, and soft copper wiring are detailed. Future design considerations to provide adequate strain relief in mounting configurations are included to ensure successful solder terminations.

CIRCUIT BOARD↗

NASA NTRS1995

A Probabilistic Tool that Aids Logistics Engineers in the Establishment of High Confidence Repair Need-Dates at the NASA Shuttle Logistics Depot

The NASA Shuttle Logistics Depot (NSLD) is tasked with the responsibility for repair and manufacture of Line Replaceable Unit (LRU) hardware and components to support the Space Shuttle Orbiter. Due to shrinking budgets, cost effective repair of LRU's becomes a primary objective. To achieve this objective, is imperative that resources be assigned to those LRU's which have the greatest expectation of being needed as a spare. Forecasting the times at which spares are needed requires consideration of many significant factors including: failure rate, flight rate, spares availability, and desired level of support, among others. This paper summarizes the results of the research and development work that has been accomplished in producing an automated tool that assists in the assignment of effective repair start-times for LRU's at the NSLD. This system, called the Repair Start-time Assessment System (RSAS), uses probabilistic modeling technology to calculate a need date for a repair that considers the current repair pipeline status, as well as, serviceable spares and projections of future demands. The output from the system is a date for beginning the repair that has significantly greater confidence (in the sense that a desired probability of support is ensured) than times produced using other techniques. Since an important output of RSAS is the longest repair turn-around time that will ensure a desired probability of support, RSAS has the potential for being applied to operations at any repair depot where spares are on-hand and repair start-times are of interest. In addition, RSAS incorporates tenants of Just-in-Time (JIT) techniques in that the latest repair start-time (i.e., the latest time at which repair resources must be committed) may be calculated for every failed unit This could reduce the spares inventory for certain items, without significantly increasing the risk of unsatisfied demand.

Bullington, J. V.↗

NASA NTRS2006

Propulsion IVHM Technology Experiment

The Propulsion IVHM Technology Experiment (PITEX) successfully demonstrated real-time fault detection and isolation of a virtual reusable launch vehicle (RLV) main propulsion system (MPS). Specifically, the PITEX research project developed and applied a model-based diagnostic system for the MPS of the X-34 RLV, a space-launch technology demonstrator. The demonstration was simulation-based using detailed models of the propulsion subsystem to generate nominal and failure scenarios during captive carry, which is the most safety-critical portion of the X-34 flight. Since no system-level testing of the X-34 Main Propulsion System (MPS) was performed, these simulated data were used to verify and validate the software system. Advanced diagnostic and signal processing algorithms were developed and tested in real time on flight-like hardware. In an attempt to expose potential performance problems, the PITEX diagnostic system was subjected to numerous realistic effects in the simulated data including noise, sensor resolution, command/valve talkback information, and nominal build variations. In all cases, the PITEX system performed as required. The research demonstrated potential benefits of model-based diagnostics, defined performance metrics required to evaluate the diagnostic system, and studied the impact of real-world challenges encountered when monitoring propulsion subsystems.

Chicatelli, Amy K.↗

NASA NTRSDate not supplied

A Summary of Test Results from a NASA Lift + Cruise eVTOL Crash Test

On November 9, 2022, the National Aeronautics and Space Administration (NASA) conducted a full-scale crash test of the NASA Lift+Cruise (LPC) reference vehicle at the NASA Langley Research Center Landing and Impact Research Facility (LandIR) under combined vertical and horizontal impact conditions to simulate a severe but survivable crash. The LPC test article is a carbon-composite skin/frame structure design, developed and fabricated for the cabin section only. The test utilized various configurations of seats and Anthropomorphic Test Devices (ATDs, a.k.a. crash test dummies) intended to encompass a variety of occupant conditions. In addition, an in-house developed energy absorbing subfloor was utilized for the evaluation of load attenuation. Overhead mass was simulated using attached lifting hardware and other systems were simulated using ballast mass. The test article impacted the ground with velocities of 38.1 ft/s horizontal and 31.4 ft/s vertical. During the first approximately 38 milliseconds (ms), the cabin section experienced a large amount of acceleration on the belly which was attenuated by the subfloor structures and seats. Over the next approximately 160 ms, the test article experienced failure in the a-, b- and c-pillars, leading to a partial collapse of the overhead structure. Test data was collected on the belly, floors, seats, overhead mass, and tail. In addition, there was high speed full-field digital image correlation analysis data collected on the port side skin surface. Collected ATD data showed that the ATDs seated in the energy absorbing seats experienced loads at limits below the those in current regulations. Even without an energy absorbing seat, the energy absorbing subfloors crushed as intended, and limited the load on the large 95 th percentile ATD to 10% over suggested limits. The collapse of the roof did affect the 95 th percentile ATD, which showed high neck loading values due to head contact, whereas survivable volume was maintained for the other ATDs. While the energy absorbing subfloor and energy absorbing seats both contributed to occupant load attenuation, further optimization is suggested to increase their robustness.

evtol↗

NASA NTRSDate not supplied

A Summary of Test Results from a NASA Lift + Cruise eVTOL Crash Test

evtol↗

NASA NTRS2001

Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB. TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly, to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC/solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

Novak, Howard L.↗

NASA NTRS2003

Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB. TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly, to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC / solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

Novak, Howard L.↗

DOE OSTI2021

Visualization, understanding, and mitigation of process-induced-membrane irregularities in gas diffusion electrode-based polymer electrolyte membrane fuel cells

Polymer electrolyte membrane fuel cells (PEMFC) show substantial promise for their application in electric vehicles. For large-scale manufacturing of PEMFCs, roll-to-roll coated gas-diffusion-electrodes (GDE) offer certain advantages over other production pathways. Procedures including hot pressing and coating an ionomer overlayer may be necessary for this manufacturing pathway to enable a suitable catalyst layer/membrane interface. The same procedures may potentially introduce membrane irregularities, especially when thin membranes are used. Limited understanding exists regarding if and to what extent such irregularities impact PEMFC performance and lifetime, and therefore be considered defects. In this study, NREL's customized fuel cell hardware that enables quasi in-situ infrared (IR) thermography studies was utilized to visualize spatial hydrogen crossover and identify membrane irregularities that originated from the GDE-based MEA fabrication process. The structure of these membrane irregularities was investigated by scanning electron microscopy (SEM) and its impact on initial H2/air performance was determined. Accelerated stress testing (AST) revealed that these irregularities develop into failure point locations. These results were validated across many MEAs with identified process-induced membrane irregularities. By selecting specific gas diffusion media properties and by fine tuning the MEA hot pressing parameters, the formation of such membrane irregularities was mitigated.

08 HYDROGEN↗

NASA NTRS2005

Addressing the Real-World Challenges in the Development of Propulsion IVHM Technology Experiment (PITEX)

The Propulsion IVHM Technology Experiment (PITEX) has been an on-going research effort conducted over several years. PITEX has developed and applied a model-based diagnostic system for the main propulsion system of the X-34 reusable launch vehicle, a space-launch technology demonstrator. The application was simulation-based using detailed models of the propulsion subsystem to generate nominal and failure scenarios during captive carry, which is the most safety-critical portion of the X-34 flight. Since no system-level testing of the X-34 Main Propulsion System (MPS) was performed, these simulated data were used to verify and validate the software system. Advanced diagnostic and signal processing algorithms were developed and tested in real-time on flight-like hardware. In an attempt to expose potential performance problems, these PITEX algorithms were subject to numerous real-world effects in the simulated data including noise, sensor resolution, command/valve talkback information, and nominal build variations. The current research has demonstrated the potential benefits of model-based diagnostics, defined the performance metrics required to evaluate the diagnostic system, and studied the impact of real-world challenges encountered when monitoring propulsion subsystems.

Maul, William A.↗

NASA NTRS1972

Reaction control system helium pressure regulator filter failure

The failure analysis of the command module reaction control system helium pressure regulators revealed that the filter element end caps were bulged by the helium pressure surge during activation. Some end caps may bulge and also some wire separation may occur during command module reaction control system activations; however, system performance should not be affected. The reaction control system design is acceptable and no change in hardware, system, or activation procedures is required.

Source record↗

NASA NTRS1992

Preliminary structural control results from the Middeck Active Control Experiment (MACE)

Results are presented of on-going closed-loop ground experiments on the MACE test article, the objective of which is to investigate the extent to which closed-loop behavior of flexible spacecraft in zero gravity can be predicted, as well as to examine orbit system identification and control reconfiguration. The MACE hardware consists of three torque wheels, a two-axis gimballing payload, inertial sensors, and a flexible support structure. With the acquisition of a second payload, this is to represent a multiple payload platform with significant structural flexibility. When linear quadratic Gaussian control is used, payload pointing accuracy is improved by an order of magnitude when disturbed by a broadband torque disturbance. The successes and failures of the design and implementation process are discussed.

Miller, David W.↗

NASA NTRSDate not supplied

An Intern Experience with NASA’s Artemis Program

“3...2...1...Go For Launch”. Nasa’s Kennedy Space Center is projected to launch the first mission of theArtemis Program by the end of this year, 2021. I have had the opportunity to contribute directly to this mission through my internship with their Engineering organization from January to August of 2021.Within their Engineering organization, I am an intern for the Avionics branch. Throughout this experience I have completed two projects with one project still in progress. These projects allowed me to work directly with the Orion vehicle’s software and hardware power ups, checkouts, and tests. I became familiarized with the engineering concepts that allowed this advanced technology to perform as intended.In addition, I became acquainted with the operations and tasks that are completed during a LaunchCountdown, both at a detailed level as well as a higher managerial level. Lastly, I worked directly with the software algorithm that detects and responds to onboard faults and failures. I have analyzed and made conclusions based on data and documentation, allowing my team to benefit from a condensed, centralized informational file. In addition to my technical experience, I have learned a significant amount about how the Kennedy Space Center operates, it’s history, and the history of the agency. The education I received from the Engineering department at Texas A&M University not only allowed me to obtain this internship, but provided me with the required background in computer and electrical engineering principles to be successful in this organization.

Sarah Bianco↗

NASA NTRS2017

Thermal cycling testing to failure of a ceramic column grid array package for space applications

Ceramic column grid array (CCGA) packages have been used increasingly in logic and microprocessor functions, telecommunications, flight avionics boards, payload electronics boards, engineering navigational and science cameras, electronic assemblies, and other applications, because of their inherent advantages such as high electrical interconnect density, very good thermal and electrical performance, and compatibility with standard surface-mount technology (SMT) packaging assembly processes. Because these advanced electronic packages tend to have less solder-joint strain-relief than do leaded flat-pack electronic packages, the reliability of CCGA packages in challenging thermal environments is a very important consideration for their short- and long-term use in JPL-NASA space missions. In this study, we assembled daisy chains of polyimide printed wiring boards from CCGA-interconnect packages, inspected the boards nondestructively, and then subjected them to thermal cycling to assess their reliability in thermal environments from +125°C to -40°C±25°C. The test hardware consists of a CCGA 1752 package (CN version). The package was divided into four daisy-chained sections that were electrically monitored for their continuity during thermal cycling. The CCGA 1752 package is roughly 45 mm × 45 mm with a 42-mm × 42-mm array of 80%/20% Pb/Sn columns on a 1.00-mm pitch. The resistance of the daisy-chained CCGA interconnects was continuously monitored during thermal cycling in a gaseous nitrogen environment. Electrical continuity resistance measurements as a function of thermal cycling are reported here; tests to date have shown significant change to an open circuit in daisy-chain resistance as a function of thermal cycling. The change in interconnect resistance becomes increasingly noticeable with increasing number of thermal cycles. This paper describes the experimental thermal-cycling test results of CCGA 1752 package reliability testing under an extremely wide temperature range. The first failure was observed at 1479th thermal cycle. We report the thermal-cycle reliability test data for ~2500 thermal cycles.

Ramesham, Rajeshuni↗

NASA NTRS2002

Environmentally Compatible Vapor-Phase Corrosion Inhibitor for Space Shuttle Hardware

USA-SRB Element is responsible for the assembly and refurbishment of the non-motor components of the SRB as part of Space Shuttle. Thrust Vector Control (TVC) frames structurally support components of the TVC system located in the aft skirt of the SRB (Solid Rocket Booster). TVC frames are exposed to the seacoast environment after refurbishment and, also, to seawater immersion after splashdown, and during tow-back to CCAFS-Hangar AF refurbishment facilities. During refurbishment operations it was found that numerous TVC frames were experiencing internal corrosion and coating failures, both from salt air and seawater intrusions. Inspectors using borescopes would visually examine the internal cavities of the complicated aluminum alloy welded tubular structure. It was very difficult for inspectors to examine cavity corners and tubing intersections and particularly. to determine the extent of the corrosion and coating anomalies. Physical access to TVC frame internal cavities for corrosion removal and coating repair was virtually impossible, and an improved method using a Liquid (water based) Vapor-phase Corrosion Inhibitor (LVCI) for preventing initiation of new corrosion, and mitigating and/or stopping existing corrosion growth was recommended in lieu of hazardous paint solvents and high VOC/solvent based corrosion inhibitors. In addition, the borescopic inspection method used to detect corrosion, and/or coating anomalies had severe limitations because of part geometry, and an improved non-destructive inspection (NDI) method using Neutron Radiography (N-Ray) was also recommended.

Novak, Howard L.↗

NASA NTRS2007

Automated Detection of Events of Scientific Interest

A report presents a slightly different perspective of the subject matter of Fusing Symbolic and Numerical Diagnostic Computations (NPO-42512), which appears elsewhere in this issue of NASA Tech Briefs. Briefly, the subject matter is the X-2000 Anomaly Detection Language, which is a developmental computing language for fusing two diagnostic computer programs one implementing a numerical analysis method, the other implementing a symbolic analysis method into a unified event-based decision analysis software system for real-time detection of events. In the case of the cited companion NASA Tech Briefs article, the contemplated events that one seeks to detect would be primarily failures or other changes that could adversely affect the safety or success of a spacecraft mission. In the case of the instant report, the events to be detected could also include natural phenomena that could be of scientific interest. Hence, the use of X- 2000 Anomaly Detection Language could contribute to a capability for automated, coordinated use of multiple sensors and sensor-output-data-processing hardware and software to effect opportunistic collection and analysis of scientific data.

James, Mark↗

NASA NTRSDate not supplied

Distributed Spacecraft Autonomy - Development of Swarm Autonomy Capability and Scalability for Spacecraft

The Distributed Spacecraft Autonomy project is developing a suite of software tools that enable an operator to command and receive data from a swarm as a single entity, enable a swarm to autonomously coordinate its actions via distributed decision making and reactive closed-loop control, and model swarm behavior in the presence of anomalies or failures. Our use case is the mapping of the electron density of the ionosphere using radio tomography by coordinating the selection of appropriate GPS channels, and by recording Total Electron Count (TEC) measurements. DSA will be demonstrated onboard the NASA Ames Starling mission – a swarm of four small, LEO spacecraft, scheduled to launch in 2021. We will also perform a ground demonstration with simulated and hardware-in-the-loop elements, to validate the tools for controlling swarms of up to 100 assets. The capability to communicate autonomously between the swarm satellites is demonstrated via a sophisticated simulation architecture. Historical Plasmasphere TEC data obtained via dual-band Novatel GPS Receivers are utilized as a representative input dataset for the swarm. The representative TEC data and GPS satellite observability information is fed to the autonomous software package in place of a true real-time ground data collection process. The swarm satellites actively share status updates amongst one another and utilize multi-agent decision making to optimally identify regions of interest in the TEC distribution. The software, aware of the bandwidth limitations of the swarm satellites, prioritizes explorative measurements, which define the range of observability for the satellites, as well as exploitative measurements, which focus on maximizing the observance potential of regions with prolonged, elevated TEC density. The science of this study can ultimately be used to determine the dynamics and coupling of Earth’s magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs. The findings can be applied to the imaging of critical, transient phenomena in the magnetosphere in later missions. Meanwhile, the swarm autonomy capabilities have far reaching potential in future satellite missions. As an experimental demonstration of the autonomous capabilities of the network, a message is first printed within a core Flight Executive (cFE) application. Two cFE applications that communicate with one another within the same core Flight System (cFS) are shown. Communication between mission applications on the internal cFE bus is extended to utilize Data Distribution Service (DDS) for vehicle-to-vehicle networking. The DDS middleware provides reliable delivery, routing, and topic subscription features over User Datagram Protocol (UDP). Leveraging Linux containerization, a networked set of satellite instances are generated by script to simulate swarm behavior. Swarm commanding and synchronization through the network is demonstrated under various topologies and data-loss conditions. Finally, autonomous swarm scalability from 2 satellites to 100 satellites is shown.

Distributed Autonomy↗

NASA NTRS2016

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31% decrease in bone volume ratio, a 14% decrease in trabecular thickness, and a 20% decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1.This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration persists during long-duration spaceflight. Furthermore, spaceflight femurs from BionM1 indicate onset of an accelerated aging-like phenotype with signs of osteoarthritic disease shown by disruption of the epiphyseal boundary and endochondral ossification. These effects are likely caused by a failure of stem cells to regenerate degraded tissues and may have significant implications for bone and cartilage health following extensive periods of mechanical unloading during long-duration spaceflight.

microgravity↗

NASA NTRS2016

Femoral Head Bone Loss Following Short and Long-Duration Spaceflight

Exposure to mechanical unloading during spaceflight is known to have significant effects on the musculoskeletal system. Our ongoing studies with the mouse bone model have identified the failure of normal stem cell-based tissue regeneration, in addition to tissue degeneration, as a significant concern for long-duration spaceflight, especially in the mesenchymal and hematopoietic tissue lineages. The 30-day BionM1 and the 37-day Rodent Research 1 (RR1) missions enabled the possibility of studying these effects in long-duration microgravity experiments. We hypothesized that the inhibition of stem cell-based tissue regeneration in short-duration spaceflight would continue during long-duration spaceflight and furthermore would result in significant tissue alterations. MicroCT analysis of BionM1 femurs revealed 31 decrease in bone volume ratio, a 14 decrease in trabecular thickness, and a 20 decrease in trabecular number in the femoral head of space-flown mice. Furthermore, high-resolution MicroCT and immunohistochemical analysis of spaceflight tissues revealed a severe disruption of the epiphyseal boundary, resulting in endochondral ossification of the femoral head and perforation of articular cartilage by bone. This suggests that spaceflight in microgravity may cause rapid induction of an aging-like phenotype with signs of osteoarthritic disease in the hip joint. However, mice from RR1 exhibited significant bone loss in the femoral head but did not exhibit the severe aging and disease-like phenotype observed during BionM1. This may be due to increased physical activity in the RH hardware. Immunohistochemical analysis of the epiphyseal plate and investigation of cellular proliferation and differentiation pathways within the marrow compartment and whole bone tissue is currently being conducted to determine alterations in stem cell-based tissue regeneration between these experiments. Our results show that the observed inhibition of stem cell-based tissue regeneration persists during long-duration spaceflight. Furthermore, spaceflight femurs from BionM1 indicate onset of an accelerated aging-like phenotype with signs of osteoarthritic disease shown by disruption of the epiphyseal boundary and endochondral ossification. These effects are likely caused by a failure of stem cells to regenerate degraded tissues and may have significant implications for bone and cartilage health following extensive periods of mechanical unloading during long-duration spaceflight.

stem cells↗